Preparation of In Situ Arsenic Formation Biological Hybrid and Evaluation of Its Anti-hepatoma Effect in Vivo and in Vitro

OBJECTIVE  To prepare a biological hybrid(CeAs-Bac) of arsenic in situ formation and to evaluate its anti-hepatocellular carcinoma efficacy in vivo and in vitro.

METHODS  CeAs-Bac was prepared by electrostatic adsorption and in situ mineralization, and its appearance, Zeta potential and element composition were evaluated by transmission electron microscope, scanning electron microscope, Malvern particle size analyzer and X-ray photoelectron spectroscopy. Dialysis bag method and X-ray photoelectron spectroscopy were used to investigate the valence changes of As before and after the release of CeAs-Bac in vitro. Indocyanine green was used as a fluorescent marker to detect HepG2 uptake, and MTT, living/dead cell staining and AnnexinV-FITC apoptosis kit were used to detect the cytotoxicity and apoptosis of CeAs-Bac. Establishment of a mouse model of H22 hepatocellular carcinoma to investigate the anti-tumor effect of CeAs-Bac in vivo.

RESULTS  The biological hybrid CeAs-Bac was successfully prepared, and transmission electron microscope, scanning electron microscope results showed that CeAs compound were closely attached to the surface of Shewanella oneidensis, and the surface Zeta potential of bacteria changed from (−32.2±2.05)mV to (−15.3±0.81)mV after modification of Ce and As. The As loading efficiency was 60.6%. CeAs-Bac had the characteristics of responsive release of lactic acid and could produce arsenic in the presence of lactic acid. The results of cell experiment showed that CeAs-Bac had high cytotoxicity to HepG2 and could induce apoptosis of HepG2 cells. The anti-tumor results in vivo showed that CeAs-Bac could effectively target the tumor site, inhibit tumor growth and promote tumor tissue necrosis.

CONCLUSION  In this study, a biological hybrid CeAs-Bac with the characteristics of responsive release of lactic acid and formation of arsenic is successfully prepared, which can effectively reduce the adverse reaction of arsenic in the application process and treat hepatocellular carcinoma safely and effectively.