Synthesis of Highly Antioxidative and Antibacterial Grafted Microcrystalline Cellulose

Cellulose is a versatile material that can be modified to possess stable and long-lasting antibacterial and antioxidant properties. Herein, we synthesized CELL-GA graft copolymers by grafting gallic acid (GA), a natural antibacterial agent, onto microcrystalline cellulose (MCC) using an indirect esterification method. The grafting rate achieved was 26.8 mg/g. The products were characterized at various stages using FTIR and ¹H NMR spectroscopic methods to validate the synthesis mechanism of CELL-GA. The antioxidant activity of the products was evaluated by measuring the scavenging rate of various free radicals and the reduction rate of Fe³⁺. It was observed that the antioxidant activity of CELL-GA increased with the higher GA grafting rate. The antibacterial capacity of CELL-GA was found to increase with its concentration through the plate counting method. The antibacterial mechanism of CELL-GA was explored by assessing ATPase activity and the extent of damage to the cell membrane. Our findings indicate that CELL-GA is a cellulose-based antibacterial material synthesized with natural antibacterial agents and MCC, is safe and non-toxic. It exhibits good biocompatibility, stable antioxidant properties, and antibacterial effects, expanding the potential applications of cellulose and offering a novel approach to creating natural biomass-based antibacterial materials.