phytochlorin and Bacterial-Infections

New, biocompatible materials with favorable antibacterial activity are highly desirable. In this work, we develop a unique conjugated polymer featuring aggregation-induced emission (AIE) for reliable bacterial eradication. Thanks to the AIE and donor-π-acceptor structure, this polymer shows a high reactive oxygen species (ROS)-generation ability compared to a low-mass model compound and the common photosensitizer Chlorin E6. Moreover, the selective binding of pathogenic microorganisms over mammalian cells was found, demonstrating its biocompatibility. The effective growth inhibition of bacteria upon polymer treatment under light irradiation was validated in vitro and in vivo. Notably, the recovery from infection after treatment with our polymer is faster than that with cefalotin. Thus, this polymer holds great promise in fighting against bacteria-related infections in practical applications.

Topics: Animals; Bacteria; Bacterial Infections; Biocompatible Materials; Cells, Cultured; Chlorophyllides; HeLa Cells; Humans; Microbial Sensitivity Tests; Photochemotherapy; Photosensitizing Agents; Polymers; Porphyrins; Reactive Oxygen Species

Simultaneous imaging and treatment of infections remains a major challenge, with most current approaches being effective against only one specific group of bacteria or not being useful for diagnosis. Here we develop multifunctional nanoagents that can potentially be used for imaging and treatment of infections caused by diverse bacterial pathogens. The nanoagents are made of fluorescent silicon nanoparticles (SiNPs) functionalized with a glucose polymer (e.g., poly[4-O-(α-D-glucopyranosyl)-D-glucopyranose]) and loaded with chlorin e6 (Ce6). They are rapidly internalized into Gram-negative and Gram-positive bacteria by a mechanism dependent on an ATP-binding cassette (ABC) transporter pathway. The nanoagents can be used for imaging bacteria by tracking the green fluorescence of SiNPs and the red fluorescence of Ce6, allowing in vivo detection of as few as 10

Topics: Anti-Bacterial Agents; Bacterial Infections; Chlorophyllides; Disaccharides; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Nanoparticles; Photochemotherapy; Porphyrins; Pseudomonas aeruginosa; Radiation-Sensitizing Agents; Staphylococcus aureus

The fact that increasing antibiotic resistance of pathogenic bacteria and a lack of new potent broad-spectrum antibiotics call for the development of alternative approaches for treating infectious diseases. With the merits of great efficacy, safety, and facile implementation, antibacterial photodynamic therapy (APDT) represents an attractive modality for this purpose. Here, we report that the newly fabricated photodynamic chitosan nano-assembly, designated CS-Ce6, could synergistically kill antibiotic-resistant bacteria with superior potency to vancomycin. CS-Ce6 nano-assembly, obtained from covalent conjugate of chlorin e6 (Ce6) with chitosan, exhibited strong association with bacteria, thus altering their morphologies and mediating great delivery efficiency of Ce6. Upon light irradiation, localized generation of singlet oxygen by CS-Ce6 nano-assembly has a remarkable bactericidal effect toward both drug-resistance Gram-positive methicillin-resistant

Topics: Animals; Anti-Bacterial Agents; Bacterial Infections; Chitosan; Chlorophyllides; Drug Resistance, Microbial; Humans; Methicillin-Resistant Staphylococcus aureus; Mice; Nanoparticles; Photochemotherapy; Photosensitizing Agents; Porphyrins; Singlet Oxygen; Vancomycin