Plasma Surface Functionalized Polyetheretherketone for Enhanced Osseo-Integration at Bone-Implant Interface

Area of Science:

• Biomaterials Science
• Surface Engineering
• Orthopedic Research

Background:

• Polyetheretherketone (PEEK) is a widely used biomaterial for orthopedic implants.
• Improving the osseointegration of PEEK implants at the bone-implant interface remains a challenge.
• Surface modification techniques are crucial for enhancing the biological performance of PEEK.

Purpose of the Study:

• To enhance the osseointegration of PEEK by utilizing water (H2O) and ammonia (NH3) plasma immersion ion implantation (PIII).
• To systematically investigate the effects of PIII on PEEK surface characteristics and in vitro biological responses.
• To evaluate the in vivo osseointegration of PIII-treated PEEK implants.

Main Methods:

• Surface characterization: surface energy, roughness, morphology, and chemical composition analysis.
• In vitro biological evaluation: cell adhesion, proliferation, alkaline phosphatase (ALP) activity, gene expression (RT-PCR), and mineralization assays.
• In vivo study: implantation of treated PEEK samples into the distal femur of rats for osseointegration assessment.

Main Results:

• H2O PIII and NH3 PIII significantly improved PEEK hydrophilicity, surface roughness, cell adhesion, and proliferation.
• Enhanced alkaline phosphatase (ALP) activity and osteogenic differentiation were observed after plasma treatments.
• In vivo studies demonstrated substantially improved osseointegration of the treated PEEK implants.

Conclusions:

• Plasma immersion ion implantation (PIII) is an effective non-line-of-sight surface functionalization method for PEEK.
• The PIII process enhances surface biological properties without compromising the bulk mechanical properties of PEEK.
• Surface-modified PEEK holds significant promise for wider applications in orthopedic implants.