Abstract
The use of beta-tricalcium phosphate (β-TCP) ceramic as a bioresorbable bone substitute is limited to non-load-bearing sites by the material׳s brittleness and low bending strength. In the present work, new biocompatible β-TCP-based composites with improved mechanical properties were developed via reinforcing the ceramic matrix with 30vol% of a biodegradable iron–magnesium metallic phase. β-TCP-15Fe15Mg and β-TCP-24Fe6Mg (vol%) composites were fabricated using a combination of high energy attrition milling, cold sintering/high pressure consolidation of powders at room temperature and annealing at 400°C. The materials synthesized had a hierarchical nanocomposite structure with a nanocrystalline β-TCP matrix toughened by a finely dispersed nanoscale metallic phase (largely Mg) alongside micron-scale metallic reinforcements (largely Fe). Both compositions exhibited high strength characteristics; in bending, they were about 3-fold stronger than β-TCP reinforced with 30vol% PLA polymer. Immersion in Ringer׳s solution for 4 weeks resulted in formation of corrosion products on the specimens׳ surface, a few percent weight loss and about 50% decrease in bending strength. In vitro studies of β-TCP-15Fe15Mg composite with human osteoblast monocultures and human osteoblast–endothelial cell co-cultures indicated that the composition was biocompatible for the growth and survival of both cell types and cells exhibited tissue-specific markers for bone formation and angiogenesis, respectively.
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•For the first time, β-TCP-based nanocomposites reinforced with a biodegradable metal are reported.•High strength of the ceramic-matrix biomaterial is obtained by high pressure consolidation at Troom.•Low temperature processing may allow for incorporation of thermally unstable bioactive agents.•Bioresorbable βTCP–FeMg nanocomposites exhibit prolonged strength retention in vitro.•βTCP-FeMg nanocomposites exhibit osteoblast and endothelial cells compatibility.
