Spider web-inspired gelatin-based bioplastic enables closed-loop recyclable, biodegradable, and sustainable packaging

Abstract

We present a spider web-inspired gelatin (GE) bioplastic engineered by the integration of natural tea polyphenols (TP), gelatin, and bio-based hyperbranched polyester (HBPE) synthesized from glycerol and itaconic anhydride. The resulting TP-HBPE-GE exhibits multifunctionality, including: Balanced optical properties for food packaging (52% visible light transmission and 99.8% UV blocking), a mechanically tunable biomimetic networks enabling glycerol-free customization of strength and toughness (11.0-33.8 MPa tensile strength, 21.6%-125.3% elongation at break), dual moisture resistance combining hydrophobic surfaces (113.3° contact angle) and low vapor permeability with high barrier properties (803.1 g/(m²·day)), and bioactive preservation through antioxidant (88.6% DPPH scavenging) and antimicrobial actions (complete eradication of E. coli and S. aureus). Practical validation demonstrates superior cherry tomato preservation compared to commercial polyvinyl chloride (PVC), maintaining firmness and retaining nutrient over 15 days. The system embodies circular design principles through its renewable composition (gelatin, TP and HBPE), energy-efficient processing (water-based fabrication and thermal remodeling), closed-loop recyclability (conversion to adhesives/coatings), and full biodegradation within 28 days. This architecturally engineered bioplastic establishes a sustainable packaging paradigm aligned with green chemistry principles, including prioritization of renewable feedstocks, minimized process environmental footprints, valorization of waste film as adhesives and coatings, and ensured end-of-life biodegradability.