10 research outputs found
PROSPECÇÃO TECNOLÓGICA SOBRE FILME BIODEGRADÁVEL INTELIGENTE
Os filmes biodegradáveis apresentam-se como uma alternativa ambientalmente sustentável para a sociedade. Podem ser utilizados em alimentos agindo como barreira a elementos externos, aumentando assim sua vida útil. Um dos novos desafios da indústria alimentícia é desenvolver materiais que além de proteger tenham a capacidade de interagir com os alimentos, essas são as conhecidas como embalagens inteligentes. O objetivo deste trabalho foi realizar um levantamento de patentes depositadas na área de filmes biodegradáveis inteligentes. Existem 10 países que possuem patentes na área, sendo o cenário dominado pela Alemanha, de onde provém cerca de 35% do total de documentos depositadas, esse resultado é reforçado quando apresenta-se o levantamento de maiores depositantes, sendo uma empresa alemã a que possui o maior número de depósitos. Constatou-se que só foi encontrado um depósito na área de filmes inteligentes para alimentos utilizando materiais desintegráveis, o que demonstra que essa tecnologia pode ser exaustivamente explorada
Production and Characterization of Starch Nanoparticles
In recent years, the increasing interest in nanomaterials of natural origin has led to several studies in the area of nano-sized particles from natural polysaccharide polymers, such as cellulose, starch, and chitin. These nanomaterials are used especially as a reinforcement in a polymeric matrix to improve the mechanical and barrier properties of the materials. Starch is a sustainable, abundant biopolymer produced by many plants as a source of storage energy; the main uses of starch are as food and industrial applications. However, recently their use as filler in polymeric matrix (nanoparticles) has attracted attention. Starch nanoparticles (SNPs) can be produced by many methods, using chemical, enzymatic, and physical treatments. The size distribution, crystalline structure, and physical properties of the SNPs may vary from one method to another. These nanoparticles are a very interesting alternatives not only for the polymeric filler but also for the renewability and biodegradability, since they show characteristics inherently of starch granules
PBAT/TPS Composite Films Reinforced with Starch Nanoparticles Produced by Ultrasound
The objective of the present work was to study the incorporation of starch nanoparticles (SNP) produced by ultrasound in blends of poly(butylene adipate-co-terephthalate) (PBAT) and thermoplastic starch (TPS). The films were produced by extrusion using varying percentages of SNP (1, 2, 3, 4, and 5% w/w). The SNP were prepared in water without the addition of any chemical reagent. The results revealed that ultrasound treatment results in the formation of SNP less than 100¿nm in size and of an amorphous character and lower thermal stability and low gelatinization temperature when compared with cassava starch. Scanning electron microscopy (SEM) showed that films presented some starch granules. The relative crystallinity (RC) of films decreases with increasing concentration of SNP. The addition of SNP slightly affected the thermal degradation of the films. The DSC results showed that the addition did not modify the interaction between the different components of the films. Mechanical tests revealed an increase in Young’s modulus (36%) and elongation-at-break (35%) with the incorporation of 1% SNP and this concentration reduced the water vapor permeability (53%) and significantly decreased the water absorption of the films, demonstrating that low concentrations of SNP can be used as reinforcement in a polymeric matrixPostprint (published version
Preparation and characterization of liposomes and microspheres useful for desensitization therapy of allergic reaction
Orientadores: Maria Helena Andrade Santana,Ricardo de Lima ZollnerTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia QuimicaResumo: Os problemas alérgicos respiratórios afetam grande parte da população mundial e 10-40% da população brasileira. Atualmente, o tratamento dessas desordens respiratórias consiste a imunoterapia convencional e na farmacoterapia. Embora a imunoterapia convencional apresente boa eficiência no tratamento de alergias respiratórias, o longo tempo de tratamento e a presença de reações sistêmicas adversas constituem grandes desvantagens, uma vez que o alérgeno é administrado na sua forma livre. Uma alternativa para reduzir ou eliminar essas desvantagens seria a encapsulação do alérgeno em sistemas de liberação controlada. Dentre esses sistemas, lipossomas e microesferas poliméricas apresentam-se promissores, uma vez que são capazes não somente de proteger e reduzir a toxicidade do composto ativo encupsulado, mas também de aumentar seu tempo de circulação in vivo. Os lipossomas são biocompatíveis, não imunogênicos, potentes adjuvantes imunológicos e apresentam a capacidade única de interagir com as células. As microesferas, no entanto, vem sendo extensivamente usadas em sistemas de liberação devido a sua capacidade de atuar como reservatório, capaz de liberar as macromoléculas por dias, meses ou anos. O objetivo deste trabalho foi a preparação e encapsulação do extratoalérgico obtido da biomassa fúngica de Drechslera (Helminthosporium) monóceras em lipossomas e microesferas. Lipossomas convencionais e furtivos e microesferas de ácido poli-lático-co-glicólico foram usados neste trabalho... Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digitalAbstract: Respiratory allergic disorders affect a great number of individuals throughout the world. Nowadays, conventional therapies for atopic individuals comprise specific immunotherapy and pharmacotherapy. In general, the immunotherapy using free allergens produces adverse systemic reactions of varying intensity and frequency. In order to circumvent these problems, several approaches have been explored. Among them, liposomes and microspheres have been studied as promising vehicles as carriers of allergens for desensitization immunotherapy in allergy. Liposomes are small phospholipid vesicles composed of nontoxic, biodegradable, and naturally occurring immune response and producing a pronounced depot effect after subcutaneous injection. Microspheres have also been widely investigated in drug delivery studies due to their capability of presenting antigens to the immune system over a long time. A large number of natural and synthetic polymers are potentially suitable for production of the wall-forming polymer. Synthetic biodegradable poly (lactide-co-glycolide) copolymers are among the primary candidates due to their excellent tissue biocompatibility, biodegradability and regulatory approval. The aim of this work is to prepare and characterize liposomes and micrspheres entrapping allergenic extract from Dechlera (Helminthosporium) monoceras and ovoalbumin. The in vivo effects of the sequential administration of both asjuvants containing ovoalbumin were also evaluated by analysis of immunoglobulin G (IgG) and immunoglobulin E (IgE) levels...Note: The complete abstract is available with the full electronic digital thesis or dissertationsDoutoradoDesenvolvimento de Processos BiotecnologicosDoutor em Engenharia Químic
ESTUDO PROSPECTIVO DE DEPÓSITOS DE PATENTES SOBRE COPOLÍMEROS DE ÁCIDO SUCCÍNICO
O presente trabalho refere-se a um estudo prospectivo de depósitos de patentes sobre o tema copolímeros de ácido succínico, avaliando a produção desses copolímeros através de processos de polimerização (código indexação CIP C08F2). Todos os dados utilizados durante a pesquisa foram obtidos no European Patent Office, o Espacenet, em maio de 2014. Através da análise minuciosa dos resultados da investigação, verificou-se que desde o ano 1939 ocorreu um aumento significativo no número de patentes. Durante a apuração da pesquisa, quando utilizaram-se apenas as palavras chaves Copolymer* e Succnic acid, foi possível constatar que o maior número de depósitos aconteceu em 2010, com 19 patentes. Quando essas palavras foram combinadas com o código de Classificação Internacional de Patentes C08F2, no qual avalia copolímeros de ácido succínico através de processos de polimerização, o maior número de depósitos aconteceu no início da década de 1980, com 5 patentes. Além disso, verificou-se que o Japão é o país com maior número de patentes depositadas e que as empresas são responsáveis pela maioria dos depósitos efetuados
Nanoscale Research Letters
p. 1-17The interest of the pharmaceutical industry in lipid drug delivery systems due to their prolonged release profile, biocompatibility, reduction of side effects, and so on is already known. However, conventional methods of preparation of these structures for their use and production in the pharmaceutical industry are difficult since these methods are usually multi-step and involve high amount of organic solvent. Furthermore, some processes need extreme conditions, which can lead to an increase of heterogeneity of particle size and degradation of the drug. An alternative for drug delivery system production is the utilization of supercritical fluid technique. Lipid particles produced by supercritical fluid have shown different physicochemical properties in comparison to lipid particles produced by classical methods. Such particles have shown more physical stability and narrower size distribution. So, in this paper, a critical overview of supercritical fluid-based processes for the production of lipid micro- and nanoparticles is given and the most important characteristics of each process are highlighted
Coating of urea granules by in situ polymerization in fluidized bed reactors
Abstract The main objective of the present work is to produce and characterize urea granules coated with polymers prepared with aqueous solutions of acrylic acid and glycerol. Both coating and drying of urea granules were performed in a fluidized bed reactor. Fourier transform infrared spectroscopy analyses indicated the presence of poly(acrylic acid) and acrylic acid / glycerol copolymers on the granule coating and the formation of chemical bonds between urea and the polymer coating. Scanning electron microscopy images showed that the original and coated urea granules presented different characteristics, reinforcing the idea that coating occurs in the fluidized bed. Finally, rates of urea release showed that the coated granules presented slightly slower rates of urea dissolution in water due to the presence of the coating layer. Therefore, it is shown that it is possible to produce coated urea granules through in-situ polymerization onto the granule surface using a fluidized bed
Chemical and Physicochemical Characterization of Alkali Pretreated and in Natura Sisal Solid Waste
Solid waste from sisal fiber is a great candidate for biorefinery feedstock and material for composite production. However, sisal solid waste needs to be pre-treated before being used for such application. One of pretreatment method is chemical pretreatment process using alkaline solution. Alkaline pretreatment can improve the digestibility and physicochemical properties of this lignocellulosic material. The aim of this study was to characterize the in natura and alkali pretreated sisal solid waste in order to evaluate their potential as biorefinery feedstock and material for composite production. The chemical characterization showed that the pretreatment resulted in an increase in cellulose content, which is in agreement with the results of infrared spectra. The DRX pattern and thermal characterization showed a crystallinity degree increase and thermal stability improving, respectively, indicating a partial removal of the amorphous fraction of the lignocellulosic material. The SEM analysis showed that the pretreatment increased the sisal solid waste superficial area, due to extractives removing. These results contributed to elucidate the potential uses of the lignocellulosic material from sisal and how the dilute alkaline pretreatment affected its composition and physicochemical properties
NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics
Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data