Injectable thermal gels are a useful tool for drug delivery and tissue engineering.However,most thermal gels do not solidify rapidly at body temperature(37C).We addressed this by synthesizing a thermo-sensitive,rapid...Injectable thermal gels are a useful tool for drug delivery and tissue engineering.However,most thermal gels do not solidify rapidly at body temperature(37C).We addressed this by synthesizing a thermo-sensitive,rapidly biodegrading hydrogel.Our hydrogel,poly(ethylene glycol)-co-poly(propanol serinate hexamethylene urethane)(EPSHU),is an ABA block copolymer comprising A,methoxy poly ethylene glycol group and B,poly(propanol L-serinate hexamethylene urethane).EPSHU was characterized by gel permeation chromatography for molecular weight and 1H NMR and Fourier transformed infrared for structure.Rheological studies measured the phase transition temperature.In vitro degradation in cholesterol esterase and in Dulbecco’s phosphate buffered saline(DPBS)was tracked using the average molecular weight measured by gel permeation chromatography.LIVE/DEAD and resazurin reduction assays performed on NIH 3T3 fibroblasts exposed to EPSHU extracts demonstrated no cytotoxicity.Subcutaneous implantation into BALB/cJ mice indicated good biocompatibility in vivo.The biodegradability and biocompatibility of EPSHU together make it a promising candidate for drug delivery applications that demand carrier gel degradation withinmonths.展开更多
基金This work was supported by the National Institutes of Health and Clinical and Translational Science Institute(NIH UL1TR000005)the National Science Foundation under grant no.1247842.The authors thank Dr Keewon Lee for helpful discussions on cell culture and fluorescence microscopy.
文摘Injectable thermal gels are a useful tool for drug delivery and tissue engineering.However,most thermal gels do not solidify rapidly at body temperature(37C).We addressed this by synthesizing a thermo-sensitive,rapidly biodegrading hydrogel.Our hydrogel,poly(ethylene glycol)-co-poly(propanol serinate hexamethylene urethane)(EPSHU),is an ABA block copolymer comprising A,methoxy poly ethylene glycol group and B,poly(propanol L-serinate hexamethylene urethane).EPSHU was characterized by gel permeation chromatography for molecular weight and 1H NMR and Fourier transformed infrared for structure.Rheological studies measured the phase transition temperature.In vitro degradation in cholesterol esterase and in Dulbecco’s phosphate buffered saline(DPBS)was tracked using the average molecular weight measured by gel permeation chromatography.LIVE/DEAD and resazurin reduction assays performed on NIH 3T3 fibroblasts exposed to EPSHU extracts demonstrated no cytotoxicity.Subcutaneous implantation into BALB/cJ mice indicated good biocompatibility in vivo.The biodegradability and biocompatibility of EPSHU together make it a promising candidate for drug delivery applications that demand carrier gel degradation withinmonths.
