| 초록 |
Magnesium alloys are considered to be promising materials for implant application due to their excellent biocompatibility, biodegradability, and mechanical properties close to bone. However, low corrosion resistance and fast degradation are limiting their application. Mg alloys have huge potential owing to a similar density to bone, good corrosion resistance. The introduction of a protective coating layer to highly corrosive magnesium (Mg) has been proposed as one of the common approaches for improved corrosion resistance of Mg-based implants as load-bearing biomedical applications. This work addresses the performance of PLLA coating with simvastatin drug on Ca-Sr-P coated biodegradable Zn60 magnesium alloy (Mg) for biomedical application. It has been proven Sr-containing calcium phosphate biomaterials can promote better preosteoblastic cells attachment and proliferation than pure calcium phosphate biomaterials. PLLA immobilized simvastatin sustain release from the alloy to implant site. Microstructural evolutions for coated alloys were characterized by optical, SEM, EDX, and XRD. In vitro degradation tests were conducted via immersion test in phosphate buffer saline solution. Ca-Sr-P conversion layer was first produced by immersing Mg alloy substrate in salt solution. The outer PLLA-simvastatin coating was then prepared using dip coating technique. This duplex coating showed improved in vitro corrosion resistance than single layered uncoated alloy samples. The duplex coating also resulted in better cell viability, cell adhesion, and cell proliferation compared to uncoated alloy. The result suggest that Mg alloy could be used as a temporary biodegradable implant material for clinical applications owing to its controlled in vivo degradation, reduced inflammation, and high bone-formation capability. |
