Deciphering the killing mechanisms of potassium iodide in combination with antimicrobial photodynamic therapy against cross-kingdom biofilm.

Introduction: The co-existence of S. mutans and C. albicans is frequently detected in root caries and early child caries and is reported to be associated with recurrent caries. The aim of this study was to investigate the effects of potassium iodide (KI) in combination with toluidine blue O-mediated antimicrobial photodynamic therapy (aPDT) on S. mutans and C. albicans mixed-species biofilm, as well as the antibiofilm mechanisms involved. Methods: Mixed-species biofilm was constructed of S. mutans and C. albicans on dentin blocks. The antibiofilm efficacy, cytotoxicity and antibiofilm mechanism of KI in combination with aPDT were determined and evaluated. Results: KI+TBO-aPDT treatment caused reduction in microorganism counts, metabolic activity, and biofilm biomass of mixed-species biofilm without inducing cytotoxicity to hDPCs (human dental pulp cells). Observations such increased ROS (reactive oxygen species) levels, impaired cell membrane function, cell apoptosis and reduced expression in several genes seem to be artifacts of reduced growth and general killing by KI+TBO-aPDT treatment. Discussion: These data suggested that KI in combination with aPDT as an innovative approach to combat S. mutans and C. albicans biofilm, and thus as an optional treatment for caries.

Clinical aPDT's effect on Candida albicans: Antifungal susceptibility, virulence gene expression, and correlation with leukocyte and neutrophil counts.

BACKGROUND: Our previous clinical trial demonstrated that antimicrobial photodynamic therapy (aPDT) with methylene blue (MB) and potassium iodide (KI) effectively killed Candida albicans (C. albicans) in adult AIDS patients with oral candidiasis, regardless of biofilm formation or 25S rDNA genotype. This study evaluated changes in antifungal susceptibility and virulence gene expression in C. albicans before and after aPDT, and explored factors related to clinical aPDT efficacy. METHODS: Twenty-one adult AIDS patients with C. albicans oral candidiasis were divided into Group a (400 µM MB, N = 11) and Group b (600 µM MB, N = 10). Both groups received two aPDT treatments, where MB was applied for 5 min, followed by 300 mM KI, and illuminated for 30 min (37.29 J/cm²). C. albicans isolates were collected before and after treatment to assess antifungal susceptibility (fluconazole, itraconazole, flucytosine, amphotericin B) and gene expression (CAT1, HWP1). Peripheral blood tests were analyzed for correlations with aPDT efficacy. RESULTS: aPDT reduced minimum inhibitory concentration (MIC) values for amphotericin B, fluconazole, and flucytosine, with significant reductions primarily after the first treatment. MIC reductions differed between groups, with Group a showing greater decreases in flucytosine and fluconazole MICs, and Group b in amphotericin B MICs. No significant changes in CAT1 or HWP1 expression were observed. Clinical efficacy of aPDT negatively correlated with leukocyte and neutrophil levels. CONCLUSIONS: aPDT effectively reduces MICs of antifungal drugs against C. albicans isolated from treated patients, particularly after the first treatment. The concentration of MB required to reduce MICs varies among different antifungal drugs. aPDT does not alter CAT1 or HWP1 expression, and its clinical efficacy in eradicating C. albicans is negatively associated with leukocyte and neutrophil levels.

Is SDF better than the SMART (silver modified atraumatic restorative technique) in the management of molar incisor hypomineralisation molars with initial caries?

