Regenerating infected bone defects with osteocompatible microspheres possessing antibacterial activity

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Nanotechnology

Background:

• Infected bone defects present significant clinical challenges.
• Developing bone implants with antibacterial and osteogenic properties is crucial for infection control and bone healing.
• Bioresorbable materials offer advantages for bone defect treatment.

Purpose of the Study:

• To fabricate and evaluate bioresorbable porous microspheres with combined antibacterial and osteogenic effects for treating infected bone defects.
• To assess the in vitro and in vivo performance of these dual-purpose microspheres.

Main Methods:

• Fabrication of bioresorbable porous microspheres from poly(l-lactide)-poly(ethyl glycol) block copolymer.
• Surface coating with polydopamine and sequential loading of nanosilver and apatite.
• In vitro evaluation of antibacterial activity and effects on bone marrow mesenchymal stem cell proliferation and differentiation.
• In vivo assessment in a rat cranial defect model infected with Staphylococcus aureus.

Main Results:

• Microspheres demonstrated strong in vitro antibacterial activity.
• Optimized nanosilver loading did not adversely affect stem cell proliferation or differentiation.
• In vivo studies showed effective bacterial clearance and significant promotion of new bone formation.
• Microspheres degraded over time while facilitating bone regeneration.

Conclusions:

• Bioresorbable microspheres with combined osteoconductive and antibacterial activities are a promising strategy for treating infected bone defects.
• The developed dual-purpose microspheres offer a potential solution for simultaneous infection control and bone regeneration.
• This approach addresses a critical unmet need in orthopedic and trauma surgery.