A method of manufacturing hydrogel coatings designed to increase the hydrophilicity of polyurethanes (PU) is presented. Coatings were obtained from polyvinylpyrrolidone (PVP) by free radical polymerisation. The authors proposed a mechanism of a two-step grafting - crosslinking process and investigated the influence of reagent concentration on the coating’s physical properties - hydrogel ratio (HG) and equilibrium swelling ratio (ESR). A surface analysis of freeze-dried coatings using scanning electron microscopy (SEM) showed a highly porous structure. The presented technology can be used to produce biocompatible surfaces with limited protein and cell adhesive properties and can be applied in fabrication of number of biomedical devices, e.g. catheters, vascular grafts and heart prosthesis.

The main objective of this study was to evaluate the intensity and character of the inflammatory reaction caused by an innovative polyester-polyurethane vascular prosthesis implanted into the abdominal aorta of 9 Beagle dogs aged 1-3 years. At 6 and 12 months post implantation the prostheses were removed and tissues samples were examined using 2 methods: histology and immunohistochemistry (IHC). Histology slides stained with hematoxylin and eosin (H&E) were evaluated for the intensity of inflammation by observing the density of inflammatory cells and graded 1 to 4 (1- light inflammation, 4 – severe inflammation). The pro-inflammatory mediator tumor necrosis factor-alpha (TNFα) and two anti-inflammatory mediators, interleukin 1 receptor antagonist (IL1ra), and interleukin 10 (IL10), were also assessed in the tissue samples by IHC methods. Mean (n=5) inflammation grade in H&E slides at 6 months post-implantation (6Mpost) was 2 and mean (n=4) inflammation grade at 12 months (12Mpost) was almost 3. IHC staining showed that TNFα and IL1ra in tissue samples obtained from 6Mpost dogs were expressed at the same intensity indicating equal pro- and anti-inflammatory cytokine levels. However, in the 12Mpost tissues TNFα was expressed more intensely than IL1ra and IL10. Moreover, in 2 dogs at 12Mpost, there were signs of infection assessed on the basis of neutrophil infiltration in the prostheses. In conclusion, the assessment of pro-inflammatory mediators such as TNFα and anti-inflammatory mediators, such as IL1ra and IL10, can help to interpret the intensity of the inflammatory process directed at synthetic prostheses.

The study discusses an experimental method for treatment of high strength domestic sewage on biofilters filled with polyurethane (PUR) waste in the form of trims of upholstery foam. We determined effectiveness of two biological preparations containing effective microorganisms in elimination of organic and biogenic compounds, indicator bacteria and total suspended solids from the sewage pretreated in a septic tank. After four months of work under a hydraulic loading of 76.4 mm∙d ^-1 we found the filter with 60 cm foam layer to be the most efficient in the elimination of BOD ₅, COD _Cr, NH ₄ ⁺-N and coliform bacteria. An average reduction in these pollutants reached 79.4%, 67.8%, 58.0% and 88.0%, respectively. Vertical filters filled with trims of upholstery foam and supplied with effective microorganisms ensured favorable conditions for development of heterotrophic and nitrifying bacteria without any need for additional aeration.

Following paper is focused on experimental and numerical studies of the behavior and energy absorption for both: quasi-static and dynamic axial crushing of thin-walled cylindrical tubes filled with foam. The experiments were conducted on single walled and double walled tubes. Unfilled profiles were compared with tubes filled with various density polyurethane foam. All experiments were done in order to possibility of the safety of the elements absorbing collision energy which can applied in car body. The dynamic nonlinear simulations were carried out by means of PAM-CRASH™ explicit code, which is dedicated calculation package to modelling of crush. Computational crushing force, plastic hinges locations and specimens post-crushed geometry found to be convergent with the real experiments results. Conducted experiments allowed to draw conclusion, that crashworthiness ability is directly proportional to foam density. The investigation of the experimental data revealed, that double walled tubes have greater energy absorbing ability. A proposed investigation enable to analyze and chosen of optimal parameters of these elements, which can use in automotive industry as an absorption energy components.

The study aimed to produce nano- and microfibrous materials from polyurethane (ChronoFlex®C75A/ C75D in 1,1,1,3,3,3–hexafluoro–2–propanol) by solution blow spinning. Experiments were carried out in order to determine the impact of solution blow spinning parameters on fibre diameter and quality of produced materials. The following properties of produced fibre scaffolds were investigated: fibre size, porosity and pore size, wettability, and mechanical properties. The results confirmed that produced nano- and microfibrous materials could be potentially used as scaffolds in three-dimensional cell and tissue cultures.