DESIGN: A prospective, randomized, split-mouth clinical study by the two previously trained and calibrated pediatric dentists without blinding operators and patients due to different protocols in both treatment groups. An SDF + potassium iodide (KI) and SDF + KI + glass ionmer cement (GIC) on International Caries Detection and Assessment System (ICDAS) 1/2 molar was received by each patient on either side of mouth. The local Ethics Committee approved this study. DATA SOURCE: Sample size calculation was not performed due to the lack of published studies on the longevity of SMART sealant on MIH-affected molars and the absence of research on the apparent difference between the effectiveness of SMART and SDF treatments in preventing further caries and sensitivity. STUDY SELECTION: These were children between the ages of 6 years to 13 years, who visited the Pediatric Dentistry Clinic at XX University School of Dentistry for routine exams and treatment between July 2019 to May 2020. They were in good health and had at least two fully erupted permanent first molars with MIH as per the European Academy of Pediatric Dentistry, ICDAS code 1/2. This study recorded 12 months of treatment outcomes on hypomineralised molars of 48 children with a follow-up of three years. Children were excluded with specific syndromes associated with enamel malformation, lack of cooperation, ongoing orthodontic treatment, and teeth with ICDAS 3/4/5/6 lesions, existing restorations, fluorosis, or pulpal symptoms. DATA ANALYSIS: Mann-Whitney U Test was used to assess differences between independent groups (SDF and SMART) and the Friedman Test between dependent groups at different time points. Kaplan-Meier analysis to evaluate the cumulative survival of SMART sealants and survival of caries-free hypomineralised molars in both groups. Chi-Square test was used to compare the success percentages of the SDF and SMART groups. To assess the changes in success percentages at three different time intervals for the caries preventive effect of SDF and SMART, and to evaluate the retention percentages for the SMART group. McNemar's test with a Bonferroni correction was used for significant differences. Cohen's kappa test indicated that the inter-examiner reliability determining the presence of MIH was 0.87. The intra-examiner reliability for US Public Health Service (USPHS)-Modified criteria was 0.90. The statistical significance level was set at p < 0.05 for all statistical analyses. RESULTS: At 12, 24 and 36 months the caries preventive effect was 100%, 67.9%, and 65.4% for SDF + KI-treated teeth; and 100%, 97.6%, and 94.7% for SMART (SDF + KI + GIC) respectively. During the recall period, there was no substantial difference in hypersensitivity scores between the groups. There was no hypersensitivity in teeth at 18 months and beyond. Compared to the baseline Schiff Cold Air Sensitivity Scale (SCASS) score 26 molar with initial hypersensitivity to hypomineralisation had a massive reduction at evaluation periods. The mean survival probabilities for the caries-preventive effect were considerably lower in SDF + KI-treated teeth (31.01 months) than in SMART-treated teeth (35.61 months) (p < 0.001). CONCLUSION: Considering the limitation of the study, both SMART (SDF + KI + GIC) sealants and 6-monthly application of SDF + KI, provided similar and substantial levels of desensitisation on the permanent MIH molars. When used as a sealing material on non-cavitated permanent MIH molars, the clinical retention rate for SMART was 88.7%, 73.1%, and 66.6% at 1, 2, and 3 years respectively. The caries preventive effect of SMART (SDF + KI + GIC) sealants was superior to SDF + KI application in hypomineralised teeth, however, a long-term monitoring and review is essential due to the gradual decrease in retention of SMART sealants.

Effect of iodine species on biofortification of iodine in cabbage plants cultivated in hydroponic cultures.

Iodine is an essential trace element in the human diet because it is involved in the synthesis of thyroid hormones. Iodine deficiency affects over 2.2 billion people worldwide, making it a significant challenge to find plant-based sources of iodine that meet the recommended daily intake of this trace element. In this study, cabbage plants were cultivated in a hydroponic system containing iodine at concentrations ranging from 0.01 to 1.0 mg/L in the form of potassium iodide or potassium iodate. During the experiments, plant physiological parameters, biomass production, and concentration changes of iodine and selected microelements in different plant parts were investigated. In addition, the oxidation state of the accumulated iodine in root samples was determined. Results showed that iodine addition had no effect on photosynthetic efficiency and chlorophyll content. Iodide treatment did not considerably stimulate biomass production but iodate treatment increased it at concentrations less than 0.5 mg/L. Increasing iodine concentrations in the nutrient solutions increased iodine content in all plant parts; however, the iodide treatment was 2-7 times more efficient than the iodate treatment. It was concluded, that iodide addition was more favourable on the target element accumulation, however, it should be highlighted that application of this chemical form in nutrient solution decreased the concetrations of selected micoelement concentration comparing with the control plants. It was established that iodate was reduced to iodide during its uptake in cabbage roots, which means that independently from the oxidation number of iodine (+ 5, - 1) applied in the nutrient solutions, the reduced form of target element was transported to the aerial and edible tissues.

Optimizing the feasibility of polyvinyl alcohol-potassium iodine gel for medical dosimeter.

