Concentrations Of Chlorhexidine Research Articles

Comparing the in vitro efficacy of chlorhexidine and povidone-iodine in the prevention of post-surgical endophthalmitis

BackgroundIntravitreal injections are a common ophthalmologic procedure. While infections following these injections are rare, they can lead to endophthalmitis, with potentially serious consequences. Various methods have been proposed to prevent endophthalmitis, including the use of antisepsis and antibiotics in patient preparation.PurposeTo evaluate the antiseptic efficacy of aqueous chlorhexidine (CHX) and povidone-iodine (PI) when used alone and in combination with lidocaine gel (LG) in vitro.MethodsTwo independent experimental trials were conducted. The first trial determined the minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) of CHX and PI against six bacterial strains. The second trial evaluated the bactericidal efficacy of the antiseptic agents (CHX 0.1% and PI 5%) and their combination with LG against the same bacterial strains.ResultsCHX was more effective than PI in reducing the number of colonies forming units (cfus) of the tested bacteria. The order in which the antiseptic and LG were administered affected their effectiveness, with CHX administered before LG resulting in greater reduction of bacterial growth.ConclusionsCHX 0.1% is more effective than PI 5% as an antiseptic agent. Application of CHX and PI prior to the use of lidocaine gel results in a more effective reduction of microorganisms.

Chlorhexidine is not effective at any concentration in preventing ventilator-associated pneumonia: a systematic review and network meta-analysis

IntroductionOral chlorhexidine has been widely used for ventilator-associated pneumonia prevention in the critical care setting; however, previous studies and evidence synthesis have generated inconsistent findings. Our study aims to investigate if different concentrations of oral chlorhexidine may be effective in preventing such complication in intensive care unit patients.MethodsAfter pre-registration (Open Science Framework: 8CUKF), we conducted a network meta-analysis with the following PICOS: adult patients (age > 18 years old) undergoing invasive mechanical ventilation admitted in ICU (P); any concentration of chlorhexidine used for oral hygiene (I); placebo, sham intervention, usual care, or no intervention (C); rate of VAP (primary outcome), mechanical ventilation length, ICU length of stay (LOS), hospital LOS, mortality (secondary outcomes) (O); randomized controlled trials (S). We used the following database: PubMed, the Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, and EMBASE without any limitation in publication date or language.ResultsChlorhexidine did not demonstrate any significant advantage over the control group in preventing ventilator-associated pneumonia or reducing mortality, duration of mechanical ventilation, length of stay in the intensive care unit, or overall mortality.ConclusionsChlorhexidine oral decontamination does not reduce the rate of ventilator-associated pneumonia in critically ill adult patients and its routine use could not be recommended.Trial registrationRegistration number: Open Science Framework: 8CUKF.

Exploring the effect of chlorhexidine concentration on the biocorrosion behavior of Ti6Al4V for dental implants.

Corrosion of dental implants is one of the most critical factors in the failure of implant treatments. Generally, corrosion depends on the type of material used in implants and the chemical composition of the oral environment. Due to the antibacterial activities, mouthwashes and chlorhexidine gels are often used after implant surgery. Ti6Al4V is commonly used in manufacturing dental implants. The present study aims to investigate the corrosion behavior of the Ti6Al4V alloy under different concentrations of chlorhexidine (0.12%, 0.2%,and 2%) during 2- and 24-h immersion. This way corrosion may be minimized while obtaining an antibacterial environment around the implant. In this regard, the electrochemical behavior of the specimens was investigated using polarization and impedance tests, and then their morphology, cross-section and nano-tribological behavior were evaluated using atomic force microscopy, scanning electron microscopy, energy dispersive x-ray spectroscopy, and nano-scratch test. The results show that using chlorhexidine solution with a concentration of 0.12% could yield a lower corrosion rate and material loss after implant surgery. RESEARCH HIGHLIGHTS: Open circuit potential values increase with immersion time, which suggests multistage passivation of the surface during immersion in chlorhexidine. Specimens in 0.12% chlorhexidine show improved thermodynamic corrosion resistance. Nano-scratch testing demonstrates higher scratch resistance for specimens in 0.12% chlorhexidine solution after 2-h immersion. Higher chlorhexidine concentration than 0.12% and longer immersion times decrease the resistance of the formed passive layer.

