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Bioelectricity plays a vital role in living organisms. Although electrical stimulation is introduced in the field of bone regeneration, the concept of a dose-response relationship between surface potential and osteogenesis is not thoroughly studied. To optimize the osteogenic properties of different surface potentials, a flexible piezoelectric membrane, poly(vinylidene fluoridetrifluoroethylene) [P(VDF-TrFE)], is fabricated by annealing treatment to control its β phases. The surface potential and piezoelectric coefficients (d 33 ) of the membranes can be regulated by increasing β phase contents. Compared with d 33  = 20 pC N -1 (surface potential = -78 mV) and unpolarized membranes, bone marrow mesenchymal stem cells (BM-MSCs) cultured on the d 33  = 10 pC N -1 (surface potential = -53 mV) membranes have better osteogenic properties. In vivo, d 33  = 10 pC N -1 membranes result in rapid bone regeneration and complete mature bone-structure formation. BM-MSCs on d 33  = 10 pC N -1 membranes have the lowest reactive oxygen species level and the highest mitochondrial membrane electric potential, implying that these membranes provide the best electrical qunantity for BM-MSCs' proliferation and energy metabolism. This study establishes an effective method to control the surface potential of P(VDF-Trfe) membranes and highlights the importance of optimized electrical stimulation in bone regeneration., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Five commercially available plastic containers were compared with glass for toxicity toward Babesia rodhaini and Babesia bigemina. Comparisons were made by using infectivity tests in mice (B. rodhaini) and cattle (B. bigemina). Low-density polypropylene and polystyrene containers were not toxic, but two of the three polyvinyl chloride containers tested significantly reduced the viability of both species of Babesia. Plasticizer present in various amounts on the surface of the toxic containers was most likely the inhibitory material.

Native human blood was exposed to polyethylene, poly(vinyl chloride), and Silastic tubing for varying time intervals, following which the relative degree of activation of the intrinsic coagulation system and alterations in cell counts were determined. The effects of pre-exposure of Silastic to purified albumin, high-density lipoprotein, or protein polysaccharide upon subsequent reactivity of blood with these surfaces was determined. In addition, the effects of aspirin, dextran, heparin, and Warfarin on reactivity of blood with Silastic were determined. In each case, changes in coagulation and cell counts were correlated with ultrastructural features of test surfaces following their exposure to blood. Pre-exposure of Silastic to purified proteins had relatively little effect upon subsequent reactivity with blood, while the presence of antithrombotic agents produced numerous changes.

Rats were given different doses (0.25-25 mg) of two forms of PVC past polymers and polystyrene by intratracheal instillation and monitored for cellular and biochemical changes in the lung lavage fluid and remaining lung tissue after 1 and 4 weeks of exposure. Changes were observed in free cell morphology, the level of pulmonary surfactant, and hydrolytic enzyme activities with all three compounds at high concentrations. Some differences in the extent of changes produced per given mass identified were noted with different formulations and the relationship between particle numbers, surface areas, and detergent coatings of samples is discussed. It is argued that PVC paste polymers and polystyrene cannot be considered totally biologically inert but that, in comparison with active cytoxic and inflammatory minerals such as chrysotile asbestos, the extent of their initial reaction in the lung is relatively weak.

Previous studies have shown that CL-2399 (Cutter) and PL-130 (Fenwal) polyvinyl chloride (PVC) plastic bags are unsatisfactory for storage of platelet concentrates (PC) at 22 degrees C. In an effort to explain the effects of plastic bags, the chemical make-up of CL-2399 and PL-130 PVC films was determined and compared with that of P1-146 (Fenwal) PVC, which is satisfactory for PC storage at 22 degrees C. The only significant difference between the three materials was the incorporation of tetrahydrofurfuryl oleate (THFO) as a secondary plasticizer in CL-2399 and PL-130. The response of platelets to aggregating agents, uptake of serotonin, recovery from hyptonic stress, and serotonin release during storage following storage in a modified CL-2399 plastic prepared without THFO and designated CL-3000 (Cutter) was equivalent to PL-146 and far superior to CL-2399. In vivo studies in two laboratories of platelets stored in CL-3000 bags showed satisfactory recovery (56 +/- 4.2% and 46.7 +/- 2.7%) and survival (6.4 +/- 0.4 days and 7.4 +/- 0.6 days). From these studies we conclude that the THFO secondary plasticizer component of PL-130 and CL-2399 is the cause of the poor platelet viability of platelets stored in these plastic bags. The mechanism of impairment is not known. The causative agent(s) may be degradation products of THFO (formed during manufacture of the PVC film) that are leached from the plastic into PC during storage.

Human nonrejuvenated and rejuvenated red bood cells were prepared for cryopreservation and subsequent pediatric transfusion. Glycerol was added to the red blood cells in the primary polyvinyl chloride plastic collection bag to achieve a concentration of 40 per cent W/V. The red blood cells were concentrated by centrifugation, and the supernatant glycerol was discarded. Each glycerolized unit was divided into four equal aliquots in the individual 600-ml bags of a dry quadruple polyvinyl chloride plastic system, and each aliquot was frozen and stored at -80 C. After thawing, sodium chloride solutions were used to wash the aliquots in the IBM Blood Processor 2991-1 or 2991-2 or the Haemonetics Blood Processor 115, and the washed aliquots were stored in a sodium chloride-glucose-phosphate solution at 4 C for 24 hours. Freeze-thaw recovery of the red blood cells was about 97 per cent, and freeze-thaw-wash recovery was about 84 per cent. Twenty-four-hour posttransfusion survival values were about 92 per cent for both nonrejuvenated and indated-rejuvenated red blood cells. Nonrejuvenated red blood cells, those frozen within three to five days of collection without biochemical modification, had normal oxygen transport function at the time of transfusion; rejuvenated red blood cells, those biochemically treated with PIGPA Solution A after three to five days of storage at 4 C, had improved oxygen transport function at the time of transfusion.

