Preparation and study on anti-tumor effect of chitosan-coated oleanolic acid liposomes

Abstract

The purpose of this work was to prepare and study the anti-tumor effect of chitosan-coated oleanolic acid (OA) liposomes. The chitosan-coated OA liposomes had marked positive charges (19.9 ± 0.814 mV), which were inclined to combine with the negative charges on the surface of tumor cells, and then targeted and inhibited the growth of tumor cells. The average size of the chitosan-coated OA liposomes was around 167.44 nm, and this dimension was more easily trapped into the tumor tissue. The chitosan-coated OA liposomes possessed stronger rigidity and stability than those of ordinary liposomes, which can prevent the leakage of encapsulated drugs from liposomes. The Fourier transform infrared spectroscopy (FTIR) result indicated that chitosan already anchored the liposomes successfully. The chitosan-coated OA liposomes exhibited a slow, controlled OA release at pH 7.4, and a rapid release at pH 5.5 in vitro, which was beneficial for controlling tumor-targeting drug release. Additionally, MTT experimental results proved that the chitosan-coated OA liposomes can achieve more ideal anti-tumor effects than OA solution and OA liposomes. The study showed that chitosan modified liposomes not only solve the poor water solubility of OA, but also improve the anti-tumor efficacy, hence, it is a most promising drug carrier.