Characterization and in vitro evaluation of nimotuzumab conjugated with cisplatin-loaded liposomes

In this paper, we report the conjugation of the humanized monoclonal antibody nimotuzumab with cisplatin-loaded liposomes and the in vitro evaluation of its affinity for tumor cells. The conjugation procedure was performed through derivatization of nimotuzumab with N-succinimidyl S-acetylthioacetate (SATA) followed by a covalent attachment with maleimide groups at the end of PEG-DSPE chains located at the membrane of pre-formed liposomes. Confocal microscopy was performed to evaluate the immunoliposome affinity for EGFR antigens from human epidermoid carcinoma (A-431) and normal lung (MRC-5) cell lines. Results showed that the procedures implemented in this work do not affect the capability of the nimotuzumab-immunoliposomes to recognize the tumor cells, which overexpress the EGFR antigens.