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    Thermogelling, ABC Triblock Copolymer Platform for Resorbable Hydrogels with Tunable, Degradation-Mediated Drug Release. Gupta Mukesh K,Martin John R,Dollinger Bryan R,Hattaway Madison E,Duvall Craig L Advanced functional materials Clinical application of injectable, thermoresponsive hydrogels is hindered by lack of degradability and controlled drug release. To overcome these challenges, a family of thermoresponsive, ABC triblock polymer-based hydrogels has been engineered to degrade and release drug cargo through either oxidative or hydrolytic/enzymatic mechanisms dictated by the "A" block composition. Three ABC triblock copolymers are synthesized with varying "A" blocks, including oxidation-sensitive poly(propylene sulfide), slow hydrolytically/enzymatically degradable poly(ε-caprolactone), and fast hydrolytically/enzymatically degradable poly(D,L-lactide--glycolide), forming the respective formulations PPS--PDMA--PNIPAAM (PDN), PCL--PDMA--PNIPAAM (CDN), and PLGA--PDMA--PNIPAAM (LGDN). For all three polymers, hydrophilic poly(,-dimethylacrylamide) and thermally responsive poly(-isopropylacrylamide) comprise the "B" and "C" blocks, respectively. These copolymers form micelles in aqueous solutions at ambient temperature that can be preloaded with small molecule drugs. These solutions quickly transition into hydrogels upon heating to 37 °C, forming a supra-assembly of physically crosslinked, drug-loaded micelles. PDN hydrogels are selectively degraded under oxidative conditions while CDN and LGDN hydrogels are inert to oxidation but show differential rates of hydrolytic/enzymatic decomposition. All three hydrogels are cytocompatible in vitro and in vivo, and drug-loaded hydrogels demonstrate differential release kinetics in vivo corresponding with their specific degradation mechanism. These collective data highlight the potential cell and drug delivery use of this tunable class of ABC triblock polymer thermogels. 10.1002/adfm.201704107
    Thermosensitive Hydrogel Based on PEO-PPO-PEO Poloxamers for a Controlled In Situ Release of Recombinant Adeno-Associated Viral Vectors for Effective Gene Therapy of Cartilage Defects. Madry Henning,Gao Liang,Rey-Rico Ana,Venkatesan Jagadeesh K,Müller-Brandt Kathrin,Cai Xiaoyu,Goebel Lars,Schmitt Gertrud,Speicher-Mentges Susanne,Zurakowski David,Menger Michael D,Laschke Matthias W,Cucchiarini Magali Advanced materials (Deerfield Beach, Fla.) Advanced biomaterial-guided delivery of gene vectors is an emerging and highly attractive therapeutic solution for targeted articular cartilage repair, allowing for a controlled and minimally invasive delivery of gene vectors in a spatiotemporally precise manner, reducing intra-articular vector spread and possible loss of the therapeutic gene product. As far as it is known, the very first successful in vivo application of such a biomaterial-guided delivery of a potent gene vector in an orthotopic large animal model of cartilage damage is reported here. In detail, an injectable and thermosensitive hydrogel based on poly(ethylene oxide) (PEO)-poly(propylene oxide) (PPO)-PEO poloxamers, capable of controlled release of a therapeutic recombinant adeno-associated virus (rAAV) vector overexpressing the chondrogenic sox9 transcription factor in full-thickness chondral defects, is applied in a clinically relevant minipig model in vivo. These comprehensive analyses of the entire osteochondral unit with multiple standardized evaluation methods indicate that rAAV-FLAG-hsox9/PEO-PPO-PEO hydrogel-augmented microfracture significantly improves cartilage repair with a collagen fiber orientation more similar to the normal cartilage and protects the subchondral bone plate from early bone loss. 10.1002/adma.201906508