This work aims to improve the post stabilty of reusable potassium iodide hydrogel dosimter. A reusable and low-cost radiochromic dosimeter containing a gel matrix of polyvinyl alcohol, potassium iodide dye, froctose as reducing agent and glutaraldehyde as cross-linking agent was developed for dose calibration in radiotherapy. The gel samples were exposed to different absorbed doses using a medical linear acceleration. UV-vis Spectrophotometry was utilized to investigate the changes in optical-properties of irradiated gels with regard to peak wavelength of 353 nm. The stability of the gel (one of the most limitation of using this dosimeter) was improved significantly by the addition of certain concentrations of dimethyl sulfoxide. The two-dimensional optical imaging system of charge-coupled-device (CCD) camera with a uniform RGB light-emitting-diode (LED) array source was used for diffusion coefficient purpose using two dimensional gel template. The value of diffusion coefficient reported is significant and highly reduced compared with other dosimeters reported in the literatures. Moreover, heating the improved gels to certain temperatures results in resetting their optical properties, which makes it possible to reuse for multiple times.

Complete photodynamic inactivation of Pseudomonas aeruginosa biofilm with use of potassium iodide and its comparison with enzymatic pretreatment.

Pseudomonas aeruginosa, a gram-negative bacterium, accounts for 7% of all hospital-acquired infections. Despite advances in medicine and antibiotic therapy, P. aeruginosa infection still results in high mortality rates of up to 62% in certain patient groups. This bacteria is also known to form biofilms, that are 10 to 1000 times more resistant to antibiotics compared to their free-floating counterparts. Photodynamic Inactivation (PDI) has been proved to be an effective antimicrobial technique for microbial control. This method involves the incubation of the pathogen with a photosensitizer (PS), then, a light at appropriated wavelength is applied, leading to the production of reactive oxygen species that are toxic to the microbial cells. Studies have focused on strategies to enhance the PDI efficacy, such as a pre-treatment with enzymes to degrade the biofilm matrix and/or an addition of inorganic salts to the PS. The aim of the present study is to evaluate the effectiveness of PDI against P. aeruginosa biofilm in association with the application of the enzymes prior to PDI (enzymatic pre-treatment) or the addition of potassium iodide (KI) to the photosensitizer solution, to increase the inactivation effectiveness of the treatment. First, a range of enzymes and PSs were tested, and the best protocols for combined treatments were selected. The results showed that the use of enzymes as a pre-treatment was effective to reduce the total biomass, however, when associated with PDI, mild bacterial reductions were obtained. Then, the use of KI in association with the PS was evaluated and the results showed that, PDI mediated by methylene blue (MB) in the presence of KI was able to completely eradicate the biofilm. However, when the PDI was performed with curcumin and KI, no additive reduction was observed. In conclusion, out of all strategies evaluated in the present study, the most promising strategy to improve PDI against P. aeruginosa biofilm was the use of KI in association with MB, resulting in eradication with 108 log bacterial inactivation.

Evaluation of Staining Propensity of Silver Diamine Fluoride With and Without Potassium Iodide in Children (Project Healthy Smiles): Protocol for a Randomized Controlled Trial.

BACKGROUND: Silver diamine fluoride (SDF) is becoming more widely recognized as a simple, cost-effective approach to minimize sensitivity and arrest caries. However, SDF results in caries that are stained black. Potassium iodide (KI) treatment with SDF may minimize or lessen the staining. However, the effectiveness of KI on staining has not been investigated. Studies demonstrating that potassium iodide reduces the black staining are still insufficient. This paper presents the study protocol for Healthy Smiles, a randomized controlled trial implemented to compare the staining propensity of SDF and SDF+KI. OBJECTIVE: This study, Healthy Smiles, aims to evaluate the staining propensity of SDF and SDF+KI using a Nix Mini color sensor among children aged 4 to 6 years. Another objective of the study is to evaluate the caries-arresting effect of SDF and SDF+KI in the treatment of carious primary teeth. METHODS: This study is a randomized controlled trial. A total of 60 children with caries that meet the criteria of the International Caries Detection and Assessment System (code 1 or above) will be randomly assigned to treatment groups, where group 1 will be treated with SDF and group 2 will be treated with SDF+KI. Discoloration of treated lesions will be assessed digitally using a Nix Mini color sensor. Participants will be followed up at 1, 3, and 6 months after treatment to digitally record the ∆L and ∆E values using the Nix Mini color sensor. Data will be analyzed using SPSS (version 28; IBM Corp). Independent sample t tests and the Mann-Whitney U test will be used to compare the 2 groups. RESULTS: Enrollment started in October 2023. It is estimated that the enrollment period will be 12 months. Data collection is planned to be completed in 2024. CONCLUSIONS: The presented paper describes Happy Smiles, a project that provides an opportunity to address the aesthetic inconvenience of patients without compromising the effectiveness of the SDF treatment. The trial findings will contribute to the limited evidence base related to discoloration after SDF intervention to improve aesthetic appearances in child oral health. If the results from the trial are promising, it will lead to the development of a model for child oral health and pave the way for further research in child oral health. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/51087.

