Electrospun Membrane Surface Modification by Sonocoating with HA and ZnO:Ag Nanoparticles-Characterization and Evaluation of Osteoblasts and Bacterial Cell Behavior In Vitro.
Cells
Guided tissue regeneration and guided bone regeneration membranes are some of the most common products used for bone regeneration in periodontal dentistry. The main disadvantage of commercially available membranes is their lack of bone cell stimulation and easy bacterial colonization. The aim of this work was to design and fabricate a new membrane construct composed of electrospun poly (D,L-lactic acid)/poly (lactic-co-glycolic acid) fibers sonocoated with layers of nanoparticles with specific properties, i.e., hydroxyapatite and bimetallic nanocomposite of zinc oxide-silver. Thus, within this study, four different variants of biomaterials were evaluated, namely: poly (D,L-lactic acid)/poly (lactic-co-glycolic acid) biomaterial, poly(D,L-lactic acid)/poly (lactic-co-glycolic acid)/nano hydroxyapatite biomaterial, poly (D,L-lactic acid)/poly (lactic-co-glycolic acid)/nano zinc oxide-silver biomaterial, and poly (D,L-lactic acid)/poly (lactic-co-glycolic acid)/nano hydroxyapatite/nano zinc oxide-silver biomaterial. First, it was demonstrated that the wettability of biomaterials-a prerequisite property important for ensuring desired biological response-was highly increased after the sonocoating process. Moreover, it was indicated that biomaterials composed of poly (D,L-lactic acid)/poly (lactic-co-glycolic acid) with or without a nano hydroxyapatite layer allowed proper osteoblast growth and proliferation, but did not have antibacterial properties. Addition of a nano zinc oxide-silver layer to the biomaterial inhibited growth of bacterial cells around the membrane, but at the same time induced very high cytotoxicity towards osteoblasts. Most importantly, enrichment of this biomaterial with a supplementary underlayer of nano hydroxyapatite allowed for the preservation of antibacterial properties and also a decrease in the cytotoxicity towards bone cells, associated with the presence of a nano zinc oxide-silver layer. Thus, the final structure of the composite poly (D,L-lactic acid)/poly (lactic-co-glycolic acid)/nano hydroxyapatite/nano zinc oxide-silver seems to be a promising construct for tissue engineering products, especially guided tissue regeneration/guided bone regeneration membranes. Nevertheless, additional research is needed in order to improve the developed construct, which will simultaneously protect the biomaterial from bacterial colonization and enhance the bone regeneration properties.
10.3390/cells11091582
Antibacterial Effects and Biocompatibility of Titania Nanotubes with Octenidine Dihydrochloride/Poly(lactic-co-glycolic acid).
Xu Zhiqiang,Lai Yingzhen,Wu Dong,Huang Wenxiu,Huang Sijia,Zhou Lin,Chen Jiang
BioMed research international
Titanium (Ti) implants with long-term antibacterial ability and good biocompatibility are highly desirable materials that can be used to prevent implant-associated infections. In this study, titania nanotubes (TNTs) were synthesized on Ti surfaces through electrochemical anodization. Octenidine dihydrochloride (OCT)/poly(lactic-co-glycolic acid) (PLGA) was infiltrated into TNTs using a simple solvent-casting technique. OCT/PLGA-TNTs demonstrated sustained drug release and maintained the characteristic hollow structures of TNTs. TNTs (200 nm in diameter) alone exhibited slight antibacterial effect and good osteogenic activity but also evidently impaired adhesion and proliferation of bone marrow mesenchymal stem cells (BMSCs). OCT/PLGA-TNTs (100 nm in diameter) supported BMSC adhesion and proliferation and showed good osteogenesis-inducing ability. OCT/PLGA-TNTs also exhibited good long-term antibacterial ability within the observation period of 7 d. The synthesized drug carrier with relatively long-term antibacterial ability and enhanced excellent biocompatibility demonstrated significant potential in bone implant applications.
10.1155/2015/836939
Design and evaluation of nano-hydroxyapatite/poly(vinyl alcohol) hydrogels coated with poly(lactic-co-glycolic acid)/nano-hydroxyapatite/poly(vinyl alcohol) scaffolds for cartilage repair.
Su Weiping,Hu Yihe,Zeng Min,Li Mingqing,Lin Shaoru,Zhou Yangying,Xie Jie
Journal of orthopaedic surgery and research
BACKGROUND:Poly(vinyl alcohol) (PVA) hydrogels have been widely used in synthetic cartilage materials. However, limitations of PVA hydrogels such as poor biomechanics and limited cell ingrowth remain challenges in this field. METHODS:This work aimed to design novel nano-hydroxyapatite (nano-HA)/poly(vinyl alcohol) (PVA) hydrogels coated with a poly(lactic-co-glycolic acid) (PLGA)/nano-HA/PVA scaffold to counter the limitations of PVA hydrogels. The core, comprising nano-HA/PVA hydrogel, had the primary role of bearing the mechanical load. The peripheral structure, composed of PLGA/nano-HA/PVA, was designed to favor interaction with surrounding cartilage. RESULTS:The double-layer HA/PVA hydrogel coated with PLGA/HA/PVA scaffold was successfully prepared using a two-step molding method, and the mechanical properties and biocompatibility were characterized. The mechanical properties of the novel PLGA/HA/PVA scaffold modified HA/PVA hydrogel were similar to those of native cartilage and showed greater sensitivity to compressive stress than to tensile stress. Rabbit chondrocytes were seeded in the composites to assess the biocompatibility and practicability in vitro. The results showed that the peripheral component comprising 30 wt% PLGA/5 wt% HA/15 wt% PVA was most conducive to rabbit chondrocyte adhesion and proliferation. CONCLUSIONS:The study indicated that the double-layer HA/PVA hydrogel coated with PLGA/HA/PVA scaffold has the potential for cartilage repair.
10.1186/s13018-019-1450-0
Fabrication and characterization of PLGA nanoparticles encapsulating large CRISPR-Cas9 plasmid.
Jo Ami,Ringel-Scaia Veronica M,McDaniel Dylan K,Thomas Cassidy A,Zhang Rui,Riffle Judy S,Allen Irving C,Davis Richey M
Journal of nanobiotechnology
BACKGROUND:The clustered regularly interspaced short palindromic repeats (CRISPR) and Cas9 protein system is a revolutionary tool for gene therapy. Despite promising reports of the utility of CRISPR-Cas9 for in vivo gene editing, a principal problem in implementing this new process is delivery of high molecular weight DNA into cells. RESULTS:Using poly(lactic-co-glycolic acid) (PLGA), a nanoparticle carrier was designed to deliver a model CRISPR-Cas9 plasmid into primary bone marrow derived macrophages. The engineered PLGA-based carriers were approximately 160 nm and fluorescently labeled by encapsulation of the fluorophore 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS pentacene). An amine-end capped PLGA encapsulated 1.6 wt% DNA, with an encapsulation efficiency of 80%. Release studies revealed that most of the DNA was released within the first 24 h and corresponded to ~ 2-3 plasmid copies released per nanoparticle. In vitro experiments conducted with murine bone marrow derived macrophages demonstrated that after 24 h of treatment with the PLGA-encapsulated CRISPR plasmids, the majority of cells were positive for TIPS pentacene and the protein Cas9 was detectable within the cells. CONCLUSIONS:In this work, plasmids for the CRISPR-Cas9 system were encapsulated in nanoparticles comprised of PLGA and were shown to induce expression of bacterial Cas9 in murine bone marrow derived macrophages in vitro. These results suggest that this nanoparticle-based plasmid delivery method can be effective for future in vivo applications of the CRISPR-Cas9 system.
10.1186/s12951-019-0564-1
Integrating silicon/zinc dual elements with PLGA microspheres in calcium phosphate cement scaffolds synergistically enhances bone regeneration.
