Evaluation of the Smear Layer Removal Ability of Various Rotary Files with/without Chemical Agents on Primary Teeth: An In Vitro Study.

AIM: The aim of the current study was to assess the cleaning and smear layer removal efficacy of two different rotary files with or without chemical agents on primary teeth. MATERIALS AND METHODS: For the study, 90 extracted primary maxillary incisors without internal or external resorption and with at least two-thirds of complete roots were chosen. Then, based on the kind of instruments used to clean and shape the canals, they were randomly assigned to three experimental groups, each consisting of 30 teeth. Group-I: The canal was instrumented manually with K-files, Group-II: The canal was instrumented with Kedo-S files, Group-III: The canal was instrumented with Kedo-SG Blue files. After the canals were finally instrumented, 2 mL of QMixTM solution was used to irrigate 15 samples from each group. The samples were subsequently allowed to remain in the canals for 90 seconds in order to eliminate the smear layer. After that a stereomicroscope was used to assess the cleaning effectiveness. RESULTS: With irrigant solution, the highest mean value was found in manual K-files (2.86 ± 0.34), followed by Kedo-S files group (1.34 ± 0.26) and Kedo-SG Blue files (1.28 ± 0.18). Without irrigant solution, the highest mean value was found in manual K-files (2.92 ± 0.22) followed by Kedo-S files group (1.44 ± 0.18) and Kedo-SG Blue files (1.36 ± 0.14). There was a statistically significant difference found at all the three levels. CONCLUSION: On conclusion, the current study's findings demonstrated that irrigation solution was significantly more effective in cleaning and removing smear layers from pediatric rotary files than manual K-files. CLINICAL SIGNIFICANCE: The effectiveness of endodontic therapy depends on a successful chemomechanical preparation. The canals are instrumented using either hand files or rotary instruments; there are several irrigation and instrumentation techniques. In order to completely sterilize the canals, chemical agents are utilized for irrigation during instrumentation. Due to their numerous biological, antibacterial, anti-inflammatory, and antioxidant qualities, many natural compounds are also utilized as irrigants. How to cite this article: Abushanan A. Evaluation of the Smear Layer Removal Ability of Various Rotary Files with/without Chemical Agents on Primary Teeth: An In Vitro Study. J Contemp Dent Pract 2024;25(4):354-357.

A biguanide chitosan-based hydrogel adhesive accelerates the healing of bacterial-infected wounds.

The development of tissue adhesives with good biocompatibility and potent antimicrobial properties is crucial for addressing the high incidence of surgical site infections in emergency and clinical settings. Herein, an injectable hydrogel adhesive composed of chitosan biguanidine (CSG), oxidized dextran (ODex) and tannin (TA) was synthesized primarily through Schiff-base reactions, hydrogen bonding, and electrostatic interactions. TA was introduced into the CSG/ODex hydrogel to prepare a physicochemically double cross-linked hydrogel. The hydrogel formulation incorporating 2 wt% TA (CSG/ODex-TA2) exhibited rapid gelation, moderate mechanical properties, good tissue adhesion, and sustained release behavior of TA. Both in vitro and in vivo studies demonstrated that CSG/ODex-TA2 showed significantly enhanced adhesion and antibacterial effectiveness compared to the CSG/ODex hydrogel and commercial fibrin glue. Leveraging the positive charge of CSG, the CSG/ODex-TA2 hydrogel demonstrated a strong contact antibacterial effect, while the sustained release of TA provided diffusion antibacterial capabilities. By integrating contact and diffusion antibacterial mechanisms into the hydrogel, a promising approach was developed to boost antibacterial efficiency and accelerate the healing of wounds infected with methicillin-resistant Staphylococcus aureus (MRSA). The CSG/ODex-TA2 hydrogel has excellent biocompatibility, hemostatic properties, and antibacterial capabilities, making it a promising candidate for improving in vivo wound care and combating bacterial infections.

Clinical use of 0.1% polyhexanide and propylbetaine on acute and hard-to-heal wounds: a literature review.