Plasma itraconazole concentrations during treatment of feline sporotrichosis.

Itraconazole (ITZ) is the most used drug to treat feline sporotrichosis; however, little is known about its pharmacokinetics in cats with this mycosis. The aim of this study was to determine plasma ITZ concentrations in cats with sporotrichosis treated with ITZ as monotherapy or in combination with potassium iodide (KI). Cats diagnosed with sporotrichosis received orally ITZ (100 mg/cat/day) or combination therapy with ITZ (100 mg/cat/day) and KI (2.5-5 mg/kg/day) in the case of worsening or stagnation of the clinical condition. At each monthly visit, blood samples were collected at an interval of 4 h for analysis of trough and peak plasma ITZ concentrations by HPLC. Clinical features and laboratory parameters were evaluated during follow-up. Sixteen cats were included in the study. The median plasma ITZ concentration of all cats was 0.75 µg/mL. The median plasma ITZ concentration was 0.5 µg/mL in cats that received ITZ monotherapy (n = 12) and 1.0 µg/mL in those treated with ITZ + KI (n = 4). The clinical cure rate was 56.3% (n = 9) and the median treatment duration was 8 weeks. Nine cats (56.3%) developed adverse clinical reactions, and hyporexia was the most frequent (n = 8; 88.9%). Serum alanine aminotransferase was elevated in four cats (25%). The median plasma ITZ concentration detected in cats was considered to be therapeutic (>0.5 µg/mL) and was reached after 4 weeks of treatment. Plasma ITZ concentrations were higher in cats that received ITZ + KI compared to those treated only with ITZ, suggesting pharmacokinetic synergism between these drugs.

Itraconazole is the most common therapy for feline sporotrichosis, and combination therapy with potassium iodide is used in nonresponsive cases. Our study showed that all cats achieved a therapeutic plasma concentration of itraconazole, with higher levels in cats treated with the combination therapy.

Clinical and forensic aspects of potassium iodide: Suddenly in high demand across Europe due to fears of radiation poisoning from a nuclear attack in Ukraine.

Potassium iodide has demonstrated several therapeutic applications over time, being the choice for shielding the thyroid during radiation emergencies involving radioiodine release. Amidst the ongoing military conflict between Ukraine and Russia and the growing concern regarding the potential deployment of nuclear weapons, there has been a surge in the demand for potassium iodide across Europe. This work aimed to comprehensively review the current knowledge regarding the pharmacology, physiology, adverse effects, the protective role in reducing the risk of thyroid cancer and recommendations for potassium iodide use during radiation emergencies. Evidence on adverse effects is scarce, as potassium iodide is generally well-tolerated. Guidelines for thyroid blocking with potassium iodide during radiation emergencies suggest that, among populations vulnerable to radioiodine exposure, the benefits of potassium iodide outweigh the risks of adverse effects. Controversial topics surrounding the utilization of potassium iodide in radiation emergencies include the prophylaxis in iodine-deficient regions and following the detonation of dirty bombs, whether granule formulations versus tablets should be used and mental health concerns. Although the rise in demand seems to be a justified security measure, it is essential to recognize that potassium iodide protects the thyroid from radioiodine and does not impact the body's absorption of other radioactive materials or defend against external radiation exposure.

Rose Bengal diacetate-mediated antimicrobial photodynamic inactivation: potentiation by potassium iodide and acceleration of wound healing in MRSA-infected diabetic mice.

Previous studies have shown that antimicrobial photodynamic inactivation (aPDI) can be strongly potentiated by the addition of the non-toxic inorganic salt, potassium iodide (KI). This approach was shown to apply to many different photosensitizers, including the xanthene dye Rose Bengal (RB) excited by green light (540 nm). Rose Bengal diacetate (RBDA) is a lipophilic RB derivative that is easily taken up by cells and hydrolyzed to produce an active photosensitizer. Because KI is not taken up by microbial cells, it was of interest to see if aPDI mediated by RBDA could also be potentiated by KI. The addition of 100 mM KI strongly potentiated the killing of Gram-positive methicillin-resistant Staphylocccus aureus, Gram-negative Eschericia coli, and fungal yeast Candida albicans when treated with RBDA (up to 15 µM) for 2 hours followed by green light (540 nm, 10 J/cm2). Both RBDA aPDI regimens (400 µM RBDA with or without 400 mM KI followed by 20 J/cm2 green light) accelerated the healing of MRSA-infected excisional wounds in diabetic mice, without damaging the host tissue.

