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For addressing the ever increasing challenge of multidrug-resistant (MDR) bacterial infections, specifically designed and prepared carbon dots (CDots) of small carbon nanoparticles with surface functionalization–passivation by oligomeric polyethylenimine were found to be readily activated by visible light to effectively and efficiently inactivate MDR bacterial strains. The inactivation was evaluated under various combinations of experimental conditions (dot concentrations, light intensities, and treatment times), with the results collectively suggesting CDots as a new class of promising agents for combating MDR bacteria. Mechanistic origins and implications of the observed strong antibacterial actions as relevant to the photoexcited state processes in CDots and the photodynamically induced cellular damages leading to the death of the bacterial cells were explored, with the results discussed.
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In vitro results of flexible light-emitting antimicrobial bandage designed for prevention of surgical site infections
Surgical site infections (SSIs) are a leading cause of morbidity and mortality and a significant expense to the healthcare system and hospitals. The majority of these infections are preventable; however, increasing bacterial resistance, biofilm persistence, and human error contribute to the occurrence of these healthcare-associated infections. We present a flexible antimicrobial blue-light emitting bandage designed for use on postoperative incisions and wounds. The photonic device is designed to inactivate bacteria present on the skin and prevent bacterial colonization of the site, thus reducing the occurrence of SSIs. This antimicrobial light emitting bandage uses blue light’s proven abilities to inactivate a wide range of clinical pathogens regardless of their resistance to antibiotics, inactivate bacteria without harming mammalian cells, improve wound healing, and inactivate bacteria in biofilms. The antimicrobial bandage consists of a thin 2”x2” silicone sheet with an array of 77 LEDs embedded in multiple layers of the material for thermal management. The 405 nm center wavelength LED array is designed to be a wearable device that integrates with standard hospital infection prevention protocols. The device was characterized for irradiance of 44.5 mW/cm2. Methicillin-resistant Staphylococcus aureus seeded in a petri dish was used to evaluate bacterial inactivation in vitro. Starting with a concentration of 2.16 x 107 colony forming units (CFU)/mL, 45% of the bacteria was inactivated within 15 minutes, 65% had been inactivated by 30 minutes, 99% was inactivated by 60 minutes, and a 7 log reduction and complete sterilization was achieved within 120 minutes.
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- PAR ID:
- 10056467
- Date Published:
- Journal Name:
- Light-Based Diagnosis and Treatment of Infectious Diseases
- Volume:
- 10479
- Page Range / eLocation ID:
- 21
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1117/12.2290743
