Synthesis and Osteoinductive Properties of Nanosized Lithium-Modified Calcium-Organic Frameworks

The development of biomaterials that enhance bone healing and integrate with native bone tissue has gained significant interest. Metal-organic frameworks (MOFs) have emerged as promising candidates due to their unique surface properties and biocompatibility. While various bioactive element-incorporated MOFs have been studied, the osteogenic potential of lithium (Li)-modified MOFs remains largely unexplored. This study presents the synthesis and characterization of a nanosized calcium-based MOF incorporating Li⁺ ions to enhance osteoinductive properties. The MOFs were evaluated in vitro for apatite mineralization, degradation, ion release, protein adsorption, cell adhesion, viability, and osteogenic differentiation using pre-osteoblast cells. The synthesized MOFs promoted apatite formation under simulated physiological conditions, facilitated by their surface nucleation properties, controlled degradation, and sustained Li⁺ and Ca²⁺ ion release. Cytocompatibility assays confirmed excellent pre-osteoblast adhesion and viability. Furthermore, CaMOF nanoparticles stimulated osteogenic differentiation by enhancing alkaline phosphatase (ALP) activity, even in the absence of osteogenic supplements. Among tested MOFs, Li/CaMOF exhibited the highest osteoinductive potential. These findings highlight lithium-modified MOFs as promising biomaterials for bone regeneration. However, further in vivo studies are necessary to assess their long-term stability, bone integration, and clinical applicability.