Objective: The aim of this study was to investigate the effects of the antimicrobial photodynamic therapy (aPDT) using the association of curcumin with the surfactant sodium dodecyl sulfate (SDS) for oral decontamination in orthodontic patients. Background data: The installation of the orthodontic appliances promotes an increase in the retentive area that is available for microbial aggregation and makes difficult the oral health promotion. However, aPDT is one possible approach that is used for the reduction of oral microbial load. Materials and methods: Twenty-four patients ( n = 24) were randomly distributed into four groups: Light group: which was treated only with the blue light, no drug; PDT group, which was treated with curcumin and blue light; PDT + S group, which was treated with curcumin plus surfactant and irradiated with blue light; and Chlorhex group, which was treated with chlorhexidine. The photosensitizer agent was prepared by adding 0.1% of SDS to a curcumin solution of 1 g/L. Two distinct LED devices emitting blue light (450 ± 10 nm) were used as follows: extra-oral irradiation (200 mW, 80 mW/cm ² , 36 J and 14 J/cm ² ) and intra-oral irradiation (1200 mW, 472 mW/cm ² , 216 J and 85 J/cm ² ).The collection of nonstimulated saliva ( n = 3; 3 mL/collection) was performed at the following steps: (1) immediately before swishing (curcumin, chlorhexidine, or water); (2) after swishing; and (3) after performing aPDT treatments. The colony-forming units (CFU) were counted visually, and the values were adjusted to CFU/mL. Results: There was significant Log reduction for PDT (from 6.33 ± 0.92 to 5.78 ± 0.96, p < 0.05), PDT + S (from 5.44 ± 0.94 to 3.83 ± 0.71, p < 0.01), and Chlorhex (from 5.89 ± 0.97 to 2.55 ± 1.80, p < 0.01) groups. The survival rate was significantly reduced in both PDT + S and Chlorhex groups compared with all situations ( p < 0.05). However, there was no significant difference between PDT + S and Chlorhex groups ( p ≥ 0.05). Conclusions: These results indicate that when associated with the surfactant SDS, the aPDT can be used as an adjutant and a convenient agent to promote the oral decontamination in clinical practice.

With the aim of contributing to the development of more efficient materials for wound care, new topical formulations based on bacterial nanocellulose (BNC) hydrogels containing propolis were produced. Characterizations confirmed the incorporation of propolis into the BNC matrix, maintaining its structure and properties. Rheological analysis confirmed that the hydrogels showed thixotropic behavior appropriate for topical application. Chromatographic profiles showed sustained release of propolis biomarkers for at least 20 h. The formulations did not present mutagenicity. For application in photodynamic inactivation (PDI), BNC/propolis hydrogels were prepared with the photosensitizers methylene blue (MB). Spectroscopy and confocal fluorescence microscopy confirmed the interaction of MB and propolis in BNC hydrogels, as well as the formation of a new composite material. In the antibacterial assays, formulations containing MB and propolis significantly reduced Staphylococcus aureus growth. In the presence of light, BNC/MB hydrogels completely inhibited the microorganism. Therefore, the results suggest potential materials for the prevention or treatment of Staphylococcus aureus infections in wounds.

Objective: The aim of this study was to evaluate the effectiveness of a new handheld equipment based on a mercury low-pressure vapor lamp. The Surface UV ^® device was tested in Staphylococcus aureus , Streptococcus mutans , Streptococcus pneumoniae , two strains of Escherichia coli , Pseudomonas aeruginosa , Candida albicans , and other clinical microorganisms isolated from different surfaces of a public health hospital. Background data: The incidence of hospital infections has increased in recent years. Despite the variety of available chemicals to reduce the microorganisms, the search for antimicrobial agents and the characterization of novel targets are a continued need. Also, the minimization of chemical procedures is a constant need, and the use of ultraviolet (UV) light as a germicidal device for microorganisms' inactivation has been an alternative and one possible approach for the reduction of contamination. Materials and methods: The in vitro decontamination was performed by application of Surface UV in different species of microorganisms (study 1). The surface decontamination was carried out by application of Surface UV on each surface of hospital environment (study 2). The device presents ultraviolet C (UV-C) light at 254 nm and produces an irradiance of 13 mW/cm ² at a distance of 1 cm of the surfaces. The light dose was 0.78 J/cm ² for 60 sec of application in both studies. Results: The results for in vitro decontamination indicated a log ₁₀ reduction factor of 6.5 for S. aureus , 6.7 for S. mutans , 6.2 for S. pneumoniae , 5.4 for E. coli , 5.2 for E. coli (ATCC 8739), 5.4 for P. aeruginosa , and 6.7 for C. albicans . The hospital level of microorganisms decreases more by 75% after the procedure. Conclusions: The study highlights the development and successful application of a new portable device that can reduce the risk of contamination in health settings. Our results suggest that Surface UV is efficient and may be an alternative decontamination method.