Synthesis of polymeric nanoparticles by double emulsion and pH-driven: encapsulation of antibiotics and natural products for combating Escherichia coli infections.

The design, development, and obtaining of nanostructured materials, such as polymeric nanoparticles, have garnered interest due to loading therapeutic agents and its broad applicability. Polymeric nanoparticle synthesis employs advanced techniques such as the double emulsion approach and the pH-driven method, allowing the efficient incorporation of active compounds into these matrices. These loading methods ensure compound stability within the polymeric structure and enable control of the release of therapeutic agents. The ability of loaded polymeric nanoparticles to transport and release therapeutic agents on target manner represents a significant advancement in the quest for effective therapeutic solutions. Amid escalating concerns regarding antimicrobial resistance, interventions using polymeric nanostructures stand out for the possibility of carrying antimicrobial agents and enhancing antibacterial action against antibiotic-resistant bacteria, making a new therapeutic approach or complement to conventional treatments. In this sense, the capability of these polymeric nanoparticles to act against Escherichia coli underscores their relevance in controlling bacterial infections. This mini-review provides a comprehensive synthesis of promising techniques for loading therapeutic agents into polymeric nanoparticles highlighting methodologies and their implications, addressing prospects of combating bacterial infections caused by E. coli. KEY POINTS: • The double emulsion method provides control over size and release of bioactives. • The pH-driven method improves the solubility, stability, and release of active. • The methods increase the antibacterial action of those encapsulated in PNPs.

Incorporation of antimicrobial agents into dental materials obtained by additive manufacturing: A literature review.

Background: This review aimed to identify antimicrobial agents incorporated into dental materials obtained through additive manufacturing and their efficacy. Methods: Protocol registration was performed in Open Science Framework (osf.io/sp3xa/) and an electronic search was carried out in the databases PubMed, Science Direct, Embase, Lilacs, and Scopus, up to February 2022, combining the terms ("additive manufacturing" OR "3D printing") AND (antimicrobial). Eligibility criteria included: experimental studies that incorporated 3D printing material with an antimicrobial agent for dental application; that evaluated antimicrobial activity; articles published in peer-reviewed journals and in English. Results: The database search resulted in 1139 references. The manual selection was carried out in 851 studies. Twenty-five articles were selected for full-text reading, of which 8 were included in this review. Polymers were the dental materials most often modified with antimicrobial agents for 3D printing, followed by metal alloy. The antimicrobials used were mainly nanoparticles, metal particles, antifungals, monomers containing quaternary ammonium salt, and antiseptics such as chlorhexidine. Conclusion: The addition of the antimicrobial agents in polymers and alloy for additive manufacturing showed promising efficacy against Candida spp., Gram-positive and Gram-negative bacteria.

A systematic quantitative analysis of the published literature on the efficacy of essential oils as sanitizers in fresh leafy vegetables.

This study carried out a systematic quantitative analysis of published literature on the efficacy of essential oils (EOs) as sanitizers in fresh leafy vegetables (FLVs). Efficacy of EO was measured by determining if their application could cause a reduction of microbial population in FLV, as well as by identifying experimental factors that might affect the achieved reduction levels. Data on efficacy of EO to reduce the microbial population and experimental conditions were collected from selected studies and compiled for a distribution and relational analysis. Reduction of an artificial inoculum and/or natural microbiota of FLV caused by 14 different EO were measured in 404 (73.8%) and 143 (26.2%) experiments, respectively. Results of quantitative analysis showed that EO are consistently effective to reduce microbial population in FLV either when the target microorganisms are forming an artificial inoculum or the natural microbiota, being overall similarly effective to or more effective than substances used ordinarily as sanitizers. EO were more effective to reduce the population of microorganisms forming an artificial inoculum than the natural microbiota. EO concentration and inoculum size had no significant effect on achieved reductions. Duration of sanitization treatment with EO had significant effect on achieved reductions and highest reductions were found when the sanitization time was >3 min. Although with the inherent variability in experimental designs found in available literature, the results of this quantitative analysis provide strong evidence that EO are promising candidates for use in strategies to sanitize FLV.

