Antimicrobial resistance is an ever-growing global concern, making the development of alternative antimicrobial agents and techniques an urgent priority to protect public health. Antimicrobial photodynamic therapy (aPDT) is one such promising alternative, which harnesses the cytotoxic action of reactive oxygen species (ROS) generated upon irradiation of photosensitisers (PSs) with visible light to destroy microorganisms. In this study we report a convenient and facile method to produce highly photoactive antimicrobial microparticles, exhibiting minimal PS leaching, and examine the effect of particle size on antimicrobial activity. A ball milling technique produced a range of sizes of anionic p(HEMA-co-MAA) microparticles, providing large surface areas available for electrostatic attachment of the cationic PS, Toluidine Blue O (TBO). The TBO-incorporated microparticles showed a size-dependent effect on antimicrobial activity, with a decrease in microparticle size resulting in an increase in the bacterial reductions achieved when irradiated with red light. The >6 logPseudomonas aeruginosa and Staphylococcus aureus reductions (>99.9999%) achieved within 30 and 60 min, respectively, by TBO-incorporated >90 μm microparticles were attributed to the cytotoxic action of the ROS generated by TBO molecules bound to the microparticles, with no PS leaching from these particles detected over this timeframe. TBO-incorporated microparticles capable of significantly reducing the bioburden of solutions with short durations of low intensity red light irradiation and minimal leaching present an attractive platform for various antimicrobial applications.
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http://dx.doi.org/10.1016/j.jphotobiol.2023.112671 | DOI Listing |
Acta Pharm Sin B
December 2024
School of Pharmacy, Institute of Hepatology and Metabolic Diseases, Department of Hepatology, the Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou 311121, China.
Specific tumor-targeted gene delivery remains an unsolved therapeutic issue due to aberrant vascularization in tumor microenvironment (TME). Some bacteria exhibit spontaneous chemotaxis toward the anaerobic and immune-suppressive TME, which makes them ideal natural vehicles for cancer gene therapy. Here, we conjugated ZIF-8 metal-organic frameworks encapsulating eukaryotic murine interleukin 2 () expression plasmid onto the surface of VNP20009, an attenuated strain with well-documented anti-cancer activity, and constructed a TME-targeted delivery system named /ZIF-8@.
View Article and Find Full Text PDFACS Appl Bio Mater
January 2025
Department of Chemistry, National Institute of Technology, Rourkela, Odisha 769008, India.
The idea of coordinating biologically active ligand systems to metal centers to exploit their synergistic effects has gained momentum. Therefore, in this report, three Ru complexes - of morpholine-derived thiosemicarbazone ligands have been prepared and characterized by spectroscopy and HRMS along with the structure of through a single-crystal X-ray diffraction study. The solution stability of - was tested using conventional techniques such as UV-vis and HRMS.
View Article and Find Full Text PDFAMB Express
January 2025
Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University, Cairo, 11566, Egypt.
In this study, Allium sativum, garlic, was selected to isolate endophytic bacteria and to evaluate the antimicrobial, antiviral, antioxidant, and cytotoxic activities of their produced metabolites followed by identification of the biosynthetic gene cluster of the antimicrobial metabolites using Oxford Nanopore Technology (ONT). Two bacterial isolates, C6 and C11, were found to have a broad-spectrum antagonistic effect against four standard microbial strains and were molecularly identified using 16 S ribosomal RNA sequence analysis and deposited in a local culture collection as B. velezensis CCASU-C6, and B.
View Article and Find Full Text PDFSci Rep
January 2025
Laser Research Centre, Faculty of Health Science, University of Johannesburg, Doornfontein, 2028, South Africa.
The simultaneous administration of multiple drugs within identical nanocarriers to cancer cells or tissues can result in the effective action of drugs at reduced concentrations. In this investigation, PAMAM dendrimers (G4-PAMAM) were employed to link with methotrexate (MTX) using DCC/NHS chemistry and followed by the entrapment of curcumin (Cur) within it. The establishment of covalent bonds between MTX and the PAMAM dendrimer led to PAMAM-MTX interaction, verified and described through FT-IR.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Department of Laboratory Medicine, School of Chemical Science and Engineering, Shanghai Tenth People's Hospital of Tongji University, Tongji University, Shanghai, 200092, P. R. China.
The healing of bacterial biofilm-infected wounds is a complex process, and the construction of emerging therapeutic modalities that regulate the microenvironment to magnify therapeutic effects and reduce biotoxicity is still highly challenging. Herein, an engineered microneedle (MN) patch is reported to mediate the efficient delivery of black phosphorus nanosheets (BP NSs) and copper peroxide nanodots (CP NDs) for dual nanodynamic sterilization and methicillin-resistant staphylococcus aureus (MRSA)-infected wound healing. Results demonstrate that the system can eliminate biofilm, reduce cytotoxicity, promote angiogenesis and tissue regeneration by the multiple advantages of chemodynamic therapy (CDT), enhanced photodynamic therapy (PDT), and improved degradation process from BP NSs to phosphate for promoting cell proliferation.
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