Addition of hydrogen peroxide to methylene blue conjugated to beta-cyclodextrin in photodynamic antimicrobial chemotherapy in S. mutans biofilm

Author(s)

Sales, Luciana Solera ^[1] ; Guimaraes, Gustavo Narvaes ^[2] ; Wijesinghe, Gayan Kanchana ^[3] ; Silva Moreira, Kelly Maria ^[1] ; Joia, Felipe ^[3] ; Stipp, Rafael Nobrega ^[3] ; Azevedo Rodrigues, Lidiany Karla ^[4] ; Nobre-dos-Santos, Marines ^[1] ; Steiner-Oliveira, Carolina ^[1]

Affiliation

^[1] Univ Campinas UNICAMP, Dept Hlth Sci & Pediat Dent, Piracicaba Dent Sch, Ave Limeira 901 Areiao, BR-13414903 Piracicaba, SP - Brazil

^[2] Univ Campinas UNICAMP, Dept Morphol, Div Histol & Embryol, Piracicaba Dent Sch, Ave Limeira 901 Areiao, BR-13414903 Piracicaba, SP - Brazil

^[3] Univ Campinas UNICAMP, Dept Oral Diag, Piracicaba Dent Sch, Ave Limeira 901 Areiao, BR-13414903 Piracicaba, SP - Brazil

^[4] Univ Fed Ceara, Fac Pharm Dent & Nursing, Cap Francisco Pedro S-N, Fortaleza, CE - Brazil

• Document type: Journal article
• Source: Photodiagnosis and Photodynamic Therapy; v. 28, p. 226-233, DEC 2019.
• Web of Science Citations: 0

Abstract

Objective: This study evaluated the effect of hydrogen peroxide addition on beta-cyclodextrin-conjugated methylene blue in antimicrobial photodynamic therapy(a-PDT) in S. mutans biofilm model using laser or light emitting diode (LED) (lambda = 660 nm). Methods: A preliminary assay was performed to evaluate the cytotoxicity of hydrogen peroxide in oral fibroblasts by the colorimetric method (MTT). Afterwards, groups were divided into (n = 3, in triplicate): C (negative control), CX - chlorhexidine 0.2% (positive control), P (methylene blue/beta-cyclodextrin), H (Hydrogen Peroxide at 40 mu M), PH, L (Laser), LP, LH (Laser + Hydrogen Peroxide), LPH, LED, LEDP, LEDH, and LEDPH. The biofilm was formed in 24 h with BHI + 1% sucrose (w/v). Light irradiations were conducted with laser, 9 J, 323 J/cm(2), 113 s or with LED, 8.1 J, 8.1 J/cm(2) for 90 s. Microbial reduction was evaluated by counting the viable microorganisms of the biofilm after the respective treatments, in a selective culture medium, and laser confocal microscopy evaluation. Results: LP, LH, LPH, LEDP, LEDH, and LEDPH groups statistically reduced the counts of S.mutans compared with the C group and the log reductions were of 1.87, 1.94, 2.19, 0.91, 0.92, and 1.33, respectively; the addition of hydrogen peroxide did not potentiate the microbial reductions (LPH and LEDPH) compared with the LP and LEDP groups. Conclusion: The association of hydrogen peroxide with the conjugated beta-cyclodextrin nanoparticle as photosensitizer did not result in an enhanced effect of a-PDT; hydrogen peroxide behaved as a photosensitizer, since it reduced the number of S. mutans when associated with laser light. (AU)

• FAPESP's process: 17/03263-3 - Development of a low-cost and robust SYBR Green buffer system for qPCR
• Grantee: Rafael Nobrega Stipp
• Support Opportunities: Regular Research Grants