• 제목/요약/키워드: Photosensitizer

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Antimicrobial Effect of Photodynamic Therapy Using Plaque Disclosing Agent (치면착색제를 이용한 광역동 치료의 항균 효과)

  • Kho, Junhee;Park, Howon;Lee, Juhyun;Seo, Hyunwoo;Lee, Siyoung
    • Journal of the korean academy of Pediatric Dentistry
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    • v.47 no.2
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    • pp.120-127
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    • 2020
  • The aim of this study was to evaluate the antimicrobial effect of photodynamic therapy (PDT) using plaque disclosing agent, 10 - 20 mM erythrosine, as a photosensitizer. Multispecies cariogenic biofilms containing Streptococcus mutans, Lactobacillus casei and Candida albicans were formed on hydroxyapatite disc. 20 μM, 10 mM and 20 mM erythrosine were applied as a photosensitizer for 3 minutes, and then light-emitting diode (LED) irradiated for 24 seconds. Colony-forming unit (CFU) were measured and biofilms were observed using confocal laser scanning microscopy (CLSM). CFU were significantly decreased in the PDT groups using 10 - 20 mM erythrosine (10 mM, 20mM) and the results were also confirmed by CLSM. This study confirms the high antimicrobial effect of photodynamic therapy using plaque disclosing agent as a photosensitizer.

Screening of Photosensitizer for Photodynamic Therapy (광역동 항암치료를 위한 광과민제 스크리닝 연구)

  • Kim, So-Young;Yoo, Gui-Jae;Park, Keun-Hyoung;Lim, Byung-Lak;Kim, Shi-Surk;Yom, Heng-Cherl;Chae, Hee-Jeong
    • KSBB Journal
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    • v.22 no.5
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    • pp.318-321
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    • 2007
  • Photodynamic therapy (PDT) is a targeted-tumor treatment system using a photosensitizer, light and oxygen to treat malignant tumor. We have investigated the cytotoxicity of 4 types of phthalocyanine derivative (silver phthalocyanine, iron (III) phthalocyanine, copper (II) phthalocyanine, nickel (II) phthalocyanine) against lung and breast cancers based on photodynamic therapy. As a result, phthalocyanine derivatives indicated a higher anticancer activity on a breast cancer cell line. Among the tested phthalocyanines, silver phthalocyanine (AgPc) showed a lower cytotoxicity against a normal cell line. In addition AgPc gave a good color characteristic when it is solubilized in water. Finally AgPc was selected as a potential antitumor agent for breast cancer.

PHOTODYNAMIC THERAPY OF PREMALIGNANT AND MALIGNANT LESIONS IN ORAL AND MAXILLOFACIAL SURGERY (구강악안면외과 영역의 전암병소 및 악성종양 치료를 위한 광역학 요법의 이용)

  • Oh, Jung-Hwan;Kubler, Alexander;Zoller, Joachim E.
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.28 no.3
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    • pp.234-238
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    • 2002
  • Photodynamic therapy (PDT) is based on a photochemical reaction which is initiated by light activation of a photosensitizer. The photosensitizer accumulates more in tumor tissues than in normal tissues and is activated with specific wavelength of light, usually laser. The photochemical reaction produces highly reactive oxygen products causing cytotoxiciy and vascular shutdown to the tumor. The advantages of PDT are its relative selective tumor destruction and tissue healing by regeneration, which can maintain important structures with very good functional and esthetic results. Therefore, PDT is considered as an alternative modality for cancers of the head and neck. In this article, we will report three cases of photodynamic therapy for treatment of oral leukoplakia, squamous cell carcinoma, and basal cell carcinoma of head and neck. It was observed that premalignant and malignant lesions responded well to the photodynamic therapy with Aminolevulinic acid (ALA) and $Foscan^{(R)}$. Photodynamic therapy can be considered as a new treatment method for the premalignant and malignant tumors in Oral and Maxillofacial Surgery.

Accelerating effect of some photosensitizers on photodegradation of the herbicide quinclorac in aqueous solution and soil (감광제에 의한 수용액 및 토양 중 제초제 quinclorac의 광분해 촉진효과)

  • Ahn, Ki-Chang;Lee, Jae-Koo
    • The Korean Journal of Pesticide Science
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    • v.4 no.4
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    • pp.12-18
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    • 2000
  • In order to artificially reduce the quinclorac residue in aqueous solution and soil, six potential photosensitizers were screened for their effectiveness in enhancing the photodegradation. The degraded amount of quinclorac in distilled water by sunlight was minor compared to that in the dark, indicating that there was little direct photolysis. The photodegradation ratio of quinclorac in methanol was 40.3%. Whereas, the ratios in the presence of photosensitizers PS-1 (aromatic ketone), PS-3 (polycyclic quinone), and PS-6 (inorganic semiconductor) were 96.6, 72.7, and 95.7%, respectively, showing the most photosensitizing effects. In sand, PS-3 was more effective than any other photosensitizer PS-1 (19.6%), PS-3 (64.1%) and PS-6 ($17.9{\sim}19.4%$). five photoproducts of quinclorac in methanol were identified by GC-MS and quinclorac added with the photosensitizer PS-1 gave three photoproducts. Photoproducts with an aldehyde group formed in methanol were confirmed by the reduction of sodium 3,5-dinitrosalicylate in the Lindsay's method. E. crus-galli war. oryzicola was not controlled by the quinclorac residues photodegraded at tile concentrations higher than 30 ppm of the photosensitizer PS-3 in a flooded rice paddy soil. These results indicate that the quinclorac residues in aqueous solution and soil can be degraded efficiently by tile photosensitizers PS-1, PS-3, and PS-6.

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Antimicrobial Photodynamic Therapy on Pseudomonas aeruginosa Using a Diode Laser and PhotoMed, Methyl Pheophorbide A, or Radachlorin® (다이오드 레이저와 PhotoMed, Methyl Pheophorbide A, Radachlorin®을 이용한 녹농균에 대한 항균 광역학 요법)

  • Young-Kyu SONG;Keun-Dol YOOK;Ji-Won KIM
    • Korean Journal of Clinical Laboratory Science
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    • v.56 no.1
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    • pp.52-58
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    • 2024
  • Photodynamic therapy (PDT) activates intracellular oxygen using a photosensitizer activated by light of a specific wavelength and is a potential means of treating wound infections caused by antibiotic-resistant bacteria. Pseudomonas aeruginosa (P. aeruginosa) is typically non-pathogenic in healthy individuals but can induce severe illnesses like sepsis in the immunocompromised. Antibiotics have been conventionally used to treat P. aeruginosa infections, but increasing antibiotic resistance caused by drug misuse poses a growing challenge to the management of these infections. This study aimed to investigate the ability of PDT using photosensitizers (PhotoMed, Methyl pheophorbide A, or Radachlorin®) and a diode laser to inhibit P. aeruginosa. Suspensions of P. aeruginosa and a photosensitizer were inoculated into Petri dishes and incubated for 30 minutes. Samples were then irradiated with the laser at 3 J/cm2, and after incubation, colony areas were measured. P. aeruginosa killing rates were 79.65% for PhotoMed, 47.36% for Methyl pheophorbide A, and 40.91% for Radachlorin®. This study shows that PDT using a diode laser and a photosensitizer constitutes an effective practical therapeutic approach for inhibiting P. aeruginosa.