The ability of different diffusing enhancers to deliver chlorhexidine into dentinal tubules: An in vitro evaluation

Background/purposeRoot canal irrigants are difficult to diffuse deep into the dentinal tubules for root canal disinfection. The purpose of this study was to assess the ability of different diffusing enhancers to deliver chlorhexidine (CHX) into dentinal tubules. Materials and methodsThe diffusing property of five diffusing enhancers (acetone, DMSO, Triton X-100, JFC-E and azone) into dentinal tubules was firstly assessed using the Rhodamine B. The ability of the diffusing enhancers to deliver CHX into dentinal tubules was then evaluated both qualitatively and quantitatively. A deep dentinal tubule Enterococcus faecalis infection model was further established to test the bactericidal effect of CHX delivered by different diffusing enhancers. Finally, the in vitro cytotoxicity of these diffusing enhancers was tested using the CCK-8 method. ResultsAzone, Triton X-100 and JFC-E exhibited the largest maximum diffusing depths at all root canal parts (P < 0.05). Azone group also showed the highest percentage of diffusing depths for all root canal parts, followed by Triton X-100 (P < 0.05). The percentage of dead bacteria in dentinal tubules close to cementum layer was significantly higher in the CHX + azone group than in the other groups (P < 0.05), followed by CHX + Triton X-100 and CHX + JFC-E groups. The concentration of CHX diffusing onto the exterior surface of root was significantly higher in CHX + azone group than in the other groups (P < 0.05). All the diffusing enhancers showed relatively low cytotoxicity. ConclusionAzone showed the highest diffusing ability with low cytotoxicity and might be employed as a carrier agent for either intracanal irrigants or medications to achieve more thorough root canal disinfection.

Antibacterial and Antifungal Properties of Citronella oil Against Streptococcus mutans and Candida albicans by In Vitro Study

Streptococcus mutans and Candida albicans are the main microorganisms that cause dental cavities. It can cause infection, damaged tissue around teeth, abscesses, and focal infection to other organs in the body. Natural products are currently widely used as products or as additives in the prevention of dental caries which have more anti-bacterial and anti-fungal activities than antibiotics that can cause resistance. Citronella (Cymbopogon citratus) is abundant and easy to grow. This study was conducted to determine the effectiveness of citronella (Cymbopogon citratus) oil on the growth of S. mutans and C. albicans microorganisms by Minimum Inhibitory Content (MIC) and Minimum Bactericidal Content (MBC). The method of MIC is broth microdilution by making chlorhexidine concentration levels of 100%, 50%, 25%, 12.5%, 6.25%, 3.125%, and 0.2% with 4 replications each. The MIC value was determined based on absorbance spectrophotometry and the MBC value was determined from the agar plate using the spread method. Biofilm eradication test was conducted by crystal-violet staining and measuring the absorbance. The results of MIC and MBC were obtained on S. mutans, namely at concentrations of 25% and 100%, respectively. Meanwhile, the results of MIC and MBC on C. albicans were obtained at concentrations of 50% and 100%, respectively. Furthermore, the citronella oil has antibacterial and antifungal activities.

Safety and efficacy of whole-body chlorhexidine gluconate cleansing with or without emollient in hospitalised neonates (NeoCHG): a multicentre, randomised, open-label, factorial pilot trial