Evaluation of staining potential of Silver Diamine Fluoride, Potassium Iodide, Nanosilver Fluoride: an in vitro study.

BACKGROUND: The black staining effect of silver-containing solutions for use to arrest caries can have a negative aesthetic impact on children and parents. This study aims to assess the staining effects of Silver Diamine Fluoride/Potassium Iodide (SDF/KI), SDF and Nanosilver Fluoride (NSF). MATERIALS AND METHODS: Forty-four extracted carious primary molars were collected and randomly divided into four groups (n = 11). The carious tissue in all teeth was removed using a chemo-mechanical caries removal agent with an excavator. After caries removal in all groups, SDF, SDF/KI, and NSF were applied to the different groups, while no solution was applied to the control group. Subsequently, the teeth in all groups were restored with compomer. Color values L*, a* and b* were measured using a spectrophotometer at three time points: immediately after compomer restoration (T0), one week later (T1), and four week later (T2). Changes in brightness (ΔL) and color (ΔE) over time were calculated and comparisons among groups were made. RESULTS: The SDF solution induced statistically significant black staining (p = 0.013) and a decrease in L* value (p < 0.001) on the compomer material compared to the other groups over time. CONCLUSIONS: It was observed that SDF/KI has the potential to reduce the black staining effect of SDF, though not entirely. Novel experimental solutions like NSF may offer an alternative to counteract the staining effect of SDF.

Potassium iodide enhances the killing effect of methylene blue mediated photodynamic therapy against F. monophora.

BACKGROUND: Chromoblastomycosis (CMB) is a chronic granulomatous fungal infection that affect the skin and subcutaneous tissues. It is clinically problematic due to limited treatment options, low cure rates, and high rates of relapse. This underscores the necessity for innovative treatment approaches. In this study, potassium iodide (KI) combined with Methylene Blue (MB) mediated antimicrobial photodynamic therapy (PDT) were assessed in the treatment of Fonsecaea monophora (F. monophora) both in vitro and in vivo. And the underlying mechanism that contributes to the efficacy of this treatment approach was investigated. METHODS: In vitro experiments were conducted using different combinations and concentrations of MB, KI, and 660 nm light (60 mW/cm2) to inhibit F. monophora. The study was carried out using colony-forming unit (CFU) counts and scanning electron microscopy (SEM). The production of singlet oxygen (1O2), free iodine (I2), hydrogen peroxide (H2O2), and superoxide anion during the KI combined MB-mediated antimicrobial PDT process was also detected. In vivo experiments were developed using a Balb/c mouse paw infection model with F. monophora and treated with PBS, 10 mM KI, 2 mM MB +100 J/cm² and 10 mM KI+2 mM MB +100 J/cm² respectively. Inflammatory swelling, fungal load and histopathological analyses of the mouse footpads were assessed. RESULTS: KI enhanced the killing effect of MB-mediated antimicrobial PDT on the conidial spores of F. monophora at the cell and infected animal model level. During the process, the main antimicrobial agents in KI combined with MB- mediated antimicrobial PDT could produce stronger toxic active species including free I2 and H2O2. CONCLUSION: KI combined with MB-mediated antimicrobial PDT could be an effective adjunct therapy for treating CBM.

Reduction of microorganisms in carious dentin by photodynamic therapy mediated by potassium iodide added to methylene blue and red laser.

