Autologous vein grafts used as aortocoronary bypasses are often prone to intimal hyperplasia, which results in stenosis and occlusion of the vein. The aim of this study was to prevent intimal hyperplasia using a newly developed perivascular system with sustained release of sirolimus. This system of controlled drug release consists of a polyester mesh coated with a copolymer of L-lactic acid and ε -caprolactone that releases sirolimus. The mesh is intended for wrapping around the vein graft during surgery. The mesh releasing sirolimus was implanted in periadventitial position onto arteria carotis communis of rabbits, and neointimal hyperplasia was then assessed. We found that implanted sirolimus-releasing meshes reduced intima thickness by 47±10 % compared to a vein graft after 3 weeks. The pure polyester mesh decreased vein intima thickness by 35±9 %. Thus, our periadventitial system for controlled release of sirolimus prevented the develo pment of intimal hyperplasia in autologous vein grafts in vivo in rabbits. A perivascularly applied mesh releasing sirolimus is a promising device for preventing stenosis of autologous vein grafts., I. Skalský ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
E. Filová, M. Rampichová, M. Handl, A. Lytvynets, R. Halouzka, D. Usvald, J. Hlučilová, R. Procházka, M. Dezortová, E. Rolencová, E. Košťáková, T. Trč, E. Šťastný, L. Koláčná, M. Hájek, J. Motlík, E. Amler. and Obsahuje bibliografii
Non-woven textile mesh from polyglycolic acid (PGA) was found as a proper material for chondrocyte adhesion but worse for their proliferation. Neither hyaluronic acid nor chitosan nor polyvinyl alcohol (PVA) increased chondrocyte adhesion. However, chondrocyte proliferation suffered from acidic byproducts of PGA degradation. However, the addition of PVA and/or chitosan into a wet-laid non-woven textile mesh from PGA improved chondrocyte proliferation seeded in vitro on the PGA-based composite scaffold namely due to a diminished acidification of their microenvironment. This PVA/PGA composite mesh used in combination with a proper hydrogel minimized the negative effect of PGA degradation without dropping positive parameters of the PGA wet-laid non-woven textile mesh. In fact, presence of PVA and/or chitosan in the PGA-based wet-laid non-woven textile mesh even advanced the PGA-based wet-laid non-woven textile mesh for chondrocyte seeding and artificial cartilage production due to a positive effect of PVA in such a scaffold on chondrocyte proliferation., M. Rampichová ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
The effect of oral supplementation with glycosaminoglycans (GAG) and radical scavengers (vitamin E/selenium) on the regeneration of osteochondral defects was investigated in rabbits. After introduction of defined osteochondral defects in the knee joint, groups of ten animals were given a GAG/vitamin E/selenium mixture or a placebo (milk sugar) for 6 weeks. Following sacrifice, histological and histochemical analysis was performed. The amount of synovial fluid was increased in the placebo group, while the viscosity of the synovial fluid was significantly enhanced in the GAG group. The amount of sulfated GAG in the osteochondral regenerates (8.8±3.6 % vs. 6.0±5.6 %; p<0.03) was significantly higher in the GAG group. In both groups, the GAG amount in the cartilage of the operated knee was significantly higher than in the non-involved knee (p<0.05). Histological analysis of the regenerates in the GAG group was superior in comparison with the placebo group. For the first time, a biological effect following oral supplementation with GAG was demonstrated in healing of osteochondral defects in vivo. These findings support the known positive clinical results., M. Handl, E. Amler, K. Bräun, J. Holzheu, T. Trč, A. B. Imhoff, A. Lytvynets, E. Filová, H. Kolářová, A. Kotyk, V. Martínek., and Obsahuje bibliografii a bibliografické odkazy