• Biomedical Science Letters
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• v.17 no.4
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• pp.363-366
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• 2011

Eradication of $H.$ $pylori$, usually carried out by using antimicrobial agents, is essential for preventing gastric ulcers and cancers. The $H.$ $pylori$ isolates, however, have continuously grown antimicrobial resistance, which have caused difficulty in treating the bacteria and in turn, photodynamic therapy (PDT) has been found to be effective in inducing deaths of variety of bacteria. After PDT treatment, the number of colony forming units (CFU), the morphologic changes, and flow cytometry were observed. In the PDT group containing 100 and 200 ${\mu}g$/ml photogem, no live $H.$ $pylori$ was observed, while 10 and 50 ${\mu}g$/ml photogem were only partially effective. $H.$ $pylori$ of the PDT group also displayed distortion and shrinkage in morphology. This study demonstrated that photogem-mediated PDT effectively induces deaths of $H.$ $pylori$.

• Biomedical Science Letters
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• v.14 no.4
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• pp.263-267
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• 2008

Photodynamic therapy (PDT) is a treatment utilizing the generation of singlet oxygen and other reactive oxygen species (ROS), which selectively accumulate in target cells. Peroxiredoxin (prx) plays an important role in eliminating peroxides generated during metabolism. Prx exert protective antioxidant role in cells though peroxidase activity. The aim of present work is to investigate the cytotoxicity of photofrin-mediated PDT in prx IV-transfectant AMC-HN3 cell lines. We confirmed that PDT has an effect on ROS generation in prx IV-induced cell lines. Treatment of PDT in prx IV-HN3 cell lines inhibits cytotoxic effects. Prx IV-induced HN3 cell lines resists in cell death during PDT. Also, prx IV-HN3 cell lines treated PDT inhibited ROS generation in contrast with vector control. We indicated that prx IV-induced AMC-HN3 cell lines have a function as inhibitors during PDT.

• Journal of Biomedical Engineering Research
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• v.25 no.1
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• pp.49-55
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• 2004

In this paper, we investigated the effects of the photodynamic therapy(PDT) for the tumor mass in mice. In the experimental method, we divided the mice into two control and test group which HepG2 and HeLa cell line induced cancer mass in mice. Photofrin was administered to the tumor-bearing mouse, followed 30 hours later by 630nm and 650nm laser light exposure. After photodynamic therapy we analyzed the two mice group for the tumor mass size, tumor growth, tumor cell necrosis, pathological anatomy change. According to the results, tumor cell necrosis was shown in the tissues which the reduce size of tumor and tumor cell necrotic change according to the irradiation time and light dose amount. The considerable difference, however, between the 630nm and 650nm wavelength was not found for the tumor cell necrotic change and other damage of normal tissue was not found.

• Molecular & Cellular Toxicology
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• v.2 no.1
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• pp.1-6
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• 2006

Photodynamic therapy (PDT), a newly established treatment for solid tumors, involves the systemic administration of a tumor localizing photosensitizer that is only activated when exposed to light of appropriate wavelength. Photoactivation of photosensitizer in the presence of oxygen results in the formation of highly cytotoxic molecular species, which precipitates necrosis. PDT has now become a promising means for the treatment of cancer due to its specificity, relatively minimal side effects, and inexpensive. However, the application of PDT has been restricted to the treatment of superficial lesions or the use of interstitial light delivery. A single photon generally activates the photochemical reaction in traditional PDT. However the use of multi photon excitation, where two or more photons simultaneously excite a photosensitizer, allows for the use of wavelengths twice as long. Such wavelengths exhibit better transmittance through tissue and thereby deeper penetration is achieved. This paper will review theoretical principles of multi photon excitation, challenges associated with multi photon PDT and update the current and future role of multi photon PDT in cancer.

• Journal of radiological science and technology
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• v.45 no.2
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• pp.165-170
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• 2022

Staphylococcus aureus is a major pathogen that causes clinical infections in humans and can also cause massively colonized in lesion skin, particularly in atopic dermatitis patients. This study investigated the effects of photodynamic inactivation with radachlorin and diode laser irradiation on the viability of S. aureus in vitro and assessed the effects of the dose of laser transmission. In the PDI group, 5 𝜇L of S. aureus suspension and 5 𝜇L of radachlorin were inoculated in a 55 mm petri dish (63.6 cm²). The samples were placed in a 37° incubator for 30 min and then irradiated with light (660 nm diode laser). After laser irradiation, the cells were stored for 24 h at 37° in an incubator with 5% CO2, and the number of colonies was counted. All CFU/mL of S. aureus were reduced by diode laser in the presence of radachlorin, with a killing rate of 87.9% at an energy dose of 9 J/cm². This study contribute to treat colonized with S. aureus in atopic dermatitis patients and wound infections by providing information on the optimal dose of laser transmission using PDI to eliminate S. aureus.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.9 no.1
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• pp.35-41
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• 2023

Photodynamic therapy (PDT), in which a photosensitizer (PS), light, and molecular oxygen are essential components, is a non-invasive and highly effective cancer therapeutic method. However, PDT suffers from the penetration limit of light caused by attenuation and scattering of light through tissues constraining its use to skin and endoscopically accessible cancers. Cerenkov luminescence (CL) is defined as the light illuminated when charged particles move in a dielectric medium at a velocity greater than the phase velocity of light. It is known that medical radioisotopes in preclinical and clinical settings have enough energy to generate CL, and lately, CL has been exploited as an excitation source for PDT without external light illumination. This review introduces state of the art studies of radioisotope-based PDT for cancer, in which radioisotopes are utilized as a light source.

