RESUMEN
Hydrogels have been used for several applications, including production of contact lenses, sanitary products and materials for wound dressing. The aim of this work was the development of new methacrylate based hydrogels. These materials present the advantage of being easily produced with different compositions and consequently different permeability and diffusion patterns. Therefore it becomes possible to synthesize hydrogels that can be used to immobilize a variety of compounds, such as drugs, proteins or even cells. During this work new polymers based on methacrylate monomers were prepared. Their characterization was accomplished by several techniques, e.g. Fourier Transform Infrared Spectroscopy (FTIR), swelling measurement, Differential Scanning Calorimetry (DSC) and evaluation of mechanical properties. Their subacute subcutaneous toxicity was also evaluated by using Wistar rats.
Hidrogéis têm sido utilizados para diversas aplicações, incluindo produção de lentes de contato, produtos sanitários e materiais para encerramento de ferimentos. O objetivo deste trabalho consistiu no desenvolvimento de novos hidrogéis a base de metacrilato. Estes materiais apresentam a vantagem de serem facilmente produzidos com diferentes composições e conseqüentemente com distintas permeabilidades e padrões de difusão. Por este motivo, torna-se possível sintetizar hidrogéis que possam ser usados para imobilizar uma grande variedade de compostos, tais como fármacos, proteínas ou mesmo células e tecidos. Neste trabalho foram preparados diferentes polímeros baseados em monômeros de metacrilato. A sua caracterização foi realizada através de diferentes técnicas, como Espectroscopia no Infravermelho com Transformada de Fourier (FTIR), avaliação da capacidade de intumescimento, Calorimetria Diferencial de Varredura (DSC) e avaliação das propriedades mecânicas. A sua toxicidade subaguda subcutânea foi também determinada utilizando ratos Wistar.
Asunto(s)
Hidrogeles/síntesis química , Calorimetría , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
Mannan and carboxymethylcellulose, previously activated by periodate oxidation, were grafted with mono-6-butylenediamino-6-deoxy-beta-cyclodextrin derivatives by reductive alkylation in the presence of sodium borohydride. The formation of supramolecular complexes between these polymers and Naproxen was confirmed by fluorescence spectroscopy. The solubility of the drug was 3.8-4.6 fold increased in the presence of the cyclodextrin-grafted polysaccharides. The in vivo anti-inflammatory property of Naproxen was 1.7 times higher after supramolecular association with beta-cyclodextrin-branched mannan.
Asunto(s)
Antiinflamatorios no Esteroideos/química , Antiinflamatorios no Esteroideos/farmacología , Carboximetilcelulosa de Sodio/química , Ciclodextrinas/química , Mananos/química , Naproxeno/química , Naproxeno/farmacología , Animales , Antiinflamatorios no Esteroideos/síntesis química , Carragenina/metabolismo , Fluorescencia , Espectroscopía de Resonancia Magnética , Masculino , Naproxeno/síntesis química , Ratas , Ratas Wistar , SolubilidadRESUMEN
Bovine liver catalase (EC 1.11.1.6) was chemically modified with mannan, carboxymethylcellulose, and carboxymethylchitin. The enzyme retained about 48-97% of the initial specific activity after glycosidation with the polysaccharides. The prepared neoglycoenzyme was 1.9-5.7 fold more stable against the thermal inactivation processes at 55 degrees C, in comparison with the native counterpart. Also, the modified enzyme was more resistant to proteolytic degradation with trypsin. Pharmacokinetics studies revealed higher plasma half-life time for all the enzyme-polymer preparations, but better results were achieved for the enzyme modified with the anionic macromolecules.
Asunto(s)
Catalasa/farmacocinética , Polisacáridos/química , Animales , Área Bajo la Curva , Secuencia de Carbohidratos , Carboximetilcelulosa de Sodio/química , Carboximetilcelulosa de Sodio/metabolismo , Catalasa/administración & dosificación , Catalasa/química , Bovinos , Estabilidad de Enzimas , Semivida , Calor , Concentración de Iones de Hidrógeno , Inyecciones Intravenosas , Hígado/enzimología , Masculino , Datos de Secuencia Molecular , Estructura Molecular , Ratas , Ratas Wistar , Solubilidad , Espectrofotometría , Especificidad por Sustrato , Agua/químicaRESUMEN
O-carboxymethylchitin (molecular weight = 1.07 x 10(5), degree of carboxymethylation = 80%, degree of N-acetylation = 91%) was chemically attached to superoxide dismutase by the formation of amide linkages through a carbodiimide catalyzed reaction. The glycosidated enzyme contained about 1.8 mole of polysaccharide per mole of protein and retained 57% of the initial catalytic activity. The anti-inflammatory activity of the enzyme was 2.4 times increased after conjugation with the polysaccharide. The modified superoxide dismutase preparation was remarkably more resistant to inactivation with H(2)O(2) and its plasma half-life time was prolonged from 4.8 min to 69 h.