Synthesis and Characterization of Chitosan Nanoparticles Derived from Fungal and Crustacean Sources

Abstract

Chitosan, a deacetylated biopolymer derived from chitin, is widely valued for its biocompatibility, biodegradability, and applications in medical, agricultural, and environmental systems. Conventional production from crustacean shells poses challenges such as allergenic proteins and seasonal variability. This study evaluates Pleurotus ostreatus as a sustainable fungal source of chitin and chitosan and compares nanoparticles synthesized from fungal-derived and commercial crustacean-derived chitosan. Chitin extracted from P. ostreatus accounted for 5–7% of dry biomass, with 70% of chitosan yield following alkaline deacetylation. Crustacean-derived commercial chitosan nanoparticles (ChNPs) and fungal-derived chitosan nanoparticles (F. ChNPs) were synthesized via the ionotropic gelation method with sodium tripolyphosphate (TPP). Particle size analysis (PSA) indicated that fungal-derived ChNPs (21.47 nm) were distinctly smaller than crustacean-derived ChNPs (31.56 nm), likely due to the higher purity and potentially lower molecular weight of fungal-derived chitosan, which enhances ionic crosslinking efficiency. SEM imaging confirmed successful nanoparticle formation, revealing irregular, unevenly distributed, and highly aggregated morphologies typical of TPP-crosslinked chitosan systems. FTIR spectra validated the presence of major functional groups associated with chitosan–TPP interactions, including O–H stretching (3100–3300 cm⁻¹), N–H bending (1626–1633 cm⁻¹), and C–O stretching (1063–1064 cm⁻¹). XRD analysis showed prominent diffraction peaks near 2θ ≈ 18°, indicating reduced crystallinity and effective nanoparticle formation. Overall, P. ostreatus is demonstrated as an efficient non-animal chitosan source, producing smaller nanoparticles with desirable chemical and crystalline properties, highlighting its potential as an eco-friendly and functionally superior alternative to crustacean-derived chitosan.