The Use of Low-Quality Cotton-Derived Cellulose Films as Templates for In Situ Conductive Polymer Synthesis as Promising Biomaterials in Biomedical Applications

Here, the use of cellulose films (CFs) produced from low-quality cotton is reported 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 are carried out to increase the amount of conductive polymer content. The contact angle (CA) for three times ANI and PPY loaded and polymerized CFs as 3PANI@CF and 3PPY@CF are determined as 26.3 +/- 2.8 and 42.3 +/- 0.6 degrees, 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 are measured for 3PANI@CF and 3PPY@CF composites. It is found that PANI@CF composites are hemolytic, whereas PPY@CF composites are not at 1 mg mL-1 concentrations. All PPY@CF composites exhibit better biocompatibility than PANI@CF composites on L929 fibroblast cells with more than 70 +/- 8% viability at 1 mg of CF-based conductive polymer composites. Moreover, MIC and MBC values of 3PPY@CF composites for Escherichia coli (ATCC8739) and Staphylococcus aureus (ATCC6538) are determined as 2.5 and 5.0 mg.mL-1, whereas these values are estimated as 5 and 10 mg.mL-1 for Candida albicans (ATCC10231). Cotton fibers are dissolved in N, N-dimethylacetamide/lithium chloride (DMAc/LiCl) solvent system and converted cellulose solutions to strong, transparent, and flexible films through casting, gelation, regeneration, plasticization, and hot-pressing. The prepared cellulose films (CFs) are used as a template for in situ synthesis of polyaniline (PANI) and polypyrrole (PPY) polymers to attain electroactive cellulose based composites with intriguing biomedical properties. image