OBJECTIVE: To summarise the findings on the effect of the clinical use of 0.1% polyhexanide-propylbetaine (PHMB/betaine) solution/gel on acute and hard-to-heal (chronic) wound healing. METHOD: A literature search was conducted in MEDLINE, CINAHL, Embase, Scopus and the CENTRAL Trials Registry of the Cochrane Collaboration. Paired reviewers conducted title and abstract screening and full-text screening to identify experimental, quasi-experimental and observational studies. Study quality and risk of bias were not formally evaluated. RESULTS: A total of 17 studies met the eligibility criteria. The findings from 12 studies indicated that the use of 0.1% PHMB/betaine solution/gel had: a low risk of contact sensitivity; could help debridement during wound cleansing; aided effective wound bed preparation; reduced wound size, odour and exudate; improved pain control; reduced microbial load; and enhanced wound healing. The results of three studies indicated that both 0.1% PHMB and saline solution were effective in reducing bacterial load, while another showed that adding 0.1% PHMB to tie-over dressings had no effect on reducing bacterial loads in wounds. Another study concluded that disinfection and granulation of pressure ulcers with hydrobalance dressing with 0.3% PHMB was faster and more effective than using 0.1% PHMB/betaine. CONCLUSION: The findings of this literature review showed that 0.1% PHMB/betaine solution/gel appeared to be useful and safe for wound cleansing, was effective in removing soft debris and slough from the wound bed, and created a wound environment optimal for healing. Although these actions cannot be attributed solely to this treatment modality, these results do highlight the unique action of this combined product. However, more robust studies are needed to confirm these results.

Chitosan-based multifunctional oxygenating antibiotic hydrogel dressings for managing chronic infection in diabetic wounds.

Current treatment strategies for infection of chronic wounds often result in compromised healing and necrosis due to antibiotic toxicity, and underlying biomarkers affected by treatments are not fully known. Here, a multifunctional dressing was developed leveraging the unique wound-healing properties of chitosan, a natural polysaccharide known for its numerous benefits in wound care. The dressing consists of an oxygenating perfluorocarbon functionalized methacrylic chitosan (MACF) hydrogel incorporated with antibacterial polyhexamethylene biguanide (PHMB). A non-healing diabetic infected wound model with emerging metabolomics tools was used to explore the anti-infective and wound healing properties of the resultant multifunctional dressing. Direct bacterial bioburden assessment demonstrated superior antibacterial properties of hydrogels over a commercial dressing. However, wound tissue quality analyses confirmed that sustained PHMB for 21 days resulted in tissue necrosis and disturbed healing. Therefore, a follow-up comparative study investigated the best treatment course for antiseptic application ranging from 7 to 21 days, followed by the oxygenating chitosan-based MACF treatment for the remainder of the 21 days. Bacterial counts, tissue assessments, and lipidomics studies showed that 14 days of application of MACF-PHMB dressings followed by 7 days of MACF dressings provides a promising treatment for managing infected non-healing diabetic skin ulcers.

Assessment between antiseptic and normal saline for negative pressure wound therapy with instillation and dwell time in diabetic foot infections.

Negative pressure wound therapy with instillation and dwell time (NPWTi-d) is increasingly used for a diverse range of wounds. Meanwhile, the topical wound irrigation solution consisting of polyhexamethylene biguanide and betaine (PHMB-B) has shown efficacy in managing wound infections. However, the effectiveness of this solution as a topical instillation solution for NPWTi-d in patients with diabetic foot infections (DFIs) has not been thoroughly studied. The objective of this retrospective study was to evaluate the impact of using PHMB-B as the instillation solution during NPWTi-d on reducing bioburden and improving clinical outcomes in patients with DFIs. Between January 2017 and December 2022, a series of patients with DFIs received treatment with NPWTi-d, using either PHMB-B or normal saline as the instillation solution. Data collected retrospectively included demographic information, baseline wound characteristics, and treatment outcomes. The study included 61 patients in the PHMB-B group and 73 patients in the normal saline group, all diagnosed with DFIs. In comparison to patients treated with normal saline, patients with PHMB-B exhibited no significant differences in terms of wound bed preparation time (P = 0.5034), length of hospital stay (P = 0.6783), NPWTi-d application times (P = 0.1458), duration of systematic antimicrobial administration (P = 0.3567), or overall cost of hospitalization (P = 0.6713). The findings of the study suggest that the use of either PHMB-B or normal saline as an instillation solution in NPWTi-d for DFIs shows promise and effectiveness, yet no clinical distinction was observed between the two solutions.