Liang Weiwei,Gao Min,Lou Jingsheng,Bai Yunyang,Zhang Jing,Lu Teliang,Sun Xiaowen,Ye Jiandong,Li Baowei,Sun Li,Heng Boon Chin,Zhang Xuehui,Deng Xuliang
Journal of materials chemistry. B
Integrating multiple pro-osteogenic factors into bone graft substitutes is a practical and effective approach to improve bone repair efficacy. Here, Si-Zn dual elements and PLGA microspheres were incorporated into calcium phosphate cement (CPC) scaffolds (PLGA/CPC-Si/Zn) as a novel strategy to synergistically enhance bone regeneration. The incorporation of PLGA microspheres and Si/Zn dual elements within CPC scaffolds improved the setting time, injectability and compressive strength. The PLGA/CPC-Si/Zn scaffolds displayed controlled sequential release of Si and Zn ions. In vitro, RAW 264.7 cells displayed the M2 phenotype with a high level of anti-inflammatory cytokines in response to PLGA/CPC-Si/Zn. The conditioned medium of RAW 264.7 cells cultured on the PLGA/CPC-Si/Zn scaffolds significantly enhanced the osteogenic differentiation of rat BMSCs. In a rat femur defect model, the implanted PLGA/CPC-Si/Zn scaffolds led to obvious new bone formation after 4 weeks, apparent bone ingrowth into the PLGA microspheres after 12 weeks, and was almost completely filled with mature new bone upon degradation of the PLGA microspheres at 24 weeks. These findings demonstrate that the PLGA/CPC-Si/Zn scaffolds promote osteogenesis by synergistically improving the immune microenvironment and biodegradability. Hence, integrating multiple trace elements together with degradable components within bone graft biomaterials can be an effective strategy for promoting bone regeneration.
10.1039/c9tb02901j
Release of simvastatin from scaffolds of poly(lactic-co-glycolic) acid and biphasic ceramic designed for bone tissue regeneration.
Encarnação Isis C,Sordi Mariane B,Aragones Águedo,Müller Carmen Maria Olivera,Moreira Anderson C,Fernandes Celso P,Ramos Jeferson V,Cordeiro Mabel M R,Fredel Márcio C,Magini Ricardo S
Journal of biomedical materials research. Part B, Applied biomaterials
The aim of this study was to evaluate the release of simvastatin from scaffolds composed of poly(lactic-co-glycolic) acid (PLGA) and biphasic ceramic designed for bone engineering and to assess the physico-chemical and mechanical properties of the scaffolds. Samples with 30% and 70% porosity were obtained with 0, 2, 5, and 8 wt %. of simvastatin through the solvent evaporation technique and leaching of sucrose particles. Scaffold degradation and simvastatin release were evaluated in phosphate-buffered saline. Scaffolds were analyzed by scanning electron microscopy and microtomography for two-dimensional and three-dimensional morphological characterization of the porosity, connectivity, and intrinsic permeability. The mechanical characterization was conducted based on the compressive strength and the chemical characterization by differential scanning calorimetry and energy dispersive X-ray spectroscopy. Gradual and prolonged simvastatin release from the scaffolds was observed. The release followed the Korsmeyer kinetics model with the predominance of case II transport for 30% porosity scaffolds, and anomalous behavior for the 70% porosity samples. Simvastatin release was also influenced by the slow scaffold degradation due to the strong chemical interaction between simvastatin and PLGA, as observed by differential scanning calorimetry. The scaffolds presented spherical and sucrose crystal-shaped pores that resulted in a homogenous porosity, with a predominance of open pores, ensuring interconnectivity. Simvastatin incorporation into the scaffolds and increased porosity did not influence the mechanical properties. The scaffolds presented gradual and prolonged simvastatin release, with satisfactory physico-chemical and mechanical properties. The scaffolds presented gradual and prolonged simvastatin release, with satisfactory physico-chemical and mechanical properties, a promise for applications in bone regeneration. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2152-2164, 2019.
10.1002/jbm.b.34311
Uniform-sized insulin-loaded PLGA microspheres for improved early-stage peri-implant bone regeneration.
Drug delivery
Poor initial stability at the first four weeks after surgery is becoming the major causes for metal implant failure. Previous attempts neglected the control release of insulin for the bone regeneration among nondiabetic subjects. The major reason may lie in the adverse effects, such as attenuated bone formation, hypoglycemia or hyperinsulinemia, that caused by the excessive insulin. Thus, spatiotemporal release of insulin may serve as the promising strategy. To address this, through solvent extraction (EMS), solvent evaporation (SMS) and cosolvent methods (CMS), we prepared three types of PLGA microspheres with various internal structures, but similar size distribution. The effects of the preparation methods on the properties of the microspheres, such as their release behavior, degradation of molecular weight, and structural evolution, were investigated. Human bone marrow mesenchymal stromal cells (BMSCs) and rabbit implant models were used to test the bioactivity of the microspheres in vitro and in vivo, respectively. The result demonstrated that these three preparation methods did not influence the polymer degradation but instead affected the internal structural evolution, which plays a crucial role in the release behavior, osteogenesis and peri-implant bone regeneration. Compared with EMS and CMS microspheres, SMS microspheres exhibited a relatively steady release rate in the first four weeks, which evidently stimulated the osteogenic differentiation of the stem cells and peri-implant bone regeneration. Meanwhile, SMS microspheres significantly enhanced the stability of the implant at Week 4, which is promising to reduce early failure rate of the implant without inducing adverse effects on the serum biochemical indices.
10.1080/10717544.2019.1682719
Preparation and Properties of Bamboo Fiber/Nano-hydroxyapatite/Poly(lactic-co-glycolic) Composite Scaffold for Bone Tissue Engineering.
Jiang Liuyun,Li Ye,Xiong Chengdong,Su Shengpei,Ding Haojie
ACS applied materials & interfaces
In this study, bamboo fiber was first designed to incorporate into nano-hydroxyapatite/poly(lactic-co-glycolic) to obtain a new composite scaffold of bamboo fiber/nano-hydroxyapatite/poly(lactic-co- glycolic) (BF/n-HA/PLGA) by freeze-drying method. The effect of their components and some factors consisting of different freeze temperatures, concentrations, and pore-forming agents on the porous morphology, porosity, and compressive properties of the scaffold were investigated by scanning electron microscope, modified liquid displacement method, and electromechanical universal testing machine. The results indicated that the 5% BF/30% n-HA/PLGA composite scaffold, prepared with 5% (w/v) high concentration and frozen at -20 °C without pore-forming agent, had the best ideal porous structure and porosity as well as compressive properties, which far exceed those of n-HA/PLGA composite scaffold. In addition, the in vitro simulated body fluids soaking and cell culture experiment showed the addition of BF into the scaffold accelerated the BF/n-HA/PLGA composite scaffolds degradation and exhibited good cytocompatibility, including attachment and proliferation. All the results of the study show that BF has improved the properties of n-HA/PLGA composite scaffolds and BF/n-HA/PLGA might have a great potential for bone tissue engineering scaffold.
10.1021/acsami.6b15032
Preparation and biological characterization of the mixture of poly(lactic-co-glycolic acid)/chitosan/Ag nanoparticles for periodontal tissue engineering.
Xue Yanxiang,Hong Xiaofang,Gao Jie,Shen Renze,Ye Zhanchao
International journal of nanomedicine
OBJECTIVE:This study aims to produce nanoparticles of chitosan (CS), poly(lactic-co-glycolic acid) (PLGA), and silver and investigate the optimal composite ratio of these three materials for periodontal tissue regeneration. METHODS:PLGA nanoparticles (nPLGA), CS nanoparticles (nCS), and silver nanoparticles (nAg) were prepared. The antibacterial properties of single nanoparticles and their effects on the proliferation and mineralization of periodontal membrane cells were investigated. Different ratios of nPLGA and nCS were combined, the proliferation and mineralization of periodontal membrane cells were investigated, and based on the results, the optimal ratio was determined. Finally, nPLGA and nCS in optimal ratio were combined with nAg, and the effects of the complex of these three materials on the proliferation and mineralization of periodontal membrane cells were investigated and tested in animals. RESULTS:The single nanoparticles were found to have no cytotoxicity and were able to promote cell mineralization. nCS and nAg in low concentrations showed antibacterial activity; however, nAg inhibited cell proliferation. The nPLGA and nCS complex in 3:7 ratio contributed to cell mineralization and had no cytotoxicity. nPLGA/nCS/nAg complex, which had the optimal proportion of the three materials, showed no cytotoxicity and contributed to cell mineralization. CONCLUSION:nPLGA/nCS/nAg complex had no cytotoxicity and contributed to cell mineralization. The 3:7 ratio of nPLGA/nCS and 50 µg/mL nAg were found as the optimal proportion of the three materials.
10.2147/IJN.S184396
Gas-foamed poly(lactide-co-glycolide) and poly(lactide-co-glycolide) with bioactive glass fibres demonstrate insufficient bone repair in lapine osteochondral defects.
