Effect of micro-arc oxidation surface modification of 3D-printed porous titanium alloys on biological properties

Abstract

Background: Three-dimensional (3D) printing technology has been widely used in orthopedics; however, it is still limited to the change of macroscopic structures. In order to further improve the biological properties of 3D-printed porous titanium scaffolds, this study introduced micro-arc oxidation (MAO) technology to modify the surface of porous titanium scaffolds and construct bioactive coatings on the surface of porous titanium scaffolds to improve the biocompatibility and osseointegration ability of the material.Methods: For in vitro experiments, human bone marrow stem cells (hBMSCs) were seeded onto untreated scaffolds (control group) and MAO-treated scaffolds (experimental group). After 24 h of co-culture, cytotoxicity was observed using live/dead staining, and cell/scaffold constructs were retrieved and processed for the assessment of cell morphology by using scanning electron microscopy (SEM). Cell proliferation was detected using the Cell Counting Kit-8 (CCK-8) assay after 3, 7, and 14 days of co-culture. The levels of alkaline phosphatase (ALP) in the cell supernatant were detected after 7 and 14 days of co-culture. For in vivo experiments, micro-computed tomography (micro-CT) and Masson Goldner's staining were used to evaluate bone ingrowth and osseointegration at 4 and 8 weeks postoperatively.Results: In vitro experiment results confirmed that the two groups of scaffolds were non-cytotoxic and the cell adhesion status on the MAO-treated scaffolds was better. Over time, cell proliferation and ALP levels were higher in the MAO-treated group than in the untreated scaffolds. In the in vivo experiments, the MAOtreated scaffolds showed better bone ingrowth and osseointegration than the untreated group at different time points. Conclusions:The MAO-treated porous titanium scaffold formed a uniform and dense bioactive coating on the surface, which was more conducive to cell adhesion, proliferation, and differentiation and showed better osseointegration and bone ingrowth in vivo.

Influence of Ultrasound on the Characteristics of CaP Coatings Generated Via the Micro-arc Oxidation Process in Relation to Biomedical Engineering

“…In the case of sample 136_450_n, the number of cells on the appropriate days of incubation was lower than that in the case of sample 136_450_rec. The cells are distributed more evenly on the UMAO coating than on the MAO coating, which may be related to the greater porosity and regularity of the microstructure of the UMAO coating . The cells are characterized by different morphologies depending on the incubation time.…”

Remote Eradication of Bacteria on Orthopedic Implants via Delayed Delivery of Polycaprolactone Stabilized Polyvinylpyrrolidone Iodine

“…The characterization results, surface morphology, and chemical composition of the coatings proved that the hybrid MAO-I 2 -PCLx coatings (x = 1, 2, 3) were successfully developed on the titanium alloy surface. After the micro-arc oxidation treatment, the titanium alloy gains a surface with a rich porous structure [ 38 , 39 ]. As the atomic force microscope showed, the surface roughness of the MAO substrate increases significantly, which creates a structural basis for the electrophoretic loading of iodine and the combination of the PCL coating in the later stage [ 40 , 41 , 42 ].…”

Micro-arc oxidation (MAO) and its potential for improving the performance of titanium implants in biomedical applications

“…Similar experiments have shown that 8 weeks after the placement of Ti implants in adult rabbits, the pure Ti surface was still covered with fibrous tissue, while new bone formed on the surface of the titanium implants with MAO coating (Zhao et al, 2020). Other experiments have shown that MAO-coated implants have better bone-to-implant contact and coverage area attached to the implant, the highest density of newly grown paragenetic bone tissue, and can withstand greater shear (Chen et al, 2021;Ding et al, 2022;Ni et al, 2022). Wang et al's study demonstrated good osseointegration of the MAO coating was found by observing gross observation and micro-CT reconstruction of the femoral condyle after implant implantation and new bone formation was observed by toluidine blue and fuchsia-methylene blue staining.…”