Recent advances in the application of quaternary ammonium compounds in biomedical materials / 口腔疾病防治

@#Microbial infections affect people worldwide. Quaternary ammonium salts serve antibacterial, antifungal, antiviral, anti-matrix metalloproteinase and polymerization functions. While the modification of biomaterials with quaternary ammonium salts cannot affect the physical or chemical properties of the biomaterials, this process can confer them with stable biological activity. Currently, quaternary ammonium salts are widely used in the development of functional orthopedic materials, sutures, dressings and dental materials, and the idea of modifying biomedical materials with quaternary ammonium salts has become the most promising, e.g., for preparing antimicrobial biomaterials. Recent studies have found that quaternary ammonium salt-modified antimicrobial monomers are cytotoxic. Therefore, it is of great significance to explore the cytotoxic mechanism of quaternary ammonium salt-modified antimicrobial monomers and determine possible cytoprotective measures for improving the biological safety of these antimicrobial resin-based materials and expanding their clinical applications. In addition, further validation of the clinical efficacy of these biomaterials is particularly important for accurately evaluating the clinical prospects of these biomaterials. Based on a literature review, this paper summarizes the applications and toxicity of biomedical materials modified with quaternary ammonium salts.

Antimicrobial wound dressing films containing essential oils and oleoresins of pepper encapsulated in sodium alginate films / Curativos medicamentosos antimicrobiano contendo óleos essenciais e oleoresinas de algumas pimentas encapsulados em filmes de alginato de sódio

ABSTRACT: Medicated wound dressings are important barriers to avoid contamination and, when they contain antimicrobial additives, can be used as treatment for infected wounds. There are several types of polysaccharide materials that serve as matrices for medicated wound dressings, among them, sodium alginate. For the preparation of the films studied in this paper, sodium alginate was employed in combination with essential oils/oleoresins (EO/OL) of six peppers that are commonly used in cooking. The EO/OL were incorporated at three different concentrations (low, intermediate and high). Most of the films prepared had better dispersion of the EO/OL at the intermediate concentration. All films studied in this research were dissolved in water at different rates. The antibacterial activity of the prepared films showed significant results against Escherichia coli, Staphylococcus aureus and Bacillus cereus, and demonstrated that the films studied may be a new alternative for medicated wound dressings.

RESUMO: Os curativos medicamentosos são importantes barreiras para se evitar contaminação e ainda, quando contém aditivos antimicrobianos, servem como tratamento para ferimentos infectados. Existem vários tipos de materiais polissacarídicos que servem como matrizes para curativos medicamentosos, dentre eles, destaca-se o alginato de sódio. Para a preparação dos filmes estudados neste trabalho, utilizou-se alginato de sódio e incorporou-se óleos essenciais/oleoresinas (OE/OL) de seis pimentas utilizadas na culinária, em três diferentes concentrações. A maioria dos filmes preparados apresentou melhor dispersão dos OE/OL na concentração intermediária destes. Todos os filmes estudados neste trabalho apresentam solubilidade em água, em uma certa extensão. A atividade antibacteriana dos filmes preparados mostra resultados significantes contra Escherichia coli, Staphylococcus aureus e Bacillus Cereus, mostrando que os filmes estudados podem ser uma nova alternativa como curativos medicamentos.

Research Progress of Polyvinyl Alcohol (PVA) Based on Hydrogel Dressings / 中国医疗器械杂志

This review introduces a brief description on the featured properties of polyvinyl alcohol based on hydrogel dressings. During past ten years many new artificial polymeric dressings have been developed, which meet requirements of wound healing. This review mainly focuses on one representative of ideal polymeric wound dressing membranes, polyvinyl alcohol based hydrogel dressings. But as the hydrogels with single component have low mechanical strength, recent trends have offered composite hydrogel membranes to achieve the ideal wound dressing requirements.

Utilization of three-dimensional printing technology for repairing skin tissue / 生物医学工程学杂志

Three-dimensional (3D) printing is a low-cost, high-efficiency production method, which can reduce the current cost and increase the profitability of skin repair material industry nowadays, and develop products with better performance. The 3D printing technology commonly used in the preparation of skin repair materials includes fused deposition molding technology and 3D bioprinting technology. Fused deposition molding technology has the advantages of simple and light equipment, but insufficient material selection. 3D bioprinting technology has more materials to choose from, but the equipment is cumbersome and expensive. In recent years, research on both technologies has focused on the development and application of materials. This article details the principles of fused deposition modeling and 3D bioprinting, research advances in wound dressings and tissue engineering skin production, and future developments in 3D printing on skin tissue repair, including cosmetic restoration and biomimetic tissue engineering. Also, this review prospects the development of 3D printing technology in skin tissue repairment.

