Journal of Engineering Research and Reports

Chitosan, a naturally derived polysaccharide obtained through the deacetylation of chitin, has emerged as a versatile biomaterial for regenerative medicine due to its biocompatibility, biodegradability, and intrinsic bioactivity. Its structural resemblance to glycosaminoglycans supports cell adhesion, proliferation, and differentiation, enabling applications in bone, cartilage, skin, and soft-tissue repair. The physicochemical properties of chitosan vary significantly based on biological source and extraction route. Marine-derived chitosan particularly from crab and shrimp shells typically exhibits high molecular weight (500–1000 kDa), elevated degrees of deacetylation (~70–85%), crystallinity indices of 55–75%, and extraction yields ranging between 60–75%. In contrast, fungal-based chitosan offers lower molecular weight (50–300 kDa), reduced crystallinity (35–45%), yet superior purity and minimal allergenicity, with yields generally between 50–70%. Insect-derived chitosan (100–400 kDa, DD 65–75%) is gaining prominence as an eco-sustainable alternative with moderate biodegradation rates suited for dermal and wound-healing applications. This review provides a comparative assessment of chitosan extraction methods from conventional acid-alkali eproteinization to enzymatic and fermentation-assisted bioprocessing while outlining performance differences across biological origins. Key challenges, including heavy-metal accumulation, seasonal variability in crustaceans, and pigment/lipid removal in insect sources, are discussed. The paper further highlights emerging innovations in green extraction systems and fungal bioproduction that may enable scalable, medical-grade chitosan. Overall, this review underscores the need for optimized extraction, property tailoring, and functional modification to enhance chitosan’s therapeutic efficiency in regenerative medicine.