2D Boron Nanoplatelets as a Multifunctional Additive for Osteogenic, Gram-Negative Anti-Microbial and Mechanically Reinforcing Bone Repair Scaffolds

Two-dimensional boron offers unique advantages in bone tissue engineering, unlocking capabilities that conventional additives struggle to achieve. In this study, we leverage the 2D morphology and intrinsic bioactivity of boron nanoplatelets, incorporated into collagen-based scaffolds, to simultaneously achieve osteogenic, neurogenic, angiogenic, anti-inflammatory, mechanically reinforcing, and anti-microbial effects. We synthesize boron nanoplatelets from non-layered precursors using liquid-phase exfoliation and combine them with collagen to form boron-collagen scaffolds (BColl). Boron significantly reinforces the collagen matrix, beneficial for mechanoresponsive bone cells. Osteoblasts and mesenchymal stem cells exhibit healthy morphology and proliferation on BColl films and scaffolds, with extended culture leading to increased alkaline phosphatase release and significantly increased calcium deposition, indicating enhanced osteogenesis. E. coli viability decreases significantly on BColl films, demonstrating their potential to limit post-implantation infections. Finally, we observe angiogenic, neurogenic and anti-inflammatory effects, with dose-dependent upregulation of vascular endothelial growth factor-A, nerve growth factor-beta and interleukin-10, and downregulation of interleukin-6 highlighting boron's potential to drive pro-reparative processes. Taken together, these data showcase boron's potential in developing next-generation bone biomaterials, by offering multifunctional benefits to clinically relevant aspects of bone regeneration such as mineralization, angiogenesis, and innervation, while improving the mechanical and anti-microbial properties of natural polymer scaffolds.