Abstract
Failure in early diagnosis and ineffective treatment are the major causes of ovarian cancer mortality. Hyaluronan and its receptor, cluster of differentiation (CD)44, have been considered to be valid targets for treating cancer. The anti-CD44 monoclonal antibody IM7 is effective in treating ovarian cancer; however, its toxicity should not be ignored. The present study has developed a new drug carrier system composed of chitosan nano-particles coated with polylactic acid (PLA) to improve the treatment efficacy and reduce toxicity. An ionic crosslinking method and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride/N-hydroxysuccinimide were used to prepare the IM7 antibody, which was loaded with chitosan nano-particles. The surfaces of the nano-particles were coated with PLA to generate PLA-chitosan-IM7. Subsequently, transmission electron microscopy (TEM) was used to observe the size and zeta potential of the nano-particles. In addition, a spectrophotometer was used to calculate the loading rate and release rate of the nano-particles in acidic and neutral environments. MTT assay was used to evaluate the anti-proliferative effect of PLA-chitosan-IM7 on the human ovarian cancer cell line HO-8910PM. In addition, an in vivo imaging system was used to further investigate the effect of PLA-chitosan-IM7 on the treatment of mice with ovarian cancer. A total of 35 days subsequent to PLA-chitosan-IM7 treatment, all animals were sacrificed by CO2, and the tumors were removed and weighted. The PLA-chitosan-IM7 nano-particles were successfully prepared, since TEM revealed that their size was 300-400 nm and their zeta potential was +25 mV. According to the spectrophotometry results, the loading rate was 52%, and PLA-chitosan-IM7 exhibited good resistance to acids. MTT assay demonstrated that PLA-chitosan-IM7 could suppress the proliferation of HO-8910PM cells in vitro. The in vivo imaging system revealed that PLA-chitosan-IM7 was effective in controlling the development of human ovarian cancer cells and the tumor weight. These results suggest that PLA-chitosan-IM7 could be effective in treating cancers in vitro and in vivo, which may provide a novel approach to enhance the effectiveness of anti-CD44 treatment while reducing its toxicity.