Digital Light Processing (DLP) of Nano Biphasic Calcium Phosphate Bioceramic for Making Bone Tissue Engineering Scaffolds

Abstract

<p>Nano-sized ceramic particles are beneficial for the properties of 3D printed structures via digital light processing (DLP). However, achieving optimal conditions for the preparation and processing of ceramic nanoparticle-based slurry is a significant challenge. In this work, a stable and well dispersed slurry with nano-sized <a href="https://www.sciencedirect.com/topics/materials-science/biphasic-calcium-phosphate" title="Learn more about biphasic calcium phosphate from ScienceDirect's AI-generated Topic Pages">biphasic calcium phosphate</a> (BCP) powders was developed and porous BCP <a href="https://www.sciencedirect.com/topics/materials-science/bioceramic" title="Learn more about bioceramic from ScienceDirect's AI-generated Topic Pages">bioceramic</a> scaffolds with good bioactivity were accurately fabricated via the DLP <a href="https://www.sciencedirect.com/topics/materials-science/three-dimensional-printing" title="Learn more about additive manufacturing from ScienceDirect's AI-generated Topic Pages">additive manufacturing</a> technology. Effects of dispersant, photoinitiator and solid loading on rheological properties and curing abilities of BCP slurries were systematically studied. The slurry having 65 wt % of nano-sized BCP powders showed a relatively low viscosity of 400 mPa s at the 50 s⁻¹ shear rate. It was found that the optimal photoinitiator concentration was tightly associated with the energy dosage in DLP. Furthermore, the effects of <a href="https://www.sciencedirect.com/topics/materials-science/sintering-temperature" title="Learn more about sintering temperature from ScienceDirect's AI-generated Topic Pages">sintering temperature</a> (1100 °C, 1200 °C and 1300 °C) on the <a href="https://www.sciencedirect.com/topics/materials-science/surface-morphology" title="Learn more about surface morphology from ScienceDirect's AI-generated Topic Pages">surface morphology</a>, shrinkage, phase constitution, hardness, compressive properties, and <em>in vitro</em> biological performance of DLP-formed bioceramics were comprehensively investigated. The results showed that DLP-formed BCP ceramics sintered at 1300 °C had the best <a href="https://www.sciencedirect.com/topics/materials-science/mechanical-property" title="Learn more about mechanical properties from ScienceDirect's AI-generated Topic Pages">mechanical properties</a>, <em>in vitro</em> cytocompatibility, and homogeneous bone-like <a href="https://www.sciencedirect.com/topics/materials-science/apatite" title="Learn more about apatite from ScienceDirect's AI-generated Topic Pages">apatite</a> formation ability. Finally, DLP-formed 3D scaffolds with different pore sizes ranging from 300 μm to 1 mm were successfully fabricated, which exhibited high fidelity and accuracy. The current study has demonstrated the great potential of using DLP technology to construct functional complex BCP <a href="https://www.sciencedirect.com/topics/materials-science/bioceramic" title="Learn more about bioceramic from ScienceDirect's AI-generated Topic Pages">bioceramic</a> scaffolds for bone tissue regeneration.</p>