OBJECTIVE: To evaluate the effect of the association of potassium iodide to antimicrobial photodynamic therapy on human carious dentin produced with a microcosm biofilm model. METHODS: A microcosm biofilm model was used to generate a caries lesion on human dentin. Pooled human saliva diluted with glycerol was used as an inoculum on specimens immersed on McBain artificial saliva enriched with 1 % sucrose (24 h at 37 °C in 5 % CO2). After refreshing culture media for 7 days, the dentin specimens were divided in 5 groups (3 specimens per group, in triplicate; n = 9): C (NaCl 0.9 %), CX (2 % chlorhexidine), PKI (0.01 % methylene blue photosensitizer+50 mM KI), L (laser at 15 J, 180 s, 22.7 J/cm2), and PKIL (methylene blue + KI + Laser). After the treatments, dentin was collected, and a 10-fold serial dilution was performed. The number of total microorganisms, total lactobacilli, total streptococci, and Streptococcus mutans was analyzed by microbial counts (CFU/mL). After normality and homoscedasticity analysis, the Welch's ANOVA and Dunnett's tests were used for CFU. All tests used a 5 % significance level. RESULTS: CX and PKIL groups showed significant bacterial decontamination of dentin, compared to group C (p < 0.05) reaching reductions up to 3.8 log10 for CX for all microorganisms' groups and PKIL showed 0.93, 1.30, 1.45, and 1.22 log10 for total microorganisms, total lactobacilli, total streptococci, and S. mutans, respectively. CONCLUSION: aPDT mediated by the association of KI and methylene blue with red laser reduced the viability of microorganisms from carious dentin and could be a promising option for cavity decontamination.

Clinical comparison of silver diamine fluoride (SDF) or silver-modified atraumatic restorative technique (SMART) on hypomineralised permanent molars with initial carious lesions: 3-year results of a prospective, randomised trial.

OBJECTIVES: This study aimed to assess the clinical outcomes of utilizing silver diamine fluoride + potassium iodide (SDF + KI) treatment and Silver-Modified Atraumatic Restorative Technique (SMART/SDF + KI + Glass Ionomer Cement) over a three-year period on hypomineralised permanent molars with initial carious lesions. METHODS: 112 hypomineralised permanent molars with ICDAS 1 or 2 lesions were selected in 48 children. The teeth were randomized into SDF + KI and SMART (SDF + KI + GIC) groups (n = 56 teeth/group) in a split-mouth design. Hypersensitivity and caries development were evaluated in both groups. Schiff Cold Air Sensitivity Scale (SCASS) was used for evaluation of hypersensitivity, and the modified USPHS criteria were utilised for clinical assessments of SMART sealants at 1,6,12,18,24 and 36 months. Fisher's Exact test, Kaplan-Meier Survival Curves, Log-rank test, Mann Whitney U test, and Friedman test was performed for the statistical analysis. RESULTS: The caries preventive effect was 100 %, 67.9 % and 65.4 % for SDF + KI-treated teeth; and 100 %, 97.6 % and 94.7 % for SMART(SDF + KI + GIC)-treated teeth at 12, 24 and 36 months, respectively. The mean survival probabilities for caries-preventive effect were significantly lower in SDF + KI-treated teeth (31.01 months) than SMART-treated teeth (35.61 months), (p < 0.001). Twenty-six molars with initial hypersensitivity due to hypomineralization demonstrated a significant reduction at all evaluation periods compared to baseline SCASS scores (p < 0.001). Additionally, there was no significant difference in hypersensitivity scores between the groups during the re-call periods, and none of the teeth exhibited hypersensitivity at the 18-month and beyond evaluations. CONCLUSIONS: During the three-year assessment, both groups demonstrated effectiveness in reducing sensitivity in hypomineralised molars. However, SMART (SDF + KI + GIC) sealants offered better protection against tooth decay over time, despite experiencing gradual retention loss. CLINICAL SIGNIFICANCE: Both SMART (SDF + KI + GIC) sealants and SDF + KI proved effective in alleviating hypersensitivity in hypomineralised molars for up to three years. SMART (SDF + KI + GIC) sealants showed greater caries-preventive effect compared to SDF + KI. However, continuous long-term monitoring is crucial due to the gradual decline in retention of SMART (SDF + KI + GIC) sealants. CLINICALTRIALS REGISTRATION NUMBER: NCT03862014.

Antibacterial effects of silver diamine fluoride, potassium iodide and nanosilver fluoride on dual-species biofilm.

