# Calcium Phosphate Honeycomb Scaffolds with Tailored Microporous Walls Using Phase Separation-Assisted Digital Light Processing

## TL;DR

This study creates 3D-printed calcium phosphate scaffolds with controlled micropores using a phase separation method, enhancing their porosity and transport properties for potential biomedical applications.

## Contribution

A novel phase separation-assisted digital light processing method to fabricate BCP scaffolds with tailored dual-scale porosity.

## Key findings

- Microporosity in BCP walls increased from ~38 to ~59 vol% as camphene content rose from 40 to 60 vol%.
- Overall scaffold porosity increased from ~51 to ~67 vol%, while compressive strength decreased from ~70.4 to ~13.7 MPa.
- Mass transport ability improved significantly with higher microporosity.

## Abstract

The present study reports on the manufacturing of biphasic calcium phosphate (BCP) honeycomb scaffolds with tailored microporous walls using phase separation-assisted digital light processing (PS-DLP). To create micropores in BCP walls, camphene was used as the pore-forming agent for preparing BCP suspensions, since it could be completely dissolved in photopolymerizable monomers composed of triethylene glycol dimethacrylate (TEGDMA) and polyethylene glycol diacrylate (PEGDA) and then undergo phase separation when placed at 5 °C. Therefore, solid camphene crystals could be formed in phase-separated BCP layers and then readily removed via sublimation after the photopolymerization of monomer networks embedding BCP particles by DLP. This approach allowed for tight control over the microporosity of BCP walls by adjusting the camphene content. As the camphene content increased from 40 to 60 vol%, the microporosity increased from ~38 to ~59 vol%. Consequently, the overall porosity of dual-scale porosity scaffolds increased from ~51 to ~67 vol%, while their compressive strength decreased from ~70.4 to ~13.7 MPa. The mass transport ability increased remarkably with an increase in microporosity.