Ionic liquid as antibacterial agent for an experimental orthodontic adhesive

ObjectiveThe aim of this study was to formulate and evaluate experimental orthodontic adhesives with different concentrations of 1-n-butyl-3-methylimidazoilium bis(trifluoromethanesulfonyl)imide (BMIM.NTf₂).MethodsThe experimental orthodontic adhesives were formulated with methacrylate monomers, photoinitiators and silica colloidal. The ionic liquid BMIM.NTf₂ was synthesized and characterized. BMIM.NTf₂ was added at 5 (G_5%), 10 (G_10%) and 15 (G_15%) wt.%. One group contained no BMIM.NTf₂ to function as control (G_Ctrl). The adhesives were evaluated for polymerization kinetics, degree of conversion (DC), Knoop hardness and softening in solvent, ultimate tensile strength (UTS), shear bond strength (SBS), thermogravimetric analysis (TGA), antibacterial activity and cytotoxicity.ResultsBMI.NTf₂ showed the characteristic chemical peaks. The polymerization kinetics were different among the groups. G_10% and G_15% showed higher DC (p < 0.05). G_5% and G_Ctrl had no differences for softening in solvent (p > 0.05). There were no differences for UTS (p > 0.05) and SBS (p > 0.05). TGA showed one different peak for G_15%. All groups with BMIM.NTf₂ showed antibacterial activity compared to G_Ctrl (p < 0.05) without cytotoxicity (p > 0.05).SignificanceTo reduce biofilm formation around brackets and to prevent demineralization at susceptible sites, materials have been developed with antibacterial properties. In this study, a new experimental orthodontic adhesive was formulated with an imidazolium ionic liquid (BMIM.NTf₂) as antibacterial agent. The incorporation of 5 wt.% of ionic liquid decreased biofilm formation without affecting the physico-chemical properties and cytotoxicity of an experimental orthodontic resin.     

某院一类切口手术预防用抗菌药物的分析

目的调查我院2012年一类切口手术抗菌药物使用情况,评价其合理性,并推出相关措施,使我院抗菌药物使用更合理,使相关数据符合规定。方法随机抽取我院2012年1月至2012年12月一类切口病例374份,进行统计与分析。结果预防用抗菌药物使用率34.5%,无指征预防用药为8.29%,品种选择合理率90.98%,二联用药率11.63%,术前给药时间合理率92.25%,用药疗程合理率73.64%。结论通过一年整治,我院的一类切口手术预防用抗菌药物使用率有所下降了,但仍有不合理使用情况。     

Effectiveness of 2 Pretreatment Methods in Antifogging of Goggles in a COVID-19 Isolation Ward: A Randomized Controlled Trial

IntroductionThis study aimed to compare the effectiveness of the pretreatment of goggles with iodophor solution and antibacterial hand sanitizer to reduce the fogging of goggles.MethodsA total of 90 health care workers were divided into a control group (n = 30), an iodophor solution group (n = 30), and an antibacterial hand sanitizer group (n = 30). This study evaluated the degree of fogging of goggles and the light transmission, comfort, eye irritation, and the impact of goggles on the medical work of staff.ResultsThe antibacterial hand sanitizer group had the lowest amount of goggle fogging and the most transparent view. Participants in the control group reported the worst light transmission and comfort level, followed by the iodophor solution group. In contrast, the goggles in the antibacterial hand sanitizer group had the best light transmission and comfort level. The iodophor solution group participants reported more eye irritation. Participants in the control group reported that the goggles severely impacted their medical work, with a less severe impact reported by the iodophor solution group. The antibacterial hand sanitizer group did not report any impact on their medical work.DiscussionWhen the goggles were internally coated with antibacterial hand sanitizer solution (diluted 1:1 with distilled water), the antifog effect was significant. Moreover, the goggles treated with antibacterial hand sanitizer had a clearer field of vision, were reported as non-irritating to the eyes, and significantly improved the efficiency of COVID-19 health care workers, including emergency nurses and providers.     

Cold-active antibacterial and antifungal activities and antibiotic resistance of bacteria isolated from an alpine hydrocarbon-contaminated industrial site

Selection pressure in hydrocarbon-contaminated soils may lead not only to increased microbial resistance to antibiotics, but also to increased capacity of the soil indigenous population to produce antimicrobial compounds. Therefore, we studied the antibiotic resistance pattern and antibacterial and/or antifungal activities of 47 bacterial strains isolated from an industrial alpine site heavily polluted with petroleum hydrocarbons. Resistance to penicillin was more widespread (49%) than resistance to chloramphenicol or rifampicin (28%) or streptomycin (26%). Only 9% of the strains were resistant to tetracycline. The ability to produce cold-active (10 °C) antimicrobial compounds was tested by using human pathogenic bacteria (Escherichia coli, Shigella flexneri, Salmonella enterica, Pseudomonas aeruginosa, Staphylococcus aureus) and yeasts (Candida albicans, Cryptococcus neoformans) as indicator microorganisms. About two-thirds of the 47 tested strains produced compounds that inhibited growth of at least one indicator microorganism. Six strains inhibited growth of both bacteria and yeast indicators; 12 and 16 strains showed either antibacterial or antifungal activity, respectively. The most versatile bacteria with regard to multiple antibiotic resistance and antimicrobial activity belonged to Actinobacteria or Gammaproteobacteria. The antimicrobial compounds produced by three Pseudomonas spp. and two Serratia spp. strains were characterized in more detail by TLC and HPLC. Depending on the sensitivity of growth inhibition to enzymes, the compounds produced by the three pseudomonads contained a proteinaceous component.     

