Influence of collagen source on fibrillar architecture and properties of vitrified collagen membranes

Abstract

Collagen vitrigel membranes are transparent biomaterials characterized by a densely organized, fibrillar nanostructure that show promise in the treatment of corneal injury and disease. In this study, the influence of different type I collagen sources and processing techniques, including acid-solubilized collagen from bovine dermis (Bov), pepsin-solubilized collagen from human fibroblast cell culture (HuCC), and ficin-solubilized collagen from recombinant human collagen expressed in tobacco leaves (rH), on the properties of the vitrigel membranes was evaluated. Postvitrification carbodiimide crosslinking (CX) was also carried out on the vitrigels from each collagen source, forming crosslinked counterparts BovXL, HuCCXL, and rHXL, respectively. Collagen membrane ultrastructure and biomaterial properties were found to rely heavily on both collagen source and crosslinking. Bov and HuCC samples showed a random fibrillar organization of collagen, whereas rH vitrigels showed remarkable regional fibril alignment. After CX, light transmission was enhanced in all groups. Denaturation temperatures after CX increased in all membranes, of which the highest increase was seen in rH (14.71°C), suggesting improved thermal stability of the collagen fibrils in the membranes. Noncrosslinked rH vitrigels may be reinforced through CX to reach levels of mechanical strength and thermal stability comparable to Bov.

Protease-sensitive atelocollagen hydrogels promote healing in a diabetic wound model

“…The influence of the collagen source on the physical and structural properties of resulting materials is known 59 and was therefore addressed by characterising both native as well as functionalised and crosslinked states.…”

Ocular adhesives: Design, chemistry, crosslinking mechanisms, and applications

“…9Eii-iii) [228]. Vitrigel membranes are another group of prefabricated patches (described in section 3.1.3) [163,232]. Chae et al developed a collagen vitrigel membrane that could help reconstruction of the corneal epithelial layer and prevent epithelial hypertrophy, minimizing complications such as immune rejection or delay in epithelialization [163].…”

Natural Biomaterials for Corneal Tissue Engineering, Repair, and Regeneration

“…In contrast, both human COLIs demonstrated higher light transmission compared to the bovine COLI. When comparing the structure of the vitrigels formed from each COLI, both the bovine and cell culture derived COLI had randomly oriented, disorganized fibrillar structures, whereas those formed from the recombinant human COLI displayed remarkable fibril alignment, which was unaffected by crosslinking . These results confirm that COLI source can have an effect on the properties and performance, although it would also be useful to see a comparison of the bovine COLI to the more commonly used medical grade porcine and rat tail collagens.…”

“…To determine the effect of these variables, vitrigel membranes were fabricated from three different sources of COLI: i) acid‐solubilized from bovine dermis, ii) pepsin‐solubilized from human fibroblast cell culture, and iii) ficin‐solubilized recombinant human COLI from tobacco leaves . The pH required for vitrification, fibrillar organization, light transmission, denaturation temperature, tensile strength, thickness, and hydration‐state of regular and crosslinked vitrigels were then compared . It was found that regardless of COLI source, a pH of 3 was necessary for the formation of a clear vitrigel and higher concentrations of both human COLIs were necessary to form vitrigels with similar handling characteristics to the bovine vitrigels .…”