Objective: To prepare nanospheres coupled with the anti-human liver cancer monoclonal antibody HAb18 and evaluate its immunoreactivity and antitumor effects.
Methods: The nanosphere coupled with the antibody was prepared by intermolecular cross-linking the anti-human liver cancer monoclonal antibody, HAb18, with human serum albumin nanospheres containing ADM [termed HAS(ADM)-NS] via a new hetero-bifunctional cross-linker SPDP. Condensation test and immunofluorescence assay were used to evaluate the immunoreactivity of the nanospheres, and specific binding of HAb18-HAS(ADM)-NS with liver cancer cell line SMMC-7721 was observed with optical and electron microscopes. The specific cytotoxic effects on the target cells were evaluated in vitro by MTT assay. HAb18-HAS(ADM)-NS, HAS(ADM)-NS and ADM were injected separately into nude mice bearing human liver carcinoma to evaluate the inhibitory activity of HAb18-HAS(ADM)-NS in vivo.
Results: The immunoreactivity of HAb18-HAS(ADM)-NS was well preserved. HAb18-HAS(ADM)-NS could bind specifically with the SMMC-7721 cells. The IC(50) of HAb18-HAS(ADM)-NS against SMMC-7721 cells was 44.6 microg/ml, lower than that of HAS(ADM)-NS (345.5 microg/ml) and ADM (365.5 microg/ml). The inhibition rate of HAb18-HAS(ADM)-NS on the growth of liver cancer xenografts was significantly higher than that of HAS(ADM)-NS and ADM (P<0.001).
Conclusion: HAb18-HAS(ADM)-NS has immunoreactivity and can actively and specifically target the liver cancer cells. The antitumor activity of HAb18-HAS(ADM)-NS is significantly higher than that of HAS(ADM)-NS and ADM.