Advancing bone biomaterial design: exploring outer microtopography and multi-BSTM membrane production from a single bone source

Bone tissue's complex microstructure has inspired the design of biomaterials, yet most approaches focus on replicating its internal structure while neglecting the outer surface topography. This study addresses this gap by developing bone surface topography-mimicked (BSTM) Poly-L-Lactic Acid (PLLA) membranes using by using Polydimethylsiloxane (PDMS) with the soft lithograph technique. Then, bone surface topography mimicked (BSTM) Poly-L-Lactic acid (PLLA) membranes were produced via the solvent casting method, and the procedure was optimized. One hundred BSTM-PLLA membranes were produced from a single bone region using our optimized method. Subsequently, Bone Morphogenic Protein-2 (BMP-2) was loaded as a model growth factor, and diclofenac was loaded as a model drug on the BSTM-PLLA membranes. BSTM-PLLA membranes were modified with collagen type-I (Coll-I) or hydroxyapatite (HAp) to mimic bone`s natural microenvironment more effectively. Surface topography influenced drug release and degradation rates, with BSTM-PLLA membranes exhibiting more controlled release profiles. Characterization studies were followed by cell culture studies using human adipose derived mesenchymal stem cells (ADMSCs). The viability of the ADMSCs on BSTM-PLLA membranes was higher than that of plain PLLA (P-PLLA) membranes. Our findings underscore the potential of BSTM-PLLA membranes for enhanced cell viability, bone regeneration, and drug delivery applications.

The soft lithography technique using PDMS enables accurate replication of bone structures, allowing for the creation of advanced biomaterials that mimic both the surface and biochemical features of natural bone, essential for effective bone repair.From a single bone piece, we efficiently produced 100 BSTM-PLLA membranes, showcasing a high yield in membrane manufacturing.The successful modification of biomimetic membranes with hydroxyapatite (HAp) and collagen type I (Coll-I) enhances their similarity to natural bone microenvironment.The effective loading of bone morphogenetic protein-2 (BMP-2) and diclofenac into these biomimetic membranes underscores their versatility for therapeutic applications.