Folic acid conjugated glycol chitosan micelles for targeted delivery of doxorubicin: preparation and preliminary evaluation in vitro

For folate receptor (FR) targeted anticancer therapy, novel folic acid (FA) conjugated cholesterol-modified glycol chitosan (FCHGC) micelles were synthesized and characterized by ¹H NMR, dynamic light scattering, transmission electron microscopy, and fluorescence spectroscopy. The degree of substitution was 1.4 FA groups and 7.7 cholesterol groups per 100 sugar residues of glycol chitosan. The critical aggregation concentration of FCHGC micelles in aqueous solution was 0.0169?mg/ml. The doxorubicin (DOX)-loaded FCHGC (DFCHGC) micelles were prepared by an emulsion/solvent evaporation method. The DFCHGC micelles were almost spherical in shape and their size increased from 282 to 320?nm with the DOX-loading content increasing from 4.53 to 11.4%. DOX released from DOX-loaded micelles displayed sustained release behavior. The targeted micelles encapsulated DOX showed significantly greater cytotoxicity against FR-positive HeLa cells than the nontargeted DOX-loaded micelles and free DOX. These results suggested that FCHGC micelles could be a potential carrier for targeted drug delivery.