Novel Collagenous Sponge Composites for Osteochondral Regeneration in Rat Knee Models: A Comparative Study of Keratin, Hydroxyapatite, and Combined Treatments

This study aims to evaluate the osteoconductive and osteoinductive potential of novel composite collagenous sponges enriched with keratin (K), hydroxyapatite (HA), and their combination (K+HA) for osteochondral regeneration in rat knee models. By examining cell proliferation, mineralization, and vascularization, we aim to determine the regenerative effectiveness of these materials in promoting osteochondral repair, particularly in load-bearing joints like the knee. Addressing the problem of osteochondral defects (OCD), which lead to osteoarthritis-a condition characterized by pain and functional impairment-the hereby research evaluates these biomaterials for their potential to foster bone and cartilage repair, especially in load-bearing joints as the knee. By leveraging an experimental living rat knee model, the effectiveness of these bio-composites is tasted through detailed morphological, biomechanical, and histological analyses. We have employed a rigorous methodology encompassing the selection of biomaterials based on their osteoconductive and osteoinductive traits, their intraosseous application in Wistar rats, and ulterior comprehensive and minutely monitoring. The comparison covers aspects such as cell growth, mean pixel intensity, and other key morphological properties, offering good insights into each material's regenerative capacity. Furthermore, in the present study we have highlighted the fabrication processes of the sponges, including lyophilization and crosslinking, underlining the importance of the biomaterials' physical characteristics in achieving targeted and optimal regenerative outcomes. Preliminary results obtained illustrate the biocompatibility and potential efficacy of these collagen-based composites in promoting bone healing and regeneration, with particular attention being given to the synergistic effects observed in the K+HA combination. This research will contribute to the understanding of material-based regeneration of osteochondral units but also might open avenues for future investigations into the optimization of such therapies for further clinical application. Through a detailed examination of the materials' integration with the test animal bone and cartilaginous tissues and their impact on bone and cartilage healing, this study sets the stage for the advancement of regenerative medicine solutions for OCD and the array of related conditions, offering hope for patients suffering from joint degeneration and injury.