Salonius Eve,Muhonen Virpi,Lehto Kalle,Järvinen Elina,Pyhältö Tuomo,Hannula Markus,Aula Antti S,Uppstu Peter,Haaparanta Anne-Marie,Rosling Ari,Kellomäki Minna,Kiviranta Ilkka
Journal of tissue engineering and regenerative medicine
Deep osteochondral defects may leave voids in the subchondral bone, increasing the risk of joint structure collapse. To ensure a stable foundation for the cartilage repair, bone grafts can be used for filling these defects. Poly(lactide-co-glycolide) (PLGA) is a biodegradable material that improves bone healing and supports bone matrix deposition. We compared the reparative capacity of two investigative macroporous PLGA-based biomaterials with two commercially available bone graft substitutes in the bony part of an intra-articular bone defect created in the lapine femur. New Zealand white rabbits (n = 40) were randomized into five groups. The defects, 4 mm in diameter and 8 mm deep, were filled with neat PLGA; a composite material combining PLGA and bioactive glass fibres (PLGA-BGf); commercial beta-tricalcium phosphate (β-TCP) granules; or commercial bioactive glass (BG) granules. The fifth group was left untreated for spontaneous repair. After three months, the repair tissue was evaluated with X-ray microtomography and histology. Relative values comparing the operated knee with its contralateral control were calculated. The relative bone volume fraction (∆BV/TV) was largest in the β-TCP group (p ≤ 0.012), which also showed the most abundant osteoid. BG resulted in improved bone formation, whereas defects in the PLGA-BGf group were filled with fibrous tissue. Repair with PLGA did not differ from spontaneous repair. The PLGA, PLGA-BGf, and spontaneous groups showed thicker and sparser trabeculae than the commercial controls. We conclude that bone repair with β-TCP and BG granules was satisfactory, whereas the investigational PLGA-based materials were only as good as or worse than spontaneous repair.
10.1002/term.2801
Manufacturing and characterization of plates for fracture fixation of bone with biocomposites of poly (lactic acid-co-glycolic acid) (PLGA) with calcium phosphates bioceramics.
Dos Santos Thaiane Maria Balestreri Knopf,Merlini Claudia,Aragones Águedo,Fredel Márcio Celso
Materials science & engineering. C, Materials for biological applications
Commercially, there are several plates and screws for bone fracture fixation made with PLA, however, its long degradation time and lack of integration with bone structure, provides interest in research using polymers with faster degradation, such as PLGA, and together with bioceramics, in order to improve bioactivity in bone regeneration. Based on this, in this study, bone fracture fixation plates composed of PLGA polymer matrix and combinations of 5 and 10%wt. of bioceramics were processed by microinjection. The bioceramics used comprehend nanostructured hydroxyapatite (n-HA), β-tricalcium phosphate (β-TCP) and calcium phosphate with ion substitution of magnesium (Mg-Ca/P) and strontium (Sr-Ca/P). The introduction of bioceramics modified thermal and mechanical properties of the polymer. The TGA analysis showed that there was a variation on the ceramic's mass inserted in relation to the expected values (5% and 10%wt.) in all groups of biocomposites. In general, Tg values obtained by DMA were slightly increased in almost all the biocomposites. The storage modulus (E') of biocomposites was higher for almost all groups of inserted ceramics, with exception of 5%n-HA. In the flexural tests, the biocomposites obtained a great dispersion in average values of fracture loading, presented lower values in relation to pure PLGA. There were difficulties in the processing of biocomposites with Mg-Ca/P and Sr-Ca/P, a factor that can be attributed to lack of homogeneity in the material mixing process. The results suggest modifications in thermal and mechanical properties of the PLGA plates with the bioceramics insertion and provide improvement understanding about of manufactured composites with PLGA and bioceramics.
10.1016/j.msec.2019.05.013
Evaluation of Electrospun PCL-PLGA for Sustained Delivery of Kartogenin.
Molecules (Basel, Switzerland)
In this study, kartogenin was incorporated into an electrospun blend of polycaprolactone and poly(lactic-co-glycolic acid) (1:1) to determine the feasibility of this system for sustained drug delivery. Kartogenin is a small-molecule drug that could enhance the outcome of microfracture, a cartilage restoration procedure, by selectively stimulating chondrogenic differentiation of endogenous bone marrow mesenchymal stem cells. Experimental results showed that kartogenin did not affect the electrospinnability of the polymer blend, and it had negligible effects on fiber morphology and scaffold mechanical properties. The loading efficiency of kartogenin into electrospun membranes was nearly 100%, and no evidence of chemical reaction between kartogenin and the polymers was detected by Fourier transform infrared spectroscopy. Analysis of the released drug using high-performance liquid chromatography-photodiode array detection indicated an abundance of kartogenin and only a small amount of its major hydrolysis product. Kartogenin displayed a typical biphasic release profile, with approximately 30% being released within 24 h followed by a much slower, constant rate of release up to 28 days. Although additional development is needed to tune the release kinetics and address issues common to electrospun scaffolds (e.g., high fiber density), the results of this study demonstrated that a scaffold electrospun from biodegradable synthetic polymers is a suitable kartogenin delivery vehicle.
10.3390/molecules27123739
Three-Dimensionally Printed Hyperelastic Bone Scaffolds Accelerate Bone Regeneration in Critical-Size Calvarial Bone Defects.
Huang Yu-Hui,Jakus Adam E,Jordan Sumanas W,Dumanian Zari,Parker Kelly,Zhao Linping,Patel Pravin K,Shah Ramille N
Plastic and reconstructive surgery
BACKGROUND:Autologous bone grafts remain the gold standard for craniofacial reconstruction despite limitations of donor-site availability and morbidity. A myriad of commercial bone substitutes and allografts are available, yet no product has gained widespread use because of inferior clinical outcomes. The ideal bone substitute is both osteoconductive and osteoinductive. Craniofacial reconstruction often involves irregular three-dimensional defects, which may benefit from malleable or customizable substrates. "Hyperelastic Bone" is a three-dimensionally printed synthetic scaffold, composed of 90% by weight hydroxyapatite and 10% by weight poly(lactic-co-glycolic acid), with inherent bioactivity and porosity to allow for tissue integration. This study examines the capacity of Hyperelastic Bone for bone regeneration in a critical-size calvarial defect. METHODS:Eight-millimeter calvarial defects in adult male Sprague-Dawley rats were treated with three-dimensionally printed Hyperelastic Bone, three-dimensionally printed Fluffy-poly(lactic-co-glycolic acid) without hydroxyapatite, autologous bone (positive control), or left untreated (negative control). Animals were euthanized at 8 or 12 weeks postoperatively and specimens were analyzed for new bone formation by cone beam computed tomography, micro-computed tomography, and histology. RESULTS:The mineralized bone volume-to-total tissue volume fractions for the Hyperelastic Bone cohort at 8 and 12 weeks were 74.2 percent and 64.5 percent of positive control bone volume/total tissue, respectively (p = 0.04). Fluffy-poly(lactic-co-glycolic acid) demonstrated little bone formation, similar to the negative control. Histologic analysis of Hyperelastic Bone scaffolds revealed fibrous tissue at 8 weeks, and new bone formation surrounding the scaffold struts by 12 weeks. CONCLUSION:Findings from our study suggest that Hyperelastic Bone grafts are effective for bone regeneration, with significant potential for clinical translation.
10.1097/PRS.0000000000005530
Simvastatin in polymer bioscaffold for bone regeneration. An in vitro and in vivo analysis.
Stomatologija
OBJECTIVE:The study aimed to fabricate and test the biocompatibility of a polylactic-co-glycolic acid (PLGA) based guided tissue regeneration membrane impregnated with 'simvastatin' to promote sustained drug delivery near osseous defects and evaluate the regenerative potential of the membrane histologically. MATERIALS AND METHODS:We tested the mechanical properties and cytotoxicity of an indigenously fabricated PLGA membrane incorporated with simvastatin (1 mg/cm2). An animal study evaluated the regenerative potential of the membrane. Twenty-four adult Wistar rats, approximately 175 g in weight, were used in this study. The rats were divided randomly into four groups based on the postoperative healing periods into ten days, 1, 3, and 6 months. Within each time group, six rats were divided into three subgroups: Subgroup A - sham surgery controls; Subgroup B - PLGA without Simvastatin; Subgroup C - PLGA with simvastatin tests. The radiographic examination intervals were ten days, 1 and 3 months, while the histological assessment was around 1, 3, and 6 months. RESULTS:Simvastatin content was distributed uniformly in all the prepared membranes and was equivalent to 1 mg/cm. 100 mg PLGA membrane with simvastatin demonstrated uniform drug release over time, excellent mechanical properties, and biocompatibility. The rat models in Subgroup C had better bone tissue formation radiographically and histologically. CONCLUSION:The study suggested that 'PLGA with Simvastatin' has the requisite properties to serve as a third-generation barrier membrane with the potential for local drug delivery.
