The effects of photodynamic therapy with blue light and papain-based gel associated with Urucum, on collagen and fibroblasts: a spectroscopic and cytotoxicity analysis.

Papacarie Duo™ is clinically used and has proven effectiveness; however, it is necessary to improve its antimicrobial action. The combined treatment of Papacarie Duo™ with Urucum (Bixa Orellana) could create a potential tool for dental caries treatment; its extract obtained from the seeds' pericarp contains a water-soluble primary pigment (cis-bixin) with smaller amounts of other carotenoids. The dicarboxylic acid salts of cis-norbixin and trans-norbixin occur in heated alkaline solutions. To analyze the absorption spectra and cytotoxicity (with human dermal fibroblasts) in different concentrations of Urucum, associated or not with Papacarie Duo™, we performed this in vitro study. The effects of pure Urucum, Papacarie Duo™, and PapaUrucum™ on the microstructure of collagen were also analyzed. The application of papain-based gel with Urucum did not present cytotoxicity, its exhibit UV absorption spectrum peak around 460 ± 20 nm. Also, it showed that the compound used did not alter the chemical structure of collagen. Consequently, this product could be used as a chemomechanical method to remove dentin caries as well as being a potential product for antimicrobial photodynamic therapy (aPDT) application.

Photodynamic Therapy Associated with a Blue Dye Papain-Based Gel and Evaluation of Its Degradation of Type I Collagen Fibers.

OBJECTIVE: The aim of this in vitro study was to evaluate the degradation of type I collagen fibers after treatment with a papain-based gel associated with a blue dye (PapaMBlue™) for use in antimicrobial photodynamic therapy. MATERIALS AND METHODS: For such, 60 bioabsorbable membrane sponge discs were used. Group 1 was the negative control group. In groups 2, 3, and 4, the papain-based gel PapaMBlue gel was applied all over the samples for 4 min and irradiated using red laser (660 ± 10 nm) with 15, 30, and 40 J/cm2, respectively. In group 5, the papain-based gel was applied all over the samples for 4 min. In group 6, the photosensitizing dye was applied all over the samples for 4 min. The compositional analysis of the samples was performed using ATR-FTIR (attenuated total reflectance-Fourier transformed infrared spectroscopy). The data were statistically analyzed using ANOVA and Tukey's test (p < 0.05). RESULTS: Neither classic Papacarie™ nor the modified product with a photosensitizing agent (PapaMBlue) promoted collagen degradation. CONCLUSIONS: The irradiation of methylene blue added to papain gel with red light did not alter the chemical structure of type I collagen.