Human hair keratin modification enhances the biocompatibility, bioactivity and osteogenic property of BCP/PMMA bone cement.

Biphasic calcium phosphate (BCP)/poly(methyl methacrylate) (PMMA) bone cement is an effective fixation material for bone tissue regeneration but has drawbacks, including poor hydrophilicity and low biological activity. To overcome these drawbacks, we present a novel human hair keratin-modified BCP/PMMA (KBP) composite. In this study, the influence of human hair keratin on the setting properties, mechanical strength, hydrophilicity, in vitro bioactivity and in vivo biocompatibility of KBP bone cement was investigated. Results show that incorporation of human hair-derived keratin improves the setting properties and hydrophilicity of bone cement, as reflected by a 16% reduction in contact angle, 80% increase in water absorption, 21% increase in porosity and 6% decrease in maximum setting temperature. The modification also improved mesenchymal stem cell viability by 15% and enhanced osteogenic differentiation. The keratin-based composite markedly promoted bone repair in a Sprague-Dawley rat bone defect model, with bone mineral density elevated by 17% and bone volume fraction increased by 15%. In vivo studies further demonstrated that KBP is nontoxic, nonpyrogenic and nonsensitizing, underscoring its potential as a safe and effective alternative for bone tissue repair. In summary, human hair keratin-modified bone cement is a promising candidate for orthopedic clinical applications.