Quality of life case series review: wound bed preparation from a UK perspective.

Previous studies have reported that polyhexamethylene biguanide (PHMB) and betaine solution and gels remove biofilm, improve wound healing and reduce infection rates. Quality of life (QoL) outcomes are not commonly reported on when it comes to wound care. This review aims to summarise QoL data from a cohort of case studies previously published on chronic lower limb ulcers using PHMB products (Prontosan® Solution, Prontosan® Wound Gel X and Prontosan® Debridement Pad). Here, we report on and review a total of 38 case studies describing 56 wounds. From these 38 case studies, 36 reported that all the wounds involved had either healed or improved by the end of their respective study period. QoL themes explore malodour, slough, and exudate, pain, mobility, hair growth, antibiotic intake, return to work, social life and mood. This case series demonstrates that treatment with Prontosan® products improves many QoL outcomes for patients with non-healing wounds.

Agmatine alleviates ethanol withdrawal-associated cognitive impairment and neurochemical imbalance in rats.

The present study aimed to investigate the role of agmatine in the neurobiology underlying memory impairment during ethanol withdrawal in rats. Sprague-Dawley rats were subjected to a 21-day chronic ethanol exposure regimen (2.4 % w/v ethanol for 3 days, 4.8 % w/v for the next 4 days, and 7.2 % w/v for the following 14 days), followed by a withdrawal period. Memory impairment was assessed using the passive avoidance test (PAT) at 24, 48, and 72 h post-withdrawal. The ethanol-withdrawn rats displayed a significant decrease in step-through latency in the PAT, indicative of memory impairment at 72 h post-withdrawal. However, administration of agmatine (40 µg/rat) and its modulators (L-arginine, arcaine, and amino-guanidine) significantly increases the latency time in the ethanol-withdrawn rats, demonstrating the attenuation of memory impairment. Further, pretreatment with imidazoline receptor agonists enhances agmatine's effects, while antagonists block them, implicating imidazoline receptors in agmatine's actions. Neurochemical analysis in ethanol-withdrawn rats reveals dysregulated glutamate and GABA levels, which was attenuated by agmatine and its modulators. By examining the effects of agmatine administration and modulators of endogenous agmatine, the study aimed to shed light on the potential therapeutic implications of agmatinergic signaling in alcohol addiction and related cognitive deficits. Thus, the present findings suggest that agmatine administration and modulation of endogenous agmatine levels hold potential as therapeutic strategies for managing alcohol addiction and associated cognitive deficits. Understanding the neurobiology underlying these effects paves the way for the development of novel interventions targeting agmatinergic signaling in addiction treatment.

Novel Effective Medical Therapy for Acanthamoeba Keratitis.

PURPOSE: To report first clinical use of novel medical treatment for Acanthamoeba keratitis. METHODS: Interventional observational case series. Two patients with Acanthamoeba keratitis were unsuccessfully treated with polihexanide (PHMB) 0.02% and propamidine 0.1% for 6 weeks, then all were shifted in a compassionate use of PHMB 0.08% with novel standardized protocol. The postinterventional follow-up of patients was at least 7 months. RESULTS: PHMB 0.08% eyedrops in a novel standardized protocol improved infection resolution and led to complete healing of the lesion after 4 weeks in the two cases. Corneal opacities and neovascularization decreased slowly, best-corrected visual acuity slightly improved and progressively increased in the further 7 months, and no infection recurrence occurred. CONCLUSIONS: This preliminary report of two cases shows promising response to polihexanide 0.08% lowering drastically the illness duration, with reduced chance of recurrence, and mostly improving patients' quality of life.

A case report of three people experiencing intractable autonomic dysreflexia following instillation of Uro-Tainer® Polyhexanide 0.02.

