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Microporous scaffolds with potential applications for tissue engineering were produced from the biodegradable aliphatic isosorbide-based polyurethane using a combined salt leaching-solvent evaporation-coagulation process. Alkaline sodium phosphate heptahydrate crystals were used as a solid porogene, and acetone-water mixture was used as a nonsolvent-coagulant. The scaffolds used in this study had interconnected pores with sizes in the range of 70-120 microm and a pore-to-volume ratio of 87%. The XPS measurements showed that the residence of the scaffold in an aqueous solution of the alkaline porogene changed its surface atomic composition, that is increased the surface concentration of oxygen and nitrogen and reduced the surface concentration of hydrocarbons relative to the control material. This also enhanced the hydrophilicity of the scaffold's surfaces as assessed from contact angle measurements. The alkaline porogene did not affect the polymer's molecular weight. The MTT cytotoxicity assay showed that the isosorbide-based polyurethane scaffold is noncytotoxic. The amounts of interleukin-6 and interleukin-8 proinflammatory cytokines released from human blood leukocytes exposed to the polyurethane scaffolds in vitro were comparable and/or lower than the amount of the cytokines released by leukocytes exposed to the culture-grade polystyrene control.

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The paper presents results of the studies on porous composites obtained using lyophilization method based on the solutions of the following polymers: chitosan, sodium alginate and polylactide, as well as ZnO-doped CaO-SiO 2 -P 2 O 5 bioglass.The researchers took the advantage of zinc ions demonstrating the bactericidal, immune-stimulating, and tissue-regenerating functions in the organism. The cytotoxicity of the composites was tested on L929 cells by means of the direct and the indirect contact method. The antibacterial properties were determined against the gram-negative bacteria Pseudomonas aeruginosa and the gram-positive bacteria Staphylococcus aureus at 24, 48 hours, and 7 days. The study demonstrated that changes due to cytotoxicity effect of the composites depend on the type of polymer and on the duration of contact with cells. The composite with polylactide was found to be the least toxic for L929 cells. ZnO added to the chemical composition of bioglass ensured bactericidal effects. The antibacterial properties of the composites depended on the ZnO content, bioglass grain size, polymer type, and composite microstructure. The composites presented in this paper are innovative as biomaterials for filling bone cavities because they can be a matrix for cells and have an antibacterial effect while supporting the regeneration of damaged tissue. K E Y W O R D Santibacterial activity, bioglass, composite, cytotoxicity

A series of esters of 4-acetyl, 4-trifluoroacetyl- and 4-(3-chloropropionyl)aminobenzenethiosulfoacids (twenty-four compounds) were synthesized and characterized by elemental analysis, H NMR and IR spectroscopy. The antibacterial activity of the novel candidates has been screened using the agar diffusion or serial dilution methods against representative Gram-positive (, ,, sp.,), Gram-negative ( sp., ,, ,, ) bacteria and fungi (, ,, ,, ,, ). Particular potency has been discovered against all tested pathogenic bacteria and fungi by compounds and at nanomolar concentrations. Some appropriate effect of thiosulfoesters structure upon their antimicrobial activity was determined.

Aim: To evaluate the activation of transcriptional nuclear factor kappa-B (NF-nB) in peripheral blood leukocytes (PBL) from patients with chronic heart failure (CHF). In vitro experiments were used to elucidate the role of lipopolysaccharide (LPS) as a stimulus for the NF-nB system in PBL. Methods and results: We examined 46 CHF patients (age: 62 T 1 years, LVEF: 31 T1%, NYHA class: 2.7 T 0.1), 11 coronary artery disease (CAD) patients without CHF, and 13 healthy young subjects. The immunocytochemical localisation of NF-nB in PBL was assessed using a polyclonal rabbit IgG anti-c-Rel-subunit antibody. NF-nB activation was expressed as the percentage of PBL nuclei stained positively for cRel (NF-nB(+)cell). PBL from healthy controls were exposed in vitro to the following concentrations of LPS from Escherichia coli (strain O111:B4): 0.1, 10 and 5000 ng/mL. CHF patients demonstrated the highest NF-nB activation in PBL (NF-nB(+)cells [%]: 37.1 T1.5) as compared to CAD patients (29.1 T 3.0%) and controls (12.6 T 1.5%) (all p < 0.05). There were three main clinical determinants of NF-nB activation in PBL from CHF patients: peak oxygen consumption (r = 0.53, p = 0.025), presence of peripheral oedema (r = 0.37, p < 0.05) and serum C-reactive protein (r = 0.40, p = 0.02). In PBL from healthy subjects, LPS at all concentrations increased NF-nB activity towards the pattern detected in CHF. Conclusions: The NF-nB system is highly overactive in PBL from CHF patients. LPS at low concentrations in peripheral blood may be involved in NF-nB activation in PBL, and is a potential target for future therapeutic applications.

In response to the demand for new implant materials characterized by high biocompatibility and bioresorption, two prototypes of fibrous nanocomposite implants for osseous tissue regeneration made of a newly developed blend of poly(l-lactide-co-glycolide) (PLGA) and syntheticpoly([R,S]-3-hydroxybutyrate), PLGA/PHB, have been developed and fabricated. Afibre-forming copolymer of glycolide and l-lactide (PLGA) was obtained by a unique method of synthesis carried out in blocksusing Zr(AcAc)4 as an initiator. The prototypes of the implants are composed of three layers of PLGA or PLGA/PHB, nonwoven fabrics with a pore structure designed to provide the best conditions for the cell proliferation. The bioactivity of the proposed implants has been imparted by introducing a hydroxyapatite material and IGF1, a growth factor. The developed prototypes of implants have been subjected to a set of in vitro and in vivobiocompatibility tests: in vitro cytotoxic effect, in vitro genotoxicity and systemic toxicity. Rabbitsshowed no signs of negative reactionafter implantation of the experimental implant prototypes.