Customized bioceramic scaffolds and metal meshes for challenging large-size mandibular bone defect regeneration and repair

Abstract

Large-size mandible graft has huge needs in clinic caused by infection, tumor, congenital deformity, bone trauma and so on. However, the reconstruction of large-size mandible defect is challenged due to its complex anatomical structure and large range bone injury. The design and fabrication of porous implants with large segments and specific shapes matching the native mandible remains a considerable challenge. Herein, the 6% Mg-doped calcium silicate (CSi-Mg6), β- and α-tricalcium phosphate (β-TCP, α-TCP) bioceramics were fabricated by digital light processing (DLP) as the porous scaffolds of over 50% in porosity, while the titanium mesh was fabricated by selective laser melting (SLM). The mechanical tests showed that the initial flexible/compressive resistance of CSi-Mg6 scaffolds was markedly higher than that of β-TCP and α-TCP scaffolds. Cell experiments showed that these materials all had good biocompatibility, while CSi-Mg6 significantly promoted cell proliferation. In the rabbit critically sized mandible bone defects (∼13 mm in length) filled with porous bioceramic scaffolds, the titanium meshes and titanium nails were acted as fixation and load bearing. The results showed that the defects were kept during the observation period in the blank (control) group; in contrast, the osteogenic capability was significantly enhanced in the CSi-Mg6 and α-TCP groups in comparison with the β-TCP group, and these two groups not only had significantly increased new bone formation, but also had thicker trabecular and smaller trabecular spacing. Besides, CSi-Mg6 and α-TCP groups showed appreciable material biodegradation in the later stage (from 8 to 12 weeks) in comparison with the β-TCP scaffolds while CSi-Mg6 group showed much outstanding mechanical capacity in vivo in the early stage compared to β-TCP and α-TCP groups. Totally, these findings suggest that the combination of customized strength-strong bioactive CSi-Mg6 scaffolds together with titanium meshes is a promising way for repairing the large-size load-bearing mandible defects.

Influence of Ag and/or Sr Dopants on the Mechanical Properties and In Vitro Degradation of β-Tricalcium Phosphate-Based Ceramics

“…However, the clinical application of HA synthesis is limited by poor mechanical properties, poor chemical stability and poor thermal stability in acidic environments [10]. By contrast, β-tricalcium phosphate (β-TCP, Ca 3 (PO4) 2 ) has high bioactivity and excellent osteoconductivity, and is a promising candidate for bone repair [10][11][12][13]. Numerous evaluations have shown that β-TCP imposes a positive effect on cell attachment, differentiation and proliferation [14][15][16][17].…”