• Journal of the korean academy of Pediatric Dentistry
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• v.51 no.1
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• pp.32-39
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• 2024

This study evaluated the additive impact of ethylenediamine tetraacetic acid (EDTA) on erythrosine-mediated photodynamic therapy (PDT) against Streptococcus mutans (S. mutans) biofilm by measuring colony-forming units and applying confocal laser scanning microscopy. Fifty-six bovine incisors, free from dental caries or structural defects, were utilized in this study. Dentin specimens were created by cutting with a low-speed diamond disk under a continuous flow of water, resulting in dimensions of 6.0 mm × 3.0 mm × 2.0 mm. The specimens were categorized into 4 groups: Control, EDTA, PDT, and EDTA + PDT. S. mutans ATCC 25175 was employed to establish biofilm on the dentin specimens. A 17% EDTA solution was applied for 1 min. For PDT, erythrosine served as the photosensitizer. Finally, a light-emitting diode source (385 - 515 nm) was employed in this study. The PDT group exhibited a significantly lower bacterial count than both the control and EDTA groups (p < 0.001). The EDTA + PDT group demonstrated a significantly reduced bacterial count compared to the other 3 groups (p < 0.001). This study demonstrated that EDTA enhances the antimicrobial efficacy of PDT on S. mutans biofilm. Even at a low concentration of photosensitizer, the combination of EDTA and PDT yields a significant antibacterial effect.

• Applied Chemistry for Engineering
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• v.27 no.6
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• pp.599-605
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• 2016

Recently, photodynamic and photothermal therapies have received increasing attention as an effective cancer treatment. In this study, a gold nanorod (AuNR) colloidal solution was synthesized as a hyperthermia agent for photothermal therapy and also modified with photosensitizer (PS) for photodynamic therapy. PEG (polyethylene glycol) and FA (folic acid) ligand were also introduced into AuNR for the long circulation in human body and efficient targeting of cancer cells, respectively and AuNRs were modified with FA-PEG and poly-${\beta}$-benzyl-L-aspartate (PBLA) block copolymers through a 3,4-dihydroxy hydrocinnamic acid (HCA) linker. A series of AuNRs with various aspect ratios were synthesized by controlling the feeding ratio of $AgNO_3$. The physicochemical property and morphology of synthesized AuNR100 and FA-PEG-$P(Asp)_{50}$-HCA-AuNR100 were analyzed by UV-visible spectrophotometer, $^1H$ NMR, XPS measurements, TEM. The surface modified AuNR carrier with biocompatibility could be applied for the effective diagnosis as well tumor phototherapy.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.1
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• pp.82-89
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• 2018

In a photodynamic therapy, the difference of antibacterial capacity was compared according to the type of source of light when the same quantity of energy is irradiated. After S. mutans is formed in planktonic state and biofilm state, erythrosine diluted to $40{\mu}M$ was treated for 3 minutes, and as the type of light source, Halogen, LED, and Plasma arc were used, which were irradiated for 30 seconds, 15 seconds and 9.5 seconds, respectively. After the completion of the experiment, CFU of each experiment arm was measured to compare the photodynamic therapeutic effects according to each condition. The CFU of each experiment arm had no statistically significant difference. Under the same quantity of energy, the photodynamic therapeutic effect can be said to be the same regardless of types of light source, which is a useful result in the clinical field with various light irradiators.

• Tuberculosis and Respiratory Diseases
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• v.63 no.1
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• pp.52-58
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• 2007

Background: Photodynamic therapy is a viable option for lung cancer treatment, and many studies have shown that it is capable of inducing cell death in lung cancer cells. However, the precise mechanism of this cell death has not been fully elucidated. To investigate the early changes in cancer cell transcription, we treated A549 cells with the photosensitizer DH-I-180-3 and then we illuminated the cells. Methods: We investigated the gene expression profiles of the the A549 lung cancer cell line, using a DEG kit, following photodynamic therapy and we evaluated the cell viability by performing flow cytometry. We identified the genes that were significantly changed following photodynamic therapy by performing DNA sequencing. Results: The FACS data showed that the cell death of the lung cancer cells was mainly caused by necrosis. We found nine genes that were significantly changed and we identified eight of these genes. We evaluated the expression of two genes, 3-phosphoglycerate dehydrogenase and ribosomal protein S29. The expressed level of carbonic anhydrase XII, clusterin, MRP3s1 protein, complement 3, membrane cofactor protein and integrin beta 1 were decreased. Conclusion: Many of the gene products are membrane-associated proteins. The main mechanism of photodynamic therapy with using the photosensitizing agent DH-I-180-3 appears to be necrosis and this may be associated with the altered production of membrane proteins.