Injectable, anti-collapse, adhesive, plastic and bioactive bone graft substitute promotes bone regeneration by...

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Nanotechnology

Background:

• Osteoporotic bone defects pose clinical challenges due to oxidative stress and high reactive oxygen species (ROS), hindering bone formation.
• Selenium nanoparticles (SeNPs) show promise in osteogenesis due to their antioxidant properties, combating bone loss and aiding regeneration in osteoporosis.
• Existing treatments for osteoporotic bone defects often fall short in addressing the complex biological environment.

Purpose of the Study:

• To develop an injectable, adhesive, and shape-adaptive bone graft substitute for treating osteoporotic bone defects.
• To investigate the osteogenic, angiogenic, anti-inflammatory, and antioxidant effects of the novel biomaterial in vitro and in vivo.
• To elucidate the mechanism by which the biomaterial protects against ferroptosis in bone cells.

Main Methods:

• A one-pot synthesis method was employed to create the PDT-TCP-SE bone graft substitute, incorporating Poly (lactic acid-carbonate) (PDT), β-Tricalcium Phosphate (β-TCP), and SeNPs.
• In vitro studies assessed the material's adhesion, osteoinductivity, angiogenic potential, anti-inflammatory effects, and antioxidant capacity, including its effect on erastin-induced ferroptosis in bone marrow-derived stem cells (BMSCs).
• In vivo experiments evaluated the biomaterial's efficacy in promoting bone regeneration in osteoporotic bone defect models, assessing its impact on ROS levels, inflammation, and new bone formation.

Main Results:

• The synthesized PDT-TCP-SE exhibited excellent adhesion, injectability, and shape-adaptive properties, suitable for bone defect repair.
• In vitro and in vivo studies confirmed the material's osteoinductive activity, angiogenic effects, anti-inflammatory properties, and significant reduction of ROS levels in the osteoporotic bone defect microenvironment.
• PDT-TCP-SE demonstrated a protective effect against erastin-induced ferroptosis in BMSCs via the Sirt1/Nrf2/GPX4 antioxidant pathway, mitigating oxidative stress.

Conclusions:

• The developed PDT-TCP-SE bone graft substitute is a promising biomaterial for treating osteoporotic bone defects, offering a simple synthesis and beneficial properties.
• The material effectively moderates oxidative stress and inhibits ferroptosis, promoting new bone regeneration in situ.
• PDT-TCP-SE presents significant potential for clinical application in bone tissue engineering due to its biocompatibility, injectability, and ability to regulate the oxidative stress level.