INTRODUCTION: Historically, bladder washouts were used to instil therapeutic reagents directly into the bladder. This practice has expanded to include instillation of solutions that deal with catheter issues such as encrustation or formation of bio-film. They appear to provide a promising strategy for people with long term catheters. These products are readily available to purchase, but there is concern that people are using these solutions without a complete understanding of the purpose for the rinse and without clinical guidance to monitor response to treatment. CASE PRESENTATION: These case studies include three people living with spinal cord injury (SCI) who developed severe autonomic dysreflexia (AD) when a catheter rinse was carried out using a particular solution. Each of the cases developed immediate and, in some cases, intractable AD requiring further intervention to resolve symptoms. DISCUSSION: Catheter-associated urinary tract infection is a significant cause of morbidity and mortality in people living with SCI. Long-term catheters provide a vector for opportunistic micro-organisms to form bio-film and create an environment that promotes formation of struvite calculi, thus increasing the risk of chronic catheter blockage and urinary tract infection. Whilst these solutions are used to reduce these risks, they also pose additional risks to people susceptible to AD. These cases highlight the need for judicious patient selection and clinical oversight and management of adverse events when using catheter rinse solutions in certain people living with SCI. This is supported by a decision-making algorithm and a response to AD algorithm. This case report was prepared following the CARE Guidelines (supplementary file 1).

Safety and effectiveness of an antiseptic wound cleansing and irrigation solution containing polyhexamethylene biguanide.

OBJECTIVE: There is currently a wide range of cleansing and irrigation solutions available for wounds, many of which contain antimicrobial agents. The aim of this study was to assess the safety of HydroClean Solution (HARTMANN, Germany), a polyhexamethylene biguanide (PHMB)-containing irrigation solution, in a standard cytotoxicity assay, and to assess its effect in a three-dimensional (3D) full-thickness model of human skin. METHOD: A number of commercially available wound cleansing and irrigation solutions, including the PHMB-containing irrigation solution, were tested in a cytotoxicity assay using L929 mouse fibroblasts (ISO 10993-5:2009). The PHMB-containing irrigation solution was then assessed in an in vitro human keratinocyte-fibroblast 3D full-thickness wounded skin model to determine its effect on wound healing over six days. The effect of the PHMB-containing irrigation solution on tissue viability was measured using a lactate dehydrogenase (LDH) assay, and proinflammatory effects were measured using an interleukin-6 (IL-6) production assay. RESULTS: The PHMB-containing irrigation solution was shown to be equivalent to other commercially available cleansing and irrigation solutions when tested in the L929 fibroblast cytotoxicity assay. When assessed in the in vitro 3D human full-thickness wound healing model, the PHMB-containing irrigation solution treatment resulted in no difference in levels of LDH or IL-6 when compared with levels produced in control Dulbecco's phosphate-buffered saline cultures. There was, however, a pronounced tissue thickening of the skin model in the periwound region. CONCLUSION: The experimental data presented in this study support the conclusion that the PHMB-containing irrigation solution has a safety profile similar to other commercially available cleansing and irrigation solutions. Evidence also suggests that the PHMB-containing irrigation solution does not affect tissue viability or proinflammatory cytokine production, as evidenced by LDH levels or the production of IL-6 in a 3D human full-thickness wound healing model. The PHMB-containing irrigation solution stimulated new tissue growth in the periwound region of the skin model.

Assessing antibacterial efficacy of a polyhexanide hydrogel versus alginate-based wound dressing in burns.

