Characterization and Cytocompatibility of Collagen–Gelatin–Elastin (CollaGee) Acellular Skin Substitute towards Human Dermal Fibroblasts: In Vitro Assessment

Abstract

Full-thickness skin wounds have become a serious burden to patients, medical care, and the socio-economic environment. The development of a safe and effective acellular skin substitute that can rapidly restore intact physiological skin is required. Natural bioactive materials including collagen, gelatin, and elastin possess significant advantages over synthetic biomaterials regarding biodegradability and biocompatibility. However, low mechanical strength, a faster biodegradation rate, and thermally unstable biomaterials lead to slow-healing and a high rate of post-implantation failure. To overcome these concerns, naturally occurring genipin (GNP) flavonoids were added to improve the mechanical strength, degradation rate, and thermal properties. Therefore, this study aimed to fabricate and characterize collagen–gelatin–elastin (CollaGee) biomaterials cross-linked with GNP as an acellular skin substitute potentially used in full-thickness wound healing. CollaGee at different ratios was divided into non-cross-linked and cross-linked with 0.1% GNP (w/v). The physicochemical, mechanical, and biocompatibility properties of CollaGee were further investigated. The results demonstrated that GNP-cross-linked CollaGee has better physicochemical (>50% porosity, pore size range of 100–200 µm, swelling ratio of >1000%) and mechanical properties (resilience and cross-linking degree of >60%, modulus of >1.0 GPa) compared to non-cross-linked CollaGee groups. Furthermore, both cross-linked and non-cross-linked CollaGee demonstrated pivotal cellular compatibility with no toxicity and sustained cell viability until day 7 towards human dermal fibroblasts. These findings suggest that GNP-cross-linked CollaGee could be a promising ready-to-use product for the rapid treatment of full-thickness skin loss.

A Comprehensive Review on Collagen Type I Development of Biomaterials for Tissue Engineering: From Biosynthesis to Bioscaffold

“…For instance, the T d for collagen in native human skin is in the range of 57–65 °C [ 114 ]. Two blends of ovine collagen–gelatine–elastin (CollaGee) biomaterial were fabricated as a skin substitute, and it was found that, without crosslinking, the T d were 64.5–69.12 °C and 57.37–61.29 °C, respectively [ 181 ]. Although this is within the range of the native skin T d , the biomaterial biodegradation was not satisfactory, and upon crosslinking with genipin, the T d increased to 76.89–81.70 °C and 92.50–99.75 °C, respectively.…”

Cell secretomes for wound healing and tissue regeneration: Next generation acellular based tissue engineered products

“…In the aspect of skin substitute toward wound healing and tissue engineering, collagen-based dressing helps stimulate new tissue growth, while promoting autolytic debridement, promote cell proliferation, angiogenesis, re-epithelialization, provide a non-immunogenic, resorbable scaffold for cellular migration and matrix deposition, guide organization of ECM deposition. 148 , 149 There is no doubt that collagen compounds meet many of these criteria and have several distinct advantages because they are biocompatible and non-toxic to various types of tissues.…”

The Fabrication of Gelatin–Elastin–Nanocellulose Composite Bioscaffold as a Potential Acellular Skin Substitute

“…However, the same review also mentioned that increasing the pore size of genipin-crosslinked gelatin hydrogels increased both cell proliferation and ECM secretion, while smaller pores led to cell over-confluence with no ECM deposition [ 48 ]. This is supported by studies employing genipin-crosslinked collagen and gelatin scaffolds that recommended pore sizes between 100 and 300 µm for skin fibroblast migration and vascular formation [ 22 , 38 ]. In reality, the optimal pore size may be influenced by the biomaterial itself, given that cell behaviours are governed not only by physical cues from the matrix, but also by the biochemical cues from the scaffold polymer [ 48 ].…”

“…Likewise, elastin allows for faster and more efficient mesh remodelling and functional tissue formation [ 21 ]. Scaffolds made from a collagen–gelatin–elastin composite demonstrated good physicochemical properties and good biocompatibility with dermal fibroblasts [ 22 ].…”

“…Its properties can be modified based on the types and concentrations of the cross-linkers used, while retaining compatibility with skin fibroblasts [ 38 ]. Nitta-Gelatin was also combined with collagen and elastin to form composite scaffolds acting as acellular templates for skin regeneration [ 22 ]. Additionally, it has been combined with elastin to form hydrogels for cutaneous wound treatment [ 39 ].…”