Effects of γ-ray irradiation on the molecular structure of collagen in different product forms

Abstract

γ-Ray irradiation is a common method to sterilize collagen-based materials. However, with more applications of collagen-based materials and more diverse product forms, reports on sensitivity differences of those different forms to irradiation have not been published. In this study, different doses of γ-ray irradiation were used to treat an acidic collagen solution, a PBS collagen solution, a collagen self-assembled gel, and their corresponding freeze-dried sponges to systematically study the effects of irradiation sterilization on the molecular structure and properties of collagen in different product forms. The results showed that irradiation destroyed the molecular structure of collagen in different morphological materials. PBS salt in the collagen sponge aggravated collagen destruction, while the ordered structure formed by collagen self-assembly improved collagen molecule tolerance to irradiation. Compared with collagen sponge samples, solution or gel collagen molecules were more sensitive to irradiation. Irradiation severely damaged the molecular structure of collagen in acidic solutions. Irradiating a collagen PBS solution not only damaged the collagen molecules but also induced self-assembly of the collagen molecules to form collagen self-assembled gels, which led to shrinkage of the collagen self-assembled gels and was accompanied by cross-linking between collagen molecules/collagen peptides.