Wound Dressings: A Primer for the Family Physician

Given the myriad of choices available on the market, selecting the appropriate wound dressing remains a challenge for most healthcare workers. It is important to exercise discretion and adopt a systematic approach in dressing selection following wound assessment, as this will directly impact on rates of wound healing, which in turns affects the patient’s quality of life and overall healthcare costs. This paper provides an overview of the common types of wound dressings in use currently and gives a brief synopsis of some of the latest advances in wound care technology and their applications in management of complex wounds. The consensus to date is for the use of hydrogels in the debridement stage, foams and low-adherence dressings in the granulation stage and hydrocolloids and low-adherence dressings for the epithelialization stage. Additional studies and research need to be undertaken to further evaluate the application of advanced wound technology in clinical practice.

Avaliação do blog interativo sobre reparo de feridas e os cuidados de enfermagem / Evaluación de blog interactivo sobre reparación de heridas y cuidados de enfermería / Evaluation of the interactive blog on wound repair and nursing care

Objetivo: descrever a elaboração e a avaliação do blog interativo sobre reparo de feridas e os cuidados de enfermagem. Método: relato de experiência do projeto inserido no programa de monitoria da disciplina Fundamentos de Enfermagem I da EEAAC-UFF. O público alvo foram acadêmicos e profissionais de enfermagem de maio a julho de 2011. O formulário contém os seguintes itens: tema; figuras do blog e seu conteúdo; disposição das cores e adequação; enquête e suas reflexões; disponibilidade dos artigos e links de pesquisa. Resultados: o blog visa à interatividade, divulgação e debate informações que são fontes de atualização sobre pesquisas e especificidades dos cuidados de enfermagem desenvolvidos com base: nos cuidados fundamentais e específicos sobre tecnologia da informação e comunicação com o conhecimento científico da enfermagem. Conclusão: a construção do conhecimento digital na Enfermagem potencializa o aprendizado dos acadêmicos de enfermagem e profissionais, apresentando ideias novas pela troca de conhecimentos

Objective: To describe the design and evaluation of the interactive blog on wound repair and nursing care. Method:experience report of the project entered into the monitoring program of the course Fundamentals of Nursing I EEAACFFU. The target audience was academics and nurses from May to July 2011. The form contains the following items: theme; figures of the blog and its contents; arrangement of colors and adequacy; survey and their reflections; availability of research articles and links. Results: The blog aims to interactivity, information dissemination and debate that are sources of update on research and specific nursing care developed based: basic and specific care information technology and communication with the scientific knowledge of nursing. Conclusion: The construction of knowledge in digital Nursing enhances the learning of nursing students and professionals, presenting new ideas for knowledge exchange

Objetivo: Describir el diseño y evaluación del blog interactivo en la reparación de heridas y cuidados de enfermería. Método: relato de experiencia del proyecto entró en el programa de monitoreo de los curso de Fundamentos de Enfermería I EEAAC-FFU. El público objetivo eran académicos y personal de enfermería, de mayo a julio de 2011. El formulario contiene los siguientes elementos: Tema, figuras del blog y sus contenidos, combinación de colores y la adecuación de la encuesta, y sus reflexiones, la disponibilidad de artículos de investigación y enlaces. Resultados: El blog tiene como objetivo la interactividad, la difusión de información y debate que son fuentes de información actualizada sobre la investigación y los cuidados de enfermería específica desarrollada basada en: la tecnología de información de atención básica y específica y la comunicación con el conocimiento científico de la enfermería. Conclusión: La construcción del conocimiento en Enfermería digital, mejora el aprendizaje de los estudiantes de enfermería y profesionales, presentando nuevas ideas para el intercambio de conocimientos

Hidrogéis de PVP e blendas de PVP/polianidridos como potenciais curativos para feridas crônicas / PVP hydrogels and PVP/Polyanhydride blends as potential materials for chronic wounds dressings

