Folate-containing dextran ligand （FA-Dextran-DTPA） was synthesized by the incorporation of diethylenetriamine- pentaacetic acid （DTPA） and folate （FA） as a tumor-targeting group into dextran as a polymer carrier...Folate-containing dextran ligand （FA-Dextran-DTPA） was synthesized by the incorporation of diethylenetriamine- pentaacetic acid （DTPA） and folate （FA） as a tumor-targeting group into dextran as a polymer carrier. This ligand was further reacted with gadolinium chloride to make a dextran gadolinium complex FA-Dextran-DTPA-Gd. The ligand and its gadolinium complex were characterized by 1H-NMR, FTIR, UV-Vis, average particle sizes and zeta potential, as well. In vitro properties including relaxivity, cytotoxicity assay, cellular uptake assay, and magnetic resonance imaging （MRI） were also evaluated. Compared with Gd-DTPA, FA-Dextran-DTPA-Gd possessed obviously higher relaxation effectiveness and lower cytotoxicity to HeLa cells. FA-Dextran-DTPA-Gd had a high affinity to the H460 and MDA-MB-231 tumor cells and can be taken up selectively by these tumor cells. Moreover, FA-Dextran-DTPA-Gd showed enhanced signal intensities （SI） of MRI and enhanced the contrast of MR images of tumor cells. These results indicated that FA-Dextran-DTPA-Gd showed the potential as a tumor-targeting contrast agent in MRI.展开更多
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 sy...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 （CaCOs/CMC, spherical, 1.7 pro） with chitosan （CS） and sodium earboxymethyl 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 pm with relatively regular sphere. After the microparticle cores was removed by complexation with ethylene diamine tctraacetic acid （EDTA） for calcium ions, the range of 200- 300 nm wall thickness of microcapsules was built, and it made the forming microeapsules to be stable. Thermogravimctric analysis confirms the deposition and modification total amount of polymer on the microtemplates is about 33.5 %. The assembly microparticles were modified by introducing PEI, and the grafting rate of folate could reach 20. 0 %. It was 4 times 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financially supported by the National Natural Science Foundation of China(Nos.51173140 and 51373128)Wuhan Scientific and Technological Project(No.2013010501010131)+1 种基金Wuhan Science and Technology Innovation Team of Hi-tech Industrial Project,Hubei Province(No.2015070504020217)Innovation Fund for Post-graduate Education(Nos.CX2014058 and CX2013083),Wuhan Institute of Technology,China
文摘Folate-containing dextran ligand （FA-Dextran-DTPA） was synthesized by the incorporation of diethylenetriamine- pentaacetic acid （DTPA） and folate （FA） as a tumor-targeting group into dextran as a polymer carrier. This ligand was further reacted with gadolinium chloride to make a dextran gadolinium complex FA-Dextran-DTPA-Gd. The ligand and its gadolinium complex were characterized by 1H-NMR, FTIR, UV-Vis, average particle sizes and zeta potential, as well. In vitro properties including relaxivity, cytotoxicity assay, cellular uptake assay, and magnetic resonance imaging （MRI） were also evaluated. Compared with Gd-DTPA, FA-Dextran-DTPA-Gd possessed obviously higher relaxation effectiveness and lower cytotoxicity to HeLa cells. FA-Dextran-DTPA-Gd had a high affinity to the H460 and MDA-MB-231 tumor cells and can be taken up selectively by these tumor cells. Moreover, FA-Dextran-DTPA-Gd showed enhanced signal intensities （SI） of MRI and enhanced the contrast of MR images of tumor cells. These results indicated that FA-Dextran-DTPA-Gd showed the potential as a tumor-targeting contrast agent in MRI.
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 （CaCOs/CMC, spherical, 1.7 pro） with chitosan （CS） and sodium earboxymethyl 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 pm with relatively regular sphere. After the microparticle cores was removed by complexation with ethylene diamine tctraacetic acid （EDTA） for calcium ions, the range of 200- 300 nm wall thickness of microcapsules was built, and it made the forming microeapsules to be stable. Thermogravimctric analysis confirms the deposition and modification total amount of polymer on the microtemplates is about 33.5 %. The assembly microparticles were modified by introducing PEI, and the grafting rate of folate could reach 20. 0 %. It was 4 times 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.
