An alternative to nerve repair using an antioxidant compound: a histological study in rats.

The fascicular composition and organisation of the inferior alveolar nerve (IAN) were determined to confirm the microarchitecture of the IAN bundles into each of the mandibular teeth, including the composition of the mental nerve. The aim of this study was to evaluate peripheral nerve repair after the application of an antioxidant compound to the damaged nerve tissue to elevate the concentration and bioavailability of elements capable of favouring tissue repair. Twenty-five Wistar rats were divided into groups: The Control 1 (Ctl 1) (n = 5) animals had the ischiatic nerve exposed with no suture injury and were sacrificed at 30 days post-operatively. The Control 2 (Ctl 2) (n = 10) animals had the ischiatic nerve exposed, and the nerve was injured using suture in three distinct regions. In the experimental (Exp) animals (n = 10), an antioxidant organic compound was applied to the nerve injury site. The animals with nerve injury (Ctl2 and Exp group) were sacrificed at 15 and 30 days post-operatively. The histological analysis showed less degeneration in the Exp group at 15 and 30 days post-operatively. Nerve neoformation forming a connection between the distal and proximal suture sites was observed in the experimental group. This study presented an alternative to nerve repair using an antioxidant compound.

An alternative to never repair using an antioxidant compound: a histological study in rats

The fascicular composition and organisation of the inferior alveolar nerve (IAN) were determined to confirm the microarchitecture of the IAN bundles into each of the mandibular teeth, including the composition of the mental nerve. The aim of this study was to evaluate peripheral nerve repair after the application of an antioxidant compound to the damaged nerve tissue to elevate the concentration and bioavailability of elements capable of favouring tissue repair. Twenty-five Wistar rats were divided into groups: The Control 1 (Ctl 1) (n = 5) animals had the ischiatic nerve exposed with no suture injury and were sacrificed at 30 days post-operatively. The Control 2 (Ctl 2) (n = 10) animals had the ischiatic nerve exposed, and the nerve was injured using suture in three distinct regions. In the experimental (Exp) animals (n = 10), an antioxidant organic compound was applied to the nerve injury site...(AU)

Cytotoxicity of cannulas for ophthalmic surgery after cleaning and sterilization: evaluation of the use of enzymatic detergent to remove residual ophthalmic viscosurgical device material.

PURPOSE: To evaluate the cytotoxicity of reusable cannulas for ophthalmic surgery after the cannulas were filled with an ophthalmic viscosurgical device (OVD) and cleaned with an enzymatic detergent. SETTING: Microbiological Testing Laboratory, Department of Medical-Surgical Nursing, University of São Paulo School of Nursing, and Cell Culture Section, Adolfo Lutz Institute, São Paulo, Brazil. DESIGN: Experimental study. METHODS: The sample consisted of 30 reusable 25-gauge injection cannulas, 20.0 mm in length, whose lumens were filled with an OVD solution for 50 minutes. The following steps were used to process the cannulas: (1) presoaking, (2) washing the lumen using a high-pressure water jet, (3) backwashing with enzymatic detergent in ultrasonic cleaner, (4) preliminary rinsing with tap water, (5) final rinsing with sterile distilled water, (6) drying with compressed filtered air, (7) wrapping in surgical-grade paper, and (8) steam sterilization at 134°C for 4 minutes. The cannulas were then tested for cytotoxicity according to the United States Pharmacopeia 32. RESULTS: The cleaning protocol used in this study removed residues of OVD solution and enzymatic detergent as shown by the lack of cytotoxicity of all sample extracts. CONCLUSION: This cleaning protocol has the potential to minimize the occurrence of toxic anterior segment syndrome associated with residues of OVD solutions and enzymatic detergents. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Estudo comparativo entre os métodos in vivo e in vitro na análise toxicológica de produtos de higiene descartáveis e sua avaliação microbiológica / Comparative study between in vivo and in vitro toxicological methods and microbiological quality assessment in disposable hygienic products

