Bactericidal methods and compositions
Inventors
Dong, Pu-Ting • Hui, Jie • Cheng, Ji-Xin • ZHU, Yifan
Assignees
Publication Number
US-12064641-B2
Publication Date
2024-08-20
Expiration Date
2040-01-31
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Abstract
Methods of the present invention comprise photoinactivation of catalase in combination with low-concentration peroxide solutions and/or ROS generating agents to provide antibacterial effects.
Core Innovation
Antibiotic resistance poses a severe global health threat, causing hundreds of thousands of deaths annually, with projections indicating millions of deaths by 2050 if resistance is not curbed. Traditional antibiotic development cannot keep pace with rapidly mutating pathogens, creating an urgent need for unconventional antimicrobial strategies.
The invention addresses this background by providing methods that photoinactivate catalase, an enzyme present in most aerobic pathogens that scavenges harmful reactive oxygen species (ROS) like hydrogen peroxide. Photoinactivation occurs optimally using blue light in the range of about 400 nm to about 430 nm, especially approximately 410 nm, rendering catalase-positive microbial pathogens vulnerable to ROS-generating antimicrobials or immune responses.
This photoinactivation is combined with administering low-concentration peroxide solutions and/or ROS-generating agents, producing a significant and unexpected enhancement in antimicrobial effects. The photoinactivation mediated by light sources such as pulsed nanosecond lasers or continuous wave LEDs synergizes with peroxide or ROS agents to effectively eradicate bacterial and fungal catalase-positive microbes in tissues or on inanimate surfaces.
Claims Coverage
The patent contains two independent claims directed to antimicrobial methods involving photoinactivation of catalase and ROS generation, focusing on treating catalase-positive microbes.
Applying visible light at about 400 nm to 430 nm to inactivate catalase
The method involves applying visible light within the wavelength range of about 400 nm to about 430 nm to catalase-positive microbes to inactivate catalase present within the microbe.
Contacting the microbe with a reactive oxygen species generating agent
After photoinactivation, the microbe is contacted with a reactive oxygen species (ROS) generating agent, such as hydrogen peroxide at concentrations of 3.0% or less, to enhance antimicrobial effects.
Producing synergistic antimicrobial effects by photoinactivation and ROS agent combination
A method producing synergistic antimicrobial effects by applying visible light at about 400 nm to about 460 nm to inactivate catalase and contacting the microbe with a ROS-generating agent.
Using specific light sources and doses for photoinactivation
Using pulsed nanosecond lasers, continuous wave LEDs, or pulsed LEDs to provide light at defined doses (about 5 J/cm2 to about 200 J/cm2) for photoinactivation of catalase within catalase-positive fungal or bacterial microbes.
The independent claims cover methods for treating catalase-positive microbes by combining photoinactivation of catalase using visible light in the approximately 400-460 nm range with administration of ROS-generating agents, effectively producing antimicrobial and synergistic effects.
Stated Advantages
Photoinactivation of catalase significantly boosts the efficacy of low-concentration hydrogen peroxide against catalase-positive microbes.
The method revives or enhances the effectiveness of conventional ROS-generating antibiotics against catalase-positive bacteria.
Photoinactivation assists immune cells such as neutrophils and macrophages in eliminating intracellular pathogens more effectively.
Using pulsed nanosecond laser light is more effective than continuous wave LED light for catalase photoinactivation and microbial eradication, while minimizing thermal tissue damage.
Documented Applications
Treatment of infected tissues, including skin, scalp, nails, and internal tissues such as gastrointestinal, oral, vaginal, or nasal cavities infected with catalase-positive bacterial or fungal microbes.
Disinfection of inanimate surfaces contaminated with catalase-positive microbes, including surfaces made of metal, plastic, fabric, rubber, stone, composite materials, or wood.
Adjunctive use with ROS-generating antimicrobial agents, including low-concentration hydrogen peroxide, antibiotics (e.g., tobramycin), antifungals (e.g., amphotericin B, azoles), and agents such as silver cation and gold nanoparticles.
Use in medical, military, hygienic, and industrial contexts for microbial elimination and control, including treatment of drug-resistant pathogens.
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