Two-step biocompatible surface functionalization for two-pathway antimicrobial action against Gram-positive bacteria.

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Infectious Disease Prevention

Background:

• Infection is a major complication of indwelling medical devices, with biofilms being difficult to eradicate.
• Novel strategies are needed to inhibit bacterial adhesion on implantable device surfaces.

Purpose of the Study:

• To develop a simple protocol for preparing surfaces that prevent bacterial growth on implantable devices.
• To investigate the surface chemistry of ampicillin adsorption on titanium and silver nanoparticles.

Main Methods:

• Multi-functionalization of titanium (Ti) surfaces with silver nanoparticles (AgNPs) and ampicillin (AMP).
• Elucidation of surface chemistry for AMP adsorption on Ti and AgNPs.
• Assessment of bacterial viability on modified surfaces.

Main Results:

• A two-step protocol successfully created Ti-AgNPs-AMP surfaces that prevent bacterial growth.
• Ampicillin binds to titanium via covalent and electrostatic interactions, and to AgNPs via thiolate-like bonds.
• The modified surface reduced bacterial viability by over 80% and maintained antimicrobial capacity over time through dual mechanisms.

Conclusions:

• The developed Ti-AgNPs-AMP surface modification is effective in preventing bacterial adhesion and growth on indwelling devices.
• The surface exhibits a sustained antimicrobial effect through contact-killing by ampicillin and release-killing by silver ions.
• This strategy holds promise for preventing infections associated with prosthetic surgery and indwelling devices.