Synthetically modified cellulose: an alternative to synthetic membranes for use in haemodialysis?

Hoenich, Nicholas A.; Woffindin, C.; Stamp, S; Roberts, S. J.; Turnbull, J. R.

doi:10.1016/s0142-9612(97)00062-8

Cited by 45 publications

(24 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Kuwahara et al 15 found a 3.7% platelet drop at 15 min with CA versus an 8.6% decrease with CU. Hoenich et al 17 found a similar fall in platelet count with PS (Fresenius) as with CA, and these were lower than that with CU. In a study comparing CA, cellulose triacetate (CTA), and Fresenius Hemoflow PS, Hoenich et al found that the intradialytic platelet fall was comparable between CTA and PS, but increased with CA.…”

Section: Platelet Countmentioning

confidence: 83%

Hemodialysis effect on platelet count and function and hemodialysis-associated thrombocytopenia

Daugirdas

Bernardo

2012

Kidney International

171

149

View full text Add to dashboard Cite

Substantial activation of platelets can occur in the course of hemodialysis. Platelet surface markers show evidence of platelet degranulation. Some activation occurs due to exposure of blood to the roller pump segment and microbubbles may play a role. Platelet activation seems to be reduced with reused dialyzers or with those containing synthetic versus cellulosic membranes. Nevertheless, a substantial degree of platelet activation can be demonstrated with polysulfone and other synthetic membranes; the amount of activation may differ substantially among polysulfone membranes, depending on the manufacturer and the polyvinylpyrrolidone content. Platelet-platelet and platelet-leukocyte aggregates have been detected in the dialyzer blood outflow line and the consequences of these to the microcirculation are unknown. Typically, the platelet count decreases slightly during the first hour of dialysis, but mostly returns to initial values by the end of dialysis. A number of chronic hemodialysis patient cases have been reported in which a marked decrease in platelet count (50% or more) during dialysis was observed, resulting in mild degrees of predialysis thrombocytopenia. In only one case was the decrease in platelet count associated with bleeding. Dialyzer hypersensitivity symptoms are infrequently associated with a fall in platelet count. Most recent cases of dialysis-associated thrombocytopenia have been with polysulfone membranes, especially polysulfone membranes sterilized by electron beam. The exact cause of these reactions remains unknown.

show abstract

Section: Platelet Countmentioning

confidence: 83%

Hemodialysis effect on platelet count and function and hemodialysis-associated thrombocytopenia

Daugirdas

Bernardo

2012

Kidney International

171

149

View full text Add to dashboard Cite

show abstract

“…Soluções de complexos inorgânicos de metais de transição, utilizando aminas ou amônia como ligantes, são capazes de dissolver a celulose. [88][89][90][91] Soluções de NaOH a 10% podem dissolver a celulose, mas esta dissolução é restrita aos componentes de menor massa molar, cujo valor de grau de polimerização é de no máximo 200. 92,93 Sais inorgânicos hidratados e fundidos têm ganhado atenção como novos meios para a dissolução e modificação da celulose.…”