Hidrogéis compreendem uma importante classe de materiais poliméricos adequados à aplicação como curativos de feridas e queimaduras. A estrutura tridimensional hidrofílica dos hidrogéis permite que estes mantenham a umidade ideal no leito das feridas, absorvam o exsudato e não causem danos ao novo tecido durante as trocas dos curativos. No caso dos hidrogéis, essas trocas podem ser menos frequentes. Além disso, curativos que auxiliem na remoção de tecidos necrosados e ainda sejam capazes de oferecer tratamentos extras que acelerem o processo de cicatrização são desejáveis. Este trabalho apresenta a produção de materiais à base de hidrogel capazes de auxiliar neste processo de diferentes maneiras. Primeiramente, são apresentados hidrogéis formados a partir de nanofibras de poli(N-vinil-2-pirrolidona) (PVP) produzidas por eletrofiação, seguido da reticulação através da utilização de radiação UV-C ou reação de Fenton. A utilização da eletrofiação como técnica auxiliar na formação dos hidrogéis permitiu o controle da porosidade através da formação de fibras de diferentes diâmetros. A evidência de tal propriedade foi constatada através da produção de materiais que apresentam diferentes perfis de liberação da proteína modelo albumina de soro bovino (BSA). O hidrogel de PVP nanoestruturado foi capaz de liberar e manter a atividade da colagenase, uma importante enzima aplicada no tratamento de feridas via desbridamento enzimático, durante as 48 horas em que foi avaliado. Além disso, hidrogéis bactericidas nanoestruturados foram produzidos a partir de nanocompósitos de PVP e nanopartículas de prata (AgNP) produzidos por eletrofiação. Esses hidrogéis apresentaram propriedades térmicas semelhantes aos hidrogéis sem AgNP, diminuindo, contudo, a sua capacidade de intumescimento. Esses hidrogéis mostraram-se ativos contra bactérias gram-positivas e gram-negativas a partir de 100 ppm de AgNPs. Adicionalmente, foi estudada a formação de um hidrogel modelo composto PVP/AgNP/Imidazol, almejando-se a produção de um material bactericida-fungicida a base de hidrogel. Este hidrogel apresentou atividade conta três espécies de Candida a partir de 500 ppm de imidazol no material. Embora exista a formação de um complexo estável entre AgNP e Imidazol, cálculos teóricos e a constatação da atividade fungicida corroboram com o fato de que derivados imidazólicos podem ser liberados a partir deste hidrogel híbrido. A produção de hidrogéis físicos compostos por blendas de PVP/Polianidridos sintetizados a partir de derivados de hidroxicinamatos e ácido salicílico, capazes de liberar moléculas de interesse biológico quando parcialmente degradados hidroliticamente, também é descrita neste trabalho. Os resultados indicam que interações hidrofóbicas entre a PVP e os polianidridos sintetizados podem ser responsáveis pela formação dos hidrogéis físicos e pela miscibilidade das blendas produzidas. Os hidrogéis físicos de PVP/Polianidridos foram obtidos na forma de filmes por evaporação do solvente. Micro- e nanofibras também foram obtidas por eletrofiação. Desta maneira, o presente trabalho contribui com o desenvolvimento de uma geração de curativos multifuncionais aplicados no tratamento de feridas crônicas e queimaduras

Hydrogels comprise an important class of polymeric materials that finds application as wound and burn dressings. The hydrophilic three-dimensional structure of hydrogels helps to provide the ideal humidity at the wound bed, to remove exsudates and to prevent damages to the new tissue during dressing substitution. Furthermore, these wound dressings are able to remove necrotic tissues and, therefore, capable to offer extra treatments that would benefit the healing processes. This work describes the production of hydrogel based materials that are able to act in wound healing by different ways. First, it is presented hydrogels composed of poly(N-vinyl-2-pyrrolidone) (PVP) nanofibers produced by electrospinning, followed by its crosslinking using UV-C radiation or Fenton reaction. The use of electrospinning in the hydrogel formation allowed porosity control by obtaining fibers of different diameters. This was evidenced by achieving materials that present different release profiles of the model protein bovine serum albumin (BSA). The nanostructured PVP hydrogel was capable of releasing and maintaining collagenase activity during 48 hour of evaluation. This is an important enzyme that find application in wound healing based on enzymatic debridement. Moreover, nanostructured bactericidal hydrogels were produced from PVP and silver nanoparticles (AgNP) composite through electrospinning, resulting in hydrogels with thermal properties similar to those hydrogels without AgNP, decreasing its swelling ability. These hydrogels were active against gram-positives and gram-negatives bacteria starting from 100 ppm of AgNP. In addition, the production of a model hydrogel composed by PVP/AgNP/Imidazole was investigated, aiming at a bactericidal-fungicidal hydrogel based material. This hydrogel was active against three Candida having 500 ppm of imidazole into the structure. In spite of the formation of a stable complex between AgNP and imidazole, theoretic calculations and the observed fungicidal activity corroborate with the fact that imidazoles derivatives can be released from this hybrid hydrogel. Physical hydrogels composed of PVP/Polyanhydrides blends were synthesized from hydroxycinammates derivatives and salicylic acid. These materials which were capable of releasing molecules with biological potential upon hydrolysis, are also described in this work. The results indicate that hydrophobic interactions between PVP and the synthesized polyanhydrides could be responsible for the hydrogel formation and blend miscibility as well. PVP/Polyanhydride physical hydrogels were obtained from cast films. Micro- and nanofibers were also obtained by electrospinning. Thus, the present work contributes with the development of the new generation of smart dressings for wound and burn healing