Photodynamic Effects of Methylene Blue-Loaded Polymeric Nanoparticles on Dental Plaque Bacteria
ABSTRACT Photodynamic therapy (PDT) is increasingly being explored for treatment of oral infections. Here, we investigate the effect of PDT on human dental plaque bacteria in vitro using methylene blue (MB)-loaded poly(lactic-co-glycolic) (PLGA) nanoparticles with a positive or negative charge and red light at 665 nm.
Dental plaque samples were obtained from 14 patients with chronic periodontitis. Suspensions of plaque microorganisms from seven patients were sensitized with anionic, cationic PLGA nanoparticles (50 µg/ml equivalent to MB) or free MB (50 µg/ml) for 20 min followed by exposure to red light for 5 min with a power density of 100 mW/cm2 . Polymicrobial oral biofilms, which were developed on blood agar in 96-well plates from dental plaque inocula obtained from seven patients, were also exposed to PDT as above. Following the treatment, survival fractions were calculated by counting the number of colony-forming units.
The cationic MB-loaded nanoparticles exhibited greater bacterial phototoxicity in both planktonic and biofilm phase compared to anionic MB-loaded nanoparticles and free MB, but results were not significantly different (P > 0.05).
Cationic MB-loaded PLGA nanoparticles have the potential to be used as carriers of MB for PDT systems.
Full-textDOI: · Available from: Mansoor Amiji, Jul 05, 2015
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ABSTRACT: Background: Growth factors such as platelet derived growth factor (PDGF) have significantly enhanced periodontal therapy outcomes but with a high degree of variability, mostly due to lack of their continual supply for a required period of time. One method to overcome this barrier is gene therapy and the aim of this in vitro study is to evaluate PDGF-B gene delivery in fibroblasts using nano-sized calcium phosphate particles (NCaPP) as vectors. Methods: NCaPP incorporating green fluorescent protein, GFP (NCaPP-GFP) and PDGF-B (NCaPP-PDGF-B) plasmids were synthesized using an established precipitation system and characterized using transmission electron microscopy and 1.2% agarose gel electrophoresis. Biocompatibility and transfection of the nanoplexes in fibroblasts were evaluated using cytotoxicity assay and florescence microscopy, respectively. Polymerase chain reaction (PCR) and enzyme linked Immunosorbent assay (ELISA) were performed to evaluate PDGF-B transfection after different time points of treatments and the functionality of PDGF-B transfection was evaluated using the cell proliferation assay. Results: Synthesized NCaPP nanoplexes incorporating the genes of GFP and PDGF-B were spherical in shape and measured about 30 to 50 nm in diameter. Gel electrophoresis confirmed DNA incorporation and stability within the nanoplexes and MTS assay demonstrated their biocompatibility in fibroblasts. In vitro transfection studies revealed a higher and longer lasting transfection after NCaPP-PDGF-B treatment, which lasted up to 96 hours. Significantly enhanced fibroblast proliferation observed in NCaPP-PDGF-B treated cells confirmed the functionality of these nanoplexes. Conclusion: NCaPP demonstrated higher levels of biocompatibility and efficiently transfected PDGF plasmids into fibroblasts under described in vitro conditions.Journal of Periodontology 03/2012; DOI:10.1902/jop.2012.120012 · 2.57 Impact Factor
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ABSTRACT: Photodynamic therapy (PDT) is based on the synergism of a photosensitive drug (a photosensitizer) and visible light to destroy target cells (e.g., malignant, premalignant, or bacterial cells). The aim of this study was to investigate the response of normal rat tongue mucosa to PDT following the topical application of hematoporphyrin derivative (Photogem®), Photodithazine®, methylene blue (MB), and poly(lactic-co-glycolic acid) (PLGA) nanoparticles loaded with MB. One hundred and thirty three rats were randomly divided in various groups: the PDT groups were treated with the photosensitizers for 10 min followed by exposure to red light. Those in control groups received neither photosensitizer nor light, and they were subjected to light exposure alone or to photosensitizer alone. Fluorescent signals were obtained from tongue tissue immediately after the topical application of photosensitizers and 24 h following PDT. Histological changes were evaluated at baseline and at 1, 3, 7, and 15 days post-PDT treatment. Fluorescence was detected immediately after the application of the photosensitizers, but not 24 h following PDT. Histology revealed intact mucosa in all experimental groups at all evaluation time points. The results suggest that there is a therapeutic window where PDT with Photogem®, Photodithazine®, MB, and MB-loaded PLGA nanoparticles could safely target oral pathogenic bacteria without damaging normal oral tissue.Lasers in Medical Science 03/2012; 28(2). DOI:10.1007/s10103-012-1091-6 · 2.42 Impact Factor
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ABSTRACT: Phthalocyanines are prospective chemicals that have applications in industry, medicine and biology due especially to their architectural flexibility and production of reactive oxygen species. Although they are used in so many areas of human activities nowadays, there is still little knowledge of their ecotoxicity. Here we present the first observation of their toxic effects on representatives of the aquatic plants Lemna minor. The tested phthalocyanines possess a wide spectrum of phytotoxicity ranging from seldom (>50 mg L(-1)) to highly toxic 0.11 mg L(-1). Moreover, the potential of phthalocyanines to be used as selective cyanocides or herbicides is discussed as well.Chemosphere 04/2012; 88(8):962-5. DOI:10.1016/j.chemosphere.2012.03.028 · 3.50 Impact Factor