Antibacterial efficacy of intracanal medicaments on bacterial biofilm: a critical review

The purpose of this paper is to discuss critically the antibacterial efficacy of intracanal medicaments on bacterial biofilm. Longitudinal studies were evaluated by a systematic review of English-language articles retrieved from electronic biomedical journal databases (MEDLINE, EMBASE, CENTRAL) and handsearching records, using different matches of keywords for root canal biofilm, between 1966 and August 1st, 2007. The selected articles were identified from titles, abstracts and full-text articles by two independent reviewers, considering the tabulated inclusion and exclusion criteria. Disagreements were resolved by consensus. The search retrieved 91 related articles, of which 8.8 percent referred to in vivo studies demonstrating the lack of efficacy of endodontic therapy on bacterial biofilm. Intracanal medicaments were found to have a limited action against bacterial biofilm.

Higiene das mãos: comparação da eficácia antimicrobiana do álcool - formulação gel e liquida - nas mãos com matéria orgânica / Hand hygiene: antimicrobial activity comparison of three alcoholic produts - gel and liquid - in hands with organic material

Indiscutivelmente, higiene de mãos (HM)é uma das medidas mais importantes para prevenir as Infecções Hospitalares. Além da tradicional lavagem com água e sabão, o uso do álcool tem se destacado na HM, pois, possui boa atividade antimicrobiana, dispensa pia, reduz o tempo e previne ressecamento de mãos. Das evidências científicas sobre seu uso na HM, ainda há contradições quanto à sua efetividade na presença da matéria orgânica nas mãos. Esta pesquisa foi desenvolvida com intuito de elucidar esta questão avaliando a eficácia antimicrobiana de três formulações alcoólicas (duas em forma de gel e uma líquida) nas mãos com matéria orgânica. Os trabalhos laboratoriais foram realizados no Laboratório de Pesquisas do Instituto de Ensino e Pesquisas (coleta de amostras bacterianas) e no Laboratório de Microbiologia do Departamento de Patologia Clínica do Hospital Albert Einstein (contagem bacteriana), utilizando a metodologia oficial Européia - EN 1500 modificada. Quatorze voluntários - pessoas saudáveis, sem problemas de pele nas mãos e que assinaram o "Termo de Consentimento Livre e Esclarecido", foram aleatorizados em três grupos e cada grupo utilizou os produtos-testes e referência em sequências diferentes. Os produtos-teste foram: produto A - álcool etílico sob a forma de gel a 62% (p/p), produto B - álcool etílico sob a forma de gel a 70%(p/p) e produto C - álcool etílico a 70% (p/v) glicerinado sob a forma líquida e o produto D - álcool 2-propanolol ---------------------|a 60%, produto referência padronizado pela metodologia EN 1500. Para cada produto-teste e referência, foi realizada a seguinte sequência de procedimentos: lavagem de mãos por um minuto com água e sabão; aplicação de 1,2 ml de sangue estéril desfibrinado de carneiro; contaminação das mãos até metade dos matacarpos no caldo tríptico de soja (TSB) com o microrganismo-desafio S. macescens ATCC 14756; coleta de amostras pré HM, friccionando os dedos na placa de Petri contendo TSB (valor inicial); HM aplicando o(s) produto(s)-teste e referência; coleta de amostras para recuperação bacteriana (valor final), com a mesma técnica da fase pré HM e cálculo do fator de redução (FR) logarítmica (log10) de S. marcescens (valor inicial - valor final). Foram realizadas análises estatísticas (teste de Wilcoxon) para verificar a equivalência entre o(s) produto(s)-teste e referência, com o nível de significância estabelecido em P=0,10, unicaudal. Os FR (log10) foram: 3,29 para o produto A; 3,36 para o produto B e 3,56 para o produto C. O produto-referência, produto, produto D, promoveu FR log10 de 3,66. Os testes de Wilcoxon indicaram que há equivalência dos produtos B (P=0,198) e C (P=0,826) com o produto referência D, e que existe diferença do produto A (P=0,074) quando comparado ao produto D. Como conclusão, este estudo revelou que os produtos-teste, utilizados em mãos artificialmente sujas com matéria orgânica reduziram significativamente a colonização transitória das mãos - mais de 3 log10, redução acima de 99,9% podendo ser utilizados para HM. Estes valores são superiores aos valores de FR log10 encontrados após a lavagem de mãos com sabão não-antimicrobiano(2,7) e sabão antimicrobiano tricosan (2,8) e semelhantes aos valores de PVP-I (3,5) e clorexidina degermante (3,1). O produto A, apesar de reprovado pela metodologia oficial EN 1500, obteve o menor FR log10 (3,26), é superior aos sabões não-antimicrobianos e com triclosan e clorexidina degermante a 4%, o que indica a possibilidade de sua utilização como segunda opção.