OBJECTIVE: Burn injuries pose a heightened risk of infection, which is primarily responsible for increased morbidity and mortality. Factors such as extensive skin damage and compromised immunity exacerbate this vulnerability. Pseudomonas aeruginosa and Staphylococcus aureus are frequently identified in burns, with Gram-negative Pseudomonas aeruginosa often resistant to antibacterial agents. While Flaminal, an alginate-based wound dressing (Flen Health, Belgium), aids wound healing, its antibacterial effects are limited compared with 1% silver sulfadiazine (1% SSD). In contrast, Prontosan Wound Gel X, a betaine and polyhexanide-based hydrogel (B. Braun Medical AG, Switzerland), has been shown to effectively combat various microbes and promotes wound healing. METHOD: In this study, two research cohorts were retrospectively established (control group: patients receiving standard of care with the alginate-based wound dressing; intervention group: patients receiving the polyhexanide hydrogel wound dressing), comprising patients admitted to a burn centre between 2019 and 2022. Patients were eligible when continuous wound treatment with either of the two wound dressings was performed. Laser Doppler imaging (LDI) scans were conducted. Regions of interest (ROIs) were selected based on LDI scans and divided into healing time categories. Wound swabs were collected and the presence of Pseudomonas aeruginosa and Staphylococcus aureus was documented. Bacterial load was evaluated using a semiquantitative scale. Wound healing was recorded. RESULTS: The control group consisted of 31 patients with 93 ROIs, while the intervention group had 67 ROIs involving 29 patients. Both groups exhibited similar proportions of healing time categories (p>0.05). The polyhexanide hydrogel dressing outperformed the alginate-based dressing in antiseptic efficacy by significantly reducing the incidence of Pseudomonas aeruginosa- and Staphylococcus aureus-positive cultures in patients' wounds. Wound healing time for conservative treatment was comparable between groups. CONCLUSION: In this study, the polyhexanide hydrogel dressing minimised Pseudomonas aeruginosa and Staphylococcus aureus colonisation in burn wounds, demonstrating strong antibacterial properties, emphasising its potential to minimise infections in burn injuries.

Time trends and regional variation in utilization of antidiabetic medicines in China, 2015-2022.

AIM: To assess the use of non-insulin antidiabetic medicines in China. MATERIALS AND METHODS: We analysed the national procurement data for 29 non-insulin antidiabetic medicines from nine subgroups in China from 2015 to 2022. We estimated the number of defined daily doses (DDDs) procured per year in seven regions of China for nine subgroups and adjusted the data by the number of patients with diabetes. For each subgroup, the regional ratio was calculated by comparing the procurement per patient in each region with the procurement nationwide. The regional disparity was the difference between the highest and lowest regional ratios. We compared the medication patterns across regions. RESULTS: Nationally, between 2015 and 2022, the number of DDDs per patient increased from 14.45 to 47.37. The two most commonly used categories were sulphonylurea and biguanides, which increased from 7.04 to 15.39 (119%) and 3.28 to 11.11 (239%) DDDs per patient, respectively. The procurement of new drugs (dipeptidyl peptidase-4 inhibitors, sodium-glucose cotransporter type 2 inhibitors and glucagon-like peptide-1 receptor agonists) increased quickly and had >5000% relative changes. Particularly for sodium-glucose cotransporter type 2 inhibitors, it increased from 0.08 to 5.03 DDDs (6662%). The southwest region had the highest relative change (319%), while the southern region had the lowest (118%). Biguanide and thiazolidinediones had the lowest (1.19) and highest level (2.21) of regional disparity in 2022, respectively. CONCLUSION: The procurement of non-insulin antidiabetic medicines in China has increased a lot from 2015 to 2022. In terms of DDDs per patient, sulphonylurea ranked first, followed by metformin. The procurement of new drugs increased greatly. A large regional disparity existed in medicine usage and patterns.

Therapeutic effect of ZnO NPs-polyhexanide-hydrogel on Staphylococcus aureus-induced skin wound infection in mice.

