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Updated: Jul 30, 2026
Multi-Scale Modification of Metallic Implants With Pore Gradients, Polyelectrolytes and Their Indirect Monitoring In vivo
Published on: July 1, 2013
Surface photosterilization of implantable silicone biomaterials: structural and functional characterization
Sahand Ghaffari1, Nafise Amiri2, Demian F Felix1
1The Stone Centre at VGH, Department of Urologic Sciences, University of British Columbia, Jack Bell Research Centre, 550-3, 2660 Oak Street, Vancouver V6H 3Z6, BC, Canada.
Insights
A novel photodynamic sterilization method using Polydimethylsiloxane (PDMS) with embedded ruthenium photosensitizers effectively prevents bacterial colonization and biofilm formation on medical implants, significantly reducing hospital-acquired infections (HAIs). This cost-effective approach shows potent in vivo antibacterial activity with no adverse effects.
Area of Science:
- Biomaterials Science
- Infectious Disease Control
- Photodynamic Therapy
Background:
- Hospital-acquired infections (HAIs), particularly catheter-associated urinary tract infections (CAUTIs), pose a significant global healthcare challenge.
- Increasing antibiotic resistance necessitates alternative strategies to combat recurrent infections linked to indwelling medical devices.
- Bacterial adhesion and biofilm formation on implant surfaces are primary drivers of CAUTIs and associated patient morbidity.
Purpose of the Study:
- To develop a simple, cost-effective method for sterilizing silicone-based implant surfaces.
- To prevent bacterial colonization and biofilm formation on Polydimethylsiloxane (PDMS) using photodynamic action.
- To evaluate the efficacy and safety of a novel PDMS-embedded ruthenium photosensitizer (PS) system for preventing infections.
Main Methods:
- Silicone PDMS surfaces were embedded with a ruthenium photosensitizer (PS).
- The PDMS+PS material was exposed to LED light to activate photokilling.
- Bacterial adhesion, biofilm formation, in vivo efficacy, cytotoxicity, and material properties were assessed.
Main Results:
- Photodynamic treatment resulted in bactericidal activity below the limit of detection (<10 CFU/mL) within 24 hours.
- Live/dead staining confirmed significant reductions in surface bacteria and biofilm formation.
- In vivo studies demonstrated over 99.5% reduction in adherent bacteria on implanted PDMS+PS coupons compared to controls over 3 days.
- Histological and in vitro cytotoxicity studies revealed no adverse reactions or cytotoxicity.
- Surface-treated PDMS exhibited comparable or improved material properties (tensile strength, roughness, hydrophobicity, encrustation) to bare PDMS.
Conclusions:
- The PDMS+PS system offers a potent, cost-effective photodynamic sterilization strategy for medical implants.
- This method effectively prevents bacterial colonization and biofilm formation, crucial for reducing CAUTIs and HAIs.
- The material is biocompatible and maintains or enhances desirable physical properties, making it suitable for clinical applications.
Abstract:
Hospital-acquired infections (HAIs) remain one of the major challenges faced by the global healthcare system. The increasing rate of pathogenic resistance against antibiotics suggests that alternative treatments are needed to control recurrent infections. Catheter-associated urinary tract infections (CAUTIs) are the third most common type of HAI worldwide, and this is mainly due to indwelling devices being excellent substrates for bacterial adhesion and growth. Subsequent biofilm formation on the implant surface acts as a constant nidus of bacteria and infection, thereby contributing to increased rates of patient morbidity and mortality. Here, we propose a simple and cost-effective method to sterilize silicone-based implant surfaces and prevent initial bacterial colonization, using Polydimethylsiloxane (PDMS) and an embedded ruthenium photosensitizer (PS). Exposure to LED light triggers potent photokilling action, resulting in significant bactericidal activity as evidenced by the number of adherent bacteria being below the level of detection (<10 CFU/mL) after 24 h. Live/dead staining studies using fluorescence microscopy indicated significant reduction in surface-adhered bacterial growth and biofilm formation. This potent antibacterial activity was verified in vivo, with exposure of contaminated PDMS coupons containing PS to LED prior to implantation resulting in over 99.5% reduction in adherent bacteria compared to controls over the 3-day implantation period. Histological analysis of the implantation site of PDMS+PS samples, in the absence of bacteria, revealed no adverse reactions. This was also confirmed using in vitro cytotoxicity studies. Tensile strength, surface roughness, hydrophobicity, and the development of encrustation of surface-treated groups exhibit comparable or improved properties to bare PDMS.
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