我院2013年住院患者抗生素使用分析

目的：调查本院2013年住院患者的抗生素使用情况及对其使用合理性进行分析，为临床合理应用抗生素提供依据。方法采用简单随机抽样法抽取本院的360例病例作为研究对象，其中手术病例180份，非手术病例180份，就其抗生素的使用情况及合理性进行统计分析。结果本院抗生素使用率为40.28%，合理用药率为51.7%，联合用药率为4.83%，使用频率最高的抗生素为头孢西丁。结论本院抗生素临床使用基本合理，但仍存在部分不合理现象，尤其是围术期用药，需加强管理规范。     

Synthesis and biological evaluation studies of novel quinazolinone derivatives as antibacterial and anti-inflammatory agents

Some novel 6,8-diiodo-2-methyl-3-substituted-quinazolin-4(3H)-ones bearing sulfonamide derivatives (4–11) were synthesized in good yields and evaluated for their possible antibacterial, anti-inflammatory activities and acute toxicity. The structures of the synthesized compounds were confirmed on the basis of their spectral data and elemental analysis. Their antibacterial activities were evaluated by the agar well diffusion method while their anti-inflammatory activities were evaluated by the carrageenan-induced hind paw edema test. All the tested compounds showed considerable antibacterial activities and high to moderate anti-inflammatory activities that last for 12 h compared to ibuprofen. All the tested compounds showed no toxic symptoms or mortality rates 24 h post-administration at tested anti-inflammatory doses. In addition, LD₅₀ for all tested compounds was higher than that for ibuprofen implying their good safety margin. The obtained results showed that the most active compounds could be useful as a template for future design, modification and investigation to produce more active analogs.     

Lipid A as a Drug Target and Therapeutic Molecule

In this review, lipid A, from its discovery to recent findings, is presented as a drug target and therapeutic molecule. First, the biosynthetic pathway for lipid A, the Raetz pathway, serves as a good drug target for antibiotic development. Several assay methods used to screen for inhibitors of lipid A synthesis will be presented, and some of the promising lead compounds will be described. Second, utilization of lipid A biosynthetic pathways by various bacterial species can generate modified lipid A molecules with therapeutic value.     

A new hydrophilic polymer for biomaterial coatings with low protein adsorption

BIOPOL® polyurethane polymers, an extension of the HYPOL® Polymer series of foamable hydrophilic polymers, have been developed which exhibit improved performance for selected biomedical applications. Members of the BIOPOL polyurethane polymer series, with molecular weights in the range of 7000 to 30000, are larger molecules than HYPOL polymers (MW < 3000) and produce hydrogels, rather than foams, when mixed with water. The prototype material in this series, BIOPOL XP-5, is a liquid prepolymer which chain extends in water and forms a hydrogel which can contain >85% water. The time required for polymerization with water was dependent on the prepolymer : water ratio. This prepolymer was coated onto silica and medical grade tubing and then cured in place with water to form a stable coating which was resistant to non-specific protein binding. In addition, soluble, isocyanate-free forms of the prepolymer were tested for toxicity and shown to produce no adverse effects when injected intravenously into mice or when applied to a chicken chorioallantoic membrane. BIOPOL polymers can be useful in applications where protein adsorption is an undesirable event.     

Synthesis of stable nanosilver particles (AgNPs) by the proteins of seagrass Syringodium isoetifolium and its biomedicinal properties

A simple eco-friendly approach for the hasty synthesis of stable, potent and benign silver nanoparticles (AgNPs) using seagrass, Syringodium isoetifolium was proposed and described here. The UV–Vis, DLS, XRD, AFM, FESEM, EDX and HRTEM analysis highly characterized and confirmed the presence of polydispersed (2–50 nm) spherical and stable AgNPs. FT-IR and phytochemical analysis suggested that the proteins act as reducing and also as capping agent. A hypothetical approach using bioinformatics tools revealed that the Phytochrome B protein of S. isoetifolium might be responsible for the biosynthesis of NPs. Furthermore, biosynthesized AgNPs showed magnificent antibacterial activity against thirteen clinical bacterial pathogens with maximum zone of inhibition of 14.3 ± 0.12 mm due to their smaller size and longer stability even at minimal nanomolar (nM) concentration. In addition, the MIC and MBC values also suggested the same. Moreover, the percentage of haemolysis (8.49 ± 3.10 to 73.34 ± 1.79%) and haemolytic index revealed the satisfactory biocompatibility of AgNPs that showed less/no haemolysis up to 3 nM concentration. Further, the toxicity effect of biosynthesized AgNPs against the brine shrimp, Artemia salina exhibited significantly increasing mortality (13 ± 4.7 to 100%) with LC₅₀ value at 4 nM concentration. Thus, the optical property, crystal structure, size, shape, stability, bactericidal activity, cytotoxicity, and biocompatibility apparently proved that the biologically synthesized AgNPs have typical properties of nanomaterials.