The effects of vacuum ultraviolet (VUV) treatment on surface chemical composition morphology and albumin adsorption for low-density polyethylene (LDPE) and high-density polyethylene (HDPE) were investigated. The attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectra and contact angle measurements indicated the formation of oxygen-containing polar groups and double bonds under VUV photooxidation in the presence of air or under VUV irradiation in vacuum. Scanning electron microscopy revealed the development of regular structure with the period about 1 microm on the surface of LDPE and HDPE during VUV photooxidation. The correlation between amount of tightly adsorbed albumin and surface concentration of carboxyl groups generated by VUV irradiation was found. The aging effect for protein adsorption during long storage of VUV irradiated samples in air or phosphate-buffered saline (PBS) was studied. The obtained results prove the VUV irradiation provides a high potential to regulate protein adsorption on polymers for biomedical applications.

Chemically skinned (by treatment with saponin, 40 μg/ml) isolated cardiomyocytes were used to study the intracellular diffusion of ADP and creatine (Cr). Stimulation of respiration was studied in these cardiomyocytes without intact sarcolemma and in isolated heart mitochondrial by addition of ADP and Cr in the presence of 0.2 mM ATP (via mitochondrial creatine kinase reaction: Cr + MgATP = MgADP + PCr). The Michaelis constant (Km) for Cr was similar in both cases, 5.67 ± 0.11 (SD) mM in skinned myocytes and 6.9 ± 0.2 mM in mitochondria, showing that there is no significant restriction to the diffusion of this substrate. However, the apparent Km for external ADP increased from 17.6 ± 1.0 μM for mitochondria to 250 ± 38 μM for skinned cardiomyocytes, showing decreased diffusivity of ADP as a result of binding to cellular structures. In the presence of 25 mM Cr, the Km for ADP for myocytes decreased to 35.6 ± 5.6 μM due to the coupling of the creatine kinase and oxidative phosphorylation reactions. Provision of substrate for the creatine kinase reaction amplified the weak ADP signal in the regulation of respiration. The activity of the mitochondrial creatine kinase was decreased by a factor of two in cardiomyopathic hamsters and human hearts and was associated with a twofold decrease in creatine-stimulated respiration. These data show a potentially key role of mitochondrial creatine kinase in the regulation of cellular respiration and the possible importance of changes in its activity for the functional disturbances of the cardiomyopathic heart. cellular respiration; creatine kinase; oxidative phosphorylation

The mechanisms of the interaction of a gas-discharge plasma and vacuum ultraviolet (VUV) radiation with medical polymers were considered. Various techniques were proposed for the use of plasma-chemical and photochemical processes for enhancing the biocompatibility of medical polymers. The plasma-chemical and photochemical processes for the surface functionalization and regulation of the biological characteristics of medical polymers by the immobilization of proteins, biologically active compounds, and liquid-crystal biosensors were described. The relationships of the surface processes that occur in the VUV photolysis of polymers with the kinetics of protein adsorption and the adhesion of blood cell components were analyzed.

No abstract