Preparation and Drug Controlled- release of Biodegradable Amphiphilic Polysaccharide Nano- micelles as Drug Delivery Systems

Objective To investigate the preparation of polylactide-grafted dextran copolymer(DEX-g-PLA),and to detect their correlative parameters and explore the application of nano-micelles for drug controlled-release.Methods The polylactide-grafted dextran copolymer(DEX-g-PLA)was synthesized in a bulk lactide polymerization reaction using dextran derivative as macroinitiator and stannous octoate as catalyst.The surface morphology of the resulting nano-micelles was characterized by transmission electron microscopy and particle size was measured by dynamic light scattering.The controlled-release of drugs of different water-solubility was tested by in-vitro release studies,and the biocompatibility of nano-micelles was measured by MTT assay in vitro.Results The DEX-g-PLA nano-micelles were of round or elliptical shape and their average diameters ranged from 50 nm to 190 nm,which were increased with the increase of content of PLA in micelles.The in-vitro release studies indicated that the release of hydrophobic vitamin B2 from nano-micelles was obviously more sustained than that of hydrophilic 5-Fluorouracil.MTT assay suggested that DEX-g-PLA nano-micelles were of fine biocompatibility.Conclusion The release of hydrophobic drugs from the biocompatible micelles of DEX-g-PLA is obviously more sustained than that of hydrophilic drugs,suggesting it would be a promising carrier for drug delivery systems.