Quantificação de fatores de crescimento na pele de equinos tratada com plasma rico em plaquetas

O plasma rico em plaquetas (PRP) é um produto derivado da centrifugação do sangue total, sendo rico em fatores bioativos, como os de crescimento. Apesar da ampla utilização em processos cicatriciais, há controvérsia sobre a eficácia da terapia na cicatrização cutânea. O objetivo desse estudo foi quantificar e comparar a concentração dos fatores TGF-β1 e PDGF-BB no PRP, plasma sanguíneo e pele, durante diferentes fases do processo de cicatrização da pele tratada ou não com PRP. Foram utilizados sete equinos machos castrados, mestiços, hígidos, com idade entre 16 e 17 (16,14±0,63) anos. Três lesões em formato quadrangular (6,25cm²) foram produzidas cirurgicamente nas regiões glúteas direita e esquerda de todos os animais. Doze horas após indução das feridas, 0,5mL do PRP foi administrado em cada uma das quatro extremidades das feridas de uma das regiões glúteas (Grupo tratado = GT), escolhida aleatoriamente. A região contralateral foi utilizada como controle (GC). As feridas foram submetidas à limpeza diária com água Milli Q, e amostras foram obtidas mediante biópsias realizadas com Punch de 6mm. Foram obtidas seis biópsias de pele, sendo a primeira realizada logo após a produção da ferida (T0), e as demais com 1 (T1) 2 (T2) 7 (T3) e 14 (T4) dias após a indução da lesão. A sexta biópsia (T5) foi obtida após completo fechamento da pele, que ocorreu aproximadamente aos 37 dias (36,85±7,45, GC; 38,85±6,46, GT). Também foram obtidas amostras de sangue com EDTA em todos os tempos mencionados. A quantificação dos fatores de crescimento TGF-β1 e PDGF-BB na pele, PRP e plasma sanguíneo foi realizada pela técnica ELISA. Os dados foram analisados estatisticamente pelo teste t, correlação de Pearson e regressão, utilizando nível de significância de 5%. Não houve diferença entre os grupos, nos valores dos dois fatores de crescimento mensurados na pele, nos diferentes tempos. Também não houve correlação entre a quantidade dos fatores de crescimento presentes na pele e no plasma. Por outro lado, correlação positiva foi observada entre PRP e pele no grupo tratado, para os fatores de crescimento TGF-β1 (r=0,31) e PDGF-BB (r=0,38), bem como entre ambos os fatores de crescimento presentes no PRP (r=0,81). Considerando as concentrações dos fatores de crescimento no T0, os maiores valores cutâneos (p<0,05) do TGF-β1, em ambos os grupos, ocorreram nos tempos T3 e T5. Valores mais elevados (p<0,05) do PDGF-BB ocorreram no T4 (GT) e T5 (GC). No plasma não houve alteração nas concentrações desses fatores em relação ao T0, o que sugere que o PRP não acarreta efeito sistêmico, quando os procedimentos adotados na presente pesquisa são utilizados. A administração local de PRP no volume estudado, 12 h após indução cirúrgica de ferida cutânea na região glútea de equinos não ocasiona maiores concentrações dos fatores de crescimento TGF-β1 e PDGF-BB no plasma sanguíneo e pele, durante o processo de cicatrização

Preparation of catalytic coatings inside microchannels for various applications

Posterpresentati

Review of patent publications from 1990 to 2010 on catalytic coatings and different substrates, including microstructured channels : preparation, deposition techniques, applications

A review of patent publications on preparation, deposition, characterization, and application of the catalytic coatings is given in this paper with view on their application in microstructured reactors for heterogeneous gas-phase processing. The paper consists of two main parts: in the first part the total overview of patents, the distribution by countries and patent applicants is shown. The main topics (coatings preparation, application, removal etc.) are discussed in the second part of the review, including description of some selected patent publications. The aim of the present review is to show the ‘hot’ topics of patent publications on catalytic coatings and the main interests of the big patentees; special attention is given to catalytic coatings on the channel walls in microstructured reactors

Review of patent publications from 1990 to 2010 on catalytic coatings and different substrates, including microstructured channels : preparation, deposition techniques, applications

A review of patent publications on preparation, deposition, characterization, and application of the catalytic coatings is given in this paper with view on their application in microstructured reactors for heterogeneous gas-phase processing. The paper consists of two main parts: in the first part the total overview of patents, the distribution by countries and patent applicants is shown. The main topics (coatings preparation, application, removal etc.) are discussed in the second part of the review, including description of some selected patent publications. The aim of the present review is to show the ‘hot’ topics of patent publications on catalytic coatings and the main interests of the big patentees; special attention is given to catalytic coatings on the channel walls in microstructured reactors

Removal and renewal of catalytic coatings from lab- and pilot-scale microreactors, accompanied by life cycle assessment and cost analysis

Microstructured reactors with a layer of heterogeneous catalyst deposited on their walls are widely recognized for their potential applications in chemical industry. However, what is the most preferable way to handle these catalytic reactors once they are deactivated? Is it better to dispose them together with the catalytic layer or is it more preferable to remove the catalytic coating and recycle the microreactor substrate? These questions were followed in the current study by experimental investigations as well as by consideration of environmental concerns and cost evaluation to get a holistic basis for decision making. Uniform Ru/alumina catalytic coatings were synthesized and deposited on stainless steel microstructured substrates. The Ru/alumina sols were applied on lab- and pilot-scale plates (50 x 35 x 1 mm and 150 x 225 x 2 mm, respectively). The quality of the coatings was checked by porosity measurements (N2 adsorption), surface and cross-section imaging (SEM). Afterwards, the mentioned catalytic coatings were successfully removed from the substrates by means of treatment by acidic, neutral and basic solutions. The influence of the removal procedure on the characteristics of the plates (surface roughness) and catalytic coatings (specific surface area, re-coating) was investigated. All methods showed good ability in coating removal without any further mechanic treatment. The best renewal of the catalytic coating was achieved to be 90% depending on the composition of the removal solution which also influences the Ru/alumina properties. In parallel, an analysis of costs and environmental impacts was performed to support the decision towards the most preferable treatment method. For cost evaluation the costs of chemicals and energy provision as well as labour costs and costs of laboratory equipment were considered. The environmental impacts of the catalytic coating and the removal of the coatings were estimated by a simplified Life Cycle Assessment (LCA) taking into account the up-stream processes of chemicals, substrates and energy supply as well as the disposal of process wastes in addition to the coating and removal procedure. Especially by cost analysis, but also by LCA the benefit of the recycling methods became obvious against the disposal of the plates. However, the advantage of the recycled plates was (partially) counterbalanced by the removal procedure. Furthermore, the procedures applied to the plates for pilot scale applications seemed to be more efficient than the procedures for the laboratory scale plates