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The aim of this research was to evaluate the effect of polyethylene terephthalate (Woven Dacron) on the expression of endothelial integrins. Human umbilical vein endothelial cells were cultured on the material for 24 h. The integrins VLA-2 (α2β1-CD49b/CD29), receptor for laminin and collagen, VLA-5 (α5β1-CD49e/CD29), receptor for fibronectin, VLA-6 (α6β1-CD49f/CD29), receptor for laminin, and αVβ3-CD51/CD61 (receptor for vitronectin) were evaluated by flow cytometry. After contact with polyethylene terephthalate, a slight but significant decrease in the percentage of both CD29 and CD49e positive cells was observed, which suggests a lower number of cells expressing the fibronectin receptor α5β1. Moreover, a significant increase in the mean channel for CD49b and for the vitronectin receptor CD51/CD61 was observed. The reduction in the fibronectin receptor could account for the poor endothelialization observed in vivo on polyethylene terephthalate. The increased expression of the vitronectin receptor, favoring the migration of smooth muscle cells, could give some information about the pathogenesis of intimal hyperplasia, which is a complication of vascular grafts. © 2001 Kluwer Academic Publishers

In order to evaluate if carbon coated polyethylene terephthalate (C-PET) could favor inflammatory reactions, the expression of interleukin-6 (IL-6) by cultured human umbilical vein endothelial cells was tested in vitro. The cultures were put in contact with C-PET for 1, 24, 48 and 72 h. The same cells cultured on tissue culture-treated polystyrene without biomaterials were tested as the negative control; the same cells incubated with LPS were the positive control. The level of IL-6 in the conditioned medium was tested by enzyme immunoassay; the mRNA expression was evaluated by RT-PCR with specific primers. The cultures incubated with C-PET produced non significantly different amount of IL-6 compared to the negative control and did not induce the expression of IL-6 specific mRNA. LPS induced a significantly higher release of IL-6 in the medium and the expression of mRNA after 24, 48 and 72 h. We conclude that C-PET does not stimulate the synthesis of IL-6 and therefore does not favor inflammatory reaction through the release of this cytokine. © 2001 Kluwer Academic Publishers

The mutagenic potential of three commercially available glass–ionomer cements used in dentistry was examined. The cement components were mixed according to the manufacturers indications and set for two defined times: 1 h or, alternatively, 1 wk. Cements B and C set spontaneously; in the case of cement A, the manufacturer suggests the use of a lamp to trigger also a photopolymerization. Photopolymerization, however, was not used. Ames tests were performed on the dimethyl sulphoxide extracts of cements by using Salmonella typhimurium strains TA 98, TA 100, TA 1535, TA 1537, TA 1538 and TA 102. Cement A showed mutagenicity only against TA 1537 strain, either in the presence or absence of metabolic activation with microsomial fraction S9. The other two cements showed no mutagenic potential. We conclude that glass–ionomer cements are, on the whole, safe materials from the viewpoint of genotoxicity, and hypothesize that the mutagenicity observed in cement A could depend on its polymerization performed without light activation. © 1998 Chapman & Hall

We evaluated the haemocompatibility of a filter of poly(butylene terephthalate) for packed red cell transfusions, which had undergone a physicochemical treatment (corona treatment) in order to reduce the filling time. Leucocyte, erythrocyte and platelet counts were carried out and haematological and coagulation parameters were examined before and after filtration. Moreover, some biochemical plasma parameters were evaluated, which are normally checked in hospitalized patients. The results obtained show that the filter treatment reduces the filling time, does not reduce the efficiency in retaining leucocytes and platelets,and does not induce alterations in filtered red blood cells. However, the treatment prolongs the activated partial thromboplastin time (APTT) and reduces the activity of some factors of the intrinsic coagulation pathway. On the other hand, it does not induce modifications in the biochemical parameters examined.