Nanometer zinc oxide (ZnONPs) offers strong antibacterial, wound healing, hemostatic benefits, and UV protection. Additionally, poly(hexamethylene biguanide)hydrochloride (PHMB) is an environmentally friendly polymer with strong bactericidal properties. However, the synergistic effect of the combination of ZnONPs and PHMB has not been previously explored. The purpose of this study is to explore the synergies of ZnONPs and PHMB and the healing efficacy of ZnO NPs-PHMB-hydrogel on skin wounds in mice infected with Staphylococcus aureus. Therefore, the mice were subjected to skin trauma to create a wound model and were subsequently infected with S. aureus, and then divided into various experimental groups. The repair effect was evaluated by assessing the healing rate, as well as measuring the levels of TNF-α, IL-2, EGF, and TGF-ß1 contents in the tissue. On the 4th and 9th days post-modeling, the Z-P group exhibited notably higher healing rates compared to the control group. However, on the 15th day, both the Z-P and AC groups achieved healing rates exceeding 99%. ZnO NPs-PHMB-hydrogel promoted the formation of a fully restored epithelium, increased new hair follicles and sebaceous glands beneath the epidermis, and markedly reduced inflammatory cell infiltration, which was markedly distinct from the control group. On the 7th day, the Z-P group exhibited significantly higher levels of EGF and TGF-ß1, along with a considerable reduction in the TNF-α levels as compared with the control group. These results affirmed that ZnO NPs-PHMB-hydrogel effectively inhibits S. aureus infection and accelerates skin wound healing.

An investigation of the antimicrobial efficacy of a nonwoven CMC PHMB dressing and the ability of the dressing to absorb wound slough.

OBJECTIVE: To conduct an in vitro investigation into the slough absorption and retention attributes of a gelling fiber dressing composed of CMC fibers and PHMB (Dressing A), and to assess its antimicrobial efficacy under compression. MATERIALS AND METHODS: Dressing A is indicated for use with secondary dressings or bandaging, and conditions that replicate this compression element were applied. Dressing A was compared with 5 other dressings. Antimicrobial efficacy testing was conducted over a 7-day challenge period. RESULTS: Dressing A absorbed an average of 33 g/100 cm2 per sample of viscous solution, 28% more than the other dressings tested. A greater than or equal to 6-log reduction of all microorganisms tested was achieved within 168 hours with Dressing A. CONCLUSION: The CMC PHMB gelling fiber dressing is able to absorb and retain viscous solutions (simulated slough). The antimicrobial efficacy of the dressing under compression was demonstrated by total eradication of all microorganisms tested.

Acanthamoeba keratitis - A review.

This is a comprehensive review after a thorough literature search in PubMed-indexed journals, incorporating current information on the pathophysiology, clinical features, diagnosis, medical and surgical therapy, as well as outcomes of Acanthamoeba keratitis (AK). AK is a significant cause of ocular morbidity, and early diagnosis with timely institution of appropriate therapy is the key to obtaining good outcomes. The varied presentations result in frequent misdiagnosis, and co-infections can increase the morbidity of the disease. The first line of therapy continues to be biguanides and diamidines, with surgery as a last resort.

Intraoperative Wound Irrigation for the Prevention of Surgical Site Infection After Laparotomy: A Randomized Clinical Trial by CHIR-Net.

Importance: Surgical site infections frequently occur after open abdominal surgery. Intraoperative wound irrigation as a preventive measure is a common practice worldwide, although evidence supporting this practice is lacking. Objective: To evaluate the preventive effect of intraoperative wound irrigation with polyhexanide solution. Design, Setting, and Participants: The Intraoperative Wound Irrigation to Prevent Surgical Site Infection After Laparotomy (IOWISI) trial was a multicenter, 3-armed, randomized clinical trial. Patients and outcome assessors were blinded to the intervention. The clinical trial was conducted in 12 university and general hospitals in Germany from September 2017 to December 2021 with 30-day follow-up. Adult patients undergoing laparotomy were eligible for inclusion. The main exclusion criteria were clean laparoscopic procedures and the inability to provide consent. Of 11 700 screened, 689 were included and 557 completed the trial; 689 were included in the intention-to-treat and safety analysis. Interventions: Randomization was performed online (3:3:1 allocation) to polyhexanide 0.04%, saline, or no irrigation (control) of the operative wound before closure. Main Outcome and Measures: The primary end point was surgical site infection within 30 postoperative days according to the US Centers for Disease Control and Prevention definition. Results: Among the 689 patients included, 402 were male and 287 were female. The median (range) age was 65.9 (18.5-94.9) years. Participants were randomized to either wound irrigation with polyhexanide (n = 292), saline (n = 295), or no irrigation (n = 102). The procedures were classified as clean contaminated in 92 cases (8%). The surgical site infection incidence was 11.8% overall (81 of 689), 10.6% in the polyhexanide arm (31 of 292), 12.5% in the saline arm (37 of 295), and 12.8% in the no irrigation arm (13 of 102). Irrigation with polyhexanide was not statistically superior to no irrigation or saline irrigation (hazard ratio [HR], 1.23; 95% CI, 0.64-2.36 vs HR, 1.19; 95% CI, 0.74-1.94; P = .47). The incidence of serious adverse events did not differ among the 3 groups. Conclusions and Relevance: In this study, intraoperative wound irrigation with polyhexanide solution did not reduce surgical site infection incidence in clean-contaminated open abdominal surgical procedures compared to saline or no irrigation. More clinical trials are warranted to evaluate the potential benefit in contaminated and septic procedures, including the emergency setting. Trial Registration: drks.de Identifier: DRKS00012251.

