Ca/P coated SMP as filler of bone defects in mini-invasive surgical procedures

Repair of bone defects could greatly benefit from fillers made of Shape Memory Polymers (SMPs), since they possess the ability to modify their shape after implant, therefore enabling to perform minimally invasive surgical procedures. To be successfully applied as a bone filler, SMPs should also promote osteointegration by Ca/P deposition onto their surface. This work was aimed at investigating the effectiveness of a biomimetic process for apatite deposition on Calo•MER™ 40, a commercially available SMP, and at evaluating the in vitro interactions between the modified surface and osteoblast-like cells. Calo•MER™ 40 underwent a Ca/P coating treatment by immersion into Simulated Body Fluid (SBF) for up to 14 days. The properties of SBF-treated Calo•MER 40 were then evaluated by DMA, SEM, and EDX analysis. Calo•MER™ 40 showed the ability of forming a homogeneous Ca/P layer onto its surface without alteration of its thermo mechanical properties. Adhesion and proliferation tests were performed onto 14 days SBF-treated samples with human osteosarcoma MG63 cells. Cell morphology was evaluated by SEM, and cell viability by appropriate biochemical tests. Results showed a good cytocompatibility, with a time-dependent increase in cell proliferation and activity. These preliminary results show promising interface properties of Calo•MER™ 40 for its use as bone filler in mini-invasive surgical procedures.