OBJECTIVES: This study aims to evaluate antibacterial effects of silver diamine fluoride (SDF), SDF/potassium iodide (KI), and nanosilver fluoride (NSF). METHODS: Antimicrobial activity of sterile saline, 5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), SDF, SDF/KI, NSF, and KI solutions against Streptococcus mutans and Lactobacillus casei was assessed through disc diffusion tests. A dual-species biofilm of S. mutans-L. casei was formed on 48 enamel samples, divided into six groups (n = 8). Group 1 was treated with sterile saline, Group 2 with 5% NaOCl, Group 3 with 2% CHX, Group 4 with SDF, Group 5 with SDF/KI, and Group 6 with NSF. The samples were analysed using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Statistical analysis utilized Shapiro-Wilk and Kruskal-Wallis tests and multiple comparisons were conducted using Dunn test. RESULTS: SDF, SDF/KI, and NaOCl displayed significantly higher antibacterial activity against dual-species biofilm compared to NSF and CHX (p < 0.050). CONCLUSIONS: In conclusion, SDF and SDF/KI demonstrated greater antibacterial activity than NSF. SDF's antibacterial activity was unaffected by KI. Further research is needed to determine the appropriate content and concentration for achieving effective antibacterial activity with NSF. CLINICAL SIGNIFICANCE: The use of silver-containing materials is increasing in popularity within pediatric dentistry. In this study, an endeavor has been made to assist pediatric dentists in determining which solution might be more advantageous for preventing caries.

Decorporation dilemma: Interplay of prussian blue and potassium iodide in radioactive contamination.

The expansion of the nuclear industry has led to various radioactive effluents, originating from routine operations or catastrophic incidents such as those at Three Mile Island (USA), Chernobyl (Ukraine), and Fukushima (Japan). Research conducted after these events emphasizes Cesium-137 (137Cs) and iodine 131 (131I) as major contributors to harmful airborne dispersion and fallout. These isotopes infiltrate the human body via inhalation, ingestion, or wounds, posing significant health risks. Understanding contamination mechanisms and devising effective countermeasures are crucial in mitigating nuclear incident consequences. We propose that concurrent administration of Pru-Decorp™/Pru-Decorp-MG and potassium iodide (KI) could synergistically reduce the levels of 137Cs and block uptake of 131I, respectively, in nuclear incident scenarios. Pru-Decorp™ capsules contain insoluble ferric hexacyanoferrate(II) and are equivalent to USFDA-approved Radiogardase®-Cs, offering radiation exposure mitigation for Cs and Tl contamination. Pru-Decorp-MG capsules consist of insoluble PB and magnesium hydroxide, serving as a prophylactic measure to reduce the risk of internal Cs and Tl contamination for rescue responders. Pru-Decorp™/Pru-Decorp-MG binds Cs/Tl ions in the gastrointestinal tract, hindering absorption and promoting excretion, while KI saturates the thyroid gland with stable iodine, decreasing the uptake of radioactive iodine isotopes. Our hypothesis is supported by studies demonstrating the effectiveness of combination therapies, such as calcium alginate, iron(III) ferrocyanide, and KI, in decreasing the retention of radioisotopes in vital organs. To test this hypothesis, we propose a comprehensive research plan, including in vitro studies simulating gastrointestinal conditions, animal studies to evaluate the efficacy of both drugs simultaneously, and safety clinical trials comparing Pru-Decorp™/Pru-Decorp-MG alone, KI alone, and their combination. Expected outcomes include insights into the synergistic effects of Pru-Decorp™/Pru-Decorp-MG and KI, guiding the development of optimized treatment protocols for simultaneous administration during radioactive contamination incidents. This research aims to address significant critical gaps in nuclear incident preparedness by providing evidence-based recommendations for concurrent antidote use in scenarios involving multiple isotope contamination. Ultimately, this will enhance public health and safety during nuclear emergencies.

Lab- and pilot-scale wet scrubber study on the redox-mediated simultaneous removal of NOx and SO2 using a CaCO3-based slurry with KI as a redox catalyst.

This study presents a novel approach that integrates ozone-driven chemical oxidation to convert NO into soluble NO2, followed by the simultaneous absorption of NO2 and SO2 into a CaCO3-based slurry using the redox catalyst potassium iodide (KI). Using cyclic voltammetry, we demonstrate the redox properties of the I2/2I- couple, which facilitates NO2 reduction into soluble NO2- and catalyst regeneration through sulfite (SO32-)-driven reduction, thus establishing a closed catalytic cycle within the components of flue gas. In lab-scale wet-scrubbing tests, we explore the effect of various operational parameters (i.e., KI concentration, pH, and SO2 concentration), with a 15 h stability test demonstrating >60% NOx and >99% SO2 removal efficiency when the pH is controlled between 7.5 and 8.5. A successful pilot-scale implementation conducted at an inlet flow rate of 1000 m3 h-1 further confirmed the reproducibility of the proposed redox-catalytic cycle. Our study offers a cost-effective, sustainable, and scalable solution for effectively mitigating NOx and SO2 emissions at low temperatures.

