Multifunctional CuO‐Loaded Egg‐Shell‐Derived Hydroxyapatite/Gelatin Biocomposite for Enhanced Wound Healing and Methylene Blue Dye Degradation

Abstract This study reports the green synthesis of a multifunctional CuO‐loaded hydroxyapatite/gelatin (HAP/CuO/GEL) biocomposite derived from eggshell and gelatin, integrated with Cynodon dactylon CuO nanoparticles (CuO Nps). Structural analyses like FTIR, XRD, FESEM, BET, PL, and XPS confirmed successful composite formation with mesoporous architecture 41.8 m 2 /g surface area, 2.02 nm pore size, and efficient charge separation. Optical studies revealed band gap narrowing of the biocomposite 1.60 eV compared to pristine HAP 3.92 eV and CuO Nps 2.84 eV, favoring visible‐light photocatalysis. The composite achieved 90.8% methylene blue degradation within 120 min, surpassing reported photocatalysts, with pseudo‐first‐order kinetics k = 0.0198 min −1 , R 2 = 0.9856. Scavenger and LC‐MS analyses demonstrated that • O 2 − radicals and photogenerated holes drive degradation, leading to mineralization into CO 2 and H 2 O . Reusability studies confirmed structural stability over five cycles. Biologically, the composite exhibited strong antimicrobial activity against Pseudomonas aeruginosa 15 mm inhibition at 100 µL and Candida albicans 13 mm, while maintaining low cytotoxicity IC 50 = 44.56 µg/mL and significant antioxidant potential IC 50 = 114.48 µg/mL. Wound‐healing assays revealed accelerated cell migration 40% closure at 48 h versus 5% control. These findings highlight the dual potential of the HAP/CuO/GEL composite as an eco‐friendly photocatalyst for wastewater remediation and a biocompatible material for wound healing.