Cellular Affinity of Particle-Stabilized Emulsion to Boost Antigen Internalization.
Journal of visualized experiments : JoVE
The cellular affinity of micro-/nanoparticles is the precondition for cellular recognition, cellular uptake, and activation, which are essential for drug delivery and immune response. The present study stemmed from the observation that the effects of charge, size, and shape of solid particles on cell affinity are usually considered, but we seldom realize the essential role of softness, dynamic restructuring phenomenon, and complex interface interaction in cellular affinity. Here, we developed poly-lactic-co-glycolic acid (PLGA) nanoparticle-stabilized Pickering emulsion (PNPE) that overcame the shortcomings of rigid forms and simulated the flexibility and fluidity of pathogens. A method was set up to test the affinity of PNPE to cell surfaces and elaborate on the subsequent internalization by immune cells. The affinity of PNPE to bio-mimetic extracellular vesicles (bEVs)-the replacement for bone marrow dendritic cells (BMDCs)-was determined using a quartz crystal microbalance with dissipation monitoring (QCM-D), which allowed real-time monitoring of cell-emulsion adhesion. Subsequently, the PNPE was used to deliver the antigen (ovalbumin, OVA) and the uptake of the antigens by BMDCs was observed using confocal laser scanning microscope (CLSM). Representative results showed that the PNPE immediately decreased frequency (ΔF) when it encountered the bEVs, indicating rapid adhesion and high affinity of the PNPE to the BMDCs. PNPE showed significantly stronger binding to the cell membrane than PLGA microparticles (PMPs) and AddaVax adjuvant (denoted as surfactant-stabilized nano-emulsion [SSE]). Furthermore, owing to the enhanced cellular affinity to the immunocytes through dynamic curvature changes and lateral diffusions, antigen uptake was subsequently boosted compared with PMPs and SSE. This protocol provides insights for designing novel formulations with high cell affinity and efficient antigen internalization, providing a platform for the development of efficient vaccines.
10.3791/64406
Fish Collagen and Hydroxyapatite Reinforced Poly(lactide- co-glycolide) Fibrous Membrane for Guided Bone Regeneration.
Jin Shue,Sun Fuhua,Zou Qin,Huang Jinhui,Zuo Yi,Li Yubao,Wang Suping,Cheng Lei,Man Yi,Yang Fang,Li Jidong
Biomacromolecules
The purpose of this study was to fabricate a low-immunogenicity fish collagen (FC) and bioactive nanohydroxyapatite (n-HA) enhanced poly(lactide- co-glycolide) (PLGA) nanofibrous membrane for guided bone regeneration (GBR) via electrospinning. The physicochemical properties and morphology study revealed that FC and n-HA particles were homogeneously dispersed in the PLGA fibrous matrix. Notably, the formation of enhanced polymeric chain network due to the interaction between FC and PLGA significantly improved the tensile strength of the PLGA membrane. The incorporation of FC altered the degradation behavior of fibers and accelerated the degradation rate of the PLGA-based membranes. Moreover, the membranes exhibited favorable cytocompatibility with bone mesenchymal stem cells (BMSCs) and human gingiva fibroblasts (HGF) cells. More importantly, the optimized membrane satisfied the requirements of the 'Biological evaluation of medical devices' during the incipient biosafety evaluation. All the results indicate that this composite fibrous membrane exhibits significant potential for guided bone or tissue regeneration.
10.1021/acs.biomac.9b00267
Enhanced bone regeneration using an insulin-loaded nano-hydroxyapatite/collagen/PLGA composite scaffold.
Wang Xing,Zhang Guilan,Qi Feng,Cheng Yongfeng,Lu Xuguang,Wang Lu,Zhao Jing,Zhao Bin
International journal of nanomedicine
Insulin is widely considered as a classical hormone and drug in maintaining energy and glucose homeostasis. Recently, insulin has been increasingly recognized as an indispensable factor for osteogenesis and bone turnover, but its applications in bone regeneration have been restricted because of the short periods of activity and uncontrolled release. In this study, we incorporated insulin-loaded poly lactic-co-glycolic-acid (PLGA) nanospheres into nano-hydroxyapatite/collagen (nHAC) scaffolds and investigated the bioactivity of the composite scaffolds in vitro and in vivo. Bioactive insulin was successfully released from the nanospheres within the scaffold, and the release kinetics of insulin could be efficiently controlled by uniform-sized nanospheres. The physical characterizations of the composite scaffolds demonstrated that incorporation of nanospheres in nHAC scaffolds using this method did not significantly change the porosity, pore diameters, and compressive strengths of nHAC. In vitro, the insulin-loaded nHAC/PLGA composite scaffolds possessed favorable biological function for bone marrow mesenchymal stem cells adhesion and proliferation, as well as the differentiation into osteoblasts. In vivo, the optimized bone regenerative capability of this composite scaffold was confirmed in rabbit mandible critical size defects. These results demonstrated successful development of a functional insulin-PLGA-nHAC composite scaffold that enhances the bone regeneration capability of nHAC.
10.2147/IJN.S150818
Bone regeneration from human mesenchymal stem cells on porous hydroxyapatite-PLGA-collagen bioactive polymer scaffolds.
Bhuiyan Didarul B,Middleton John C,Tannenbaum Rina,Wick Timothy M
Bio-medical materials and engineering
We have developed a novel multicomponent nano-hydroxyapatite-poly(D,L-lactide-co-glycolide)-collagen biomaterial (nHAP-PLGA-collagen) with mechanical properties similar to human cancellous bone. To demonstrate the bone forming capacity of nHAP-PLGA-collagen prior to in vivo experiments, nHAP-PLGA-collagen films and 3D porous scaffolds were seeded with human mesenchymal stem cells (hMSCs) to characterize cell proliferation and osteogenic differentiation. Over 21 days hMSCs seeded on 2D nHAP-PLGA-collagen films proliferate, form nodules, deposit mineral and express high alkaline phosphatase activity (ALP) indicating commitment of hMSCs towards osteogenic lineage. When seeded in 3D scaffolds, hMSCs migrate throughout the connected porous network of the nHAP-PLGA-collagen scaffold and proliferate to fill the scaffold voids. Over 35 days, cells express ALP, osteocalcin and deposit minerals with kinetics similar to osteogenesis in vivo. Adipogenic or chondrogenic differentiation is not detected in 3D constructs, indicating that in an osteogenic environment the presence of bone ECM specific molecules in nHAP-PLGA-collagen scaffolds support homogeneous bone tissue development. This ability of nHAP-PLGA-collagen matrices to provide biochemical stimulation to support osteogenesis from stem cells along with its high mechanical strength suggests that nHAP-PLGA-collagen is a suitable biomaterial for bone regeneration. This platform technology of covalently attaching ECM proteins and molecules with synthetic and natural polymers to adjust material properties and biochemical signaling has a potential for a wider range of applications in tissue engineering and regenerative medicine.
10.3233/BME-171703
Microsphere-based scaffolds encapsulating tricalcium phosphate and hydroxyapatite for bone regeneration.
Journal of materials science. Materials in medicine
Bioceramic mixtures of tricalcium phosphate (TCP) and hydroxyapatite (HAp) are widely used for bone regeneration because of their excellent cytocompatibility, osteoconduction, and osteoinduction. Therefore, we hypothesized that incorporation of a mixture of TCP and HAp in microsphere-based scaffolds would enhance osteogenesis of rat bone marrow stromal cells (rBMSCs) compared to a positive control of scaffolds with encapsulated bone-morphogenic protein-2 (BMP-2). Poly(D,L-lactic-co-glycolic acid) (PLGA) microsphere-based scaffolds encapsulating TCP and HAp mixtures in two different ratios (7:3 and 1:1) were fabricated with the same net ceramic content (30 wt%) to evaluate how incorporation of these ceramic mixtures would affect the osteogenesis in rBMSCs. Encapsulation of TCP/HAp mixtures impacted microsphere morphologies and the compressive moduli of the scaffolds. Additionally, TCP/HAp mixtures enhanced the end-point secretion of extracellular matrix components relevant to bone tissue compared to the "blank" (PLGA-only) microsphere-based scaffolds as evidenced by the biochemical, gene expression, histology, and immunohistochemical characterization. Moreover, the TCP/HAp mixture groups even surpassed the BMP-2 positive control group in some instances in terms of matrix synthesis and gene expression. Lastly, gene expression data suggested that the rBMSCs responded differently to different TCP/HAp ratios presented to them. Altogether, it can be concluded that TCP/HAp mixtures stimulated the differentiation of rBMSCs toward an osteoblastic phenotype, and therefore may be beneficial in gradient microsphere-based scaffolds for osteochondral regeneration.
