A novel poly（d, /-lactic acid） （PDLLA） based biomimetic polymer was synthesized by grafting maleic anhydride, butanediamine and arg-gly-asp-ser （RGDS） peptides onto the backbone of PDLLA, aiming to overcome the ...A novel poly（d, /-lactic acid） （PDLLA） based biomimetic polymer was synthesized by grafting maleic anhydride, butanediamine and arg-gly-asp-ser （RGDS） peptides onto the backbone of PDLLA, aiming to overcome the acidity and auto-accelerating degradation of PDLLA during degradation and to improve its biospecificity and biocompatibility. The synthetic copolymer was characterized by FTIR, ^13C NMR and amino acid analyzer （AAA）.展开更多
A series of novel poly（urethane-urea）（PUU） was synthesized from poly（lactide-co-p-dioxanone） macrodiol（HO-P（LA-co-PDO）-OH）, hexamethylene diisocyanate（HDI） and butanediamine（BDA）.The obtained PUU,which i...A series of novel poly（urethane-urea）（PUU） was synthesized from poly（lactide-co-p-dioxanone） macrodiol（HO-P（LA-co-PDO）-OH）, hexamethylene diisocyanate（HDI） and butanediamine（BDA）.The obtained PUU,which is recorded as P（LA-co-PDO）-PUU here,may demonstrate enhanced phase separation and thus improved shape memory property.FTIR was employed to characterize the copolymers,and the effects of NCO/OH molar ratios on Tg of PUU was investigated by means of differential scanning calorimetry （DSC）.The results revealed the successful synthesis of P（LA-co-PDO）-PUU.In addition,the Tg of P（LA-co-PDO）-PUU increased from 37.9℃to 44.2℃with the increase NCO/OH ratios from 1.1 to 1.2.The P（LA-co-PDO）-PUU with Tg close to body temperature will have potential applications as shape memory polymers in biomedical fields,especially in minimally invasive surgery.展开更多
A novel degradable pH-sensitive hydrogel with pendent carboxyl groups was designed and synthesized from ethylenediaminetetraacetic dianhydride （EDTAh） and butanediamine （BDA） with dicyclohexylcarbodiimide （DCC） ...A novel degradable pH-sensitive hydrogel with pendent carboxyl groups was designed and synthesized from ethylenediaminetetraacetic dianhydride （EDTAh） and butanediamine （BDA） with dicyclohexylcarbodiimide （DCC） as a condensating agent and BDA as a crosslinking agent. The obtained polymers were characterized by ^13C NMR, ^1H NMR and FTIR. The swelling experiments of the hydrogel in pH 3, 7, and 12 media indicated much higher swelling ratio in pH 12 media than in pH 3 and pH 7 media, exhibiting sound pH sensitivity. The pH sensitivity of this type of hydrogel may be regulated through controlling the type and the dose of the crosslinking agent.展开更多
The degradation of butanediamine-grafted poly（DL-lactic acid） polymers （BDPLAs） in vitro together with PDLLA and maleic anhydride-grafted poly（DL-lactic acid） polymers （MPLAs） was investigated by observation o...The degradation of butanediamine-grafted poly（DL-lactic acid） polymers （BDPLAs） in vitro together with PDLLA and maleic anhydride-grafted poly（DL-lactic acid） polymers （MPLAs） was investigated by observation of the changes of the pH value of incubation media, and weight loss ratio during degradation duration of 12 weeks. The results reveal that the acidity of PDLLA degradation products was weakened or neutralized by grafting butanediamine onto PDLLA. A uniform degradation of BDPLAs was observed in comparison with an acidity-induced auto-accelerating degradation featured by PDLLA and MPLAs. The biodegradation behaviors of BDPLAs can be adjusted by controlling the content of BDA. BDPLAs might be a new derivative of PDLLA-based biodegradable materials for medical applications without acidity-caused irritations and acidity-induced auto-accelerating degradation behavior as that of PDLLA.展开更多
基金This study was supported by the National Natural Science Foundation of China(No.30270395 and 30300084)the National"863"Project(No.2003AA32X210).
文摘A novel poly（d, /-lactic acid） （PDLLA） based biomimetic polymer was synthesized by grafting maleic anhydride, butanediamine and arg-gly-asp-ser （RGDS） peptides onto the backbone of PDLLA, aiming to overcome the acidity and auto-accelerating degradation of PDLLA during degradation and to improve its biospecificity and biocompatibility. The synthetic copolymer was characterized by FTIR, ^13C NMR and amino acid analyzer （AAA）.
基金supported by the National Key Technologies R&D Program of China(No.2006BA103B04)the Natural Key Scientific and Technological Project of Chongqing(No.CSTC 2008AB0027)
文摘A series of novel poly（urethane-urea）（PUU） was synthesized from poly（lactide-co-p-dioxanone） macrodiol（HO-P（LA-co-PDO）-OH）, hexamethylene diisocyanate（HDI） and butanediamine（BDA）.The obtained PUU,which is recorded as P（LA-co-PDO）-PUU here,may demonstrate enhanced phase separation and thus improved shape memory property.FTIR was employed to characterize the copolymers,and the effects of NCO/OH molar ratios on Tg of PUU was investigated by means of differential scanning calorimetry （DSC）.The results revealed the successful synthesis of P（LA-co-PDO）-PUU.In addition,the Tg of P（LA-co-PDO）-PUU increased from 37.9℃to 44.2℃with the increase NCO/OH ratios from 1.1 to 1.2.The P（LA-co-PDO）-PUU with Tg close to body temperature will have potential applications as shape memory polymers in biomedical fields,especially in minimally invasive surgery.
基金supported by Natural Science Foundation of Chongqing (No.CSTC2006BB5010)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry (No.2007-1108).
文摘A novel degradable pH-sensitive hydrogel with pendent carboxyl groups was designed and synthesized from ethylenediaminetetraacetic dianhydride （EDTAh） and butanediamine （BDA） with dicyclohexylcarbodiimide （DCC） as a condensating agent and BDA as a crosslinking agent. The obtained polymers were characterized by ^13C NMR, ^1H NMR and FTIR. The swelling experiments of the hydrogel in pH 3, 7, and 12 media indicated much higher swelling ratio in pH 12 media than in pH 3 and pH 7 media, exhibiting sound pH sensitivity. The pH sensitivity of this type of hydrogel may be regulated through controlling the type and the dose of the crosslinking agent.
基金the National Natural Science Foundation of China(No.30470474)the Chongqing Key Technologies R&D Program(No.CSTC2006AB4007)
文摘The degradation of butanediamine-grafted poly（DL-lactic acid） polymers （BDPLAs） in vitro together with PDLLA and maleic anhydride-grafted poly（DL-lactic acid） polymers （MPLAs） was investigated by observation of the changes of the pH value of incubation media, and weight loss ratio during degradation duration of 12 weeks. The results reveal that the acidity of PDLLA degradation products was weakened or neutralized by grafting butanediamine onto PDLLA. A uniform degradation of BDPLAs was observed in comparison with an acidity-induced auto-accelerating degradation featured by PDLLA and MPLAs. The biodegradation behaviors of BDPLAs can be adjusted by controlling the content of BDA. BDPLAs might be a new derivative of PDLLA-based biodegradable materials for medical applications without acidity-caused irritations and acidity-induced auto-accelerating degradation behavior as that of PDLLA.