Os objetivos deste trabalho foram comparar os métodos in vivo e in vitro na avaliação da toxicidade dérmica e estimar a qualidade microbiológica de 60 amostras de produtos de higiene descartáveis comercializados na cidade de São Paulo. Nos testes de toxicidade in vivo foram utilizados o “Método deDraize” e o “Método Modificado por Magnusson e Kligman” e nos testes in vitro o Método de “difusão em agar”, empregando as linhagens celulares, NCTC clone 929 (ATCC- CCL1) e SIRC (ATCC-CCL-60). A análise microbiológica foi realizada de acordo com o “Bacteriological Analytical Manual OnLine”, 2001. Os produtos analisados não apresentaram irritação dérmica primária, cumulativa e sensibilização cutânea, mas nos testes in vitro, foi observada em 18 amostras toxicidade leve à severa, com índice de zona (IZ) variando de 2,0 - 4,0 nas duas linhagens celulares testadas. A análise microbiológica apresentou número elevado de bactérias aeróbias mesófilas, resultados positivos para bolores, presença de Enterobacter sp, Enterobacter agglomerans e Enterobacter cloacae. De acordo com os resultados obtidos e para garantir a segurança da saúde do usuário recomenda-se que, além dos testes já mencionados pela legislação vigente, seja também preconizado teste de citotoxicidade in vitro, para os produtos de uso interno e externo. A realização prévia deste teste pode se constituir em mecanismo de triagem.

Biocompatibility study of polymeric biomaterials.

Polymeric hydrogels are used as wound dressing material since these materials show advantages such as pain relief, exudates absorption, barrier to microorganisms, permeability, and others. This article shows the results obtained in a study aiming to know the biological performance of different polymeric materials to be used in contact with skin: PVP hydrogels and acrylate adhesive. The biocompatibility was determined by in vitro assay of cytotoxicity and in vivo assay by using the contact test of irritability in rabbits. All the tested samples presented no toxicity and no dermal irritation.

Citotoxicidade in vitro das membranas de hidrogel reticuladas por radiação ionizante / In vitro cytotoxicity of hydrogel membranes reticulate by ionizing radiations

Hidrogéis constituídos de poli N-vinil-2-porrolidona (PVP), ágar e polietilenoglicol (PEG) säo utilizados como membranas para uso tópico, no tratamento de lesöes de pele. Com o objetivo de melhorar algumas das propriedades mecânicas da membrana, como tensäo de ruptura e elongaçäo, substituiu-se o PEG pelo copolímero poli (dimetilsiloxano)-co-poli (óxido de etileno) (SEO). A biocompatibilidade "in vitro" das membranas de PVP-SEO com diferentes concetraçöes de SEO foi testada em cultura de células. O teste de citotoxicidade foi realizado pelo estudo comparativo de dois métodos: 1) difusäo em ágar, utilizando-se as linhagens celulares RC-IAL e NCTC Clone L-929 e 2) inibiçäo da formaçäo de colônias utilizando-se a linhagem celular CHO-K1. Os resultados obtidos nos dois métodos foram análogos e demonstraram que as membranas do PVP-SEO apresentaram toxicidade nas concentraçöes testadas e nas linhagens celulares utilizadas. Foi possível também concluir que a adiçäo de SEO ocasiona caráter citotóxico às membranas de PVP

Hydrogels composed by PVP, agar and PEG are used as wound dressings in the treatmentof skin ulcers. In order to improve the mechanical properties of the membrane, such as tensile strengthand elongation, PEG was replaced by copolymer poly (dimethilsiloxane)-co-polyoxiethylene (SEO).The "in vitro" biocompatibility evaluation of PVP-SEO membranes with different concentrations of SEOwas carried out in cell culture. A comparative study of cytotoxicity assays was performed by twomethods: 1) diffusion agar assay, using RC-IAL and NCTC Clone L-929 cells and 2) colony suppressionassay, using CHO-K1 cells. In the cytotoxic evaluation of PVP-SEO membranes by both methods,analogous results were obtained. It was also possible to conclude that the addition of SEO promotescytotoxicity in PVP membranes