10.1007/s10856-016-5734-1
Poly (lactic-co-glycolic acid)/graphene oxide composites combined with electrical stimulation in wound healing: preparation and characterization.
International journal of nanomedicine
PURPOSE:In this study, we fabricated multifunctional, electrically conductive composites by incorporating graphene oxide (GO) into a poly (lactic-co-glycolic acid) (PLGA) copolymer for wound repair. Furthermore, the resultant composites were coupled with electrical stimulation to further improve the therapeutic effect of wound repair. METHODS:We evaluated the surface morphology of the composites, as well as their physical properties, cytotoxicity, and antibacterial activity, along with the combined effects of composites and electrical stimulation (ES) in a rat model of wound healing. RESULTS:Application of the PLGA/GO composites to full-thickness wounds confirmed their advantageous biological properties, as evident from the observed improvements in wound-specific mechanical properties, biocompatibility, and antibacterial activity. Additionally, we found that the combination of composites and ES improved composite-mediated cell survival and accelerated wound healing in vivo by promoting neovascularization and the formation of type I collagen. CONCLUSION:These results demonstrated that combined treatment with the PLGA/GO composite and ES promoted vascularization and epidermal remodeling and accelerated wound healing in rats, thereby suggesting the efficacy of PLGA/GO+ES for broad applications associated with wound repair.
10.2147/IJN.S216365
Porous poly(DL-lactic-co-glycolic acid)/calcium phosphate cement composite for reconstruction of bone defects.
Ruhé P Quinten,Hedberg-Dirk Elizabeth L,Padron Nestor Torio,Spauwen Paul H M,Jansen John A,Mikos Antonios G
Tissue engineering
Calcium phosphate (Ca-P) cements are injectable, self-setting ceramic pastes generally known for their favorable bone response. Ingrowth of bone and subsequent degradation rates can be enhanced by the inclusion of macropores. Initial porosity can be induced by CO(2) foaming during setting of the cement, whereas secondary porosity can develop after hydrolysis of incorporated poly(DL-lactic- co-glycolic acid) (PLGA) microparticles. In this study, we focused on the biological response to porous PLGA/Ca-P cement composites. Pre-set composite discs of four formulations (4 wt% or 15 wt% PLGA microparticles and low or high CO(2) induced porosity) were implanted subcutaneously and in cranial defects in rats for 12 weeks. Histological analysis of the explanted composites revealed that bone and fibrous tissue ingrowth was facilitated by addition of PLGA microparticles (number average diameter of 66 +/- 25 microm). No adverse tissue reaction was observed in any of the composites. Significant increases in composite density due to bone ingrowth in cranial implants were found in all formulations. The results suggest that the PLGA pores are suitable for bone ingrowth and may be sufficient to enable complete tissue ingrowth without initial CO(2) induced porosity. Finally, bone-like mineralization in subcutaneous implants suggests that, under appropriate conditions and architecture, porous PLGA/Ca-P cement composites can exhibit osteoinductive properties. These PLGA/Ca-P composites are a promising scaffolding material for bone regeneration and bone tissue engineering.
10.1089/ten.2006.12.789
The Effect of Magnetic Poly(lactic-co-glycolic acid) Microsphere-Gelatin Hydrogel on the Growth of Pre-Osteoblasts Under Static Magnetic Field.
Wang Jingxi,Li Ping,Li Kun,Xu Junwei,Liu Meili,Fan Yubo
Journal of biomedical nanotechnology
A number of bone repair materials are demanded due to bone injury in clinical treatment. Magnetic hydrogels combined with the magnetic field have showed great promoting potential in the field of bone regeneration. Considering the superiority of magnetic microspheres in magnetic localization and drug release, magnetic poly(lactic-co-glycolic acid) microspheres, obtained by electrospraying, were combined with gelatin hydrogel to construct a magnetic poly(lactic-co-glycolic acid) microsphere-gelatin hydrogel for bone repair in our study. Particularly, we investigated the combined effect of 20 mT static magnetic field and magnetic poly(lactic-co-glycolic acid) microsphere-gelatin hydrogel on the proliferation of MC3T3-E1 pre-osteoblasts, indicating that it could significantly promote cell growth at a low concentration of Fe₃ O₄. Furthermore, the hydrogel containing 400 mg˙ LFe₃ O₄ presented the highest growth-promoting effect under a 20 mT static magnetic field. Therefore, the magnetic poly(lactic-co-glycolic acid) microsphere-gelatin hydrogel possesses impressive application value in promoting osteogenesis and bone repair.
10.1166/jbn.2020.2998
3D-printed bioresorbable poly(lactic-co-glycolic acid) and quantum-dot nanocomposites: Scaffolds for enhanced bone mineralization and inbuilt co-monitoring.
Nasrin Aklima,Hassan Mahbub,Mirabet Maria Montero,Windhab Norbert,Gomes Vincent G
Journal of biomedical materials research. Part A
Multifunctional 3D-printed nanocomposites based on poly(lactic-co-glycolic acid), that is, PLGA (RESOMER® LG857S) were developed for simultaneous monitoring of cells and scaffold as a function of time and spectral responses. These were achieved by impregnating carbon quantum dots (CQDs) on PLGA using melt-blending, plasticating extrusion, and 3D-printing. The nanocomposites enabled enhanced bio-affinity and cellular interactions for bone tissue engineering (TE). PLGA (control) and PLGA-CQD scaffolds were used for growing human adipose-derived-stem-cells (ADSCs) and tested for cell biocompatibility, cellular adhesion, growth, and osteogenesis. CQDs were found to enhance the hydrophilicity of nanocomposites and promote cellular nesting. MTS assays confirmed that CQDs on PLGA act as cell anchoring sites, thereby enhancing seeding efficiency and cell proliferation. Alkaline phosphate tests showed increased osteogenesis and Alizarin assays confirmed enhanced bone mineralization on PLGA-CQD. The qPCR tests based on selected mRNA expressions showed that the incorporation of CQDs significantly enhanced osteogenesis of ADSCs during all three phases of cell differentiation. The intrinsic luminescence of the composites allowed label-free monitoring of cell proliferation and bone mineralization on the scaffolds. Thus, the CQDs facilitated significant enhancements in composite processability with customized fabrication of 3D printed scaffolds, bone tissue osteoconductivity, and monitoring of cell-scaffold activities, offering multifunctional benefits for bone TE.
10.1002/jbm.a.37340
RhBMP-2-loaded Poly(lactic-co-glycolic acid) microspheres fabricated by coaxial electrospraying for protein delivery.
Zhang Mei,Ma Yali,Li Rongjun,Zeng Jiehui,Li Ziqi,Tang Yajun,Sun Dahui
Journal of biomaterials science. Polymer edition
In this study, we fabricated recombinant human bone morphogenetic protein-2 (rhBMP-2) loaded Poly(lactic-co-glycolic acid) (PLGA) microspheres with core-shell structures and particle sizes ranging from 2.5 to 8 μm by coaxial electrospraying. The manufacturing process of core-shell microspheres by coaxial electrospraying is simpler than that with other methods, and a smaller diameter can be obtained. The microspheres were analyzed by environmental scanning electron microscopy, transmission electron microscopy (TEM), and laser scanning confocal microscopy (LSCM). Moreover, the drug release profiles and degradation of rhBMP-2-loaded PLGA microspheres in vitro were investigated for 21 days and for 7 weeks, respectively. The rhBMP-2 was stabilized by using bovine serum albumin (BSA) to ensure protein activity in the electrospraying process. Fluorescently labeled protein that was loaded into the core-shell PLGA microspheres was verified by LSCM. The distinct layered structure that existed in the manufactured core-shell microspheres can be observed by TEM. Cell Counting Kit-8 (CCK-8) indicated that the core-shell PLGA microspheres loaded with rhBMP-2 have great potential for the treatment of bone defects, for bone regeneration, and in bone tissue engineering.
