Copolymerization of chitosan selectively grafted by polyethylene glycol was prepared. Chitosan was selectively grafted by monomethoxy polyethylene glycol（mPEG-OH）, which contained a hydroxyl group combining with hex...Copolymerization of chitosan selectively grafted by polyethylene glycol was prepared. Chitosan was selectively grafted by monomethoxy polyethylene glycol（mPEG-OH）, which contained a hydroxyl group combining with hexamethylene diisocyanate（HDI） to form a novel macromonomer namely monomethoxy polyethylene glycol isocyanate（mPEG-NCO） containing a isocyanate group with higher chemical activity in ethyl glyoxalate solution absolutely without water. The selective grafted copolymerization of Chitosan with mPEG-NCO was conducted under heterogeneous conditions as suspension in dimethylformamide. The hydrophilic copolymers of chitosan were prepared by condensation reaction of isocyanate group on mPEG- NCO with hydroxy groups on chitosan chains because amino groups on chitosan chains were protected by complexion formation with copper ions. The effect of reaction condition on the grafting extents was discussed. Swelling properties of mPEG-g-CS were researched. The graft copolymer mPEG-g-CS was characterized by the infrared spectra. The experimental result showed that the copper ions were very effective to protect amino groups from condensation reaction. The swelling degree in water increases with adding of grafting ratio. The maximum swelling degree was up to above 132% when the grafting ratio was about 270%. The graft copolymer can be soluble partially in pure water.展开更多
With the advent of the era of organ donation after citizen's death,split liver transplantation(SLT)can effectively increase the supply of donor livers and shorten the transplantation wait time for patients,especia...With the advent of the era of organ donation after citizen's death,split liver transplantation(SLT)can effectively increase the supply of donor livers and shorten the transplantation wait time for patients,especially pediatric recipients.In recent years,SLT has been performed to varying degrees in many transplant centers in China,and varying levels of efficacy have been achieved.The quality of donors and donor livers for SLT is an important factor affecting the outcome of the surgery.At this stage,it is necessary to reach a consensus on the evaluation of SLT donor and liver donor that is suitable for the conditions in China by combining the well-established experience of the international community with advanced transplantation technology.This approach will aid in enhancing the efficacy of SLT.Based on the experience of experts,a consensus on the evaluation of donors and donor livers for SLT has been formulated in this study,which focuses on evaluation of donors and donor livers,evaluating the functional and anatomical aspects of the donor liver and donorerecipient matching.展开更多
基金Funded by the Program of Beijing Municipal Commission of Education
文摘Copolymerization of chitosan selectively grafted by polyethylene glycol was prepared. Chitosan was selectively grafted by monomethoxy polyethylene glycol（mPEG-OH）, which contained a hydroxyl group combining with hexamethylene diisocyanate（HDI） to form a novel macromonomer namely monomethoxy polyethylene glycol isocyanate（mPEG-NCO） containing a isocyanate group with higher chemical activity in ethyl glyoxalate solution absolutely without water. The selective grafted copolymerization of Chitosan with mPEG-NCO was conducted under heterogeneous conditions as suspension in dimethylformamide. The hydrophilic copolymers of chitosan were prepared by condensation reaction of isocyanate group on mPEG- NCO with hydroxy groups on chitosan chains because amino groups on chitosan chains were protected by complexion formation with copper ions. The effect of reaction condition on the grafting extents was discussed. Swelling properties of mPEG-g-CS were researched. The graft copolymer mPEG-g-CS was characterized by the infrared spectra. The experimental result showed that the copper ions were very effective to protect amino groups from condensation reaction. The swelling degree in water increases with adding of grafting ratio. The maximum swelling degree was up to above 132% when the grafting ratio was about 270%. The graft copolymer can be soluble partially in pure water.
基金grants from National 13th Five-Year Science and Technology Plan Major Projects of China(2017ZX10203205)National Key Research and Development Program of China(2017YFA0104304)+3 种基金National Natural Science Foundation of China(81770648,81972286)Natural Science Foundation of Guangdong Province,China(2015A030312013,2020A1515010574,2020A1515010302)Science and Technology Program of Guangdong Province,China(2017B020209004,2019B020236003,2020B1212060019)and Guangzhou Science and Technology Project,China(201803040005).
文摘With the advent of the era of organ donation after citizen's death,split liver transplantation(SLT)can effectively increase the supply of donor livers and shorten the transplantation wait time for patients,especially pediatric recipients.In recent years,SLT has been performed to varying degrees in many transplant centers in China,and varying levels of efficacy have been achieved.The quality of donors and donor livers for SLT is an important factor affecting the outcome of the surgery.At this stage,it is necessary to reach a consensus on the evaluation of SLT donor and liver donor that is suitable for the conditions in China by combining the well-established experience of the international community with advanced transplantation technology.This approach will aid in enhancing the efficacy of SLT.Based on the experience of experts,a consensus on the evaluation of donors and donor livers for SLT has been formulated in this study,which focuses on evaluation of donors and donor livers,evaluating the functional and anatomical aspects of the donor liver and donorerecipient matching.
