Chitosan-Based Antimicrobial Treatments

Chitosan (deacetylated chitin, DD >75%, MW 50,000–500,000 Da) is a natural biopolymer derived from crustacean shells applied to textiles at 0.5–3.0% owf from 0.5–2.0% acetic acid solution via padding or exhaustion, dried at 80–100°C. Protonated amino groups (–NH₃⁺ at pH <6.5) electrostatically disrupt anionic bacterial membranes, achieving 2–4 log reduction against gram-positive bacteria and 1–3 log against gram-negative bacteria (ISO 20743). Crosslinking with glutaraldehyde (0.5–2%) or citric acid improves wash durability from 5–10 to 20–30 cycles. Additional benefits include moisture absorption (20–30% uptake), wound healing promotion, and biodegradability meeting ISO 14855. Chitosan textile market is valued at $180 million, growing in medical and eco-textile sectors.