Engineering medical-grade collagen scaffolds for bone tissue regeneration

The stability and mechanical performance of collagen scaffolds are critical for bone tissue engineering. This study evaluated two neutralization methods and two physical crosslinking strategies in Viscolma®, a medical-grade collagen. Dropwise or non-dropwise neutralization during synthesis promoted fiber formation, followed by scaffold fabrication via freeze-drying. Crosslinking was achieved by ultraviolet irradiation (UV) (30 min) or dehydrothermal (DHT) treatment at 75 °C or 100 °C for 24–48 h. UV irradiation impaired the physical properties of the scaffold, whereas DHT preserved collagen fiber integrity and produced favourable morphological, physicochemical, and mechanical characteristics. Human bone marrow mesenchymal stem cells grown on DHT-treated scaffolds exhibited high viability, enhanced alkaline phosphatase activity, and increased RUNX2, osteopontin, and osteocalcin expression. These findings highlight DHT crosslinking as a simple, chemical-free approach to produce mechanically robust, biologically active collagen scaffolds with strong potential for trabecular bone regeneration.