Development and evaluation of tilapia skin-derived gelatin, collagen, and acellular dermal matrix for potential use as hemostatic sponges

Hemostasis plays a critical role in the early stage of wound healing, especially in acute wounds which can significantly improve the survival of patients. Based on the excellent biocompatibility of natural biomaterials, in this study, we prepared a series of novel hemostatic sponges by using tilapia skin, a marine biological resource, and extracting tilapia skin-derived gelatin, collagen, and acellular dermal matrix through five different methods. Using in vitro sheep blood and in vivo rat liver hemorrhage models, we found that tilapia skin sponges had excellent coagulation and hemostatic abilities. Among them, the collagen sponge exhibited optimal hemostasis performance because it could accelerate clotting by binding to the specific sites of blood cells and platelets. Furthermore, the sponges' porous structure enhanced the capability to absorb blood, thus effectively promoting hemostasis. In summary, we reported an efficient and convenient method to prepare marine biological resources into sponges, which provided a novel class of alternatives for hemostasis in acute wounds with broad application prospects.

Marine collagen peptides: A novel biomaterial for the healing of oral mucosal ulcers

The purpose of this study was to analyze the therapeutic effects of marine collagen peptides (MCPs) from tilapia skin on oral mucosal ulcers in a rat model. CCK-8 and wound healing assays were performed in vitro to evaluate proliferation and migration of L929 cells after treatment with MCPs. The effects of MCPs on the healing of oral mucosal ulcers in a rat model were macroscopically and microscopically analyzed in vivo. Results showed that MCPs promoted proliferation and migration of L929 cells. Moreover, 75%MCPs enhanced the ulcer healing process, suppressed inflammatory response and up-regulated the expression levels of vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF). MCPs are potentially used as a new therapeutic strategy for oral mucosal ulceration.

Vacuum freeze-drying of tilapia skin affects the properties of skin and extracted gelatins

Herein, the effects of vacuum freeze-drying treatment of tilapia skin on the properties of skin, the molecular properties of extracted gelatins, and the emulsion stabilization properties of extracted gelatins were studied. The results suggested that all the bound, entrapped, and free water molecules were simultaneously sublimated (quickly at the first 30 min and then slowly) by sublimation in the vacuum freeze-drying process. Long vacuum freeze-drying times (60 and 150 min) decreased the amount of the four bands in SDS-PAGE pattern, increased β-sheet and random coil percentages, and decreased other three secondary structure percentages of extracted gelatins. Finally, vacuum freeze-drying of tilapia skin increased the emulsion stability of fish oil-loaded oil-in-water emulsions. This work provided basic knowledges to illustrate the effect of vacuum freeze-drying of protein-enriched tissues on the molecular and functional properties of extracted proteins. It also provided a potential route to increase the emulsion stabilization ability of proteins.

Evaluation of a novel tilapia-skin acellular dermis matrix rationally processed for enhanced wound healing

Acellular Dermal Matrix (ADM) is mainly made with human or porcine skins and has the risk of zoonotic virus transmission. The fish skin-derived ADM could overcome the shortcoming. Fish skin acellular matrix has been used as wound dressing, but there is few systematic studies on tilapia-skin acellular dermal matrix (TS-ADM). In the present study, a novel TS-ADM was made by an alkaline decellularization process and γ-irradiation. The physical properties, biocompatibility, pre-clinical safety and wound healing activity of TS-ADM were systematically evaluated for its value as a functionally bioactive wound dressing. Histopathological analysis (hematoxylin and eosin staining, 4,6-diamidino-2-phenylindole (DAPI) staining) and DNA quantification both proved that the nuclear components of tilapia skin were removed sufficiently in TS-ADM. Compared to the commercial porcine acellular dermal matrix (DC-ADM), TS-ADM has distinctive features in morphology, thermal stability, degradability and water vapor transmission. TS-ADM was more readily degradable than DC-ADM in vitro and in vivo. In both rat and mini-pig skin wound healing experiments, TS-ADM was shown to significantly promote granulation growth, collagen deposition, angiogenesis and re-epithelialization, which may be attributed to the high expression of transforming growth factor-beta 1 (TGF-β1), alpha-smooth muscle actin (α-SMA) and CD31. Herein, the novel TS-ADM, used as a low-cost bioactive dressing, could form a microenvironment conducive to wound healing.