Osteoimmunomodulation refers to the regulation of immune responses to enhance bone healing. Research in osteoimmunology has shown that immune cells play a vital role in bone repair, which is often overlooked in traditional approaches, leading to inconsistencies between lab and in vivo results. A supportive osteo-immune environment is essential for effective bone regeneration, with biomaterial properties like surface charge, porosity, wettability, and bioactive ion release significantly influencing cell behaviour, including adhesion, proliferation, and immune cell response.

This study explores how the topographical and chemical properties of bone-mimicking surfaces affect cellular behaviour, specifically focusing on osteogenic differentiation and immune modulation. Poly-L-Lactic Acid (PLA) membranes, designed to replicate natural bone features using soft lithography, were further modified with collagen type I and hydroxyapatite (HA) for enhanced functionality. Results show that HA-deposited BSM PLA membranes significantly promoted osteogenic differentiation in adipose-derived mesenchymal stem cells (ADMSCs) and supported sequential M1/M2 polarization in RAW 264.7 macrophages. These findings demonstrate the potential of HA-modified bone-mimicking membranes to stimulate bone regeneration and support an osteoimmune response, providing a promising direction for future biomaterials research.