Rational Design and Fabrication of Porous Calcium–Magnesium Silicate Constructs That Enhance Angiogenesis and Improve Orbital Implantation

Tissue integration of orbital implants, following orbital enucleation treatment, represents a challenge for rapid fibrovascularization, long-time stability, anti-infection, and even induction of vascule regeneration. The objective of this study was to develop porous calcium-magnesium silicate materials, with good stability, bioactivity, and antibacterial potential as new orbital fillers. Three-dimensional (3D) diopside scaffolds (low dissolvability) were fabricated by direct ceramic ink writing assembly and then followed by one-step sintering at 1150 °C for 3 h. The pore wall of the scaffold was modified by another calcium-magnesium silicate, such as bredigite or akermanite, which dissolves quickly but shows greater angiogenic potential. These two Ca-Mg-silicates can be coated onto the pore strut, and the coating layers were observed to slowly dissolve in Tris buffer. The vascularization-favorable Cu ions, which had been doped into the bredigite or akermanite coating, could also be measured in the immersion medium. A primary angiogenic test in a panniculus carnosus muscle model in rabbit indicated that the Cu-doped bredigite and akermanite coatings were significantly beneficial for the neovascularization in the early stages. These results suggest that the diopside-based porous materials modified with functional coatings hold great potential for application in orbital reconstruction.