Healthcare-associated infections account for substantial neonatal in-hospital mortality. Chlorhexidine gluconate (CHG) whole body skin application could reduce sepsis by lowering bacterial colonisation density, although safety and optimal application regimen is unclear. Emollients, including sunflower oil, may independently improve skin condition, thereby reducing sepsis. We aimed to inform which concentration and frequency of CHG, with or without emollient, would best balance safety and the surrogate marker of efficacy of reduction in bacterial colonisation, to be taken forward in a future pragmatic trial evaluating clinical outcomes of sepsis and mortality. In this multicentre, randomised, open-label, factorial pilot trial, neonates in two hospital sites (South Africa, Bangladesh) aged 1-6 days with gestational age ≥ 28 weeks and birthweight 1000-1999 g were randomly assigned in a factorial design stratified by site to three different concentrations of CHG (0.5%, 1%, and 2%), with or without emollient (sunflower oil) applied on working days vs alternate working days. A control arm received neither product. Caregivers were unblinded although laboratory staff were blinded to randomisation Co-primary outcomes were safety (change in neonatal skin condition score incorporating dryness, erythema, and skin breakdown) and efficacy in reducing bacterial colonisation density (change in total skin bacterial log10CFU from randomisation to day-3 and day-8). The trial is registered at the ISRCTN registry, ISRCTN69836999. Between Apr 12 2021 and Jan 18 2022, 208 infants were randomised and 198 were included in the final analysis. Skin condition scores were low with mean 0.1 (sd=0.3; N=208) at baseline, 0.1 (sd=0.3; N=199) at day 3 and 0.1 (sd=0.3; N=189) at day 8, with no evidence of differences between concentration (1% CHG vs 0.5% estimate=-0.3, 95% CI= (-1.2, 0.6), p=0.55. 2% CHG vs 0.5% CHG estimate=0.5 (-0.4, 1.4), p=0.30), increasing frequency (estimate=-0.4; 95% CI= (-1.1, 0.4), p=0.33), emollient (estimate=-0.5, (-1.2, 0.3), p=0.23) or with control (estimate=-0.9, (-2.3, 0.4), p=0.18). Mean log10CFU was 4.9 (sd=3.0; N=208) at baseline, 6.3 (sd=3.1; N=198) at day 3 and 8.4 (sd=2.6; N=183) with no evidence of differences between concentration (1% CHG vs 0.5% estimate=-0.4; 95% CI= (-1.1, 0.23); p=0.23. 2% CHG vs 0.5% CHG estimate=0.0 (-0.6, 0.6), p=0.96), with increasing frequency (estimate=-0.4; 95% CI= (-0.9, 0.2); p=0.17), with emollient (estimate=0.4, 95% CI= (-0.2, 0.9); p=0.18) or with control (estimate=-0.2, 95% CI= (-1.3, 0.9); p=0.73). By day-8, overall 158/183 (86%) of neonates were colonised with Enterobacterales, and 72/183 (39%) and 69/183 (9%) with Klebsiella spp resistant to third-generation cephalosporin and carbapenems, respectively. There were no CHG-related SAEs, emollient-related SAEs, grade 3 or 4 skin scores or grade 3 or 4 hypothermias. In this pilot trial of CHG with or without sunflower oil, no safety issues were identified, and further trials examining clinical outcomes are warranted. The relatively late start application of emollient, at a mean of 3.8 days of life, may have reduced the impact of the intervention although no subgroup effects were detected. There was no clear evidence in favour of a specific concentration of chlorhexidine, and there was rapid colonisation with Enterobacterales with frequent antimicrobial resistance, regardless of skin application regimen. The MRC Joint Applied Global Health award, the Global Antibiotic Research and Development Partnership (GARDP), MRC Clinical Trials Unit core funding (UKRI) and St. George's, University of London.

Effect of curcumin, betadine and chlorhexidine in gingival wound healing.

The effect of chlorhexidine (CHX) digluconate, Betadine (BET), curcumin (CUR) on gingival wound healing is of interest to dental practitioners. Hence, we studied the average fibroblast viability % for each of the concentrations of CUR, BET and CHX over various time durations. It was found that mean percentage of viability of fibroblasts is high in CUR and low in CHX at all time periods while the mean percentage of viability of fibroblasts in BET 1% was greater than CHX but lower than CUR at all time periods. Thus, curcumin at a concentration of 0.003% demonstrates the least cytotoxicity for fibroblasts. Hence, it is the most effective bacterial suppression, and the best wound healing.

Regeneration Membranes Loaded with Non-Antibiotic Anti-2 Microbials: A Review.

