The combination of micro-carriers and polymer scaffolds as promising bone grafts have attracted considerable interest in recent decades.The poly(L-lactic acid)/poly(lactic-co-glycolic acid)/polycaprolactone(PLLA/PLGA/...The combination of micro-carriers and polymer scaffolds as promising bone grafts have attracted considerable interest in recent decades.The poly(L-lactic acid)/poly(lactic-co-glycolic acid)/polycaprolactone(PLLA/PLGA/PCL)composite scaffold with porous structure was fabricated by thermally induced phase separation(TIPS).Dexamethasone(DEX)was incorporated into PLGA microspheres and then loaded on the PLLA/PLGA/PCL scaffoldtopreparethedesiredcompositescaffold.The physicochemical properties of the prepared composite scaffold were characterized.The morphology of rat bone marrow mesenchymal stem cells(BMSCs)grown on scaffolds was observed using scanning electron microscope(SEM)and fluorescence microscope.The resultsshowedthatthePLLA/PLGA/PCLscaffoldhad interconnected macropores and biomimetic nanofibrous structure.In addition,DEX can be released from scaffold in a sustained manner.More importantly,DEX loaded composite scaffold can effectively support the proliferation of BMSCs as indicated by fluorescence observation and cell proliferation assay.The results suggested that the prepared PLLA/PLGA/PCL composite scaffold incorporating drug-loaded PLGA microspheres could hold great potential for bone tissue engineering applications.展开更多
Sequential administration and controlled release of different drugs are of vital importance for regulating cellular behaviors and tissue regeneration,which usually demands appropriate carriers like microspheres(MS)to ...Sequential administration and controlled release of different drugs are of vital importance for regulating cellular behaviors and tissue regeneration,which usually demands appropriate carriers like microspheres(MS)to control drugs releases.Electrospray has been proven an effective technique to prepare MS with uniform particle size and high drug-loading rate.In this study,we applied electrospray to simply and hierarchically fabricate sphere-in-sphere composite microspheres,with smaller poly(lactic-co-glycolic acid)MS(~8-10 lm in diameter)embedded in a larger chitosan MS(~250-300 lm in diameter).The scanning electron microscopy images revealed highly uniform MS that can be accurately controlled by adjusting the nozzle diameter or voltage.Two kinds of model drugs,bovine serum albumin and chlorhexidine acetate,were encapsulated in the microspheres.The fluorescence-labeled rhodamine-fluoresceine isothiocyanate(Rho-FITC)and ultraviolet(UV)spectrophotometry results suggested that loaded drugs got excellent distribution in microspheres,as well as sustained,slow release in vitro.In addition,far-UV circular dichroism and matrixassisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS)results indicated original secondary structure and molecular weight of drugs after electrospraying.Generally speaking,our research proposed a modified hierarchically electrospraying technique to prepare sphere-in-sphere composite MS with two different drugs loaded,which could be applied in sequential,multi-modality therapy.展开更多
基金National Natural Science Foundations of China(Nos.31271028,31570984)Innovation Program of Shanghai Municipal Education Commission,China(No.13ZZ051)+2 种基金International Cooperation Fund of the Science and Technology Commission of Shanghai Municipality,China(No.15540723400)Open Foundation of State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,China(No.LK1416)“111 Project” Biomedical Textile Materials Science and Technology,China(No.B07024)
文摘The combination of micro-carriers and polymer scaffolds as promising bone grafts have attracted considerable interest in recent decades.The poly(L-lactic acid)/poly(lactic-co-glycolic acid)/polycaprolactone(PLLA/PLGA/PCL)composite scaffold with porous structure was fabricated by thermally induced phase separation(TIPS).Dexamethasone(DEX)was incorporated into PLGA microspheres and then loaded on the PLLA/PLGA/PCL scaffoldtopreparethedesiredcompositescaffold.The physicochemical properties of the prepared composite scaffold were characterized.The morphology of rat bone marrow mesenchymal stem cells(BMSCs)grown on scaffolds was observed using scanning electron microscope(SEM)and fluorescence microscope.The resultsshowedthatthePLLA/PLGA/PCLscaffoldhad interconnected macropores and biomimetic nanofibrous structure.In addition,DEX can be released from scaffold in a sustained manner.More importantly,DEX loaded composite scaffold can effectively support the proliferation of BMSCs as indicated by fluorescence observation and cell proliferation assay.The results suggested that the prepared PLLA/PLGA/PCL composite scaffold incorporating drug-loaded PLGA microspheres could hold great potential for bone tissue engineering applications.
基金supported by National Natural Science Foundation of China(nos.31771056,81671827 and 51572144).
文摘Sequential administration and controlled release of different drugs are of vital importance for regulating cellular behaviors and tissue regeneration,which usually demands appropriate carriers like microspheres(MS)to control drugs releases.Electrospray has been proven an effective technique to prepare MS with uniform particle size and high drug-loading rate.In this study,we applied electrospray to simply and hierarchically fabricate sphere-in-sphere composite microspheres,with smaller poly(lactic-co-glycolic acid)MS(~8-10 lm in diameter)embedded in a larger chitosan MS(~250-300 lm in diameter).The scanning electron microscopy images revealed highly uniform MS that can be accurately controlled by adjusting the nozzle diameter or voltage.Two kinds of model drugs,bovine serum albumin and chlorhexidine acetate,were encapsulated in the microspheres.The fluorescence-labeled rhodamine-fluoresceine isothiocyanate(Rho-FITC)and ultraviolet(UV)spectrophotometry results suggested that loaded drugs got excellent distribution in microspheres,as well as sustained,slow release in vitro.In addition,far-UV circular dichroism and matrixassisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS)results indicated original secondary structure and molecular weight of drugs after electrospraying.Generally speaking,our research proposed a modified hierarchically electrospraying technique to prepare sphere-in-sphere composite MS with two different drugs loaded,which could be applied in sequential,multi-modality therapy.