10.1080/09205063.2017.1390381
Ba/Mg co-doped hydroxyapatite/PLGA composites enhance X-ray imaging and bone defect regeneration.
Liu Xiangji,Ma Yihang,Chen Minjiang,Ji Jiansong,Zhu Yuhang,Zhu Qingsan,Guo Min,Zhang Peibiao
Journal of materials chemistry. B
Hydroxyapatite (HA) is the most commonly used orthopedic implant material. In recent years, the emergence of cationic doped hydroxyapatite has revealed more possibilities for the biological application of HA. Conventional HA does not promote new bone formation because of its poor osteoinductive activity, and has a similar density to that of bone, leading to difficulty in distinguishing both via imaging. Magnesium ions are useful for regulating the cellular behavior and promoting bone regeneration. Ba ion related compounds, such as BaSO, have a strong X-ray shielding effect. In this study, Ba/Mg@HA was synthesized to prepare Ba/Mg@HA/PLGA composites, and we aimed to investigate if Ba/Mg@HA/PLGA composites enhanced bone repair on osteoblasts and tibial defects, as well as the X-ray and CT imaging ability of bone implants in rats. The in vitro experimental results showed that the Ba/Mg@HA/PLGA composites significantly improved the attachment and osteogenic differentiation of MC3T3-E1 cells. These include the promotion of mineral deposition, enhancement of alkaline phosphatase activity, upregulation of OCN and COL-1 gene expression, and increase in COL-1 and OCN protein expression in a time- and concentration-dependent manner. The in vivo experimental results showed that the Ba/Mg@HA/PLGA composites significantly increased the rate of bone defect healing and the expression of BMP-2 and COL-1 in the bones of rats. X-ray and CT imaging results showed that the Ba/Mg@HA/PLGA composites enhanced the X-ray imaging ability. These findings indicate that the Ba/Mg@HA/PLGA composites can effectively promote bone formation and improve the X-ray and CT imaging abilities to a certain extent.
10.1039/d1tb01080h
Poly(Dopamine) Coating on 3D-Printed Poly-Lactic-Co-Glycolic Acid/β-Tricalcium Phosphate Scaffolds for Bone Tissue Engineering.
Molecules (Basel, Switzerland)
Bone defects caused by osteoporosis, bone malignant tumors, and trauma are very common, but there are many limiting factors in the clinical treatment of them. Bone tissue engineering is the most promising treatment and is considered to be the main strategy for bone defect repair. We prepared polydopamine-coated poly-(lactic-co-glycolic acid)/β-tricalcium phosphate composite scaffolds via 3D printing, and a series of characterization and biocompatibility tests were carried out. The results show that the mechanical properties and pore-related parameters of the composite scaffolds are not affected by the coatings, and the hydrophilicities of the surface are obviously improved. Scanning electron microscopy and micro-computed tomography display the nanoscale microporous structure of the bio-materials. Biological tests demonstrate that this modified surface can promote cell adhesion and proliferation and improve osteogenesis through the increase of polydopamine (PDA) concentrations. Mouse cranial defect experiments are conducted to further verify the conclusion that scaffolds with a higher content of PDA coatings have a better effect on the formation of new bones. In the study, the objective of repairing critical-sized defects is achieved by simply adding PDA as coatings to obtain positive results, which can suggest that this modification method with PDA has great potential.
10.3390/molecules24234397
Hydrogel-Embedded Poly(Lactic--Glycolic Acid) Microspheres for the Delivery of hMSC-Derived Exosomes to Promote Bioactive Annulus Fibrosus Repair.
Cartilage
OBJECTIVE:Intervertebral disk degeneration is a prevalent postoperative complication after discectomy, underscoring the need to develop preventative and bioactive treatment strategies that decelerate degeneration and seal annulus fibrosus (AF) defects. Human mesenchymal stem cell-derived exosomes (MSC-Exos) hold promise for cell-free bioactive repair; however, their ability to promote AF repair is poorly understood. The objective of this study was to evaluate the ability of MSC-Exos to promote endogenous AF repair processes and integrate MSC-Exos within a biomaterial delivery system. DESIGN:We characterize biophysical and biochemical properties of normoxic (Nx) and hypoxic (Hx) preconditioned MSC-Exos from young, healthy donors and examine their effects on AF cell proliferation, migration, and gene expression. We then integrate a poly(lactic--glycolic acid) microsphere (PLGA µSphere) delivery platform within an interpenetrating network hydrogel to facilitate sustained MSC-Exo delivery. RESULTS:Hx MSC-Exos led to a more robust response in AF cell proliferation and migration than Nx MSC-Exos and was selected for a downstream protection experiment. Hx MSC-Exos maintained a healthy AF cell phenotype under a TNFα challenge and attenuated catabolic responses. In all functional assays, AF cell responses were more sensitive to Hx MSC-Exos than Nx MSC-Exos. PLGA µSpheres released MSC-Exos over a clinically relevant timescale without affecting hydrogel modulus or pH upon initial embedment and µSphere degradation. CONCLUSIONS:This MSC-Exo treatment strategy may offer benefits of stem cell therapy without the need for exogenous stem cell transplantation by stimulating cell proliferation, promoting cell migration, and protecting cells from the degenerative proinflammatory microenvironment.
10.1177/19476035221113959
Local administration of aspirin with β-tricalcium phosphate/poly-lactic-co-glycolic acid (β-TCP/PLGA) could enhance osteoporotic bone regeneration.
Tao Zhou-Shan,Wu Xing-Jing,Zhou Wan-Shu,Wu Xin-Ju,Liao Wei,Yang Min,Xu Hong-Guang,Yang Lei
Journal of bone and mineral metabolism
Composite materials β-tricalcium phosphate (β-TCP) and poly-lactic-co-glycolic acid (PLGA) have achieved stable bone regeneration without cell transplantation in previous studies. Recent research shows that aspirin (ASP) has great potential in promoting bone regeneration. The objective of the present study was to incorporate PLGA into β-TCP combined with a lower single-dose local administration of ASP to enhance its in vivo biodegradation and bone tissue growth. After the creation of a rodent critical-sized femoral metaphyseal bone defect, PLGA -modified β-TCP (TP) was prepared by mixing sieved granules of β-TCP and PLGA (50:50, v/v) for medical use, then TP with dripped 50 µg/0.1 ml and 100 µg/0.1 ml aspirin solution was implanted into the defect of OVX rats until death at 8 weeks. The defected area in distal femurs of rats was harvested for evaluation by histology, micro-CT, biomechanics and real time RT-PCR. The results of our study show that a single-dose local administration of ASP combined with the local usage of TP can increase the healing of defects in OVX rats. Single-dose local administration of aspirin can improve the transcription of genes involved in the regulation of bone formation and vascularization in the defect area, and inhibits osteoclast activity. Furthermore, treatments with a higher single-dose local administration of ASP and TP showed a stronger effect on accelerating the local bone formation than while using a lower dose of ASP. The results from our study demonstrate that the combination of a single-dose local administration of ASP and β-TCP/PLGA had an additive effect on local bone formation in osteoporosis rats, and bone regeneration by PLGA/β-TCP/ASP occured in a dose-dependent manner.
10.1007/s00774-019-01008-w
NF-κB Decoy ODN-Loaded Poly(Lactic-co-glycolic Acid) Nanospheres Inhibit Alveolar Ridge Resorption.
International journal of molecular sciences
Residual ridge resorption combined with dimensional loss resulting from tooth extraction has a prolonged correlation with early excessive inflammation. Nuclear factor-kappa B (NF-κB) decoy oligodeoxynucleotides (ODNs) are double-stranded DNA sequences capable of downregulating the expression of downstream genes of the NF-κB pathway, which is recognized for regulating prototypical proinflammatory signals, physiological bone metabolism, pathologic bone destruction, and bone regeneration. The aim of this study was to investigate the therapeutic effect of NF-κB decoy ODNs on the extraction sockets of Wistar/ST rats when delivered by poly(lactic-co-glycolic acid) (PLGA) nanospheres. Microcomputed tomography and trabecular bone analysis following treatment with NF-κB decoy ODN-loaded PLGA nanospheres (PLGA-NfDs) demonstrated inhibition of vertical alveolar bone loss with increased bone volume, smoother trabecular bone surface, thicker trabecular bone, larger trabecular number and separation, and fewer bone porosities. Histomorphometric and reverse transcription-quantitative polymerase chain reaction analysis revealed reduced tartrate-resistant acid phosphatase-expressing osteoclasts, interleukin-1β, tumor necrosis factor-α, receptor activator of NF-κB ligand, turnover rate, and increased transforming growth factor-β1 immunopositive reactions and relative gene expression. These data demonstrate that local NF-κB decoy ODN transfection via PLGA-NfD can be used to effectively suppress inflammation in a tooth-extraction socket during the healing process, with the potential to accelerate new bone formation.
