Multi-functional PEEK implants enhance osseointegration in OVX rat by remodeling the bone immune microenvironment

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Orthopedic Surgery

Background:

• Osteoporosis significantly impairs osseointegration due to increased reactive oxygen species (ROS) and inflammation.
• Current treatments for osteoporotic bone defects often have limited efficacy in promoting bone regeneration and implant integration.

Purpose of the Study:

• To develop and evaluate a modified polyether ether ketone (PEEK) implant, PEEK-PDA-Sr, for enhanced osseointegration and osteogenesis in osteoporotic conditions.
• To investigate the immunomodulatory effects and bone regeneration capabilities of PEEK-PDA-Sr in vitro and in vivo.

Main Methods:

• PEEK implants were modified with a mussel-inspired polydopamine (PDA) layer and conjugated with strontium (Sr) ions (PEEK-PDA-Sr).
• In vitro studies assessed biocompatibility, ROS regulation, macrophage differentiation, and osteogenesis of bone marrow stromal cells (BMSCs).
• In vivo studies utilized an ovariectomized (OVX) rat model to evaluate osseointegration in femoral bone defects.

Main Results:

• PEEK-PDA-Sr demonstrated excellent biocompatibility and effectively regulated intracellular ROS levels.
• The modified implant promoted M2 macrophage differentiation, indicating an anti-inflammatory response.
• PEEK-PDA-Sr significantly enhanced BMSC osteogenesis in vitro and improved osseointegration in OVX rats in vivo.

Conclusions:

• PEEK-PDA-Sr acts as an effective immunoregulator, promoting osteogenesis and enhancing osseointegration in osteoporotic bone defects.
• The strontium-releasing PEEK-PDA-Sr implant offers a promising therapeutic strategy for treating bone defects associated with osteoporosis.
• This approach provides a viable method for improving implant success rates in osteoporotic patients.