Digital light processing strength-strong ultra-thin bioceramic scaffolds for challengeable orbital bone regeneration and repair in Situ

The orbital fracture regeneration and reconstruction is still a catastrophic challenge due to the extremely thin anatomical structure and different defect shapes in various clinical conditions. The conventional bio-materials and preparation technique are often inefficient in satisfying porous scaffold architecture designs with respect to their required structural stability and biological performances. Here we developed the ultrathin scaffolds with high-precision pore structure and appreciable osteogenic activity for orbital bone repair via digital light processing (DLP) stereolithography. The dilute magnesium-substituting wollastonite (CSi-Mg) bioceramic scaffolds of similar to 1.5 mm in thickness and over 60% in porosity were investigated systematically, and compared with another calcium-magnesium silicate (i.e. akermanite) and the pure wollastonite porous counterparts. The results showed that the flexural strengths (similar to 6-22 MPa) and in vitro biodegradation of such bioceramic scaffolds could be tuned during their chemical composition (i.e. Mg content) design stage, and the CSi-Mg scaffolds were also beneficial for osteogenic cell activity in vitro. In particular, the CSi-Mg scaffolds could readily enhance the new bone ingrowth at 4 weeks of implantation in a critical-sized rabbit orbital bone defect model, and such strength-strong scaffolds exhibited outstanding orbital defect repair efficacy after 12 weeks of implantation, in comparison with the structural instability of other scaffolds. Basically, it is demonstrated that the dilute magnesium doping in wollastonite bioceramic can be favorable for developing the mechanically reliable scaffolds with high porosity and bioactivity but quite thin wall morphology, and meanwhile the DLP-assisted additive manufacturing help us to optimize such porous bioceramic design with respect to their required structural stability for orbital bone reconstruction. (C) 2020 Published by Elsevier Ltd.

Automated summary

Ultrathin scaffolds with high-precision pore structure and appreciable osteogenic activity were developed for orbital bone repair using digital light processing (DLP) stereolithography. Magnesium-substituting wollastonite (CSi-Mg) bioceramic scaffolds exhibited tunable mechanical properties and enhanced osteogenic activity, promoting new bone ingrowth and efficient repair of orbital bone defects in rabbits. This study demonstrates the potential of dilute magnesium doping in bioceramic for developing mechanically reliable scaffolds with high porosity and bioactivity for orbital bone reconstruction.