Potassium Iodide's Effect on Silver Diammine Fluoride Staining Properties as Measured Through Objective Color Analysis Using CIELAB.

Purpose: To determine the effect of potassium iodide (KI) on the black/gray staining caused by silver diammine fluoride (SDF) when applied to carious lesions. Methods: Extracted caries-free molar surfaces had caries induced to examine the use of SDF and SDF followed by KI (SDF+KI) on extracted permanent molars that had caries induced on their surfaces and were monitored for a period after application. To monitor the color changes, CIELAB color space readings???a color space defined by the International Commission on Illumination???were used. The system is composed of three values, of which the L* measures black to white across a span of zero (black) to 100 (white). Measurements were taken at eight intervals between days zero to 72. Results: L* values were found to be significantly different between SDF and SDF+KI groups and from baseline. On average, the SDF+KI group versus the SDF group was 9.47 units lighter. Conclusion: The findings indicate the application of silver diammine fluoride followed by potassium iodide can reduce the black staining SDF alone causes, potentially making it a viable esthetic option for patients with anterior tooth caries.

In vitro photoinactivation effectiveness of a portable LED device aimed for intranasal photodisinfection and a photosensitizer formulation comprising methylene blue and potassium iodide against bacterial, fungal, and viral respiratory pathogens.

Antimicrobial photodynamic therapy (aPDT) can be a viable option for management of intranasal infections. However, there are light delivery, fluence, and photosensitizer-related challenges. We report in vitro effectiveness of an easily fabricated, low-cost, portable, LED device and a formulation comprising methylene blue (MB) and potassium iodide (KI) for photoinactivation of pathogens of the nasal cavity, namely, methicillin-resistant Staphylococcus aureus, antibiotic-resistant Klebsiella pneumoniae, multi-antibiotic-resistant Pseudomonas aeruginosa, Candida spp., and SARS-CoV-2.In a 96-well plate, microbial suspensions incubated with 0.005% MB alone or MB and KI formulation were exposed to different red light (~ 660 ± 25 nm) fluence using the LED device fitted to each well. Survival loss in bacteria and fungi was quantified using colony-forming unit assay, and SARS-CoV-2 photodamage was assessed by RT-PCR.The results suggest that KI addition to MB leads to KI concentration-dependent potentiation (up to ~ 5 log10) of photoinactivation in bacteria and fungi. aPDT in the presence of 25 or 50 mM KI shows the following photoinactivation trend; Gm + ve bacteria > Gm - ve bacteria > fungi > virus. aPDT in the presence of 100 mM KI, using 3- or 5-min red light exposure, results in complete eradication of bacteria or fungi, respectively. For SARS-CoV-2, aPDT using MB-KI leads to a ~ 6.5 increase in cycle threshold value.The results demonstrate the photoinactivation effectiveness of the device and MB-KI formulation, which may be helpful in designing of an optimized protocol for future intranasal photoinactivation studies in clinical settings.

2-iodohexadecanal induces autophagy during goiter involution.

BACKGROUND: Iodine plays an important role in thyroid physiology and biochemistry. The thyroid is capable of producing different iodolipids such as 2-iodohexadecanal (2-IHDA). Data from different laboratories have shown that 2-IHDA inhibits several thyroid parameters and it has been postulated as intermediary on the action of iodide function. OBJECTIVE: To explore different mechanisms involved during the involution of the hyperplastic thyroid gland of Wistar rats towards normality induced by 2-IHDA. METHODS: Goiter was induced by the administration of MMI for 10 days, then the treatment was discontinued and Wistar rats were injected with 2-IHDA or KI. RESULTS: During involution, 2-IHDA treatment reduced PCNA expression compared to spontaneous involution. KI treatment caused an increase of Caspase-3 activity and TUNEL-positive cells. In contrast, 2-IHDA failed to alter this value but induced an increase of LC3B expression. KI but not 2-IHDA led to an increase in peroxides levels, catalase and glutathione peroxidase activity. CONCLUSIONS: We demonstrated that 2-IHDA, in contrast to iodide, did not lead to an increase in oxidative stress or apoptosis induction, indicating that the involution triggered by 2-IHDA in Wistar rats, is primarily due to the inhibition of cell proliferation and the induction of autophagy.