Antibacterial behaviour of chitosan nanoparticles prepared from shrimp shells against bacteria causing skin infections: Usability in skin tissue engineering

Bacterial skin infections remain a significant clinical concern due to rising antibiotic resistance and the limited efficacy of conventional treatments. Chitosan, a biopolymer derived from crustacean shells, has emerged as a promising natural antimicrobial agent, particularly in its nanoparticulate form. In this study, chitosan nanoparticles (CSNPs) were synthesized from shrimp shell waste and evaluated for their antibacterial activity against five common skin-infecting bacterial strains: Staphylococcus aureus, β-hemolytic Streptococcus, Pseudomonas aeruginosa, Escherichia coli, and Enterobacter aerogenes. The CSNPs were characterized by SEM, TEM, FT-IR, and dynamic light scattering, confirming a uniform nanoscale structure with enhanced surface functionality. Antibacterial assays, including inhibition zone measurement, MIC, and MBC testing, demonstrated strong, dose-dependent bacteriostatic and bactericidal effects. At 1.25–2.5 mg/mL, CSNPs inhibited over ~ 90% of bacterial growth in all tested strains, with P. aeruginosa showing ~ 91.8% inhibition and E. aerogenes up to ~ 98.6%. Interestingly, beyond 1.25 mg/mL, further increases in concentration led to reduced efficacy, likely due to particle aggregation. These findings underscore the potential of shrimp shell-derived CSNPs as sustainable, biocompatible agents for controlling skin infections and advancing skin tissue engineering applications. The optimized antimicrobial activity and eco-friendly synthesis of CSNPs highlight their promise in next-generation wound care strategies.