Cytotoxic study in the treatment of tetracycline by using magnetic Fe₃O₄–PAMAM–antibody complexes

Antibiotics are widely used as drugs to treat human and animal diseases. However, the widespread use of antibiotics has induced environmental contamination by antibiotics and development of resistant bacteria. There thus a need for advanced methods to remove antibiotics, e.g. from natural waters. Here we used the concept that antigens and antibodies bind specifically to remove tetracycline. Magnetic Fe₃O₄–polyamidoamine(PAMAM)–antibody complexes were synthesized to remove tetracycline at optimum pH and temperature. In vitro cytotoxicity of tetracycline/treated solutions was evaluated in human skin fibroblasts (HSF) cells by using MTT dye assay, along with flow cytometry study for cell cycle distributions and cell apoptosis. The results show that the toxicity of tetracycline solutions was highly reduced after treatment by magnetic Fe₃O₄–PAMAM–antibody complexes, and the survival rate of the cells was increased. The tetracycline may induce the disintegration of the nucleosomes of the HSF cells and eventually lead to the cell apoptosis. The results show that the method of removing tetracycline has higher biosafety.