Chemicals leached from plastic blood bags are potentially immunogenic when introduced parenterally into humans. The experiments reported here represent an attempt to sensitize B6C3F1 mice to parenteral injections of solutions used to extract potentially immunogenic material from plastic blood bags. Mice were given intraperitoneal injections: blood bag extracts prepared from phosphate-buffered saline and ethanol; mouse red cells stored in extract solution; or blood bag extracts prepared from mouse serum. None elicited a significant in vitro immunologic reaction as determined by 3H-thymidine or 3H-leucine uptake into spleen cells. In contrast, intraperitoneal injections in mice of large amounts (0.5 ml) of the phosphate-buffered saline and ethanol extracts decreased spleen cellularity to 59 percent of the control value and reduced spleen cell blastogenic activity in vitro. When solutions of either mouse serum extract or mouse cells stored in extract were given intraperitoneally to mice, no spleen toxicity or increased blastogenic activity was observed. In addition, the extracts obtained from plastic blood bags by using either allogenic serum or buffered saline and ethanol did not elicit an immunologic response when they were administered parenterally to mice.

A recent publication suggested that the 24-hour allowable shelf-life of apheresis platelet concentrates collected by open-system techniques be extended to 48 hours because platelets collected in this fashion usually remain sterile for that length of time. The current studies, however, show that the quality of platelet concentrates deteriorates rapidly after storage for more than 24 hours in the relatively small-volume, polyvinyl chloride containers of currently marketed, open-system software, as evidenced by the falling pH, the disintegration of platelets, and the inability of platelets to recover from hypotonic shock. Platelets were markedly defective within 48 hours. Thus, it seems unwise to extend the shelf-life of such platelet concentrates beyond 24 hours solely because they are likely to remain sterile. Collection techniques and software must also be modified to ensure satisfactory platelet quality before the period of storage should be extended.

Human serum was incubated with representative portions of polyvinyl chloride (PVC) blood storage bags and vascular prostheses. The in vitro interaction process with lipoprotein was followed by polyacrylamide gel electrophoresis (PAGE) using sudan black and nitroblue tetrazolium (NBT) in the prestaining procedure. Densitometric scan of all the lipoprotein bands in serum after incubation with PVC bag material when prestained with sudan black showed remarkable increase in intensity. However, in the same experiment when NBT was used for prestaining no increase in the intensity of any of the lipoprotein bands could be observed. Since sudan black is known to bind cholesterol specifically we suggest that a molecular unfolding occurs when lipoprotein interacts with PVC bag material. When similar experiments were carried out with vascular prosthesis there was conspicuous decrease in the intensity of the high-density lipoprotein (HDL) band especially when stained with NBT. This indicates preferential adhesion of HDL during interaction with vascular prosthesis.

The hydrolytic enzyme activity associated with the tissue reaction to implanted polyvinyl chloride rods containing graded concentrations of an organotin stabilizer was quantitated by microphotometry of tissue sections. The procedure was more sensitive to the effects of the additive than the usual histologic evaluation. It is considered that this type of approach offers a sensitive and objective index to supplement the more subjective morphologic observations in judging the acute histotoxicity of implants.

Determination of soluble protein level and bound sialic acid in 0,15 M SSA (seromucoid) as well as of protein levels and total sialic acid (NANA) were made both in blood serum and serous fluid. These tests were performed before and after subcutaneous and intra-abdominal implantation of different PVC samples. The subcutaneous implantation of samples caused the appearance of serous fluid and subsequently inflammation characterized by an increase of levels of sialic acid and seromucoid--the so-called "acute protein reaction". There were also observed the increased electrophoretic alpha 1, alpha 2 and beta globulin levels. Intra-abdominal implantation caused a decrease in the sialic acid level. Also the albumin fraction decreased but the concentration of the alpha 1 globulin fraction stayed within normal limits.

The influence of the plasticizers, di-(2-ethylhexyl)phthalate (DEHP) and tri-(2-ethylhexyl)trimellitate (TOTM), on granulocyte function was examined. Polyvinyl chloride (PVC) bags with DEHP (DEHP-PVC) leaked DEHP into plasma, but TOTM did not dissolve in plasma under the same conditions. Glow discharge treatment inhibited the leakage of DEHP from DEHP-PVC bags. Depending on the amount of DEHP added into granulocyte suspension, chemotaxis and bactericidal activity decreased, but cell counts and phagocytosis were not affected. During storage for 24 h at 22 degrees C, granulocyte function decreased greatly in DEHP-PVC, but was well maintained in the bags which did not leak plasticizers, TOTM-PVC and glow-discharged DEHP-PVC.

Materials used in drinking water may lead to an increase of microorganisms. Microbiological examinations of material in jar tests have been repeatedly dealt with in literature. However they yielded contradictory results. Within the scope of these examinations it was to be found out if and under which conditions an experimental examination of materials, the criterion of test being microbial growth in water, is possible. For the examinations in jar tests it is necessary to have a minimal concentration of mineral salt in the water and to use germs which can degrade the components issued by the materials.

The methods of oscillographic polarography and pulse differential polarography were used to test the release of some contaminating substances from polyvinylchloride (PVC) during autoclaving of water suspensions. The polarographic technique was able to detect in some extracts the presence of several contaminants, while the other PVC preparations did not release such substances. However the chemical nature of the contaminating substances has not been elucidated, the methods can serve as a screening method to detect heavy polymer contamination.