High cytotoxicity and resistant-cell reversal of novel paclitaxel loaded micelles by enhancing the molecular-target delivery of the drug.

Many antitumor drugs, such as paclitaxel (PTX), are widely used in cancer chemotherapy. However, their clinical use is limited by systemic toxicity, rapid blood clearance, and the occurrence of resistance. To increase the therapeutic index of these drugs, the antitumor drug PTX was encapsulated in novel micelles with glycolipid-like structure, which were formed by stearate grafted chitosan oligosaccharide in aqueous medium. The micelles could load the poorly soluble antitumor drug (PTX) with high entrapment efficiency and drug loading. PTX release was retarded as a result of the encapsulation of the micelles. PTX loaded micelles present excellent internalization into tumor cells as well as resistant cells and subsequently reside in cytoplasm, which results in increased intracellular accumulation of PTX in its molecular-target site. Consequently, cytotoxicity of PTX loaded micelles was improved sharply and resistant cells were reversed. In conclusion, high cytotoxicity can be obtained and resistant cells can be reversed by enhancing PTX's molecular-target delivery and accumulation via the encapsulation of the micelles. The present micelles are a promising carrier candidate for effective therapy of antitumor drugs with the target molecule in cytoplasm.