Precisely Tuning the Pore-Wall Surface Composition of Bioceramic Scaffolds Facilitates Angiogenesis and Orbital Bone Defect Repair

Abstract

Orbital bone damage (OBD) may result in severe post-traumatic enophthalmos, craniomaxillofacial deformities, vision loss, and intracranial infections. However, it is still a challenge to fabricate advanced biomaterials that can match the individual anatomical structure and enhance OBD repair in situ. Herein, we aimed to develop a selective surface modification strategy on bioceramic scaffolds and evaluated the effects of inorganic or organic functional coating on angiogenesis and osteogenesis, ectopically and orthotopically in OBD models. It was shown that the low thermal bioactive glass (BG) modification or layer-by-layer assembly of a biomimetic hydrogel (Biogel) could readily integrate into the pore wall of the bioceramic scaffolds. The BG and Biogel modification showed appreciable enhancement in the initial compressive strength (∼30−75%) or structural stability in vivo, respectively. BG modification could enhance by nearly 2-fold the vessel ingrowth, and the osteogenic capacity was also accelerated, accompanied with a mild scaffold biodegradation after 3 months. Meanwhile, the Biogel-modified scaffolds showed enhanced osteogenic differentiation and mineralization through calcium and phosphorus retention. The potential mechanism of the enhanced bone repair was elucidated via vascular and osteogenic cell responses in vitro, and the cell tests indicated that the Biogel and BG functional layers were both beneficial for in vitro osteoblastic differentiation and mineralization on bioceramics. Totally, these findings demonstrated that the bioactive ions or biomolecules could significantly improve the angiogenic and osteogenic capabilities of conventional bioceramics, and the integration of inorganic or organic functional coating in the pore wall is a highly flexible material toolbox that can be tailored directly to improve orbital bone defect repair.

Silicon-containing nanomedicine and biomaterials: materials chemistry, multi-dimensional design, and biomedical application

“…444 Recently, Peng et al developed a selective surface modification strategy of coating inorganic or organic components on Mg-substituted wollastonite scaffolds and evaluated the corresponding effects on angiogenesis and osteogenesis. 445 The BG coating exhibited appreciable angiogenic capability. Alternatively, a layer-by-layer coating technique involving biomimetic gels demonstrated superior intramembranous osteogenic capabilities.…”

Efforts to promote osteogenesis–angiogenesis coupling for bone tissue engineering

“…Bioceramics were a major kind of bulk materials. For example, Peng Y et al 45 applied two types of coating (low thermal bioglass and hyaluronic acid-chitosan biogel) on bioceramic scaffolds (CSi-Mg10) to enhance the performances of osteogenesis and angiogenesis. The results showed that both the bioglass and the biogel coatings could integrate well into the surface pore structure of the scaffolds, thus significantly enhancing their compressive strength and structural stability.…”

A triphasic biomimetic BMSC-loaded scaffold for osteochondral integrated regeneration in rabbits and pigs

“…41 Based on these results, the 3Dprinted CSi-Mg6 scaffold alone was planted for bone defect and orbital reconstruction, and the vascularization efficacy was evaluated via μ-CT and H&E staining. 43,44 It has been found that the porous bioceramic scaffold has good structural stability, biodegradation, vascular cell migration and vascular inward growth at 4 weeks. The percentage of vessel area, vessel density and mean vessel diameter in the porous scaffold increases with time.…”