SERITSIN - WATER-SOLUBLE SILK PROTEIN

Sericin, a water-soluble glycoprotein from Bombyx mori silk cocoons (20-30% of mass), acts as a protective layer around fibroin fibers. Once discarded as degumming waste causing environmental issues like high COD in wastewater, it is now valued for biocompatibility, biodegradability, low immunogenicity, and bioactive properties (antioxidant, anti-inflammatory, antimicrobial, anti-tyrosinase, anti-aging, neuroprotective, anticancer). This review synthesizes 2020-2025 advancements from over 100 studies in PubMed, Scopus, Web of Science, and ResearchGate, covering extraction, structure, properties, and applications in biomedical, cosmetic, pharmaceutical, food, textile, and environmental fields. Extraction methods—HTHP degumming, alkaline/acidic hydrolysis, urea, enzymatic (alcalase, papain, subtilisin), microwave, ultrasonic, infrared—yield 10-35%, MW 10-400 kDa, purity >95%, preserving functionality. Structural analyses (FTIR, NMR, XRD, CD) show dominant amino acids: serine (28-35%), aspartic acid (12-18%), glycine (12-20%), threonine (8-12%), glutamic acid (6-10%), with hydrophilic random coils (60-80%) and β-sheets (20-40% under stress). Thermal properties: Tg 170-180°C, Tm 210-230°C, decomposition 280-320°C. Biomedical uses include scaffolds (80-95% porosity), drug delivery (>85% encapsulation), wound dressings (30-50% faster healing), and regeneration for bone/cartilage/neural tissues. Cosmetics leverage moisturizing (300-400% water retention), UV protection (20-30% SPF boost), anti-wrinkle (40-60% collagen increase) in creams/serums/hair products. Pharmaceuticals: antimicrobial coatings (70-90% inhibition of E. coli/S. aureus), anticancer (apoptosis at 50-100 μg/mL), controlled release (e.g., doxorubicin over 72-96 hours). Food: antioxidant packaging (2-3x shelf life), nutraceuticals (ACE-inhibitory IC50 <1 mg/mL). Challenges like low strength (<5 MPa), high swelling (>500%), variability, scalability are addressed via crosslinking (genipin/glutaraldehyde 0.5-2%), nanocomposites (200-300% modulus gain), green processes (40-60% reduced impact). Publications rose 500% since 2010, patents tripled in five years. Market: USD 361.5-412.2M in 2025, projected USD 586-638.9M by 2035 (CAGR 5.8-6.4%). Future: nanotechnology (quantum dots), personalized medicine (gene vectors), circular economy for silk waste.