Giuseppe Greco1, Simone Di Piazza2, Jiemei Chan3, Mirca Zotti2, Reem Hanna4, Ezio Gheno5, Angelina O Zekiy6, Claudio Pasquale3, Nicola De Angelis7, Andrea Amaroli8. 1. Laboratory of Mycology, Department of Earth, Environmental and Life Sciences, University of Genoa, Genoa, Italy. Electronic address: giuseppe.greco@edu.unige.it. 2. Laboratory of Mycology, Department of Earth, Environmental and Life Sciences, University of Genoa, Genoa, Italy. 3. Laser Therapy Centre, Department of Surgical and Diagnostic Sciences, University of Genoa, Genoa, Italy. 4. Laser Therapy Centre, Department of Surgical and Diagnostic Sciences, University of Genoa, Genoa, Italy; Department of Oral Surgery, Dental Institute, King's College Hospital NHS Foundation Trust, Denmark Hill, London, SE5 9RS, UK. 5. Laser Therapy Centre, Department of Surgical and Diagnostic Sciences, University of Genoa, Genoa, Italy; Dental Clinical Research Center, Dentistry School, Fluminense Federal University, Rua São Paulo, 28, Campus do Valonguinho Centro, Niterói, RJ, 24020 150, Brazil. 6. Department of Orthopedic Dentistry, Sechenov First Moscow State Medical University, Trubetzkaya St., 8, Bd. 2, 119991, Moscow, Russian Federation. 7. Laser Therapy Centre, Department of Surgical and Diagnostic Sciences, University of Genoa, Genoa, Italy; Faculty of Dentistry, University of Technologi MARA, Sungai Buloh Campus, Jalan Hospital, 47000 Sungai Buloh, Selangor, Malaysia. 8. Laser Therapy Centre, Department of Surgical and Diagnostic Sciences, University of Genoa, Genoa, Italy; Department of Orthopedic Dentistry, Sechenov First Moscow State Medical University, Trubetzkaya St., 8, Bd. 2, 119991, Moscow, Russian Federation. Electronic address: andrea.amaroli.71@gmail.com.
Abstract
BACKGROUND: A large number of systemic diseases can be linked to oral candida pathogenicity. The global trend of invasive candidiasis has increased progressively and is often accentuated by increasing Candida albicans resistance to the most common antifungal medications. Photodynamic therapy (PDT) is a promising therapeutic approach for oral microbial infections. A new formulation of 5-aminolevulinic acid (5%ALA) in a thermosetting gel (t) (5%ALA-PTt) was patented and recently has become available on the market. However, its antimicrobial properties, whether mediated or not by PDT, are not yet known. In this work we characterised them. METHODS: We isolated a strain of C. albicans from plaques on the oral mucus membrane of an infected patient. Colonies of this strain were exposed for 1 24 h, to 5%ALA-PTt, 5%ALA-PTt buffered to pH 6.5 (the pH of the oral mucosa) (5%ALA-PTtb) or not exposed (control). The 1 h-exposed samples were also irradiated at a wavelength of 630 nm with 0.14 watts (W) and 0.37 W/cm2 for 7 min at a distance of <1 mm. RESULTS AND CONCLUSION: The 5% ALA-PTt preparation was shown to be effective in reducing the growth of biofilm and inoculum of C. albicans. This effect seems to be linked to the intrinsic characteristics of 5%ALA-TPt, such acidic pH and the induction of free radical production. This outcome was significantly enhanced by the effect of PDT at relatively short incubation and irradiation times, which resulted in growth inhibition of both treated biofilm and inoculum by ∼80% and ∼95%, respectively.
BACKGROUND: A large number of systemic diseases can be linked to oral candida pathogenicity. The global trend of invasive candidiasis has increased progressively and is often accentuated by increasing Candida albicans resistance to the most common antifungal medications. Photodynamic therapy (PDT) is a promising therapeutic approach for oral microbial infections. A new formulation of 5-aminolevulinic acid (5%ALA) in a thermosetting gel (t) (5%ALA-PTt) was patented and recently has become available on the market. However, its antimicrobial properties, whether mediated or not by PDT, are not yet known. In this work we characterised them. METHODS: We isolated a strain of C. albicans from plaques on the oral mucus membrane of an infectedpatient. Colonies of this strain were exposed for 1 24 h, to 5%ALA-PTt, 5%ALA-PTt buffered to pH 6.5 (the pH of the oral mucosa) (5%ALA-PTtb) or not exposed (control). The 1 h-exposed samples were also irradiated at a wavelength of 630 nm with 0.14 watts (W) and 0.37 W/cm2 for 7 min at a distance of <1 mm. RESULTS AND CONCLUSION: The 5% ALA-PTt preparation was shown to be effective in reducing the growth of biofilm and inoculum of C. albicans. This effect seems to be linked to the intrinsic characteristics of 5%ALA-TPt, such acidic pH and the induction of free radical production. This outcome was significantly enhanced by the effect of PDT at relatively short incubation and irradiation times, which resulted in growth inhibition of both treated biofilm and inoculum by ∼80% and ∼95%, respectively.