Enhancing the mechanical properties and surface morphology of individualized Ti-mesh fabricated through additive manufacturing for the treatment of alveolar bone defects.

Titanium meshes are widely utilized in alveolar bone augmentation, and this study aims to enhance the properties of titanium meshes through heat treatment (HT) and the synergistic finishing technology of electric field and flow field (EFSF). Our findings illustrate that the titanium mesh exhibits improved mechanical properties following HT treatment. The innovative EFSF technique, in combination with HT, has a substantial impact on improving the surface properties of titanium meshes. HT initiates grain fusion and reduces surface pores, resulting in enhanced tensile and elongation properties. EFSF further enhances these improvements by significantly reducing surface roughness and eliminating adhered titanium powder, a byproduct of selective laser melting printing. Increased hydrophilicity and surface-free energy are achieved after EFSF treatment. Notably, the EFSF-treated titanium mesh exhibits reduced bacterial adhesion and is non-toxic to osteoblast proliferation. These advancements increase its suitability for clinical alveolar bone augmentation.

Bioprinted PDLSCs with high-concentration GelMA hydrogels exhibit enhanced osteogenic differentiation in vitro and promote bone regeneration in vivo.

OBJECTIVES: We aimed to explore the osteogenic potential of periodontal ligament stem cells (PDLSCs) in bioprinted methacrylate gelatine (GelMA) hydrogels in vitro and in vivo. MATERIALS AND METHODS: PDLSCs in GelMA hydrogels at various concentrations (3%, 5%, and 10%) were bioprinted. The mechanical properties (stiffness, nanostructure, swelling, and degradation properties) of bioprinted constructs and the biological properties (cell viability, proliferation, spreading, osteogenic differentiation, and cell survival in vivo) of PDLSCs in bioprinted constructs were evaluated. Then, the effect of bioprinted constructs on bone regeneration was investigated using a mouse cranial defect model. RESULTS: Ten percent GelMA printed constructs had a higher compression modulus, smaller porosity, lower swelling rate, and lower degradation rate than 3% GelMA. PDLSCs in bioprinted 10% GelMA bioprinted constructs showed lower cell viability, less cell spreading, upregulated osteogenic differentiation in vitro, and lower cell survival in vivo. Moreover, upregulated expression of ephrinB2 and EphB4 protein and their phosphorylated forms were found in PDLSCs in 10% GelMA bioprinted constructs, and inhibition of eprhinB2/EphB4 signalling reversed the enhanced osteogenic differentiation of PDLSCs in 10% GelMA. The in vivo experiment showed that 10% GelMA bioprinted constructs with PDLSCs contributed to more new bone formation than 10% GelMA constructs without PDLSCs and constructs with lower GelMA concentrations. CONCLUSIONS: Bioprinted PDLSCs with high-concentrated GelMA hydrogels exhibited enhanced osteogenic differentiation partially through upregulated ephrinB2/EphB4 signalling in vitro and promoted bone regeneration in vivo, which might be more appropriate for future bone regeneration applications. CLINICAL RELEVANCE: Bone defects are a common clinical oral problem. Our results provide a promising strategy for bone regeneration through bioprinting PDLSCs in GelMA hydrogels.