For monomer reactivity ratios study, the copolymerization of D,L-3-methylglycolide (MG) with glycolide (GA) or D,L-lactide (LA) was carried out in bulk to a certain low conversion in the presence of stannous octoate a...For monomer reactivity ratios study, the copolymerization of D,L-3-methylglycolide (MG) with glycolide (GA) or D,L-lactide (LA) was carried out in bulk to a certain low conversion in the presence of stannous octoate at 140 degrees C. The copolymer compositions were determined by H-1 NMR spectroscopy. The monomer reactivity ratios were evaluated by Fineman-Ross method, Kelen-Tudos method and linear least-squares method. The monomer reactivity ratios of D,L-3-methylglycolide and glycolide or D,L-lactide are r(mg)= 0.73, r(ga)= 1.47; r(mg)= 1.71, r(la)= 0.92, respectively.展开更多
A novel polyester containing glycolic acid(GA)and 2 hydro 2 oxo 1,3,2 dioxaphosphorinane(TMP)was prepared by ring opening polymerization.The composition and the structure of the titled polymer were investigated by 1...A novel polyester containing glycolic acid(GA)and 2 hydro 2 oxo 1,3,2 dioxaphosphorinane(TMP)was prepared by ring opening polymerization.The composition and the structure of the titled polymer were investigated by 1H NMR, 13 C NMR,FT IR,EA,and VPO.The influence of time on total conversion and molecular weight was also studied.展开更多
This paper reviewed all types of the polymer - based synthetic absorbable surgical sutures that have been commercially produced. The chemical component, biological and mechanical properties, and using effect of these ...This paper reviewed all types of the polymer - based synthetic absorbable surgical sutures that have been commercially produced. The chemical component, biological and mechanical properties, and using effect of these sutures were discussed. The recent development and the possible coming research orientation in these areas were also presented.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
Biodegradable poly(alc-alt-Asp) was synthesized by ring-opening polymerization of the monomer 3-(S)-[(benzyloxycarbonyl)methyl] -morpholine-2, 5-dione and subsequent catalytic hydrogenation. Copolymers of the monomer ...Biodegradable poly(alc-alt-Asp) was synthesized by ring-opening polymerization of the monomer 3-(S)-[(benzyloxycarbonyl)methyl] -morpholine-2, 5-dione and subsequent catalytic hydrogenation. Copolymers of the monomer with glycolide, D,L-lactide and L-lactide were also prepared.展开更多
基金This work was supported by the Key Project of the National Natural Science Foundation of China!(59833 140).
文摘For monomer reactivity ratios study, the copolymerization of D,L-3-methylglycolide (MG) with glycolide (GA) or D,L-lactide (LA) was carried out in bulk to a certain low conversion in the presence of stannous octoate at 140 degrees C. The copolymer compositions were determined by H-1 NMR spectroscopy. The monomer reactivity ratios were evaluated by Fineman-Ross method, Kelen-Tudos method and linear least-squares method. The monomer reactivity ratios of D,L-3-methylglycolide and glycolide or D,L-lactide are r(mg)= 0.73, r(ga)= 1.47; r(mg)= 1.71, r(la)= 0.92, respectively.
文摘A novel polyester containing glycolic acid(GA)and 2 hydro 2 oxo 1,3,2 dioxaphosphorinane(TMP)was prepared by ring opening polymerization.The composition and the structure of the titled polymer were investigated by 1H NMR, 13 C NMR,FT IR,EA,and VPO.The influence of time on total conversion and molecular weight was also studied.
文摘This paper reviewed all types of the polymer - based synthetic absorbable surgical sutures that have been commercially produced. The chemical component, biological and mechanical properties, and using effect of these sutures were discussed. The recent development and the possible coming research orientation in these areas were also presented.
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.
文摘Biodegradable poly(alc-alt-Asp) was synthesized by ring-opening polymerization of the monomer 3-(S)-[(benzyloxycarbonyl)methyl] -morpholine-2, 5-dione and subsequent catalytic hydrogenation. Copolymers of the monomer with glycolide, D,L-lactide and L-lactide were also prepared.
