A novel biodegradable and biocompatible multilayer hollow microcapsules,modified by folate-conjugated polyethyleneimine(PEI),as targeted and sustained release carriers of doxorubicin(DOX),were successfully synthesized...A novel biodegradable and biocompatible multilayer hollow microcapsules,modified by folate-conjugated polyethyleneimine(PEI),as targeted and sustained release carriers of doxorubicin(DOX),were successfully synthesized using the sequential layer-by-layer electrostatic assembly technique from the sacrificial microtemplates(CaCOj/CMC,spherical,1.7 μm) with chitosan(CS) and sodium carboxymethyl cellulose(CMC) as the polycation and polyanion polyelectrolyte.Scanning electron microscope(SEM) observation showed that the diameter of the seven assembly multilayer microparticles was about 2.0 μm with relatively regular sphere.After the microparticle cores was removed by complexation with ethylene diamine tetraacetic acid(EDTA) for calcium ions,the range of 200- 300 nm wall thickness of microcapsules was built,and it made the forming microcapsules to be stable.Thermogravimetric analysis confirms the deposition and modification total amount of polymer on the microtemplates is about33.5%.The assembly microparticles were modified by introducing PEI,and the grafting rate of folate could reach 20.0%.It was 4times that of traditional method.The high grafting rate helped to improve targeting action of microcapsules.The deposition of DOX was prominent and the encapsulation efficiency was 96.9%,and the plateaued release of loaded drug reached 78%in pH 7.4 buffer solution,and then in pH 5.7 showed significantly a slow release.展开更多
基金National Natural Science Foundation of China(No.21472126)
文摘A novel biodegradable and biocompatible multilayer hollow microcapsules,modified by folate-conjugated polyethyleneimine(PEI),as targeted and sustained release carriers of doxorubicin(DOX),were successfully synthesized using the sequential layer-by-layer electrostatic assembly technique from the sacrificial microtemplates(CaCOj/CMC,spherical,1.7 μm) with chitosan(CS) and sodium carboxymethyl cellulose(CMC) as the polycation and polyanion polyelectrolyte.Scanning electron microscope(SEM) observation showed that the diameter of the seven assembly multilayer microparticles was about 2.0 μm with relatively regular sphere.After the microparticle cores was removed by complexation with ethylene diamine tetraacetic acid(EDTA) for calcium ions,the range of 200- 300 nm wall thickness of microcapsules was built,and it made the forming microcapsules to be stable.Thermogravimetric analysis confirms the deposition and modification total amount of polymer on the microtemplates is about33.5%.The assembly microparticles were modified by introducing PEI,and the grafting rate of folate could reach 20.0%.It was 4times that of traditional method.The high grafting rate helped to improve targeting action of microcapsules.The deposition of DOX was prominent and the encapsulation efficiency was 96.9%,and the plateaued release of loaded drug reached 78%in pH 7.4 buffer solution,and then in pH 5.7 showed significantly a slow release.