Polyhexanide based contact lens storage fluids frequently exhibit insufficient antifungal activity against Fusarium species.

PURPOSE: Fusarium keratitis is a severe infection of the anterior eye, frequently leading to keratoplasty or surgical removal of the affected eye. A major risk factor for infection is the use of contact lenses. Inadequate hygiene precautions and mold-growth permissive storage fluids are important risk factors for fungal keratitis. The aim of this study was to comparatively analyze contact lens storage fluids disinfection efficacy against Fusarium species. METHODS: Eleven commercially available storage fluids were tested. The storage fluids were classified according to their active ingredients myristamidopropyldimethylamine (Aldox), polyhexanide and hydrogen peroxide. Efficacy was tested against isolates belonging to the Fusarium solani and Fusarium oxysporum species complexes as the most common agents of mould keratitis. Tests were carried out based on DIN EN ISO 14729. RESULTS: All Aldox and hydrogen peroxide (H2O2) based fluids were effective against Fusarium spp., while the majority of polyhexanide based storage fluids showed only limited or no antifungal effects. Efficacy of polyhexanide could be restored by the addition of the pH-regulating agent tromethamine - an additive component in one commercially available product. CONCLUSIONS: In summary, the use of Aldox- or hydrogen peroxide-based storage fluids may reduce the risk of Fusarium keratitis, while polyhexanide-based agents largely lack efficacy against Fusarium.

Polarity-dominated chitosan biguanide hydrochloride-based nanofibrous membrane with antibacterial activity for long-lasting air filtration.

Facemasks play a significant role as personal protective equipment during the COVID-19 pandemic, but their longevity is limited by the easy dissipation of electrostatic charge and the accumulation of bacteria. In this study, nanofibrous membranes composed of polyacrylonitrile and chitosan biguanide hydrochloride (PAN@CGH) with remarkable antibacterial characteristics were prepared through the coaxial electrospinning process. Particulate matter could be efficiently captured by the fibrous membrane, up to 98 % or more, via polarity-dominated forces derived from cyano and amino groups. As compared commercial N95 masks, the PAN@CGH was more resistant to a wider variety of disinfection protocols. Additionally, the nanofibrous membrane could kill >99.99 % of both Escherichia coli and Staphylococcus aureus. Based on these characteristics, PAN@CGH nanofibrous membrane was applied to facial mask, which possessed an excellent and long-lasting effect on the capture of airborne particles. This work may be one of the most promising strategies on designing high-performance face masks for public health protection.

Multifunctional polymeric guanidine and hydantoin halamines with broad biocidal activity.

