title: Bactericidal effects of hematoporphyrin monomethyl ether-mediated photosensitization against pathogenic communities from supragingival plaque.
abstract: Photodynamic antimicrobial chemotherapy (PACT) is proposed as a potential candidate to inactivate pathogens in localized infections due to the rapid evolution of bacterial resistance. The treatment modality utilizes nontoxic agents called photosensitizers and harmless visible light to generate reactive oxygen species which result in microbial cells' killing. Hematoporphyrin monomethyl ether (HMME) as a novel and affordable photosensitizer has been used in treating various clinical diseases for years, but few applications in infection. In this report, we studied the bactericidal effects of the HMME-mediated photodynamic reaction on the pathogenic microbes in supragingival plaque which can lead to many oral infectious diseases such as caries, gingivitis, and so on. Our findings demonstrated that HMME promoted an effective action in bacterial reduction with the application of laser energy. Moreover, the antimicrobial activities were dramatically enhanced as the HMME concentration and exposure time were increased, but reached a plateau when matched the appropriate agent concentration and illumination. It was found that the survival fraction of microorganisms is exponentially dependent on the product of HMME concentration and irradiation time. These promising results suggest the HMME may be an excellently cost-effective photosensitizing agent for mediating PACT in the treatment of supragingival plaque-related diseases. An optimized HMME concentration and irradiation time has been found to achieve the best results under our experimental conditions. The high HMME concentration matching short curative time, or vice versa, can achieve the similar therapeutic effect, which may provide more flexible treatment plans according to specific conditions.
authors.affiliation: Department of Stomatology, The Fourth Affiliated Hospital, Harbin Medical University, P.O. Box 31, YinHang Street, Nangang District, Harbin, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Sun
authors.forename: Defeng
authors.initials: D
authors.lastname: Xing
authors.forename: Lanhua
authors.initials: L
authors.lastname: Shen
authors.forename: Miao
authors.initials: M
authors.lastname: Sun
authors.forename: Ming
authors.initials: M
authors.lastname: Fang
authors.forename: Liangjia
authors.initials: L
authors.lastname: Bi
authors.forename: Yanjiao
authors.initials: Y
authors.lastname: Sui
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Zhang
authors.forename: Wenwu
authors.initials: W
authors.lastname: Cao
mesh_terms: D001419:Bacteria / Q000187:drug effects / Q000302:isolation & purification* / Q000528:radiation effects; D003773:Dental Plaque / Q000382:microbiology*; D004305:Dose-Response Relationship, Drug; D006415:Hematoporphyrins / Q000494:pharmacology*; D006801:Humans; D007834:Lasers; D008027:Light; D050296:Microbial Viability / Q000187:drug effects* / Q000528:radiation effects*; D010787:Photosensitivity Disorders; D017319:Photosensitizing Agents / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D006415:Hematoporphyrins; D017319:Photosensitizing Agents; C494379:hematoporphyrin monomethyl ether