The use of low-quality cotton-derived cellulose films as templates for in situ conductive polymer synthesis as promising biomaterials in biomedical applications

Abstract

Due to the growing interest in biopolymer-based composites in many applications, noticeable devotion has been directed to natural polymer-derived products not only because of their renewable and eco-friendly characteristics but also for their versatility in processing conditions and cost-effectiveness in fabricating the final products. Here, we report the use of cellulose films (CFs) produced from low-quality cotton as a template for in situ synthesis of well-known conductive polymers, e.g., polyaniline (PANI) and polypyrrole (PPY) via oxidative polymerization. Three successive monomer loading/polymerization cycles of aniline (ANI) and pyrrole (PY) within CFs as PANI@CF or PPY@CF were carried out to increase the extent of conductive polymer content. The contact angle (CA) for three times ANI and PPY loaded and polymerized CFs as 3PANI@CF and 3PPY@CF were determined as 26.3 ± 2.8o and 42.3 ± 0.6o, respectively. As the electrical conductivity is increased with increased number of conductive polymer synthesis within CF, the higher conductivity values, 3x10− 4±8.1x10− 5 S.cm− 1 and 2.1x10− 3±5.8x10− 4 S.cm− 1, respectively were measured for 3PANI@CF and 3PPY@CF composites that were approximately 3.3K-fold and 30K-fold higher, respectively, compared to bare CF. It was also found that PANI@CF composites are hemolytic, whereas PPY@CF composites are not at 1 mg/mL concentrations. In the presence of 1 mg of CF-based conductive polymer composites, all PPY@CF composites exhibit better biocompatibility than PANI@CF composites on L929 fibroblast cells with 81 ± 9, 71 ± 8, and 70 ± 8% cell viability for 1PPY@CF, 2PPY@CF, and 3PPY@CF composites, respectively. Moreover, the minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) of 3PPY@CF composites for Escherichia coli ATCC8739, Staphylococcus aureus ATCC6538 are determined as 2.5 and 5 mg/mL, whereas these values were estimated to 5 and 10 mg/mL for Candida albicans ATCC10231.