Nanoparticles of eight-arm PEG (polyethylene glycol)-oleanolic acid drug carrier and preparation

The invention discloses a preparation method of nanoparticles of an eight-arm PEG (polyethylene glycol)-oleanolic acid drug carrier. The preparation method comprises steps as follows: eight-arm PEG and oleanolic acid are subjected to an esterification reaction, and a conjugate of eight-arm PEG-oleanolic acid is obtained; 10-hydroxycamptothecine is wrapped with eight-arm PEG-oleanolic acid through self-assembly, and the nanoparticles are obtained. The nanoparticles have a double-layer structure, the outer layer is hydrophilic PEG, and the inner layer is hydrophobic oleanolic acid drug and 10-hydroxycamptothecine. The preparation method has the advantages that the drug loading capacity is greatly increased with the adoption of PEG; the water solubility and stability of oleanolic acid are increased, and the half-life period of oleanolic acid is prolonged; pH sensitive release of the drug in tumor cells can be realized; the toxic and side effects on normal tissue are reduced; the preparation process is simple and