Novel Bio-functional Magnesium Coating on Porous Ti6Al4V Orthopaedic Implants: In vitro and In vivo Study

Abstract

Titanium and its alloys with various porous structures are one of the most important metals used in orthopaedic implants due to favourable properties as replacement for hard tissues. However, surface modification is critical to improve the osteointegration of titanium and its alloys. In this study, a bioactive magnesium coating was successfully fabricated on porous Ti6Al4V by means of arc ion plating, which was proved with fine grain size and high film/substrate adhesion. The surface composition and morphology were characterized by X-ray diffraction and SEM equipped with energy dispersive spectroscopy. Furthermore, the in vitro study of cytotoxicity and proliferation of MC3T3-E1 cells showed that magnesium coated porous Ti6Al4V had suitable degradation and biocompatibility. Moreover, the in vivo studies including fluorescent labelling, micro-computed tomography analysis scan and Van-Gieson staining of histological sections indicated that magnesium coated porous Ti6Al4V could significantly promote bone regeneration in rabbit femoral condylar defects after implantation for 4 and 8 weeks, and has better osteogenesis and osteointegration than the bare porous Ti6Al4V. Therefore, it is expected that this bioactive magnesium coating on porous Ti6Al4V scaffolds with improved osteointegration and osteogenesis functions can be used for orthopedic applications.

Effects of magnesium coating on bone‐implant interfaces with and without polyether‐ether‐ketone particle interference: A rabbit model based on porous Ti6Al4V implants

“…This result is inconsistent with our previous results, which indicated that Mg-coated porous Ti6Al4V had better osteogenesis and osteointegration properties than bare porous Ti6Al4V. 15 However, in this study, the porous substrate was relatively smaller than that in our previous work, which means this structure was easily filled with osteoblasts without the help of the Mg coating. In other words, the osteogenic ability of Mg may not have been completely demonstrated in this study.…”

“…It was speculated that the porous structure itself could enhance osteogenesis, which may explain why there was no difference between the porous structures of the Mg and control groups—the Mg coating may not further enhance osteogenesis. This result is inconsistent with our previous results, which indicated that Mg‐coated porous Ti6Al4V had better osteogenesis and osteointegration properties than bare porous Ti6Al4V . However, in this study, the porous substrate was relatively smaller than that in our previous work, which means this structure was easily filled with osteoblasts without the help of the Mg coating.…”

Comprehensive Evaluation of the Biological Properties of Surface-Modified Titanium Alloy Implants

“…However, low osteoconduction and integration of titanium-based implants with the bone for long-term survival, their weak anti-inflammatory properties, and the possibility of toxic components releasing into the human body requires surface modification and the formation of a layer, which significantly eliminates these above-mentioned adverse factors. These surface modifications can be carried out into two ways: (a) The roughness and wettability changes of the titanium implants' surface, which can stimulate a durable connection between the implant and the bone [9][10][11]; and (b) the formation of bioactive coatings, which accelerate bone formation (e.g., hydroxyapatite layers [12,13]) or increase their biocidal activity (e.g., bio-functional magnesium coating, as well as silver nanoparticles [14][15][16]). The formation of an oxide layer (passivation layer) on the surface of titanium/titanium alloy implants, which is practically insoluble and largely responsible for their high corrosion resistance and biocompatibility, is an important way to approach implants' surface modification [17].…”

Characteristics and Efficacy of a New 3-Dimensional Printed Mesh Structure Titanium Alloy Spacer for Posterior Lumbar Interbody Fusion

“…9,10,21 Porous titanium devices have been reported to promote bone ingrowth, provide initial fixation stability, and achieve intersegmental fusion in many orthopedic departments. 11,13,22 However, few studies have shown their efficacy and safety in spinal surgery. 23 This study found that posterior lumbar interbody fusion with 3-dimensional printed mesh structure titanium alloy spacers showed satisfactory radiographic and clinical results without significant complications.…”

“…Porous titanium alloy offers greater contact area between the bone and implants as well as bone ingrowth and a high coefficient of friction that can improve initial segmental stability. [11][12][13] These implants provide mechanical support during the early postoperative stage, induce recovery of lordosis, and achieve higher fusion rates that are similar to those for autogenous bone grafts. However, few studies have assessed the efficacy of mesh structure titanium alloy implants during spinal surgery.…”