Both guided bone and guided tissue regeneration are techniques that require the use of barrier membranes. Contamination and infection of the surgical area is one of the most feared complications. Some current lines of research focus on functionalizing these membranes with different antimicrobial agents. The objective of this study was to carry out a review of the use and antibacterial properties of regeneration membranes doped with antimicrobials such as zinc, silver, chlorhexidine, and lauric acid. The protocol was based on PRISMA recommendations, addressing the PICO question: "Do membranes doped with non-antibiotic antimicrobials have antibacterial activity that can reduce or improve infection compared to membranes not impregnated with said antimicrobial?" Methodological quality was evaluated using the RoBDEMAT tool. A total of 329 articles were found, of which 25 met the eligibility criteria and were included in this review. Most studies agree that zinc inhibits bacterial growth as it decreases colony-forming units, depending on the concentration used and the bacterial species studied. Silver compounds also decreased the secretion of proinflammatory cytokines and presented less bacterial adhesion to the membrane. Some concentrations of chlorhexidine that possess antimicrobial activity have shown high toxicity. Finally, lauric acid shows inhibition of bacterial growth measured by the disk diffusion test, the inhibition zone being larger with higher concentrations. Antimicrobial agents such as zinc, silver, chlorhexidine, and lauric acid have effective antibacterial activity and can be used to dope regenerative membranes in order to reduce the risk of bacterial colonization.

Sub-lethal concentrations of chlorhexidine inhibit Candida albicans growth by disrupting ROS and metal ion homeostasis

ABSTRACT Candida albicans is a normal resident of the human oral cavity. It is also the most common fungal pathogen, causing various oral diseases, particularly in immunocompromised individuals. Chlorhexidine digluconate (CHG) is a broad-spectrum antimicrobial agent widely used in dental practice and has been recommended to treat oral candidiasis. However, its action mechanism against the fungal pathogen C. albicans remains poorly understood. The aim of the present study was to investigate the effect of CHG at sub-lethal concentrations against C. albicans. CHG inhibited the growth of C. albicans in a dose- and time-dependent manner. Cells treated with CHG exhibited altered membrane permeability, reduced metabolic activity, and enhanced metal ion and reactive oxygen species (ROS) accumulation. Copper-sensing transcription factor Mac1, iron-sensing transcription factors Sfu1 and Sef2, and copper transporter Ctr1 regulated intracellular metal ion and ROS homeostasis in response to CHG. Deletion of MAC1, SFU1, or SEF2 increased intracellular ROS production and cell susceptibility to CHG. This study revealed a novel mechanism by which CHG induced apoptosis of C. albicans cells through the disruption of metal ion and ROS homeostasis, which may help to identify new targets for fungal infections.

Pulmonary Toxicity Assessment after a Single Intratracheal Inhalation of Chlorhexidine Aerosol in Mice.

Guanidine disinfectants are important chemical agents with a broad spectrum of activity that are effective against most microorganisms. Chlorhexidine, one of the most used guanidine disinfectants, is added to shampoo and mouthwash and applied in medical device sterilization. During the use of chlorhexidine, aerosols with micron particle size may be formed, which may cause inhalation toxicity. To assess the toxicity of inhaled chlorhexidine aerosol, mice underwent the intratracheal instillation of different concentrations of chlorhexidine (0, 0.125%, 0.25%, 0.5%, and 1%) using a MicroSprayer Aerosolizer. The mice were exposed for eight weeks and then sacrificed to obtain lung tissue for subsequent experiments. Histopathology staining revealed damaged lung tissues and increased collagen exudation. At the same time, pulmonary function tests showed that chlorhexidine exposure could cause restrictive ventilatory dysfunction, consistent with pulmonary fibrosis. The results of transcriptome analyses suggest that chlorhexidine may trigger an inflammatory response and promote the activation of pathways related to extracellular matrix deposition. Further, we identified that chlorhexidine exposure might enhance mucus secretion by up-regulating Muc5b and Muc5ac genes, thereby inducing fibrosis-like injury. These findings underscore the need for standardized use of disinfectants and the assessment of their inhalation toxicity.

Synergistic effect of chlorhexidine and azoles on candida biofilm on titanium surface.

