A novel biodegradable poly(glyceric acid) (PGA) was synthesized by the polycondensation of glyceric acid.The hydrophobic and biocompatible molecule cholesterol was immobilized on the pendant functional group of PGA.The micelles were formed by the self-assemble driven by the hydrophilic-hydrophobic interaction.Anti-tumor drug doxorubicin was loaded in the micelles to study the drug release profile.The anti-tumor effects in vitro were evaluated with liver cancer cell HepG2. The results demonstrated that the content of cholesterol grafted was nearly the same as the feeding dose.The micelles of poly(glyceric acid)-g-cholesterol were formed in phosphate buffer solution (PBS) and the critical micellization concentration was 63 g/mL.The micelles were spherical with narrow size distribution; the average diameter was around 120 nanometers.The drug-loading rate and entrapment efficiency of the micelles with 5 mol% cholesterol content in the copolymer were 18.71% and 46.78%

respectively.The sustaining drug release time of the micelles was as long as 12 h.The study of cytotoxicity found that the micelle was nontoxic when the concentration was below 0.5 mg/mL and it showed low cytotoxicity when the concentration was 1 mg/mL.The in vitro anti-tumor effect study showed that the drug loaded micelles could enter into the cancer cells by endocytosis

and the anti-tumor effect of the micelles was better than that of free doxorubicin.