Photoactive Porphyrin Derivative with Broad-Spectrum Activity against Oral Pathogens In Vitro

Abstract

Photodynamic therapy (PDT) has historically been used as a means to treat cancerous tumors but has recently been used to kill bacterial cells through the use of targeted photosensitizers. PDT is a potential adjunct to scaling and root planing in the treatment of periodontal disease. However, the effectiveness of porphyrin derivatives against microorganisms has been limited because some gram-negative bacteria are refractory to photodynamic treatment with these agents. We have designed a porphyrin derivative conjugated to a pentalysine moeity that endows the molecule with activity against gram-positive and gram-negative bacteria. Whereas the porphyrin, chlorin e6, showed in vitro activity against a limited spectrum of bacteria, chlorin e6 conjugated to pentalysine showed in vitro activity against all oral microorganisms tested, including Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Campylobacter rectus, Eikenella corrodens, Fusobacterium nucleatum subsp. polymorphum, Actinomyces viscosus, and the streptococci. Potent antimicrobial activity (>5-log-unit reduction in the numbers of CFU per milliliter) was retained in the presence of up to 25% whole sheep blood. The use of potent, selective agents such as this chlorin e6-pentalysine conjugate to more effectively reduce the pathogenic bacteria in the

Inativação fotodinâmica de microrganismos

“…Azul de metileno, por ex., pode erradicar totalmente C. albicans da cavidade oral com administração tópica do corante 36 . Rovaldi et al sugerem o uso de um potente derivado de clorina para reduzir diversas bactérias patogênicas na cavidade periodontal e que o método pode se tornar uma ferramenta importante para tratamento de doenças periodontais 37 .…”

Antimicrobial photodynamic therapy using visible light plus water-filtered infrared-A (wIRA)

“…The differences in the cell wall structure of Gram-positive and Gram-negative bacteria lead to variations in the binding ability of photosensitizing agents to different bacterial surfaces. For example, the affinity of negatively charged photosensitizers to Gram-negative bacteria can be enhanced by modifying the sensitizer by using cationic molecules such as chlorine e6 (Rovaldi et al, 2000). This emphasizes the necessity for the identification of an effective photosensitizer and a suitable light source, which together are capable of eliminating various resistant micro-organisms in the presence of a pronounced bacterial diversity in the oral cavity.…”

The Phenothiazine Compound Antimicrobial Activity

“…Аíòèì³êðîбíà фîòîх³ì³îòåðàп³ÿ (ФХТ) пîëÿгàє ó ñåëåêòèâí³é äåñòðóêö³ї пàòîгåííèх ì³êðîîðгàí³зì³â пðè êîìб³íîâàíîìó âпëèâ³ ñпîëóêè -фîòîñåíñèб³ë³зàòîðà (ФС) òà âèпðîì³íюâàííÿ â³äпîâ³äíîгî ñпåêòðàëüíîгî ñêëàäó [10]. Дî îб'єêò³â àíòèì³êðîбíîї ФХТ â³äíîñÿòü â³ðóñè, бàêòåð³ї òà ³íш.…”