Development and properties of duplex MgF2/PCL coatings on biodegradable magnesium alloy for biomedical applications

Abstract

The present work addresses the performance of polycaprolactone (PCL) coating on fluoride treated (MgF2) biodegradable ZK60 magnesium alloy (Mg) for biomedical application. MgF2 conversion layer was first produced by immersing Mg alloy substrate in hydrofluoric acid solution. The outer PCL coating was then prepared using dip coating technique. Morphology, elements profile, phase structure, roughness, mechanical properties, invitro corrosion, and biocompatibility of duplex MgF2/PCL coating were then characterized and compared to those of fluoride coated and uncoated Mg samples. The invivo degradation behavior and biocompatibility of duplex MgF2/PCL coating with respect to ZK60 Mg alloy were also studied using rabbit model for 2 weeks. SEM and TEM analysis showed that the duplex coating was uniform and comprised of porous PCL film (~3.3 μm) as upper layer with compact MgF2 (~2.2 μm) as inner layer. No significant change in microhardness was found on duplex coating compared with uncoated ZK60 Mg alloy. The duplex coating showed improved invitro corrosion resistance than single layered MgF2 or uncoated alloy samples. The duplex coating also resulted in better cell viability, cell adhesion, and cell proliferation compared to fluoride coated or uncoated alloy. Preliminary invivo studies indicated that duplex MgF2/PCL coating reduced the degradation rate of ZK60 Mg alloy and exhibited good biocompatibility. These results suggested that duplex MgF2/PCL coating on magnesium alloy might have great potential for orthopedic applications.

Degradation, Bone Regeneration and Tissue Response of an Innovative Volume Stable Magnesium-Supported GBR/GTR Barrier Membrane

“…As a promising surface modification for the delay of premature degradation, and thus, hydrogen release, hydrofluoric acid (HF)-treatments and the resulting magnesium fluoride (MgF 2 )-layers have been previously investigated for a broader range of applications, varying from orthopedic to cardiovascular and oropharyngeal applications [47][48][49]. Thereby, a generally higher corrosion resistance could be detected [37,[47][48][49][50][51][52][53][54][55]. Therefore, the combination of a magnesium mesh embedded in a native collagen membrane allows volume-stable interventions and complete biodegradation.…”

“…Closer examination of inflammatory relationships (e.g., the involvement of different cell types and the alignment of macrophages) could also be of interest for further development of this material class [19]. Finally, the direct comparison or amplification of other surface modifications such as duplex-(MgF 2 /PCL) [50], nanocomposite- [73] and composite-coatings [51,74] as well as the extension of other magnesium alloys [47][48][49][50][51][75][76][77][78][79][80][81] should be investigated and might promise new results in the future. Overall, especially in comparison with other studies, there is further need for simplification and standardization of in vitro and in vivo studies of magnesium-based materials.…”

A surface-eroding poly(1,3-trimethylene carbonate) coating for magnesium based cardiovascular stents with stable drug release and improved corrosion resistance

“…The surface of magnesium alloys has been first modified by fluoride treatment to promote the formation of a Mg(OH) x F 2-x layer [ 35 ]. It can increase the corrosion resistance of magnesium substrate and can be used as a pretreatment process to improve the adhesion of PLA [ 36 , 37 ], PCL [ 38 , 39 ] and PEI [ 40 ] on magnesium substrate. After that, the fluoride surface has been modified via the introduction of amine groups through a combination of plasma and silane treatment.…”

An in vivo comparative study of the gelatin microtissue‐based bottom‐up strategy and top‐down strategy in bone tissue engineering application

“…Five male adult Sprague Dawley rats (age: 1 months; weight: 200–250 g) supplied by the Laboratory Animal Center of Huazhong University of Science and Technology were subjected to a distress protocol before the surgical procedures, in which each rat was kept in a separate cage for 1 day. Rats were anesthetized with intraperitoneal injection of Ketamine (90 mg/kg) and xylazine (9 mg/kg) . On the back of each rat, four subcutaneous pockets were created by drawing a straight line followed by the middle line.…”

“…Rats were anesthetized with intraperitoneal injection of Ketamine (90 mg/kg) and xylazine (9 mg/kg). 22 On the back of each rat, four subcutaneous pockets were created by drawing a straight line followed by the middle line. Subcutaneous tissues were separated from the skin to cover the TEBGs, thus preventing the leakage of TEBGs to surrounded tissues.…”