Skin wound healing is a complex and dynamic process that aims to restore lesioned tissues. Collagen-based skin substitutes are a promising treatment to promote wound healing by mimicking the native skin structure. Recently, collagen from marine organisms has gained interest as a source for producing biomaterials for skin regenerative strategies. This preliminary study aimed to describe the application of a collagen-based skin-like scaffold (CBSS), manufactured with collagen extracted from sea urchin food waste, to treat experimental skin wounds in a large animal. The wound-healing process was assessed over different time points by the means of clinical, histopathological, and molecular analysis. The CBSS treatment improved wound re-epithelialization along with cell proliferation, gene expression of growth factors (VEGF-A), and development of skin adnexa throughout the healing process. Furthermore, it regulated the gene expression of collagen type I and III, thus enhancing the maturation of the granulation tissue into a mature dermis without any signs of scarring as observed in untreated wounds. The observed results (reduced inflammation, better re-epithelialization, proper development of mature dermis and skin adnexa) suggest that sea urchin-derived CBSS is a promising biomaterial for skin wound healing in a “blue biotechnologies” perspective for animals of Veterinary interest.

The mutable collagenous tissue (MCT) of echinoderms possesses biological peculiarities that facilitate native collagen extraction and employment for biomedical applications such as regenerative purposes for the treatment of skin wounds. Strategies for skin regeneration have been developed and dermal substitutes have been used to cover the lesion to facilitate cell proliferation, although very little is known about the application of novel matrix obtained from marine collagen. From food waste we isolated eco-friendly collagen, naturally enriched with glycosaminoglycans, to produce an innovative marine-derived biomaterial assembled as a novel bi-layered skin substitute (Marine Collagen Dermal Template or MCDT). The present work carried out a preliminary experimental in vivo comparative analysis between the MCDT and Integra, one of the most widely used dermal templates for wound management, in a rat model of full-thickness skin wounds. Clinical, histological, and molecular evaluations showed that the MCDT might be a valuable tool in promoting and supporting skin wound healing: it is biocompatible, as no adverse reactions were observed, along with stimulating angiogenesis and the deposition of mature collagen. Therefore, the two dermal templates used in this study displayed similar biocompatibility and outcome with focus on full-thickness skin wounds, although a peculiar cellular behavior involving the angiogenesis process was observed for the MCDT.

Germ cell xenotransplantation is a promising tool for enhancing aquaculture production and supporting the conservation of declining fish species. A major limitation is the reliable identification of germ stem cells, which remains challenging due to the scarcity of validated molecular markers. This study assessed the suitability of different immunohistochemical approaches for identifying ovarian germ stem cells (OGSCs) in three Mediterranean species of commercial interest: European hake (Merluccius merluccius), meagre (Argyrosomus regius), and flathead grey mullet (Mugil cephalus). Among the antibodies tested (anti-OCT4, anti-VASA, anti-Sox2), only anti-VASA and anti-Sox2 labeled cells with morphological features consistent with OGSCs, although staining intensity, specificity, and cross-reactivity with early oocytes varied across species. In parallel, preliminary protocols for OGSC isolation and in vitro proliferation were developed for European hake and meagre. Enzymatic dissociation with collagenase, followed by Ficoll-Paque density separation and culture in Leibovitz’s L-15 medium supplemented with 2% fetal bovine serum at 25 °C, resulted in the highest OGSC recovery and detectable increases in proliferating cells. A sequential pre-plating step enhanced enrichment in meagre but caused substantial cell loss in hake. Overall, this study provides a comparative evaluation of female germline stem cell markers in these species, contributing to future surrogate reproduction and germplasm conservation strategies.