Phyto-assisted synthesized CuO NPs embedded in crosslinked zein/alginate composite films for hastening wound healing and tissue regeneration in rats bio-template

Biopolymer-based composite films were primed by incorporating alginate and zein natural polymers using a solution-casting method and superbly assisted by eco-friendly prepared copper oxide nanoparticles (CuO NPs). The influence of the addition method of CaCl₂ as a crosslinker and CuO NPs loading content (0.1, 0.2, and 0.4 wt%) on the microstructural, physical, and mechanical properties of the films, were appraised. The formation of composite films and incorporation of CuO NPs were verified by FT-IR and XRD studies. The results unearthed that double crosslinking (Dipping method) succeeded in forming a firm, homogenous film that maintains its integrity in water for up to 24 h in comparison to the single (Blending) method. Inclusion of zein in the film and further loading with CuO NPs are manifested in a significant decrease in water vapor permeability, swelling and degradation percentage about (58.57, 52.26, and 25.80%); respectively. In addition to 1.26-folds increase in the tensile strength and 1.19-folds decrease in elongation to break, endorsing the excellent barrier property and durability of the formed films. Nevertheless, CuO loaded composite film proposes high biocompatibility against HBF4 cells with the highest IC50 and EC100 values, compared to alginate film and free-CuO NPs. The composite film exhibited the most effective antimicrobial activity against extremely drug-resistant human pathogens of both Gram-ve and Gram + ve bacteria strains, as well as fungal cells. The healed diabetic wound demonstrated an intact fully thickened keratinized epidermal epithelialization, and a complete absence of any inflammatory infiltrate after 13 days of treatment, emphasizing its suitability as a promising dressing candidate for skin tissue bioengineering.