Fabrication of a Porous and Formable Ceramic Composite Bone Tissue Scaffold at Ambient Temperature

Broken or diseased bone tissue requires a multitude of repair strategies ranging from autografts, to allografts, to synthetic bone grafts. Herein we describe a fabrication approach to create all-ceramic resorbable porous scaffolds for bone tissue repair in the absence of traditional consolidation techniques for ceramics—a technique that has potential for in situ use in operating rooms, or in field hospitals. The room temperature and pressure process utilizes a reaction with a liquid ceramic precursor to form a silicate-glass binder phase to consolidate bioactive glass frit particles and make a formable paste. This formable paste is designed to be applied directly to a bone defect, hardening in situ to become a rigid scaffold and acting as a bone ‘spackling’ paste. Characterization of the composite scaffolds is evaluated with respect to design specifications required in biomedical implant materials, namely: formability, geometric stability, porosity, and load-bearing capacity. Of the fabricated scaffolds, the composite scaffold with 7.4 vol pct sodium silicate binder was found to have the most dispersed, well distributed, and largest amount of open porosity (44 pct), average compressive strength of 1.3 MPa (with the least amount of variability), surface area to volume ratio of 33 mm⁻¹ (slightly greater than trabecular bone), and excellent geometric stability. Results of this study indicate that the developed fabrication method should be further explored for synthetic bone graft materials.