An innovative gas foaming-assisted decellularizing strategy to construct decellularized tilapia skin matrix with improved porosity, piezoelectricity, and biocompatibility

Gas foaming-assisted decellularization improves porosity and cell removal in fish skin. • The matrix shows a porous structure with preserved collagen integrity and content. • The scaffold exhibits wet-state adaptability, rapid wettability, and high swelling capacity. • The material shows electromechanical response, biocompatibility, and antibacterial activity without exogenous agents. • This strategy enables valorization of fish by-products into marine-derived biomaterials for soft tissue repair. Tilapia skin, a major by-product of aquaculture, represents an abundant and sustainable resource for the construction of biomedical scaffolds, but its dense structure with limited pores limits the efficiency of conventional decellularization methods. In this study, a novel gas foaming-assisted decellularization strategy using sodium borohydride (NaBH 4 ) as foaming agent was designed and developed to fabricate decellularized tilapia skin matrix (dTSM). Some key parameters like NaBH 4 concentration and foaming time were systematically investigated. It was found that, under optimized conditions (2 M NaBH 4 , 30 min), the dTSM exhibited significantly enhanced porosity (70.2 ± 1.8% vs. 17.1 ± 2.9% in native skin), reduced residual deoxyribonucleic acid (DNA, 18.9 ± 5.4 ng/mg), and well-preserved collagen content and structure. Moreover, the obtained dTSM showed excellent hydrophilicity with complete water absorption within 5 s, a high swelling ratio (~300%), and improved mechanical adaptability under wet conditions (ultimate stress: 35.0 ± 3.7 MPa, elongation: 127.5 ± 21.5%). Stable piezoelectric outputs of 2.5–4.0 V and ~6 nA were generated under cyclic compression. Biocompatibility tests confirmed that the dTSM obtained from under optimized conditions exhibited low hemolysis (1.1 ± 0.6%) and effective support for cell adhesion and proliferation, while antibacterial rates exceeded 99% against both Escherichia coli and Staphylococcus aureus . This foaming-assisted approach offers a promising strategy for valorizing fish by-products into functional biomaterials for soft tissue regeneration and marine-based biomedical applications. Download: Download high-res image (199KB) Download: Download full-size image