Candida infections of orthopedic implants are one of the most detrimental orthopedic implant-related complications with unsuccessful treatment and a poor prognosis. Most orthopedic Candida infections form biofilms and have resistance to the commonly used antifungal agents. This study aimed to develop a novel combination of normally prescribed drugs against Candida biofilm on orthopedic implants. We cultured 26 clinical isolates of Candida strains to form biofilm without titanium sheets or on titanium sheets, which are the most commonly used materials for permanent or orthopedic implants. The checkerboard method was used to evaluate the synergistic effects of chlorhexidine (CHL) and azoles on these Candida biofilms. For the evaluation of synergistic effects, we constructed the cell viability assay by fluorescence staining and CFU reduction hot map of Candida. Twenty-six clinical isolates of Candida strains formed biofilm in 96-well plates without titanium sheets, and we selected 9 of them to form biofilm on titanium sheets in 24-well plates. In Candida biofilm formed in 96-wells, the synergistic rates of CHL with fluconazole, itraconazole, and voriconazole were 61% (16/26), 65% (17/26), and 23% (6/26), respectively. When compared to the blank control group, CHL monotherapy significantly inhibited biofilm formation on titanium sheets (P < 0.05). We demonstrated 100% synergistic rates of the CHL and fluconazole combination against Candida biofilm formation on titanium sheets, and the minimum inhibitory concentration of CHL and FLU decreased four- to eight-fold. We concluded that CHL combined with azoles inhibited the Candida biofilm formation 96-wells or on titanium sheets and has the potential to control the infections of orthopedic implants.

Chemical Corneal Burn After Short Exposure to Alcohol-Containing Chlorhexidine Antiseptic

Chlorhexidine is used routinely for asepsis in craniofacial surgeries. A solution containing a lower concentration of chlorhexidine diluted with alcohol has been developed to decrease chlorhexidine-related side effects. Herein, we report a case of chemical corneal burn caused by hexitanol solution (2% chlorhexidine + 72% ethanol) in a patient after undergoing closed reduction for nasal fracture under general anesthesia. Although the presumptive exposure time of the cornea was short, slit-lamp examination revealed epithelial defects. The patient received conservative care with extensive saline irrigation and conservative treatment with 0.3% gatifloxacin, 1% prednisolone, and carbomer eye drops. Among the various antiseptic solutions, ethanol markedly decreases cell viability in a concentration-dependent manner by inducing cell lysis, even after short exposure. Moreover, chlorhexidine induces corneal toxicity, necessitating corneal transplantation. Therefore, surgeons should be aware of the complications associated with the use of chlorhexidine or alcohol-containing antiseptics and the use povidone for its low ocular toxicity.

Comparative analysis of chlorhexidine-containing antiseptic agents used in periodontics and implantology

Relevance. Despite the variety of antibacterial drugs, including multicomponent ones, chlorhexidine-containing antiseptics are nowadays the gold standard of antiseptic products relevant for periodontal therapy. At the same time, adverse side effects and new data about unfavourable chlorhexidine effects on the microbiome determine it necessary to search for a new optimal chlorhexidine-containing product that combines high effectiveness and relative safety. Purpose. The study aimed to compare and analyze the effectiveness of chlorhexidine-containing antiseptics used in dental practice.Material and Methods. The study analyzed the results of clinical studies published from 2018 to 2023 and devoted to the investigation of chlorhexidine effectiveness in the treatment of periodontal diseases. The publications were searched in the Pub Med database by the keywords 'chlorhexidine', 'periodontal disease', and 'periodontitis'. A total of eighty-four publications corresponded to the search criteria. After the primary analysis of all available publications corresponding to the inclusion and exclusion criteria, we studied and analyzed 32 publications.Results. The analysis of the publications for the past five years extracted a trend for a more frequent increase of chlorhexidine concentrations to 0.12% and 0.2% in periodontal therapy medications.Conclusion. Prescribing chlorhexidine-containing medications should be reasonable and respond to the characteristics of the clinical picture. At that, a thorough selection of chlorhexidine active agent concentration, a form of presentation and duration of use should correspond to the clinical situation and goal.

