RESUMEN
Spider silks were implanted subcutaneously in pigs for a study of the tolerance against this material. Four types of spider silks of high purity and cleanliness were implanted: (i) major ampullate dragline silk reeled from the golden silk spider Nephila clavipes, (ii) native (unsterilised) silk reeled from a Brachypelma spider, (iii) native silk taken from this spider's web and (iv) its web silk thermally treated at 80 degrees C. For comparison we used fibrous silk analogue protein polymers and four already marketed wound dressings (polyurethane film, collagen dressings, gauze pads). All materials were applied epicutaneously to split skin wounds. The implants were examined macroscopically as well as by light microscopy. Superficially, all sites healed rapidly. There were marked inflammatory reactions in all sites with lympho-plasmacellular infiltrations, evidence of phagocytosis and granuloma formation as indicated by the appearance of giant cells. However there was a marked absence of epitheloid cells indicating that the observed reaction was a foreign body granuloma. Furthermore, the histopathological images recorded after 14 days revealed no marked differences between the dressings. Polyurethane films, however, seemed to be superior with respect to the duration of the wound healing process.
Asunto(s)
Materiales Biocompatibles/farmacología , Proteínas de Insectos/farmacología , Poliuretanos/farmacología , Arañas , Cicatrización de Heridas/efectos de los fármacos , Animales , Colágeno/farmacología , Femenino , Cobayas , Seda , Piel/patología , SuturasRESUMEN
Clinical dextrans can be separated in fractions of different molecular size by permeation chromatography on porous glass columns. The apparatus, which is rather simple, is described in detail. The conversion of the elution diagrams in molecular weight distributions is possible if an adequate calibration curve and the magnitude of peak broadening are known. This information can be obtained experimentally. The analysis of the elution diagram is uncomplicated and generally applicable if both the elution curve and the boradening function are approximately Gaussian distributions. Usually this is the case in the systems in question. With the method described clinical dextrans can be characterized as to their molecular weights with high accuracy. The separation method can also be applied to the production of dextran fractions of narrow molecular weight distributions in a preparative scale.