• Molecular & Cellular Toxicology
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• 제2권1호
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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.

• Archives of Pharmacal Research
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• 제29권3호
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• pp.188-190
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• 2006

In this study, a newly-synthesized metalloporphyrin, Gd-chlorin (PB Chlorin), was investigated by using a simple tissue phantom to test its efficacy as an MRI contrast agent. This study demonstrated the potential activity of Gd-chlorin as not only a MRI contrast agent, but also as a PDT photosensitizer by using a simple tissue phantom and conducting a very brief MRI experiment.

• Journal of Gastric Cancer
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• 제20권4호
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• pp.355-375
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• 2020

Selective accumulation of a photosensitizer and the subsequent response in only the light-irradiated target are advantages of photodynamic diagnosis and therapy. The limited depth of the therapeutic effect is a positive characteristic when treating surface malignancies, such as peritoneal carcinomatosis. For photodynamic diagnosis (PDD), adjunctive use of aminolevulinic acid- protoporphyrin IX-guided fluorescence imaging detects cancer nodules, which would have been missed during assessment using white light visualization only. Furthermore, since few side effects have been reported, this has the potential to become a vital component of diagnostic laparoscopy. A variety of photosensitizers have been examined for photodynamic therapy (PDT), and treatment protocols are heterogeneous in terms of photosensitizer type and dose, photosensitizer-light time interval, and light source wavelength, dose, and dose rate. Although several studies have suggested that PDT has favorable effects in peritoneal carcinomatosis, clinical trials in more homogenous patient groups are required to identify the true benefits. In addition, major complications, such as bowel perforation and capillary leak syndrome, need to be reduced. In the long term, PDD and PDT are likely to be successful therapeutic options for patients with peritoneal carcinomatosis, with several options to optimize the photosensitizer and light delivery parameters to improve safety and efficacy.

• 대한소아치과학회지
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• 제51권1호
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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.

• 대한의생명과학회지
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• 제15권3호
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• pp.233-239
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• 2009

The aim of this study was to evaluate the photodynamic effect of various photosensitizing agents against methicillin-resistant Staphylococcus aureus (MRSA). MRSA was exposed to light from a 632 urn diode laser (15 J/$cm^2$) in the presence of various photosensitizer, such as photofrin, photogem, radachlorine and ALA. In vivo study was performed using ICR mice. Twenty eight mice had a standard wound ($100\;mm^2$) created on the dorsum, and MRSA was inoculated into the wound region. The four groups were classified as follows: (1) the untreated control group (bacteria alone), (2) the bacteria plus light group (15 J/$cm^2$), (3) the bacteria plus photofrin group (kept in the dark), and (4) the photodynamic therapy (PDT) group (bacteria, photofrin, and light). After photofrin (dose 1 mg/kg) injection, the experimental group was irradiated with 632 urn diode laser (15 J/$cm^2$) for 30 minutes after In vitro results of PDT showed the complete killing of MRSA at the photofrin, radachlorine, and photogem However, ALA-PDT was ineffective on MRSA viability. In vivo results showed that photofrin has therapeutic effect on the wound infection. These results demonstrate that selective lethal photosensitization of MRSA can be achieved using phofrin, photogem and radachlorin. Thus, PDT can inactivate MRSA survival.

• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2465-2468
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• 2011

• Bulletin of the Korean Chemical Society
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• 제29권12호
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• pp.2505-2508
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• 2008

• 대한의생명과학회지
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• 제15권1호
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• pp.87-91
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• 2009

In photodynamic therapy (PDT), oxygen plays important role. Because of singlet oxygen which is produced by activated photosensitizer after laser irradiation of specific wavelength. The aim of this study is to find how oxygen concentration affects anticancer effect in PDT. Groups were divided into PDT with oxygen applied group and only PDT applied group. PDT with oxygen applied group supplied oxygen for 15 minute before laser irradiation. In vitro, CT-26 cell was incubated with various concentration of photofrin $(50.0{\sim}0.05{\mu}g/ml)$ and was irradiated with 632nm diode laser 6hr after application of photofrin. The cell viability of two groups was assessed by MTT assay. In vivo, CT-26 cell line was transplanted into the subcutaneous tissue of BALB/c mouse. The anticancer effect of two groups was measured by tumor volume change. In vitro study, the cell viability was significantly decreased at $1.56{\sim}3.13{\mu}g/ml$ in PDT with oxygen applied group. In vivo study, the PDT with oxygen applied group significantly higher reduction rate of tumor volume 7 days after PDT compared to PDT only group. The high oxygen concentration might enhance the anticancer effect of the photodynamic therapy.

• KSBB Journal
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• 제22권5호
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• pp.318-321
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• 2007

광역동요법 (photodynamic therapy, PDT)은 악성종양을 치료하기 위해 광과민제와 레이저광을 이용하는 표적지향적 항암치료법이다. 본 연구에서는 PDT에 적용할 수 있는 새로운 광과민제를 스크리닝하기 위해 4종의 phthalocyanine계 광과민제 (silver phthalocyanine, iron (III) phthalocyanine, copper (II) phthalocyanine, nickel (II) phthalocyanine)을 이용하여 폐암과 유방암 세포주에 대한 항암활성 테스트를 수행하였다. 연구결과 phthalocyanine계 광과민제들은 폐암보다 유방암에 높은 활성을 나타냈으며, 그 중 silver phthalocyanine (AgPc)는 정상세포에 대해서는 세포독성이 낮으면서도 물에 용해할 경우 청색증을 유발하지 않아 유방암에 대한 항암제로서의 개발가능성을 확인하였다.

• Tuberculosis and Respiratory Diseases
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• 제57권4호
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• pp.358-363
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• 2004

연구배경 : 폐암에서 광역동치료는 미세침습성 비소세포폐암 및 기관지폐쇄를 일으키는 악성종양에 대한 기관지내 치료를 미국식품의약국(FDA)에서 승인한 상태이다. 국내에서는 폐암세포주에 대한 보고 외에 폐암에 대한 광역동치료 연구가 많지 않아 임상 성적에 대한 보고가 없어 이에 저자들은 폐암에서 시행된 광역동치료에 대한 결과를 문헌고찰과 함께 보고하고자 한다. 방 법 : 2002년 8월부터 2003년 5월까지 조선대학교 병원에서 기관지 내시경을 통해 조직학적으로 진단된 폐암환자 중 10명을 대상으로 하여 광역동치료 48시간 전에 광과민제(Photogem$^{(R)}$, Lomonosov institute of Fine Chemical, Russia)를 2.0mg/Kg을 정맥 주사한 후 48시간, 72시간에 Diode LASER system(Biolitec Inc., Germany, wavelength; 633nm)을 사용하여 광역 동치료를 시행하였다. 결 과 : 10명 중 9예에서 부분관해와 함께 기관지 개통을 보였으며, 1예에서는 변화를 보이지 않았다. 결 론 : 저자들은 광역동치료를 통해 기관지폐쇄로 인한 호흡곤란 및 기관지 폐쇄와 관련된 폐렴이 개선됨을 확인 하였으며, 합병증이 적어 안전한 기관지내 치료법으로 생각된다. 앞으로 광역동 치료에 대한 장기적인 결과 및 적절한 치료 적응증 및 조기 폐암에서 치료효과 등에 대한 연구가 필요할 것으로 생각된다.