Assessment of the Susceptibility of Chlorhexidine to Specific Microorganisms

Objectives: This study aimed to identify the range of susceptibility of E. coli, S. enterica, P. aeruginosa, and S. aureus to chlorhexidine. Methods: First, an antibacterial evaluation was conducted using the zone of inhibition by disc diffusion method. For the statistical analyses, Shapiro-Wilk was used to verify normality, Kruskal-Wallis' H analysis was performed for comparison between groups, and Bonferroni was carried out as a post-hoc analysis. Results: The zone of inhibition for each concentration of chlorhexidine by disc diffusion was different for each strain at 2%, 1%, and 0.1% (p&lt;0.05). The Minimal Inhibitory Concentration (MIC) of chlorhexidine were 0.003% for E. coli, 0.005% for S. enterica, 0.009% for P. aeruginosa, and 0.006% for S. aureus; the Minimal Bactericidal Concentration (MBC) was measured as 0.1% for E. coli, 0.1% for S. enterica, 0.2% for P. aeruginosa, and 0.1% for S. aureus. Conclusions: The results of this study confirmed that the disc diffusion, MIC, MBC, and sensitivity of chlorhexidine to specific microorganisms are different depending on the microorganism type. Therefore, in the hospital environment, frequently used disinfectants should be managed more frequently, and susceptibility evaluation should be monitored more regularly.

BIOCOMPATIBLE AND ANTIMICROBIAL CELLULOSE ACETATE NANOFIBER MEMBRANE FROM BANANA (MUSA ACUMINATA X BALBISIANA) PSEUDOSTEM FIBERS FOR WOUND HEALING AND TISSUE ENGINEERING

Electrospun nanofiber membranes play a vital role in the biomedical field, especially for wound healing and tissue engineering applications. This study explored the development of biocompatible and antibacterial cellulose acetate electrospun nanofiber membranes prepared from banana pseudostem fibers. Cellulose rich dissolving pulp from alkali treated banana pseudostem fibers was subjected to esterification reaction to produce cellulose acetate. The synthesized cellulose acetate and chlorhexidine (CHX), an antimicrobial agent, were dissolved in 2:1 acetone:N,N-dimethylacetamide solvent and subsequently electrospun into a nanofiber membrane. FT-IR spectroscopy of the nanofiber confirmed the presence of cellulose acetate and the successful incorporation of CHX into the nanofibers. SEM imaging showed that the fiber diameter of the nanofiber membrane ranged from 200 nm to 300 nm. The MTT cytotoxicity assay and antimicrobial assay of nanofibers revealed that the nanofiber membrane with chlorhexidine concentration of 1.0 w/v was the optimum formulation as it achieved potent antimicrobial activity (zone of inhibition (ZOI): Escherichia coli – 18.38 mm and Staphylococcus aureus – 22.51 mm), while exhibiting low cytotoxicity to human intestinal epithelial cell line, HIEC-6 (percent cell inhibition: 13.07% and IC50: &gt;100 μg/mL). The results indicated successful preparation of biocompatible and antimicrobial nanofiber membranes from banana pseudostem fiber with potential application in wound healing and tissue engineering.

The Antibacterial and Antifungal Activity of Chlorhexidine Diacetate Incorporated into Acrylic Resins Used in Provisional Restorations.

The surface of provisional restorations applied before conventional or implant- supported fixed restorations may cause bacterial or fungal biofilm formation. The aim of this study was to evaluate the antimicrobial activity of acrylic resins used in provisional restorations modified with chlorhexidine diacetate. 120 cylindrical, auto-polymerized resin samples modified with chlorhexidine diacetate were prepared at concentrations of 0 (control), 1, 3, 5 wt %. The antimicrobial activity was examined against Streptococcus mutans, Enterococcus faecalis, and Candida albicans using Crystal Violet quantification, MTT assay, and Scanning Electron Microscopy. Data were analyzed by ANOVA and paired sample t-tests (α=0.05). The addition of chlorhexidine diacetate influenced the growth rate and metabolic activity of microorganisms. The antimicrobial effect against C. albicans and S. mutans statistically increased with the percentage of chlorhexidine diacetate. E. faecalis bacteria were less affected by chlorhexidine diacetate compared to other pathogens. It has been shown that the effectiveness of CHDA in inhibiting the proliferation of microorganisms correlated positively with increasing concentration levels. More research is needed to confirm the impact of different chlorhexidine concentrations on the mechanical properties, clinical efficacy, and antimicrobial properties of CDHA.

