Incorporation of carbon nanotubes into a gelatin-catechin conjugate: Innovative approach for the preparation of anticancer materials

A new hybrid material made of gelatin, catechin and carbon nanotubes was prepared by the non-covalent incorporation of carbon nanotubes (CNTs) into a gelatin–catechin covalent conjugate. The composite materials was tested by means of determination of the dispersion stability in water and the functionalization degree was assessed by the Folin–Ciocalteu method, finding a 0.9 mg of CT/g of protein conjugate. Subsequently, the complete retention of the antioxidant properties of the flavonoid after incorporation into the composite was proved by DPPH and ABTS assays and IC50 values of 5.74 mg mL−1 and 0.39 mg mL−1 were recorded. The presence of CNT into the materials did not interfere with the scavenging activities of the catechin. Finally, the anticancer activity on HeLa cancer cells was evaluated and a considerable increase in the therapeutic activity of the flavonoid was recorded moving from the free to the conjugated form in the presence of CNT, while in absence of CNT a reduction of the efficiency was observed.