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Electrospun polyacrylonitrile (PAN) nanofibers integrated with different loadings of the photosensitizer rose bengal (RB) were synthesized for photodynamic inactivation of bacteria. Our results suggest that the ionic strength in the medium does not significantly affect the RB release from the RB-integrated electrospun PAN nanofibers (RBiEPNs), which could release RB effectively in phosphate-buffered saline (PBS), physiological saline (0.85% NaCl), and deionized H 2 O. However, the pH of the medium significantly influenced the release of RB. A larger amount of RB was released in PBS at a higher pH (RB release: pH 9.0 > pH 7.4 > pH 5.0). The RBiEPNs depicted high antimicrobial efficacy against both Gram-negative Escherichia coli ( E. coli ) and Gram-positive Bacillus subtilis ( B. subtilis ) bacteria under white light irradiation. The antimicrobial efficacy was potent and immediate against the bacterial cells, especially B. subtilis . The RBiEPNs containing 0.33 wt% RB demonstrated complete bacterial kills for B. subtilis and E. coli cells with log reductions of 5.76 and 5.94 in 30 s and 40 min, respectively. The generation of intracellular reactive oxygen species (iROS) was examined after white light treatment of the bacterial cells in the presence of the RBiEPNs. A significant correlation was found between the amount of iROS and the antimicrobial efficacy of the RBiEPNs. The high antimicrobial efficacy could be attributed to several factors, such as the encapsulation efficiency, loading capacity, and RB release behavior of the RBiEPNs, the presence of white light, and the generation of iROS. Taken together, the facile incorporation of a photosensitizer into polymeric nanofibers via blend electrospinning offers a feasible strategy for water disinfection.
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This content will become publicly available on April 1, 2026
Static and Dynamic Assessments of a Sulfur-Triglyceride Composite for Antimicrobial Surface Applications
Over 80 MT of elemental sulfur, a byproduct of fossil fuel desulfurization, are generated annually. This has spurred the development of high sulfur content materials (HSMs) via inverse vulcanization as a productive pathway towards sulfur utilization. In this study, we evaluate the antimicrobial performance of SunBG90, an HSM made from brown grease and sulfur, as tiles or infused into fabric squares. The static antimicrobial activity of SunBG90 tiles was assessed, revealing excellent efficacy against Gram-positive bacteria, with reductions of 96.84% for Staphylococcus aureus and 91.52% for Listeria monocytogenes. The tiles also exhibited strong antifungal activity, reducing Candida auris by 96.20% and mold (fumigatus) by 83.77%. In contrast, efficacy against Gram-negative bacteria was more variable, with moderate reductions for Escherichia coli (61.10%) and Salmonella enteritidis (62.15%), lower activity against Campylobacter jejuni and Salmonella typhi, and no effect on Clostridium perfringens. Under dynamic conditions, SunBG90-infused fabrics achieved a near-complete inhibition of L. monocytogenes (99.91%) and high reduction of E. coli (98.49%), along with a 96.24% inhibition of Candida auris. These results highlight the potential and limitations of SunBG90 for antimicrobial applications, emphasizing the need for further optimization to achieve consistent broad-spectrum activity.
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- Award ID(s):
- 2203669
- PAR ID:
- 10650101
- Publisher / Repository:
- mdpi
- Date Published:
- Journal Name:
- Molecules
- Volume:
- 30
- Issue:
- 7
- ISSN:
- 1420-3049
- Page Range / eLocation ID:
- 1614
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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