Evaluation of P. aeruginosa attachment on mineralized collagen scaffolds and addition of manuka honey to increase mesenchymal stem cell osteogenesis

Abstract

The design of biomaterials to regenerate bone is likely to increasingly require modifications that reduce bacterial attachment and biofilm formation as infection during wound regeneration can significantly impede tissue repair and typically requires surgical intervention to restart the healing process. Here, we investigate the ability of a mineralized collagen biomaterial to natively resist infection as well as how the addition of manuka honey affects bacterial colonization and mesenchymal stem cell osteogenesis. We incorporate manuka honey into these scaffolds via either direct fabrication into the scaffold microarchitecture or via soaking the scaffold in a solution of Manuka honey after fabrication. Direct incorporation results in a change in the surface characteristics and porosity of mineralized collagen scaffolds. Soaking scaffolds in honey concentrations greater than 10% had significant negative effects on mesenchymal stem cell metabolic activity but soaking or incorporating 5% honey had no impact on endothelial cell tube formation. Soaking and incorporating 5% honey into scaffolds reduced metabolic activity of mesenchymal stem cells, however, soaking 5% honey into scaffolds increased calcium and phosphorous mineral formation, osteoprotegerin release, and alkaline phosphatase activity. The addition of manuka honey did not prevent P. aeruginosa attachment but may be able to limit attachment of other common wound-colonizing bacteria. Overall, our results demonstrate the potential for soaking mineralized collagen scaffolds in 5% manuka honey to increase osteogenesis of mesenchymal stem cells.