Bioactivity and Biocompatibility of a Polydopamine-Bridged, BMP-2-Functionalized Multilayer Coating on Stainless...

Area of Science:

• Biomaterials Science
• Orthopedic Engineering
• Infectious Disease Research

Background:

• Implant failure is a significant clinical challenge, often caused by inadequate bone regeneration (osteogenesis) and bacterial infections.
• Enhancing both osteogenic and antibacterial properties of implant surfaces is crucial for improving clinical outcomes.

Purpose of the Study:

• To develop a functionalized stainless steel (SS) substrate with enhanced osteogenic and antibacterial activities for improved implant performance.
• To investigate the efficacy of a polydopamine (PDA)-bridged bone morphogenetic protein-2 (BMP2) coating on a benzophenone (BP)-photoinitiated 2-methacryloyloxyethyl phosphorylcholine (MPC)-modified SS surface.

Main Methods:

• Grafting BMP2 onto BP-MPC-coated SS using a PDA bridge to create SS-BP-MPC-PDA-BMP2.
• Evaluating BMP2 immobilization, release kinetics, surface properties (wettability, smoothness), antibacterial efficacy against *Staphylococcus aureus*, and preosteoblast (MC3T3-E1) cell response.

Main Results:

• The PDA bridge significantly increased BMP2 immobilization (6-fold) and enabled controlled, sustained release over 10 days.
• The modified surface exhibited improved wettability and smoothness, with enhanced antibacterial fouling efficacy (41%) against *S. aureus* compared to controls.
• The SS-BP-MPC-PDA-BMP2 substrate effectively prevented biofilm formation and promoted preosteoblast metabolic activity and proliferation.

Conclusions:

• The developed PDA-BMP2 functionalized SS substrate demonstrates superior osteogenic and antibacterial properties.
• This approach offers a promising strategy for modifying implant materials to reduce failure rates in orthopedic and dental applications.