# Three-dimensional-printed triply periodic minimal surface scaffolds via digital light processing for enhanced osteogenesis

## TL;DR

Researchers created 3D-printed bone scaffolds using triply periodic minimal surfaces and bioactive glass to improve bone regeneration and cell growth.

## Contribution

A novel heterogeneous scaffold combining I and G TPMS units with Sr-doped bioactive glass is developed for enhanced osteogenesis.

## Key findings

- The IG scaffolds achieved a compressive strength of 5.8 ± 0.6 MPa and porosity of ∼63%, matching cancellous bone parameters.
- The scaffolds promoted adhesion, proliferation, and differentiation of bone mesenchymal stem cells.
- Osteogenic ability was confirmed in a rabbit femoral condylar defect model.

## Abstract

Natural bone is a naturally mineralized material with a nonhomogeneous porous structure, which is difficult to construct using conventional manufacturing methods. Triply periodic minimal surfaces (TPMS) have emerged as an excellent solution in recent years for constructing porous artificial bone structures, characterized by smooth surfaces, highly interconnected porous structures and mathematically controllable geometries. In this work, digital light processing (DLP) printing technology was used to construct a nonhomogeneous TPMS structure with strontium-doping 13-93 bioactive glass (Sr@BG) prepared by fusion method. The heterogeneous scaffolds were obtained by integrating high-strength I-wrapped package (I) and high-permeability Gyroid (G) units behaving a sufficient compressive strength of 5.8 ± 0.6 MPa, a porosity of ∼63% and a permeability of 0.97 × 10−8 m2, which matched the microstructural parameters of cancellous bone. Meanwhile, the biomimetic structure and Sr doping could cooperatively promote the adhesion, proliferation and differentiation of bone mesenchymal stem cells (BMSCs). In addition, the osteogenic ability of IG scaffolds was verified in rabbit’s femoral condylar defect. In general, heterogeneous IG scaffolds possess desirable bioactivity and mechanical property which meet the functional and structural requirements of bone regeneration.