Healing bones at the nanoscale: Black phosphorus dots for bone tissue repair, addressing long-term effects of chemotherapy

Chemotherapy-induced bone loss is a persistent clinical challenge, often leading to long-term skeletal complications. In this work, we developed black phosphorus (BP) dots as a nanoscale therapeutic platform to promote bone tissue repair. The BP dots were synthesized via liquid-phase exfoliation and subsequently functionalized with poly- l -lysine to enhance their colloidal stability and cell uptake. Structural and physicochemical characterization was performed using transmission electron microscopy (TEM), Raman spectroscopy, and zeta potential analysis, confirming their nanoscale morphology, crystalline integrity, and surface charge modification. We demonstrate that BP dots possess intrinsic biocompatibility for osteoblast cells. Additionally, BP dots promote biomineralisation by increasing local calcium phosphate concentrations, thereby accelerating hydroxyapatite formation and bone matrix deposition. Our findings highlight the functionality of BP dots as biocompatiblemineralization support, as a promising strategy to counteract chemotherapy-associated bone degeneration and restore bone homeostasis.