Singlet oxygen mediated oxidation has been shown to be responsible for photodynamic inactivation (PDI) of viruses in solution with photosensitisers such as 5, 10, 15, 20-tetrakis (1-methyl-4-pyridinio) porphyrin tetra p-toluenesulfonate (TMPyP). The capsids of non-enveloped viruses, such as bacteriophage MS2, are possible targets for viral inactivation by singlet oxygen oxidation. Within the capsid (predominantly composed of coat protein), the A-protein acts as the host recognition and attachment protein. The A-protein has two domains; an α-helix domain and a β-sheet domain. The α-helix domain is attached to the viral RNA genome inside the capsid while the β-sheet domain, which is on the surface of the capsid, is believed to be the site for attachment to the host bacteria pilus during infection. In this study, 4 sequence-specific antibodies were raised against 4 sites on the A-protein. Changes induced by the oxidation of singlet oxygen were compared to the rate of PDI of the virus. Using these antibodies, our results suggest that the rate of PDI is relative to loss of antigenicity of two sites on the A-protein. Our data further showed that PDI caused aggregation of MS2 particles and crosslinking of MS2 coat protein. However, these inter- and intra-capsid changes did not correlate to the rate of PDI we observed in MS2. Possible modes of action are discussed as a means to gaining insight to the targets and mechanisms of PDI of viruses.
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http://dx.doi.org/10.1016/j.jphotobiol.2017.11.032 | DOI Listing |
Adv Sci (Weinh)
January 2025
State Key Laboratory of Digital Medical Engineering, Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering, Southeast University, 2 Southeast University Road, Nanjing, 211189, P. R. China.
Gram-positive bacteria pose significant threats to human health, necessitating the development of targeted bacterial detection and eradication strategies. Nevertheless, current approaches often suffer from poor targeting specificity. Herein, the study utilizes purple rice lixivium to synthesize biomass carbon dots (termed BCDs) with wheat germ agglutinin-like residues for precisely targeting Gram-positive bacteria.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2025
Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.
Environmental changes, such as applied medication, nutrient depletion, and accumulation of metabolic residues, affect cell culture activity. The combination of these factors reflects on the local temperature distribution and local oxygen concentration towards the cell culture scaffold. However, determining the temporal variation of local temperature, independent of local oxygen concentration changes in biological specimens, remains a significant technological challenge.
View Article and Find Full Text PDFActa Biomater
January 2025
Department of radiology, Affiliated Hospital of Jiangnan University, Wuxi, Jiangsu, 214122, China. Electronic address:
Nanohybrids combining phenylboronic acid-modified carbon dots (PCDs) and proteinase K have been engineered for addressing the formidable challenges of antimicrobial photodynamic therapy (aPDT) against bacterial biofilm infections, overcoming biofilm barrier obstruction, the limited diffusion of reactive oxygen species (ROS), and the inadequate ROS generation of traditional photosensitizers. PCDs are formulated for superior water solubility and robust singlet oxygen (O) production, mitigating issues related to dispersion and aggregation-induced quenching typical of conventional photosensitizers. The conjugation of phenylboronic acid to CDs not only enhanced O generation through increased electron-hole separation but also imparted strong bacterial binding capabilities to the PCDs, enabling broad-spectrum sterilization by maximizing the ROS-mediated bacterial destruction.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
Biomedical Polymers Laboratory, College of Chemistry, Chemical Engineering and Materials Science, and State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou 215123 China; College of Pharmaceutical Sciences, Soochow University, Suzhou 215123 China. Electronic address:
Phototherapy including photothermal therapy (PTT) and photodynamic therapy (PDT) is widely used for cancer treatment because of its non-invasiveness, spatiotemporal controllability, and low side effects. However, the PTT and PDT capabilities of photosensitizers (PSs) compete so it's still a crucial challenge to simultaneously enhance the PDT and PTT capabilities of PSs. In this work, donor-π-acceptor (D-π-A)-based boron dipyrromethene (BODIPY) dyes were developed via molecular engineering and applied for enhanced phototherapy of triple-negative breast cancer.
View Article and Find Full Text PDFCarbohydr Polym
March 2025
Key Laboratory of Coal Conversion and New Carbon Materials of Hubei Province, Institute of Advanced Materials and Nanotechnology, School of Chemistry and Chemical Engineering, School of Medicine, Wuhan University of Science and Technology, Wuhan, China.
Drug-resistant bacterial infections represent a critical global public health challenge, driven largely by the misuse and overuse of antibiotics. Tackling the growing threat of bacterial resistance necessitates the development of innovative antibacterial agents that function independently of traditional antibiotics. In this study, novel antibacterial nano-micelles were rationally designed by conjugating quaternized chitosan with the photosensitizer chlorin e6.
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