Hand hygiene is considered the most important measure to reduce the transmission of nosocomial pathogens in health care settings. Because alcohol has excellent antimicrobial activity, requires less time, results in less skin irritation and does not require proximity to a sink, is the preferred agent for hand hygiene. In the face of scientific evidence, there's still contradiction concerning the effectiveness of alcohol in the hands with proteinaceous material. This research was developed in order to compare the antimicrobial activity of three alcoholic products commonly used (two alcohol-based gel and one liquid formulation) in the hands with organic material. It was conducted in the Research Laboratory (bacterial samples) and in the Microbiology Laboratory of the Clinical Pathology Department (bacterial counting) of the Hospital Albert Einstein, using modified European Standard EN 1500. The test products were: A - ethanol alcohol-based gel 62% (p/p), product B - ethanol alcohol-based gel 70% (p/p) and product C - ethanol alcohol-based liquid 70% (p/v) with glycerol 2% compared to reference product: D - alcohol 2-propanolol 60% (v/v) on artificially contaminated hands with S. marcescens ATCC 14756, using a cross-over design. Fourteen healthy volunteers, with no skin hand problems and who signed written consent form were randomized in 3 groups. For each reference and test products, the following sequence was carried through: hands were washed with soft soap, 1,2 ml of sterile sheep blood defibrinated was dispensed by sterile syringe into the hands, air-dried and immersed in the contamination fluid up to the mid-metacarpals. Bacterial sample were recovered for the inicial count by rubbing the fingertips of each hand for 1 min in the petri dish containing tryptone soya broth (TSB) . The hands were rubbed thoroughly over their entire surface (30 to 60 seconds) with 2 -3 ml of the test products. The reference product was used twice (total of 6 ml) and rubbed for 60 seconds. Both hands were rinsed in running water and excess water was drained off. Final bacterial count was obtained rubbing the fingertips of each hand for 1 min in the petri dish containing TSB. For both reference and test products, the mean log10 reduction factors (RF) were calculated (difference between the pre-value and post-value) and for testing the RF of the test products against that of reference product the Wilcoxon teste was used (level of significance was set at P=0,1, one sided) The RF log10 calculated were: 3,29 for the product A; 3,36 for the product B; 3,56 for the product C and 3,66 for the product D. The Wilcoxon test indicated that product A did not meet standard criteria (P = 0,074) and the products B (P = 0,198) and C (P = 0,826) met the EN 1500 requirement. As conclusion, this study indicated that the test products, used in hands with organic material, significantly reduced the transient flora, more than 3 log10 (99,9% of reduction), may be used for hand hygiene. These values are greater than the values of RF log10 after washing hands with plain soap (2,70) and triclosan (2,8) or similar or even exceeding when comparing with antimicrobial detergents used for hand washing, as PVP-I (3,5) or chlorhexidine 4% (3,1). Although the product A did not meet the EN 1500 criteria and had the lowest RF log10, its RF is superior to soaps (plain soap, triclosan and chlorhexidine 4%). This indicates a possibility of its usage as a second option.