Dual nanocarrier of chlorhexidine and fluconazole: Physicochemical characterization and effects on microcosm biofilms and oral keratinocytes

ObjectivesThis study assembled and characterized a dual nanocarrier of chlorhexidine (CHX) and fluconazole (FLZ), and evaluated its antibiofilm and cytotoxic effects. MethodsCHX and FLZ were added to iron oxide nanoparticles (IONPs) previously coated by chitosan (CS) and characterized by physical-chemical analyses. Biofilms from human saliva supplemented with Candida species were grown (72 h) on glass discs and treated (24 h) with IONPs-CS carrying CHX (at 39, 78, or 156 µg/mL) and FLZ (at 156, 312, or 624 µg/mL) in three growing associations. IONPs and CS alone, and 156 µg/mL CHX + 624 µg/mL FLZ (CHX156-FLZ624) were tested as controls. Next, microbiological analyses were performed. The viability of human oral keratinocytes (NOKsi lineage) was also determined (MTT reduction assay). Data were submitted to ANOVA or Kruskal-Wallis, followed by Fisher's LSD or Tukey's tests (α=0.05). ResultsNanocarriers with spherical-like shape and diameter around 6 nm were assembled, without compromising the crystalline property and stability of IONPs. Nanocarrier at the highest concentrations was the most effective in reducing colony-forming units of Streptococcus mutans, Lactobacillus spp., Candida albicans, and Candida glabrata. The other carriers and CHX156-FLZ624 showed similar antibiofilm effects, and significantly reduced lactic acid production (p<0.001). Also, a dose-dependent cytotoxic effect against oral keratinocytes was observed for the dual nanocarrier. IONPs-CS-CHX-FLZ and CHX-FLZ significantly reduced keratinocyte viability at CHX and FLZ concentrations ≥7.8 and 31.25 µg/mL, respectively (p<0.05). ConclusionThe nanotherapy developed outperformed the effect of the combination CHX-FLZ on microcosm biofilms, without increasing the cytotoxic effect of the antimicrobials administered. Clinical SignificanceThe dual nanocarrier is a promising topically-applied therapy for the management of oral candidiasis considering that its higher antibiofilm effects allow the use of lower concentrations of antimicrobials than those found in commercial products.

ASSESSMENT OF ANTIBACTERIAL AND ANTIADHESIVE PROPERTIES OF ANTISEPTICS AGAINST CLINICAL ISOLATES OF KOCURIA SPP

According to the literature, microorganisms of the genus Kocuria are becoming widespread, but not as avirulent representatives of the normal microbiota of the human body, but as pathogens.&#x0D; Recently, after the identification of the causative agents of infectious and inflammatory processes, various types of Kocuria have been included in the list of etiological agents isolated from patients with cholecystitis, endocarditis, peritonitis, and meningitis as well as from carious tooth cavities and post-extraction tooth sockets. Bacteria of the genus Kocuria possess pathogenicity that enables them to play an important role in the occurrence of infectious and inflammatory processes in various organs and systems of the human body. Given that antibiotics are the most commonly used drugs of choice in medical and dental practice for the treatment of infections and inflammations, antibiotic resistance is considered as a global health and development threat.&#x0D; In order to overcome the challenge of antibiotic resistance, antiseptics, a group of medicines with a pronounced antimicrobial effect, are being increasingly used for the treatment of infectious and inflammatory processes. The purpose of this study is to investigate the antibacterial and antiadhesive activity of dekasan, and drugs of comparison, chlorhexidine and iodoform, against clinical isolates of Kocuria spp. isolated from the oral cavity of patients with infectious inflammatory post-extraction complications. Materials and methods: five clinical isolates of Kocuria spp. were studied as microorganisms isolated from patients, who received the treatment for infectious and inflammatory post-extraction complications at the medical and surgical departments of Poltava Regional Center of Stomatology – Dental Polyclinic. We determined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBcC) of antiseptics against clinical isolates of Kocuria spp. taking into account ISO recommendations. The adhesive properties of clinical isolates of Kocuria spp. were assessed by exposing them to subbacteriostatic concentrations of antiseptics, namely dekasan, chlorhexidine, and iodoform. The evaluation was conducted using erythrocytes of blood group 1(0) Rh+ and considering the index of microorganism adhesion (IAM) following the method developed by V. I. Brillis. The results obtained have demonstrated variations in the antimicrobial and anti-adhesive activities among the tested antiseptics, dekasan, chlorhexidine, and iodoform.

