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

MXenes are nanomaterials, composed of layered transition metal carbides and nitrides, and represent significant potential in the biomedical translation fields. 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, 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)) were synthesized, and further their physicochemical interactions with model protein immunoglobin G (IgG) from human serum were studied. After exposing IgG to MXenes for 15 min, the conformational, thermal, and colloidal stabilities of IgG were investigated at IgG/MXene ratios of 40:1 and 20:1. Circular dichroism (CD) spectroscopy revealed that the IgG secondary structure underwent conformational change upon association with all the MXene, nonetheless, the overall effect of MXenes was diminished at lower concentrations of MXenes. From ζ-potential studies, it was observed that among the MXenes tested, Ti3C2Tx −ML MXenes had a highly negative surface charge due to the presence of abundant fluorine (−F) surface functional groups, as a result of which the hydrophilicity of the protein-solution increased and eventually caused IgG aggregation and destabilization. Thus, Ti3C2Tx-ML MXene exhibits a greater propensity than the other three MXenes to fabricate a protein-corona. This study provides a versatile means of examining the properties of MXenes responsible for protein coronas and will potentially lay the foundation for establishing the connection between protein corona formation and the biological functions of MXenes.