Milkfish (Chanos chanos) is an abundant fish commodity in the Philippines that generates a large number of wastes such as skin, scales, viscera, and bones, which, upon disposal, cause environmental pollution. The abundance of these wastes, such as fish skin, rich in bioactive natural products such as collagen, elicits interest in their conversion into high-market-value products. The decellularization of milkfish skin waste can extract its extracellular matrix (ECM), a potential raw material for biomedical applications such as the repair of damaged skin tissues. In particular, this study characterized the developed decellularized ECM with different concentrations (0.1%, 1.0%) of the decellularizing agents (Triton X-100, SDS) and temperature (4 °C, room temperature) using milkfish skin. The decellularized ECM structure was better preserved using Triton X-100, while SDS was more effective in cell component removal, especially at 1% concentration and 4 °C temperature. There were significant effects of varying the temperatures and concentrations on the physical and mechanical properties of the decellularized ECM. Future studies could explore more variables to further establish protocols and more analyses to better characterize the decellularized milkfish skin.

Tilapia (Oreochromis niloticus), which is extensively farmed globally and ranks as the second most cultivated fish in the Philippines, generates significant amounts of waste that are often underutilized. One specific type of waste material consists of fish heads, which contain a valuable source of extracellular matrix (ECM). This study aims to evaluate the effects of sonication as a viable decellularization method for the extraction of ECM from tilapia fish heads. Particularly, two treatments were tested on the head samples: sonication-assisted decellularization (dWS) using a water bath sonicator, and decellularization without sonication (dNS), each with different contact times (5 min and 10 min). Histological analysis with H and E staining and DNA quantification revealed that sonication-assisted samples (dWS) showed a greater reduction in basophilic components and DNA content, achieving a 93.7% removal rate. These dWS samples also had the highest protein loss, retaining only 33.86% of the original protein. SDS–PAGE analysis indicated that both dWS and dNS samples maintained similar collagen structures, as evidenced by identical subunit bands. ATR–FTIR spectra confirmed the presence of collagen type I in all samples, detecting characteristic amides A, B, I, II, and III. The results revealed that varying treatments and contact times had significant effects on the physical and mechanical properties of the decellularized extracellular matrix (ECM). These findings highlight the effectiveness of sonication in the decellularization process, particularly for utilizing waste tilapia heads.

Tilapia, the second most extensively farmed fish in the Philippines, generates significant amounts of waste that are often underutilized, leading to environmental concerns. One specific waste material is tilapia heads, which contain a valuable extracellular matrix (ECM) and an abundant source of bioactive materials that have a potential application in various fields, including biomaterials for wound healing and nutraceuticals. This study aims to evaluate the effects of sonication as a viable decellularization method for extracting ECM from tilapia fish heads. Histological analyses, employing H&E staining, revealed a higher reduction in basophilic components in the sonication-assisted (dWS) samples compared to those without sonication (dNS), as confirmed by DNA quantification. Notably, dWS samples subjected to 1% SDS sonication for 10 minutes exhibited the lowest DNA content with a removal rate of 93.7%. However, the same dWS sample also manifested the highest protein removal with a retained protein of 33.86%. The SDS-PAGE analysis of both dWS and dNS samples exhibited a uniform pattern, featuring identical four subunit bands—namely, the β-dimer (225-227 kDa), γ bands (228-230 kDa), and two alpha chains (α1 and α2 chains) (116-120 kDa)—indicating that sonication did not introduce discernible alterations in the helical structure of collagen. ATR-FTIR spectra further confirmed the presence of collagen as indicated by the detection of collagen type I indicators, including amides A, B, I, II, and III, in all decellularized samples. The above findings highlight the potential of sonication to aid in the decellularization of waste tilapia heads with future research targeting practical applications in wound healing, nutraceuticals, and sustainable environmental preservation through waste utilization.