Layer by layer assembly of strontium substituted nanowire hydroxyapatite and hybrid of carbon derivatives as potential biomaterial for bone metastasis treatment

To devise a highly effective implant for addressing bone metastasis with the unique capability of self-oxygen generation, a multifunctional film was engineered using a Layer-by-Layer technique. The film, comprised of strontium-substituted hydroxyapatite nanowires (SrwHAP) and a graphitic carbon nitride/graphene oxide (g-CN/GO) hybrid, was meticulously designed. To optimize the film's interaction with mesenchymal stem cells (MSCs), the number of layers was adjusted. Subsequent surface coating involved extracellular matrix (ECM) derived from osteogenic cells. The final film, ((CN/GO). SrwHAP)₂. ECM, exhibited pronounced MSC attachment and an accelerated proliferation rate. Key osteogenic markers such as alkaline phosphatase activity, mineralization, RUNX2, and osteocalcin expression remarkably increased when compared to the glass substrate. Notably, the presence of LED irradiation yielded further enhancements in proliferation and osteogenic markers, attributed to the photocatalytic properties of the (CN/GO) hybrid alongside O₂ generation. Direct co-culturing of MSCs and breast cancer cells (MCF7) on its surface, coupled with LED irradiation not only bolstered the osteogenic potential of MSCs but also reduced tumor colonies over time. Impressively, ((CN/GO). SrwHAP)₂. ECM also demonstrated potent antibacterial properties against Gram-positive bacteria (Staphylococcus aureus). Based on the results obtained, ((CN/GO). SrwHAP)₂. ECM emerges as a promising candidate for addressing bone defects in patients afflicted by breast cancer bone metastasis.