Goal
Treat infections on metal-based implants by using weak electric currents to sensitize microbes and enhance antibiotic efficacy.
Problem
Chronic infections and biofilm formation on metal implants caused by antibiotic-resistant microbes.
Concept Summary
A weak electrical current is passed through a metal implant (e.g., titanium) to create electrochemical stress that damages microbial cell membranes, increasing permeability. This "bioelectric effect" makes the microbes more susceptible to antibiotics, achieving high levels of eradication of both planktonic and biofilm cells.
Detailed Description
The method applies 1-500 uA cm^-^2 (~=75 uA cm^-^2 preferred) direct current to the implant surface in a conductive saline solution (0.85 % NaCl). The current induces ion flux and redox reactions at the electrode, disrupting cell walls, impairing metabolism, and altering biofilm structure. When followed by an antibiotic (e.g., fluconazole), the combined treatment yields up to 7-log killing of Candida albicans and >99 % reduction of bacterial biofilms.
Principles
- Weak electric current
- Electrochemical stress
- Cell membrane permeabilization
- Synergistic antibiotic effect
Scientific Domains
Materials
- Titanium
- Sodium chloride (NaCl)
- Fluconazole
- Other antibiotics
Mechanisms of Action
- Electrochemical disruption of microbial cell membranes
- Increased cell permeability
- Redox alteration of bacterial metabolism
- Synergistic enhancement of antibiotic killing
Energy Sources
Applications
- Treatment of infected dental, orthopedic, and cardiovascular implants
- Wound dressing antimicrobial therapy
- Decontamination of medical devices
Claimed Performance
99.7 % reduction of planktonic Candida albicans, 96.0-99.99 % reduction of biofilm cells, and complete 7-log killing when combined with fluconazole.
Experimental Evidence
The peer-reviewed study reported a 99.7 % decrease in viable planktonic cells and a 96.0-99.99 % decrease in biofilm cells after low-level electrochemical treatment, with 7-log killing when the antibiotic was applied subsequently.
Replication Status
Method described in a patent (US8663914) and a peer-reviewed paper; no independent replication reported in the article.
Limitations
- Requires electrical connection to the implant
- Effectiveness may vary with biofilm thickness and geometry
- Potential for tissue heating if current exceeds safe limits
