A comprehensive study on the surface property changes of antibodies on interacting with Ti3C2Tx, V2CTx, or Mo2TiC2Tx MXenes

Abstract

MXenes are nanomaterials composed of layered transition metal carbides and nitridesand are considered to have considerable potential in the biomedical translation field. However, the biological and toxicological behaviours of nanomaterials (NMs) are regulated by protein-corona formation, which leads to conformational changes in proteins and impacts their biological functions. Thus, in this work, we synthesized four different MXenes (multi-layered titanium carbide (Ti3C2Tx-ML); single-layered titanium carbide (Ti3C2Tx-SL); single-layered molybdenum titanium carbide (Mo2TiC2Tx-SL); and multi-layered vanadium carbide (V2CTx-ML)) and studied their physicochemical interactions with a model protein immunoglobin G (IgG) from human serum. The conformational, thermal, and colloidal stabilities of IgG were investigated after exposing IgG to MXenes for 15 min at IgG/MXene ratios of 40:1 and 20:1. Circular dichroism (CD) spectroscopy revealed that the secondary structure of IgG underwent a concentration-dependent conformational change after exposure to all four MXenes. ζ-potential studies showed that Ti3C2Tx-ML MXene had the highest negative surface charge due to the presence of abundant fluorine (F) surface groups. However, this increased the hydrophilicity of IgG/MXene solution and eventually caused IgG aggregation and destabilization. Furthermore, Ti3C2Tx-ML MXene had a greater tendency to produce protein coronas than the other MXenes. This study describes a versatile means of examining the properties of MXenes responsible for protein coronas and lays a foundation for establishing the connection between protein corona formation and the biological functions of MXenes.