Purified bone xenografts: A novel and efficient animal bone substitute derived from an optimized supercritical CO₂...

Bone xenografts represent a promising alternative to autologous or allograft transplants, yet antigenicity in animal-derived tissues remains a major limitation to their clinical use. To provide any risk of contamination or allogenic rejection, the Supercrit® process was developed to treat allogeneic human bone combining a supercritical CO₂ treatment followed by a chemical treatment using high quantities of different solvents. The aim of this study was to produce a xenogeneic bone substitute thanks to the development of a new one-step supercritical process, 'Goxcrit', and to test it in vivo. This new process reduces the use of solvents by injecting them under pressure into the supercritical CO₂ flow, while maintaining the cleaning quality of the bone matrix and better preserving its inner structure, essential for its future bone integration. Porcine derived bone samples were treated using Goxcrit or Supercrit®, and compared with human bone treated with Supercrit®, the commercialized bone allograft. In vitro analyses demonstrated the absence of cytotoxicity and of the alpha-gal epitope mainly responsible for cross-species immunogenicity. Additionally, in vivo experiments revealed improved bone formation in rats critical calvarial defects (BV/TV and von Kossa analyses) implanted with Goxcrit samples, with bone remodeling (TRAP/ALP stains), compared to those treated with Supercrit®. These results can be attributed to the less aggressive chemical process of the Goxcrit, which preserves the bone's inner structure critical for remodeling. Our study highlighted the interest of using a porcine bone source treated with the Goxcrit process to meet the growing demand for reliable and effective bone substitutes.