Poly （ l- lactide- co-glycolide ） （ PLGA ） with different compositions was prepared using stannous octaoate as catalyst by bulk ring-opening copolymerization of l-lactide and glycolide. The structure and properti...Poly （ l- lactide- co-glycolide ） （ PLGA ） with different compositions was prepared using stannous octaoate as catalyst by bulk ring-opening copolymerization of l-lactide and glycolide. The structure and properties of the PLGA copolymers were cbaracterized by means of attenuated total reflectance-Fourier transform infrared （ATR-FTIR）, ^1H NMR, differential scanning calorimeter （ DSC and X-ray diffraction （XRD） methods, The experimented results indicate that the synthetic conditions and the composition of copolymers have art obvious influence on the structure of PLGA copolymers, The degradation rate of eopolymers increased with the increasing of the glycolide component in the copolymers.展开更多
In order to encapsulate and controlled-release bioactive proteins,three fibrous membranes,i.e.,poly（L-lactide-co-glycolide）（PLGA）,hybrid PLGA and chitosan（H-PLGA/CS）,and core/shell PLGA/CS （C-PLGA/CS）,were pro...In order to encapsulate and controlled-release bioactive proteins,three fibrous membranes,i.e.,poly（L-lactide-co-glycolide）（PLGA）,hybrid PLGA and chitosan（H-PLGA/CS）,and core/shell PLGA/CS （C-PLGA/CS）,were produced by emulsion electrospinning,co-electrospinning and coaxial electrospinning,respectively.Bovine serum albumin（BSA） was selected as a model protein.The loading efficiency of BSA in the PLGA membrane was 1.56%,lower than those of H-PLGA/CS（5.98%） and C-PLGA/CS（4.80%）.BSA release profiles from the three membranes showed initial burst releases in the first 7 d and then sustained release for 28 d.Cumulative releases at the end of the releasing period,28 d,from the above three membranes were nearly 63%,88% and 94%,respectively,indicating that the introduction of chitosan and the core/shell fiber structure could enhance BSA release rate.In addition,all these electrospun membranes could retain their fibrous morphologies after in vitro release of BSA for 28 d.展开更多
A micro-envioment for nerve cells and tissue growth were designed and constructed via surface modification of poly（L-lactide-co-glycolide）（PLGA） with chitosan and hydroxyapatire（HA）. The poly（L_lactide-co-glyco...A micro-envioment for nerve cells and tissue growth were designed and constructed via surface modification of poly（L-lactide-co-glycolide）（PLGA） with chitosan and hydroxyapatire（HA）. The poly（L_lactide-co-glycolide）/chitosan/hydroxyapatite （PLGA/chitosan/HA） conduits were manufactured by a combined solvent casting and particulate leaching technique. The conduits were highly porous with an interconnected pore structure and 76.5% porosity. Micropores with 50-100 micrometer diameter were formed in the conduits. In vivo application of PLGA/chitosan/HA conduits for reconstruction of 10 mm sciatic nerve defect was assessed by the walking track analysis, the quantifying of the wet weight of tibialis anterior muscle and the histological assessment. The conduits in host rats in vivo can not only be an effective in promoting regenerating of nerves but can also lead to favorable nerve functional recovery.展开更多
文摘Poly （ l- lactide- co-glycolide ） （ PLGA ） with different compositions was prepared using stannous octaoate as catalyst by bulk ring-opening copolymerization of l-lactide and glycolide. The structure and properties of the PLGA copolymers were cbaracterized by means of attenuated total reflectance-Fourier transform infrared （ATR-FTIR）, ^1H NMR, differential scanning calorimeter （ DSC and X-ray diffraction （XRD） methods, The experimented results indicate that the synthetic conditions and the composition of copolymers have art obvious influence on the structure of PLGA copolymers, The degradation rate of eopolymers increased with the increasing of the glycolide component in the copolymers.
基金Supported by the National Natural Science Foundation of China(Nos.50273027,50573055,30828008)the Natural Science Foundation of Tianjin City,China(No.09JCZDJC18600)
文摘In order to encapsulate and controlled-release bioactive proteins,three fibrous membranes,i.e.,poly（L-lactide-co-glycolide）（PLGA）,hybrid PLGA and chitosan（H-PLGA/CS）,and core/shell PLGA/CS （C-PLGA/CS）,were produced by emulsion electrospinning,co-electrospinning and coaxial electrospinning,respectively.Bovine serum albumin（BSA） was selected as a model protein.The loading efficiency of BSA in the PLGA membrane was 1.56%,lower than those of H-PLGA/CS（5.98%） and C-PLGA/CS（4.80%）.BSA release profiles from the three membranes showed initial burst releases in the first 7 d and then sustained release for 28 d.Cumulative releases at the end of the releasing period,28 d,from the above three membranes were nearly 63%,88% and 94%,respectively,indicating that the introduction of chitosan and the core/shell fiber structure could enhance BSA release rate.In addition,all these electrospun membranes could retain their fibrous morphologies after in vitro release of BSA for 28 d.
基金Funded by the National Natural Science Foundation of China(No.50774096)
文摘A micro-envioment for nerve cells and tissue growth were designed and constructed via surface modification of poly（L-lactide-co-glycolide）（PLGA） with chitosan and hydroxyapatire（HA）. The poly（L_lactide-co-glycolide）/chitosan/hydroxyapatite （PLGA/chitosan/HA） conduits were manufactured by a combined solvent casting and particulate leaching technique. The conduits were highly porous with an interconnected pore structure and 76.5% porosity. Micropores with 50-100 micrometer diameter were formed in the conduits. In vivo application of PLGA/chitosan/HA conduits for reconstruction of 10 mm sciatic nerve defect was assessed by the walking track analysis, the quantifying of the wet weight of tibialis anterior muscle and the histological assessment. The conduits in host rats in vivo can not only be an effective in promoting regenerating of nerves but can also lead to favorable nerve functional recovery.