10.3390/ijms24043699
Incorporation of fast dissolving glucose porogens and poly(lactic-co-glycolic acid) microparticles within calcium phosphate cements for bone tissue regeneration.
Acta biomaterialia
This study investigated the effects of incorporating glucose microparticles (GMPs) and poly(lactic-co-glycolic acid) microparticles (PLGA MPs) within a calcium phosphate cement on the cement's handling, physicochemical properties, and the respective pore formation. Composites were fabricated with two different weight fractions of GMPs (10 and 20 wt%) and two different weight fractions of PLGA MPs (10 and 20 wt%). Samples were assayed for porosity, pore morphology, and compressive mechanical properties. An in vitro degradation study was also conducted. Samples were exposed to a physiological solution for 3 days, 4 wks, and 8 wks in order to understand how the inclusion of GMPs and PLGA MPs affects the composite's porosity and mass loss over time. GMPs and PLGA MPs were both successfully incorporated within the composites and all formulations showed an initial setting time that is appropriate for clinical applications. Through a main effects analysis, we observed that the incorporation of GMPs had a significant effect on the overall porosity, mean pore size, mode pore size, and in vitro degradation rate of PLGA MPs as early as after 3 days (p < 0.05). After 4 wks and 8 wks, these same properties were affected by the inclusion of both types of MPs (p < 0.05). Advanced polymer chromatography confirmed that the degradation of PLGA MPs coincided with an increase in composite porosity, mean pore size, and mode pore size. Finally, it was observed that the inclusion of GMPs slowed the degradation of PLGA MPs in vitro and reduced the solution acidity due to PLGA degradation products. Our results suggest that the dual inclusion of GMPs and PLGA MPs is a valuable approach for the generation of early macropores, while also mitigating the effect of acidic degradation products from PLGA MPs on their degradation kinetics. STATEMENT OF SIGNIFICANCE:A multitude of strategies and techniques have been investigated for the introduction of macropores with calcium phosphate cements (CPC). However, many of these strategies take several weeks to months to generate a maximal porosity or the degradation products of the porogen can trigger a localized inflammatory response in vivo. As such, it was hypothesized that the fast dissolution of glucose microparticles (GMPs) in a CPC composite also incorporating poly(lactic-co-glycolic acid) (PLGA) microparticles (MPs) will create an initial macroporosity and increase the surface area within the CPC, thus enhancing the diffusion of PLGA degradation products and preventing a significant decrease in pH. Furthermore, as PLGA degradation occurs over several weeks to months, additional macroporosity will be generated at later time points within CPCs. The results offer a new method for generating macroporosity in a multimodal fashion that also mitigates the effects of acidic degradation products.
10.1016/j.actbio.2018.07.054
Enhanced osteoinductive capacity of poly(lactic-co-glycolic) acid and biphasic ceramic scaffolds by embedding simvastatin.
Sordi Mariane B,Curtarelli Raissa B,Mantovani Iara F,Moreira Anderson C,Fernandes Celso P,Cruz Ariadne C C,Magini Ricardo S
Clinical oral investigations
OBJECTIVES:This study evaluated the effect of embedding simvastatin (SIM) on the osteoinductive capacity of PLGA + HA/βTCP scaffolds in stem cells from human exfoliated deciduous teeth (SHED). MATERIALS AND METHODS:Scaffolds were produced by PLGA solvent dissolution, addition of HA/βTCP, solvent evaporation, and leaching of sucrose particles to impart porosity. Biphasic ceramic particles (70% HA/30% βTCP) were added to the PLGA in a 1:1 (w:w) ratio. Scaffolds with SIM received 1% (w:w) of this medication. Scaffolds were synthesized in a disc-shape and sterilized by ethylene oxide. The experimental groups were (G1) PLGA + HA/βTCP and (G2) PLGA + HA/βTCP + SIM in non-osteogenic culture medium, while (G3) SHED and (G4) MC3T3-E1 in osteogenic culture medium were the positive control groups. The release profile of SIM from scaffolds was evaluated. DNA quantification assay, alkaline phosphatase activity, osteocalcin and osteonectin proteins, extracellular calcium detection, von Kossa staining, and X-ray microtomography were performed to assess the capacity of scaffolds to induce the osteogenic differentiation of SHED. RESULTS:The release profile of SIM followed a non-liner sustained-release rate, reaching about 40% of drug release at day 28. Additionally, G2 promoted the highest osteogenic differentiation of SHED, even when compared to the positive control groups. CONCLUSIONS:In summary, the osteoinductive capacity of poly(lactic-co-glycolic) acid and biphasic ceramic scaffolds was expressively enhanced by embedding simvastatin. CLINICAL RELEVANCE:Bone regeneration is still a limiting factor in the success of several approaches to oral and maxillofacial surgeries, though tissue engineering using mesenchymal stem cells, scaffolds, and osteoinductive mediators might collaborate to this topic.
10.1007/s00784-021-04240-9
Bone Regeneration from PLGA Micro-Nanoparticles.
Ortega-Oller Inmaculada,Padial-Molina Miguel,Galindo-Moreno Pablo,O'Valle Francisco,Jódar-Reyes Ana Belén,Peula-García Jose Manuel
BioMed research international
Poly-lactic-co-glycolic acid (PLGA) is one of the most widely used synthetic polymers for development of delivery systems for drugs and therapeutic biomolecules and as component of tissue engineering applications. Its properties and versatility allow it to be a reference polymer in manufacturing of nano- and microparticles to encapsulate and deliver a wide variety of hydrophobic and hydrophilic molecules. It additionally facilitates and extends its use to encapsulate biomolecules such as proteins or nucleic acids that can be released in a controlled way. This review focuses on the use of nano/microparticles of PLGA as a delivery system of one of the most commonly used growth factors in bone tissue engineering, the bone morphogenetic protein 2 (BMP2). Thus, all the needed requirements to reach a controlled delivery of BMP2 using PLGA particles as a main component have been examined. The problems and solutions for the adequate development of this system with a great potential in cell differentiation and proliferation processes under a bone regenerative point of view are discussed.
10.1155/2015/415289
Porous calcium phosphate-poly (lactic-co-glycolic) acid composite bone cement: A viable tunable drug delivery system.
Roy Abhijit,Jhunjhunwala Siddharth,Bayer Emily,Fedorchak Morgan,Little Steve R,Kumta Prashant N
Materials science & engineering. C, Materials for biological applications
Calcium phosphate based cements (CPCs) are frequently used as bone void fillers for non-load bearing segmental bone defects due to their clinically relevant handling characteristics and ability to promote natural bone growth. Macroporous CPC scaffolds with interconnected pores are preferred for their ability to degrade faster and enable accelerated bone regeneration. Herein, a composite CPC scaffold is developed using newly developed resorbable calcium phosphate cement (ReCaPP) formulation containing degradable microspheres of bio-compatible poly (lactic-co-glycolic acid) (PLGA) serving as porogen. The present study is aimed at characterizing the effect of in-vitro degradation of PLGA microspheres on the physical, chemical and structural characteristics of the composite cements. The porosity measurements results reveal the formation of highly interconnected macroporous scaffolds after degradation of PLGA microspheres. The in-vitro characterizations also suggest that the degradation by products of PLGA reduces the pH of the local environment thereby increasing the dissolution rate of the cement. In addition, the in-vitro vancomycin release from the composite CPC scaffold suggests that the drug association with the composite scaffolds can be tuned to achieve control release kinetics. Further, the study demonstrates control release lasting for longer than 10weeks from the composite cements in which vancomycin is encapsulated in PLGA microspheres.
10.1016/j.msec.2015.09.081
Fast Degradable Calcium Phosphate Cement for Maxillofacial Bone Regeneration.
