Potential of amphiphilically modified low molecular weight chitosan as a novel carrier for hydrophobic anticancer drug: Synthesis, characterization, micellization and cytotoxicity evaluation

Amphiphilically modified low molecular weight chitosan (LMWC) with long chain alkyl groups as hydrophobic moieties and carboxymethyl groups as hydrophilic moieties (N-octyl-N,O-carboxymethyl LMWC, OC-LMWC) was synthesized. Self-assembled polymeric micelles of OC-LMWC were prepared in aqueous environment. Critical micelle concentrations (CMC) of OC-LMWCs were varied from 8.7 to 27.7 mg/l. Paclitaxel (PTX) was successfully encapsulated into the hydrophobic cores of the nanoparticles. The drug loading content and entrapment efficiency were higher to 32.17% (w/w) and 80.61%, respectively. Differential scanning calorimetry (DSC), transmission electron microscope (TEM) observation and dynamic light scattering (DLS) measurements were carried out to determination the physicochemical properties of the micelles. MTT assay showed that the in vitro cytotoxic effect of the PTX-loaded micelles was comparable to that of the commercial formulation, but the blank micelles were far less than the Cremophor EL® vehicle. These results suggested that OC-LMWC micelles were promising carriers for hydrophobic anticancer agents.