Prolonged and excessive use of biocides during the coronavirus disease era calls for incorporating new antiviral polymers that enhance the surface design and functionality for existing and potential future pandemics. Herein, we investigated previously unexplored polyamines with nucleophilic biguanide, guanidine, and hydantoin groups that all can be halogenated leading to high contents of oxidizing halogen that enables enhancement of the biocidal activity. Primary amino groups can be used to attach poly(N-vinylguanidine) (PVG) and poly(allylamine-co-4-aminopyridine-co-5-(4-hydroxybenzylidene)hydantoin) (PAH) as well as a broad-spectrum commercial biocide poly(hexamethylene biguanide) (PHMB) onto a solid support. Halogenation of polymer suspensions was conducted through in situ generation of excess hypobromous acid (HBrO) from bromine and sodium hydroxide or by sodium hypochlorite in aqueous solutions, resulting in N-halamines with high contents of active > N-Br or > N-Cl groups. The virucidal activity of the polymers against human respiratory coronavirus HCoV-229E increased dramatically with their halogenation. Brominated PHMB-Br showed activation activity value > 5 even at 1 mg/L, and complete virus inhibition was observed with either PHMB-Br or PAH-Br at 10 mg/mL. Brominated PVG-Br and PAH-Br possessed fungicidal activity against C. albicans, while PHMB was fungistatic. PHMB, PHMB-Br and PAH polymers demonstrated excellent bactericidal activity against the methicillin-resistant S. aureus and vancomycin-resistant E. faecium. Brominated polymers (PHMB-Br, PVG-Br, PAH-Br) were not toxic to the HeLa monolayers, indicating acceptable biocompatibility to cultured human cells. With these features, the N-halamine polymers of the present study are a worthwhile addition to the arsenal of biocides and are promising candidates for development of non-leaching coatings.

The Orphan Drug for Acanthamoeba Keratitis (ODAK) Trial: PHMB 0.08% (Polihexanide) and Placebo versus PHMB 0.02% and Propamidine 0.1.

PURPOSE: To compare topical PHMB (polihexanide) 0.02% (0.2 mg/ml)+ propamidine 0.1% (1 mg/ml) with PHMB 0.08% (0.8 mg/ml)+ placebo (PHMB 0.08%) for Acanthamoeba keratitis (AK) treatment. DESIGN: Prospective, randomized, double-masked, active-controlled, multicenter phase 3 study (ClinicalTrials.gov identifier, NCT03274895). PARTICIPANTS: One hundred thirty-five patients treated at 6 European centers. METHODS: Principal inclusion criteria were 12 years of age or older and in vivo confocal microscopy with clinical findings consistent with AK. Also included were participants with concurrent bacterial keratitis who were using topical steroids and antiviral and antifungal drugs before randomization. Principal exclusion criteria were concurrent herpes or fungal keratitis and use of antiamebic therapy (AAT). Patients were randomized 1:1 using a computer-generated block size of 4. This was a superiority trial having a predefined noninferiority margin. The sample size of 130 participants gave approximately 80% power to detect 20-percentage point superiority for PHMB 0.08% for the primary outcome of the medical cure rate (MCR; without surgery or change of AAT) within 12 months, cure defined by clinical criteria 90 days after discontinuing anti-inflammatory agents and AAT. A prespecified multivariable analysis adjusted for baseline imbalances in risk factors affecting outcomes. MAIN OUTCOME MEASURES: The main outcome measure was MCR within 12 months, with secondary outcomes including best-corrected visual acuity and treatment failure rates. Safety outcomes included adverse event rates. RESULTS: One hundred thirty-five participants were randomized, providing 127 in the full-analysis subset (61 receiving PHMB 0.02%+ propamidine and 66 receiving PHMB 0.08%) and 134 in the safety analysis subset. The adjusted MCR within 12 months was 86.6% (unadjusted, 88.5%) for PHMB 0.02%+ propamidine and 86.7% (unadjusted, 84.9%) for PHMB 0.08%; the noninferiority requirement for PHMB 0.08% was met (adjusted difference, 0.1 percentage points; lower one-sided 95% confidence limit, -8.3 percentage points). Secondary outcomes were similar for both treatments and were not analyzed statistically: median best-corrected visual acuity of 20/20 and an overall treatment failure rate of 17 of 127 patients (13.4%), of whom 8 of 127 patients (6.3%) required therapeutic keratoplasty. No serious drug-related adverse events occurred. CONCLUSIONS: PHMB 0.08% monotherapy may be as effective (or at worse only 8 percentage points less effective) as dual therapy with PHMB 0.02%+ propamidine (a widely used therapy) with medical cure rates of more than 86%, when used with the trial treatment delivery protocol in populations with AK with similar disease severity. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.