Tissue engineering. Part A
The aim of this preclinical study was to test the applicability of calcium phosphate cement (CPC)-poly(lactic-co-glycolic acid) (PLGA)-carboxymethylcellulose (CMC) as a bone substitute material for guided bone regeneration (GBR) procedures in a clinically relevant mandibular defect model in minipigs. In the study, a predicate device (i.e., BioOss) was included for comparison. Critical-sized circular mandibular bone defects were created and filled with either CPC-PLGA-CMC without coverage with a GBR membrane or BioOss covered with a GBR membrane and left to heal for 4 and 12 weeks to obtain temporal insight in material degradation and bone formation. Bone formation increased significantly for both CPC-PLGA-CMC and BioOss with increasing implantation time. Further, no significant differences were found for bone formation at either 4 or 12 weeks between CPC-PLGA-CMC and BioOss. Finally, bone substitute material degradation increased significantly for both CPC-PLGA-CMC and BioOss from 4 to 12 weeks of implantation, showing the highest degradation for CPC-PLGA-CMC (∼85%) compared to BioOss (∼12%). In conclusion, this minipig study showed that CPC-PLGA-CMC can be used as a bone-grafting material and stimulates bone regeneration to a comparable extent as with BioOss particles. Importantly, CPC-PLGA-CMC degrades faster compared to BioOss, is easier to apply into a bone defect, and does not need the use of an additional GBR membrane. Consequently, the data support the further investigation of CPC-PLGA-CMC in human clinical trials. Impact statement Guided bone regeneration (GBR) is a frequently used dental surgical technique to regenerate the alveolar ridge to allow stable implant installation. However, stabilization of the GBR membrane and avoidance of bone graft movement remain a challenge. Consequently, there is need for the development of alternative materials to be used in GBR procedures that are easier to apply and induce predictable bone regeneration. In this minipig study, we focused on the applicability of calcium phosphate cement-poly(lactic-co-glycolic acid)-carboxymethylcellulose as an alternative bone substitute material for GBR procedures without the need of an additional GBR membrane.
10.1089/ten.TEA.2022.0177
Toward accelerated bone regeneration by altering poly(D,L-lactic-co-glycolic) acid porogen content in calcium phosphate cement.
van Houdt C I A,Preethanath R S,van Oirschot B A J A,Zwarts P H W,Ulrich D J O,Anil S,Jansen J A,van den Beucken J J J P
Journal of biomedical materials research. Part A
This work aimed to compare in vitro degradation of dense PLGA microspheres and milled PLGA particles as porogens within CPC, considering that the manufacturing of milled PLGA is more cost-effective when compared with PLGA microspheres. Additionally, we aimed to examine the effect of porogen amount within CPC/PLGA on degradation and bone formation. Our in vitro results showed no differences between both forms of PLGA particles (as porogens in CPC; spherical for microspheres, irregular for milled) regarding morphology, porosity, and degradation. Using milled PLGA as porogens within CPC/PLGA, we evaluated the effect of porogen amount on degradation and bone forming capacity in vivo. Titanium landmarks surrounded by CPC/PLGA with 30 and 50 wt % PLGA, were implanted in forty femoral bone defects of twenty male Wistar rats. Histomorphometrical results showed a significant temporal decrease in the amount of CPC, for both formulas, and confirmed that 50 wt % PLGA degrades faster than 30 wt%, and allows for a 1.5-fold higher amount of newly formed bone. Taken together, this study demonstrated that (i) milled PLGA particles perform equal to PLGA microspheres, and (ii) tuning of the PLGA content in CPC/PLGA is a feasible approach to leverage material degradation and bone formation.
10.1002/jbm.a.35584
Novel Strategy to Accelerate Bone Regeneration of Calcium Phosphate Cement by Incorporating 3D Plotted Poly(lactic-co-glycolic acid) Network and Bioactive Wollastonite.
Qian Guowen,Fan Peirong,He Fupo,Ye Jiandong
Advanced healthcare materials
Inefficient bone regeneration of self-hardening calcium phosphate cement (CPC) increases the demand for interconnected macropores and osteogenesis-stimulated substances. It remains a challenge to fabricate porous CPC with interconnected macropores while maintaining its advantages, such as plasticity. Herein, pastes containing CPC and wollastonite (WS) are infiltrated into a 3D plotted poly(lactic-co-glycolic acid) (PLGA) network to fabricate plastic CPC-based composite cement (PLGA/WS/CPC). The PLGA/WS/CPC recovers the plasticity of CPC after being heated above the glass transition temperature of PLGA. The presence of the 3D PLGA network significantly increases the flexibility of CPC in prophase and generates 3D interconnected macropores in situ upon its degradation. The addition of WS is helpful to improve the attachment, proliferation, and osteogenic differentiation of mouse bone marrow stromal cells in vitro. The in vivo experimental results indicate that PLGA/WS/CPC promotes rapid angiogenesis and bone formation. Therefore, the plastic CPC-based composite cement with a 3D PLGA network and wollastonite shows an obviously improved efficiency for repairing bone defects and is expected to facilitate the wider application of CPC in the clinic.
10.1002/adhm.201801325
Accelerating bone regeneration using poly(lactic-co-glycolic acid)/hydroxyapatite scaffolds containing duck feet-derived collagen.
International journal of biological macromolecules
Collagen, with low antigenicity and excellent cell adhesion, is a biomaterial mainly used for regenerating bone, cartilage, and skin, owing to its biocompatibility and biodegradability. Results from a previous study confirmed that a scaffold mixed with duck feet-derived collagen (DC) and Poly(lactic-co-glycolic acid) (PLGA) reduced inflammatory reaction and increased bone regeneration. To develop an optimal bone substitute we included hydroxyapatite (HAp), a key osteoconductive material, in a DC and PLGA mixture. We fabricated 0, 10, 20, 40, 60, and 80 wt% DC/PLGA/HAp scaffolds and studied their potential for bone tissue engineering. Characteristic analysis of the scaffold and seeding of rabbit bone marrow mesenchymal stem cells (rBMSCs) on the scaffold were conducted to investigate cell proliferation, osteogenic differentiation, and bone formation. We confirmed that increasing DC concentration not only improved the compressive strength of the DC/PLGA/HAp scaffold but also cell proliferation and osteogenic differentiation. It was found through comparison with previous studies that including HAp in the scaffold also promotes osteogenic differentiation. Our study thus shows through in vivo results that the 80 wt% DC/PLGA/HAp scaffold promotes bone mineralization and collagen deposition while reducing the inflammatory response. Hence, 80 wt% DC/PLGA/HAp has excellent potential as a biomaterial for bone regeneration applications.
10.1016/j.ijbiomac.2022.12.296
Synthesis and characterization of a calcium phosphate bone cement with quercetin-containing PEEK/PLGA microparticles.
Biomedical materials (Bristol, England)
This study aimed to describe the synthesis and characterization of a calcium phosphate cement (CPC) with polyetheretherketone/poly (lactic-co-glycolic) acid (PEEK/PLGA) micro-particles containing quercetin. CPC powder was synthesized by mixing dicalcium phosphate anhydrate and tetracalcium phosphate. To synthesize PEEK/PLGA microparticles, PLGA85:15 was mixed with 90 wt% PEEK. The weight ratio of quercetin/PLGA/PEEK was 1:9:90 wt%. PEEK/PLGA/quercetin microparticles with 3, 5, and 6 wt% was added to CPC. The setting time, compressive strength, drug release profile, solubility, pH, and porosity of synthesized cement were evaluated. The morphology and physicochemical properties of particles was analyzed by scanning electron microscopy, Fourier-transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), and inductively coupled plasma. Cytotoxicity was assessed by the methyl thiazolyl tetrazolium assay using dental pulp stem cells. Expression of osteoblastic differentiation genes was evaluated by real-time polymerase chain reaction. Data were analyzed by one-way ANOVA and Tukey's test (alpha = 0.05). The setting time of 3 wt% CPC was significantly longer than 5 and 6 wt% CPC (< 0.001). The 6 wt% CPC had significantly higher compressive strength than other groups (= 0.001). The release of quercetin from CPCs increased for 5 d, and then reached a plateau. XRD and FTIR confirmed the presence of hydroxyapatite in cement composition. Significantly higher expression of osteocalcin (OCN) and osteopontin (OPN) was noted in 3 wt% and 6 wt% CPCs. Addition of quercetin-containing PEEK/PLGA microparticles to CPC enhanced its compressive strength, decreased its setting time, enabled controlled drug release, and up-regulated OPN and OCN.
10.1088/1748-605X/ac9ffe