Nanocellulose-based antifungal nanocomposites against the polymorphic fungus Candida albicans

The design of functional materials capable of fighting fungal infections is of paramount importance given the intricate problem of multidrug-resistant pathogenic fungi. Herein, nanocomposites consisting of cross-linked poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) (PMETAC) and bacterial nanocellulose (BNC) were prepared, characterized and tested towards the polymorphic fungus Candida albicans. The BNC three-dimensional network enabled the in-situ polymerization of the non-toxic and bioactive quaternary-ammonium monomer, which originated transparent nanocomposites containing 10 and 40 wt.% of cross-linked PMETAC. Furthermore, the nanocomposites exhibit UV-A and UV-B blocking properties, high water-uptake capacity, thermal stability up to 200 °C, good viscoelastic (storage modulus > 1.7 GPa) and mechanical (Young's modulus ≥2.4 GPa) properties and are non-cytotoxic to human keratinocytes (HaCaT cells). The fungal inactivation reached a 4.4 ± 0.14-log CFU reduction for the nanocomposite containing only 10 wt.% of cross-linked PMETAC. Hence, these bioactive and non-cytotoxic materials can constitute potentially effective systems for the treatment of C. albicans infections.