Synthesis Of Stearate Grafted Dextran And Characteristics For Drug Carrier

In aqueous medium, amphipathy polymers could self-assemble into micelles who act as a passive targeted drug delivery system. In this research, dextran was hydrophobic decorated, and then Dex-SA was synthesized. Through varying the molecular weight of dextran and feeding amount of stearic acid, six types of Dex-SAs were synthesized and physicochemical properties were investigated:the chemical composition, thermal stability and critical micelle concentration. With dialysis method, an anti-tumor drug doxorubicin (DOX) was entrapped into micelles. The physicochemical properties of DOX-loaded Dex-SA micelles were investigated:the particle size, morphology, drug entrapment efficiency and loading content, in vitro drug release profiles, cellular uptake ability, cytotoxicities against model tumor cells and treatment efficiency in nude mice.The results showed that when the feeding amount of stearic acid was increased, Stearic acid grafted ratio and critical micelles concentration of Dex-SA were both improved. Particle size of blank micelles was below 100 nm and decreased with the reducing molecular weight of dextran or increasing feeding amount of stearic acid. After loading DOX, the micelles particle size was increased significantly. Drug loading content increased with the enhanced feeding amount of DOX or the enhanced stearic acid graft ratio. In vitro drug release could be prolonged to 48 h and the release rate was slowed down when the molecular weight of dextran, stearic acid graft ratio and drug loading were increased. Cytotoxicities of Dex-SA against model tumor cells were low. DOX-loaded Dex-SA micelles had excellent internalization ability, effectively suppressed proliferation of tumor cells and reversed the drug resistance of MCF-7/Adr cells. Compared with commercial doxorubicin injection, DOX-loaded Dex-SA micelles treatment could effectively suppress the tumor growth and reduced the toxicity against animal body.