Section: Ligninaunclassified

Aplicações de fibras lignocelulósicas na química de polímeros e em compósitos

2009

View full text Add to dashboard Cite

Recebido em 19/1/09; aceito em 25/3/09; publicado na web em 2/4/09 APPLICATIONS OF LIGNOCELLULOSIC FIBERS IN POLYMER CHEMISTRY AND IN COMPOSITES. The use of lignocellulosic fibers and their constituents, as raw materials in the production of polymeric and composite materials, represent an exceptional opportunity of sustainable technological development. In the present report works that discuss promising alternatives of obtaining and use of materials such as cellulose, hemicellulose, lignin, cellulose nanocrystals and biocomposites were revised. The advance in the use of biomass can be, in a near future, capable of going beyond the application difficulties of these vast materials, especially in relation to the economical unviability, by the production of high performance polymeric and composite materials. This advance would represent a higher profitability to some areas of agrobusiness, especially the sector of biofuels, which produces elevated amounts of biomass waste.Keywords: lignocellulosic fibers; nanowhiskers; biocomposites. introduçÃoNos últimos anos tem surgido um grande interesse mundial no desenvolvimento de tecnologias "verdes" que possibilitem a utilização de produtos de menor impacto ambiental.1-4 A química "verde", como um todo, implica no desenvolvimento de processos químicos e produtos que levem a um ambiente mais limpo, saudável e sustentável. Neste contexto, os materiais plásticos sintéticos têm recebido especial atenção por conter em seus métodos de preparação questões que devem ser priorizadas. As questões que devem ser priorizadas são a não-biodegradabilidade dos plásticos sintéticos e por serem oriundos de fontes não-renováveis. 5-8Na busca pela sustentabilidade, várias pesquisas e trabalhos na área de materiais poliméricos e compósitos foram, e estão sendo, realizados para garantir a preservação ambiental e proporcionar um melhor padrão de vida à sociedade.9-13 Dentre as pesquisas nesta área, as que buscam a aplicação de recursos naturais na preparação dos materiais vêm crescendo, podendo-se destacar o uso de fibras naturais. [14][15][16][17][18][19][20][21][22] A Organização das Nações Unidas para a Agricultura e a Alimentação (FAO-ONU -Food and Agriculture Organization of the United Nations) declarou o ano de 2009 como o ano internacional das fibras naturais.23 A medida visa conscientizar e estimular a utilização de fibras naturais, encorajando políticas governamentais de incentivo ao setor e às ações empresariais sustentáveis, para a exploração dessas matérias-primas.Destaque ainda maior deve ser dado à utilização de fibras naturais de origem vegetal, em razão da enorme variedade de espécies passí-veis de serem pesquisadas. Diversas fibras vegetais são produzidas em praticamente todos os países e usualmente são designadas como materiais lignocelulósicos. Algumas fibras ocorrem espontaneamente na natureza, outras são cultivadas como atividade agrícola e ainda há aquelas que são resíduos gerados, principalmente, pela agroindústria. Na Tabela 1 pode ser verificada a produção anual das princ...

show abstract

“…Due to several drawbacks there is a continuous search for new cellulose derivatives with higher blood compatibility and reduced cell adhesion (Sasaki et al 2000;Diamantoglou et al 1999;Hoenich et al 1997;Yuan et al 2003). Cellulose based membranes are also of interest for the development of artificial biohybrid systems containing biological derivates (cells, biomacromolecules).…”

Section: Cellulose With Antioxidant Propertiesmentioning

confidence: 99%

Polymeric membranes with antioxidant activity based on cellulose esters and poly(vinylidene fluoride)/cellulose ester blends

et al. 2011

View full text Add to dashboard Cite

A series of novel cellulose membranes with antioxidant activity was prepared and characterized. Microcrystalline cellulose was functionalized with lipoic acid, ferulic acid and alpha-tocopherol moieties. These materials were characterized by FT-IR and NMR spectroscopy and their degree of substitution (DS) was determined by volumetric analysis. The manuscript discusses the antioxidant activity of cellulose derivatives in inhibiting lipid peroxidation in ratliver microsomal membranes, induced in vitro by two different sources of free radicals: 2,2 0 -azobis-(2-amidinopropane) (AAPH), which exogenously produces peroxyl radicals by thermal decomposition, and tertbutyl hydroperoxide (tert-BOOH), which endogenously produces alkoxyl radicals by Fenton reactions. Membranes were prepared by the nonsolvent-induced phase inversion technique. Membranes of the pure cellulose derivatives were thin, mechanically weak and generally unsuitable for practical application. As an alternative, mechanically resistant poly(vinylidene fluoride)/cellulose ester blend membranes were obtained by direct phase inversion of the polymer/ polymer/solvent mixture. These membranes were characterized by means of water permeability measurements, optical and scanning electron microscopy, determination of the antioxidant activity in comparison with starting materials. The membranes exhibited a good preservation of peroxidation inhibition and the performance of this kind of cellulose membrane as a scavenger of Reactive Oxygen Species (ROS) offers interesting perspectives for an effective control of intradialytic oxidative stress.

show abstract

Synthetically modified cellulose: an alternative to synthetic membranes for use in haemodialysis?

Cited by 45 publications

References 10 publications

Hemodialysis effect on platelet count and function and hemodialysis-associated thrombocytopenia

Hemodialysis effect on platelet count and function and hemodialysis-associated thrombocytopenia

Aplicações de fibras lignocelulósicas na química de polímeros e em compósitos

Polymeric membranes with antioxidant activity based on cellulose esters and poly(vinylidene fluoride)/cellulose ester blends

Contact Info

Product

Resources

About