RESUMO
Biopolishing is a textile process that uses cellulases to improve the pilling resistance of fabrics. Although the process improves the pilling resistance, softness and color brightness of fabrics, it causes a significant loss of tensile strength in treated fabrics. The present work studied the use of cellulase immobilized on kaolin by adsorption and covalent bonding in biopolishing to get around this problem. The cellulase immobilization has been reported as promising alternative to overcome the inconvenient of biopolishing, but it has been very poorly explored. The results showed that cellulase immobilized by both covalent bonding and adsorption methods provided to the knitted fabric similar or superior pilling resistance to free cellulase, but with greater tensile strength. Immobilization also allowed for efficient recovery and reuse of the enzyme. The present work is a relevant contribution to the literature, since, as far as we know, it is the first work that shows it is possible to minimize the loss of tensile strength and also reuse the immobilized enzyme, giving a better-quality product and also contribution to reducing the cost of the polishing step.
Assuntos
Celulase , Celulases , Enzimas Imobilizadas , Caulim , TêxteisRESUMO
Scaffold-type biomaterials are crucial for application in tissue engineering. Among them, the use of a nonwoven scaffold has grown in recent years and has been widely investigated for the regeneration of different types of tissues. Several polymers, whether they are synthetic, biopolymers or both, have been used to produce a scaffold that can mimic the natural tissue to which it will be applied to. The scaffolds used in tissue engineering must be biocompatible and allow cell adhesion and proliferation to be applied in tissue engineering. In addition, the scaffolds should maintain the mechanical properties and architecture of the desired tissue. Nonwoven fabrics have produced good results and are more extensively applied for the regeneration of cartilage, epithelial and bone tissues. Recent advances in tissue engineering have shown promising results, however, no ideal material or standardization parameters and characteristics of the materials were obtained. The present review provides an overview of the application of nonwoven scaffolds, including the main results obtained regarding the properties of the biomaterials and their applications in vitro and in vivo, focusing on the cartilaginous, the epithelium, and bone tissue regeneration.
Assuntos
Cartilagem/citologia , Engenharia Tecidual/métodos , Animais , Materiais Biocompatíveis/química , Regeneração Óssea , Humanos , Medicina Regenerativa/métodos , Células-Tronco/citologia , Alicerces Teciduais/químicaRESUMO
The removal of dyes present in industrial effluent has received great attention in the past few years. This is partly due to increasing environmental awareness and the implementation of ever stricter environmental rules. However, some treatments for color removal from these effluents do not guarantee the absence of other secondary toxic substances, often originating from the treatment process itself. The aim of this study is to evaluate the toxicity level of the adsorbent Neem, used in adsorption processes for color removal, as well as that of the dye solution before and after the adsorption process. The toxicity tests were carried out according to the Environment Agency FATMA regulation no. 017/02. They consisted of exposing representative microorganisms from the environment, for a certain time interval, to several concentrations of one or more substances, under different environmental conditions, and then evaluating the toxic effects. The results show that the Neem leaf extract had a harmful affect on the test organism used. Thus, it is recommended that the leaf extract is removed prior to effluent treatment, since the results of this study indicate that this will reduce the toxicity of the effluent and also improve the efficiency of the adsorption process.