Sustainable Synthesis of Zeolitic Imidazolate Framework-8 Nanoparticles and Application in the Adsorption of the Drug Chlorhexidine

In an attempt to synthesize nanomaterial concerning chemistry, the sustainable synthesis of Zeolitic Imidazolate Framework-8 (ZIF-8) nanoparticles by a low-cost approach through the recycling of waste mother liquors was explored and then indicated the potential to remove chlorhexidine (CHLX) from an aqueous solution. ZIF-8 was produced under solvothermal reaction at 25°C and characterized by Fourier Transform Infrared Spectroscopy, X-ray diffraction, adsorption/desorption of N&lt;sub&gt;2&lt;/sub&gt;, dynamic light scattering and contact angle. The water Chemical stability test was conducted using ZIF-8 and it was immersed in pure water for 24 h at room temperature. Batch-type adsorption was used to check the potential of ZIF-8 (first and second generation) for the adsorption of the chlorhexidine with initial chlorhexidine concentration (0.05, 0.06 and 0.07 mol/L), agitation time (1, 3.5 and 6 h) and the mass of nano-adosrbent (0.04, 0.05 and 0.06 g). Process optimization was performed through a Factorial experimental design. The optimum conditions were selected for the nano-adsorbent mass of 0.04 g, agitation time of 1 h and initial chlorhexidine concentration 0.07 mmol/L. The ZIF-8 sustainable synthesis was efficient and generated a crystalline nanomaterial. The result shows that ZIF-8 is stable in water under ambient conditions. The ZIF-8 first generation and ZIF-8 second generation exhibit a high adsorption capacity (27.17 mg/g and 30.96 mg/g). It was found that, under the synthesis conditions, the recycled mother liquor user did not affect the final characteristics of this nanomaterial. The results indicated that the initial concentration of chlorhexidine and nano-adsorbent mass influenced the adsorption capacity. Experimental design provided the process optimum conditions (1 h, 0.04 g of adsorbent mass and 0.07 mmol/L).

Local Ugandan Production of Stable 0.2% Chlorhexidine Eye Drops.

The purpose of this study was to develop a protocol to prepare buffered chlorhexidine (CHX) eye drops (0.2% w/v) in the United Kingdom that can be reproduced at a production facility in Uganda. Buffered CHX eye drops can prevent CHX degradation and improve ocular tolerability during the treatment of fungal keratitis. Buffered CHX eye drops in amber glass containers were prepared using sodium acetate buffer at pH 5.90 to 6.75. Two commercial CHX solutions and CHX in water were used as controls. Eye drops were stored at 40°C (70% humidity, 21 months) in the United Kingdom and at ambient temperature in Uganda (30 months). High-performance liquid chromatography was used to determine CHX stability over time, and pH was monitored. Sterility was achieved using an autoclave (121°C, 15 minutes) and water bath (100°C, 30 minutes). The pH of acetate-buffered CHX eye drops did not change over 21 months at 40°C or at ambient temperature (30 months), whereas the pH of the unbuffered aqueous CHX displayed significant fluctuations, with an increase in acidity. The CHX concentration remained the same in both buffered and unbuffered eye-drop solutions. Eye drops sterilization was successful using an autoclave and a water bath. Stable, sterile, buffered CHX eye drops (pH 6.75) were successfully prepared first in the United Kingdom and then reproducibly in Uganda. This eye drops can be prepared in a hospital or pharmacy setting with limited resources, thus providing a cost-effective treatment for fungal keratitis. A protocol has been developed to prepare buffered CHX eye drops in low- and middle-income countries to treat fungal keratitis.