With the rapid development of 3D printing technology, porous titanium scaffolds have provided a new restoration method to repair bone defects. Compared with the traditional body-centered cubic (bcc) dot matrix structure with a simple arrangement and repetitive structure, the topology-driven properties of triply periodic minimal surfaces (TPMS) can offer a continuous surface and smooth curvature, an excellent platform for cell proliferation. In this study, we used reverse engineering techniques to model the mandible. Sheet and solid networks of gyroid structure, the most common type of TPMS, were selected for porous design and then molded using metal 3D printing technology. At the same time, the surface treatment parameters of sandblasted, large-grit, and acid-etched (SLA) were optimized by orthogonal experimental design. Then, the optimized SLA parameter was used to treat the gyroid with 70% porosity. The result showed that reverse engineering reconstructed the TPMS-based mandibular model had good formability. Furthermore, the best surface morphology, wettability, and roughness were obtained for 3D printed Ti6Al4V under the treatment of 80 mesh Al2O3, blasting distances of 4 cm, and a 1:1:2 acid ratio. Moreover, the mechanical properties of Sheet-Gyroid and Solid-Gyroid were significantly different at 70% porosity. The porosity of the scaffolds was close to the design porosity after SLA treatment. However, no significant changes were found in its mechanical properties, all matching the mandible’s mechanical properties to meet the implantation conditions.
In this work, TiNi samples were prepared by Selective Laser Melting (SLM) technology, and the influence of microstructure, fluoride ion, and pH value on corrosion behavior in a saline environment was investigated and compared with TiNi alloy fabricated by traditional forging technology. The results indicated that the corrosion resistance of the SLM sample was slightly superior to that of the wrought sample in a saline environment due to the uniform and dense oxide film formed on the SLM sample surface. However, in acidic Artificial Saliva Solution (ASS) containing fluoride ions, the corrosion current density of the SLM sample increased from 9.85 × 10−2 to 13.9 μA/cm2 because of the presence of F−. Fluorine ions disrupted the passive film on the surface, and the Ti-F compound formed in the film, which deteriorated the corrosion resistance of the SLM sample. The increase in fluoride concentration and the decrease in pH value could accelerate the corrosion of the SLM sample.
To investigate the ability of novel Gyroid-shaped titanium alloy (TC4) porous bioscaffolds to induce angiogenesis and osteogenesis in bone defect areas. This study employed selective laser melting (SLM) technology to fabricate Gyroid shaped and Cube-shaped TC4 porous bioscaffolds, using the commonly used cube shape as a control. The unit cell size was 4 mm, with a wall thickness or rod diameter of 300 μm and a porosity of approximately 80%. These scaffolds were implanted into rabbit mandibular defect sites (10 mm × 7 mm × 5 mm) to evaluate the angiogenic and osteogenic potential of the Gyroid-shaped scaffold. Material characterization revealed that sandblasted and acid-etched (SLA) TC4 scaffolds met design specifications, exhibiting uniformly distributed micrometer-scale pores and enhanced surface hydrophilicity. Histological staining revealed that compared to the Cube-shaped scaffold, the Gyroid-shaped scaffold induced greater angiogenesis and new bone formation within the bone defect area. Both scaffolds demonstrated good biocompatibility. Western Blot and RT-qPCR results indicated that the Gyroid-shaped scaffold possessed superior angiogenesis potential (compared to the Cube-shaped scaffold). During the early implantation phase (1-2 weeks), Gyroid-shaped scaffolds exhibited higher expression of platelet-endothelial cell surface adhesion molecule 1 (CD31) and endothelial mucin (EMCN). Concurrently, vessel distribution within the scaffold showed spatial variation. Additionally, gene expression of hypoxia-inducible factor 1α (HIF-1α) and vascular endothelial growth factor A (VEGFA) was elevated in the early bone defect area. Imaging analysis confirmed successful implantation of both scaffolds, with the Gyroid-shaped scaffold exhibiting a higher proportion of new bone formation. Consequently, the novel Gyroid-shaped TC4 porous bioscaffold demonstrates excellent potential for angiogenesis and osteogenesis, providing a reference for Gyroid-shaped scaffold-based bone defect repair.
Background: Titanium implant osseointegration is hierarchically governed by surface properties directing protein adsorption, cell recognition, immune modulation, and bone formation. Photofunctionalization creates ultrahydrophilic surfaces by removing hydrocarbons. To integrate it with 3D-printed architectures requires systematic synthesis. Problem: The classical static view of osseointegration obscures its dynamic, multiscale nature. How photofunctionalization-induced ultrahydrophilicity modulates the surface–protein–cell–bone interface as a continuous, hierarchical system remains unclear. Scope: This review synthesizes evidence on how photofunctionalized ultrahydrophilic titanium surfaces control protein adsorption, integrin-mediated mechanotransduction, immune responses, and in vivo osseointegration, with an emphasis on 3D-printed porous architectures. Conclusions: Photofunctionalization enhances protein adsorption, preserves bioactive conformation, and stabilizes protein layers, selectively engaging osteogenic integrins and amplifying FAK–Src/YAP–TAZ signaling. In 3D-printed implants, ultrahydrophilicity enables capillary-driven fluid infiltration and uniform bone ingrowth. Through this review, knowledge gaps—in surface aging and limited in situ characterization—are identified, and an interface-informed design integrating surface chemistry, architecture, and biological timing is proposed.