Pineapple agro waste derived polyphenol enriched polyvinyl alcohol mucoadhesive films for enhanced bioadhesion and bioactivity

Polyphenol enriched polyvinyl alcohol (PVA)-glycerol mucoadhesive films were developed using pineapple (Ananas comosus) peel/crown agro waste to enhance mucosal adhesion and biological functionality. Pineapple peel exhibited high moisture content (90.07%), and aqueous Soxhlet extraction yielded the highest total phenolic content (0.7274 mg GAE/g dry extract). The optimized blank formulation (P5G1) demonstrated uniform thickness (0.130 ± 0.018 mm), tensile strength (28.5 ± 1.1 MPa), elongation (9.2 ± 0.35%), folding endurance (285 ± 12 folds), and surface pH (6.78 ± 0.07). Incorporation of 1% ethanolic (EPE) and aqueous (APE) polyphenolic extracts significantly modified mechanical behavior. Tensile strength decreased to 4.2 ± 0.5 MPa (EPE-P5G1) and 15.6 ± 0.9 MPa (APE-P5G1), while elongation increased to 50.3 ± 1.8% and 28.8 ± 1.1%, respectively, indicating extract induced plasticization. Mucoadhesive strength increased markedly from 0.20 N (Blank) to 0.34 N (EPE-P5G1) and 0.43 N (APE-P5G1), demonstrating enhanced interfacial interaction with mucosal tissue. Water contact angle reduction confirmed improved hydrophilicity, correlating with swelling and adhesion behavior. APE-P5G1 exhibited sustained polyphenol release up to 45 min, whereas EPE-P5G1 showed rapid release within 10 min. Antioxidant activity reached 56% (APE) and 54% (EPE) DPPH scavenging at 50 µg/mL. MTT assay revealed high cytocompatibility with IC₅₀ values of 22.69 µg/mL (APE), 18.14 µg/mL (EPE), and 14.88 µg/mL (blank). Overall, aqueous extract loaded films demonstrated superior adhesion, controlled release, and biological functionality, indicating strong potential as sustainable mucoadhesive delivery platforms.