Effect of Antimicrobial Photodynamic Therapy in a murine model of oral candidosis. In vivo evaluation of a Photodithazine hydrogel and Aluminum-Chlorine-Phthalocyanine cationic nanoemulsion.

Abstract

The aim of this study is to evaluate the effectiveness of photodynamic therapy (PDT) mediated by Photodithazine® (PDZ) hydrogel and aluminum-chloro-phthalocyanine cationic nanoemulsion (ClAlPc), as photossensitizer (PS), associated with LED light (660nm). A hundred- forty- four 6-week-old female Swiss mice were immunosuppressed with subcutaneous injections of prednisolone 100mg/kg on the 1st, 5th and 9th day of the experiment. On day 2nd, standardized cell suspension will be prepared and adjusted to 107 Ufc / mL. The animals will be anesthetized with 0.1 mL of chlorpromazine hydrochloride 2mg/mL, and then C. albicans will be inoculated in the tongue of mice. PDT will be performed during 5 consecutive days. The PS will be evaluated at concentrations of 100 mg / L for PDZ and 31.7 µM for ClAlPc associated with a dose of 37.5 J/cm2 and 100J/cm2, respectively. Experimental groups will be named P + L + 100mg / L, P + L + 31.7 µM. To evaluate the effect of PDZ or ClAlPc, only, the PSs will be applied on the tongue of mice without illumination(P+L-100mg / L, P + L-31.7 µM). To investigate the effect of light only, the tongue of all animals will beilluminated with a dose of 37.5 J/cm2 for PDZ and 100J/cm2 for ClAlPc, without application of PS(P-L+ 37.5 J/cm2 and P-L+ 100J/cm2. One group will receive only inoculation with Candida (positive control group - P-L-), the other group will receive no treatment and no fungal inoculation (negative control group - NC). For comparison, there is a group in which animals will be treated with Nystatin (group - Nis) 2 times daily for 5 days. After the experiments the recovery of C. albicans of the tongue of animals will be performed with small cotton pads. These swabs will be embedded in tubes with 1 mL of saline and serial dilutions will be made and placed in petri dishes with SDA at 37 ° C for 48 hours. The yeast colony counts will be quantified and the number of CFU/mL determined. Animals will be killed immediately and 7 days after treatment, the tongue of all mice will be surgically removed for histological analysis and biomolecular analysis to evaluate the presence of pré and antiinflammatory cytokines. Additionally, the damage of the cell nucleus will be analyzed, and biomolecular analysis of proteinase production will be performed. The results will be evaluated by appropriate statistical method.