Bioresorbable β-TCP-FeAg nanocomposites for load bearing bone implants: High pressure processing, properties and cell...

Area of Science:

• Biomaterials Science
• Materials Engineering
• Orthopedic Research

Background:

• Beta-tricalcium phosphate (β-TCP) is a bone-like biomaterial suitable for bone regeneration but suffers from brittleness and low strength.
• Current β-TCP materials are not ideal for load-bearing applications due to their inherent mechanical limitations.

Purpose of the Study:

• To develop iron-toughened bioresorbable β-TCP nanocomposites with improved mechanical properties for bone healing applications.
• To investigate the effect of silver addition on the properties and degradation of β-TCP-Fe nanocomposites.

Main Methods:

• Nanocomposite powders of β-TCP with 30vol% iron (Fe), with and without silver (Ag) addition, were processed using high-energy attrition milling.
• High-pressure consolidation/cold sintering at 2.5 GPa was employed to produce near fully dense nanocomposites.
• Mechanical properties (compression, bending) and in vitro degradation (Ringer's, saline solutions) were evaluated before and after immersion.

Main Results:

• The developed β-TCP-Fe-Ag nanocomposites exhibited significantly higher bending strength compared to polymer-toughened β-TCP and pure β-TCP.
• Partial substitution of iron with silver enhanced both strength and ductility of the nanocomposites.
• Silver addition accelerated the in vitro degradation of the β-TCP nanocomposites through galvanic action, with retained ~50% bending strength after 1 month.
• β-TCP-27Fe3Ag nanocomposites showed no cytotoxicity towards human osteoblasts in cell culture.

Conclusions:

• Iron-toughened β-TCP nanocomposites, particularly with silver addition, offer superior mechanical properties and tunable degradation rates for bone regeneration.
• The developed β-TCP-Fe-Ag materials demonstrate potential as biocompatible and mechanically robust implant materials for load-bearing bone defect applications.