The role of cellulose nanoparticles in enhancing human iPSC compatibility with composite conductive PANI/cellulose films

Abstract

The development of composites with tailored surface properties and electrical conductivity is critical for various biomedical applications. However, a substantial gap remains in understanding how the unique properties of cellulose, such as biocompatibility and renewability can be effectively combined with those of polyaniline (PANI), including electrical conductivity, antibacterial, and antioxidant activity, to create composite films with advanced multifunctional performance. Indeed, conductivity can be used not only to monitor biological functions but also as a cell instructive factor. To meet these requirements, thin composite films were synthetized using oxidative polymerization of aniline hydrochloride with ammonium peroxydisulfate in the presence of either cellulose nanocrystals (CNC) or cellulose nanofibres (CNF). Their cytocompatibility was demonstrated with the NIH/3 T3 fibroblast line and highly progressive human induced pluripotent stem cells. The films also showed antibacterial activity against Staphyloccocus aureus and Escherichia coli, surpassing that of pristine PANI and meeting the EN ISO 20743 criteria for materials with significant activity (reducing CFU value to zero). Comprehensive physicochemical characterization revealed that the films possessed exceptional DPPH radical scavenging achieving their complete (100 %) removal within 15 min, and electrical conductivity within units of S cm−1. Raman spectroscopy showed that PANI/CNC composites were more resistant to deprotonation caused by laser illumination than PANI/CNF, which resulted from the presence of sulfate groups on the CNC surface. These findings highlight that PANI/CNC and PANI/CNF films are promising materials for applications requiring surfaces that are simultaneously biocompatible, electrically conductive, and antibacterial.