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Volume 36, Issue 4
Displaying 1-12 of 12 articles from this issue
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Shiro SUZUKI, Tamotsu KONDO1979 Volume 36 Issue 4 Pages 197-201
Published: April 25, 1979
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSThe interactions between poly (Nα, Nε-terephthaloyl-L-lysine) membrane (PPL membrane), an artificial red cell membrane, and serum proteins were studied at different pH and ionic strengths of the medium. PPL membrane was prepared by an interfacial polycondensation reaction between L-lysine dissolved in the aqueous phase and terephthaloyl dichloride dissolved in the organic phase. The interactions were found to depend strongly on the pH of the medium while the ionic strength had little or no effect. At pH 2.0, the proteins with a high positive net charge were adsorbed on the negatively charged surface of PPL membrane to lower the zeta potential of the microcapsules, thereby causing their aggregation to a great extent. Since the proteins bore only a very low positive net charge at pH 4.0, their electrostatic interactions with the capsules were weak ; the protein adsorption decreased to decline zeta potential lowering and capsule aggregation. Neither protein adsorption nor capsule aggregation was observed at pH 7.0 where both the capsules and the proteins were negatively charged.View full abstractDownload PDF (904K) -
Kenji HONDA, Hideaki ITOH, Ichiro HOSHI, Shigeru SASAKAWA1979 Volume 36 Issue 4 Pages 203-207
Published: April 25, 1979
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSTo investigate the effects of container materials on platelet preservation, platelet-rich plasma was preserved on a Petri dish, the surface of which was coated with various polymers, and the decreases of the number of single platelets and their aggregability were examined. The polymers used were silicone, poly (vinyl chloride), sodium polyacrylate (polyanion), and polyionene (polycation). The rate of decrease in the number of single platelets was in the following order: silicone << poly (vinyl chloride) ≈uncoated glass < polycation. The number of single platelets decreased rapidly on the polyanioncoated surface as well as on the polycation-coated surface. The difference among the effects of polymers was not clearly found in the changes of platelet aggregability with time. The morphological characteristics of platelets adhered onto the Petri dishes were observed: the platelets on the silicone showed discoid-shape, on polycation formed multiple pseudopods, and on poly (vinyl chloride) were spread out.View full abstractDownload PDF (1247K) -
Teruo OKANO, Shoji NISHIYAMA, Isao SHINOHARA, Toshihiro AKAIKE, Yasuhi ...1979 Volume 36 Issue 4 Pages 209-216
Published: April 25, 1979
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSBlood protein adsorption and the surface pressure of the adsorbed protein on the film surface of 2-hydroxyethyl methacrylate (HEMA) -styrene block copolymer were studied with respect to the hydrophilic-hydrophobic type of microphase separated structure and compared with those on the film surfaces of PHEMA and polystyrene. By electron microscopic observation using osmium tetroxid fixation technique, it was elucidated that adsorption rate of the protein on the hydrophobic surface was higher than that on the hydrophilic surface. Corresponding with this result, the value of surface pressure on the hydrophobic surface was high comparing with that on the hydrophilic surface. From the result of initial stage of protein adsorption, affinity of the proteins for polymer surface was evaluated, i. e., the order of the affinity for the hydrophobic surface was albumin<γ-globulin<fibrinogen, whereas the order was reversed for the hydrophilic surface. In the case of the surface with microphase separated structure, it was found that albumin was adsorbed onto the hydrophilic domains selectively while both γ-globulin and fibrinogen was were onto the hydrophobic domains selectively. These selective adsorptions were maintained for long time at which monolayer coverage had dome as for both homopolymer surfaces. From the results of both electron microscopic observation and surface pressure analysis, selectivity and orientation of adsorbed protein were discussed.View full abstractDownload PDF (2261K) -
Toshihiro AKAIKE, Yasuhisa SAKURAI, Kazuhiro KOSUGE, Yoshihiko SENBA, ...1979 Volume 36 Issue 4 Pages 217-222
Published: April 25, 1979
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSA new method for estimating the amount of adsorbed proteins on polymer surface and the conformational change of the proteins was developed by means of circular dichroism (CD) and ultraviolet spectroscopy (UV). The interaction between plasma proteins and newly synthesized polyion complexes (PIC) was studied conformationally and quantitatively to clarify the effect of electric charge balance of PIC on the adsorption of proteins. A notable difference in charge effect of PIC was observed among protein species; i. e., bovine serum albumin (BSA), γ-globulin (BγG) and fibrinogen (BPF). In the BSA system, few proteins were adsorbed on polyanion-rich PIC and neutral PIC and a large amount of proteins were on polycation-rich PIC. In the BγG system and the BPF systern, however, notable amount of proteins were adsorbed even on polyanion-rich PIC. The conformational change in ad a relationship with the amount of adsorbed BSA. On the other hand the conformational change in β-structure of BγG and especially the change of α-helix content of BPF seemed not to be correlated to the amount of adsorbed proteins.View full abstractDownload PDF (1002K) -
Shoji NAGAOKA, Yuichi MORI, Hiroshi TANZAWA, Tetsuya KIKUCHI1979 Volume 36 Issue 4 Pages 223-229
Published: April 25, 1979
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSA new antithrombogenic elastomer (H-USD) for ventricular assist device has been developed by ionical heparinization of cationic blend polymer (USD+) composed of segmented polyurethane (U) and a terpolymer (SD+) containing cationic (quarternary ammonium salt), hydrophilic (polyethylene glycol segment), and crosslinkable (epoxy ring) sites. The phase separated structure of H-USD, which depended on the blend composition, effectively controlled the mechanical strength and antithrombogenicity of H-USD. The optimum blend ratio (BR) of SD+ to U (SD+/U) was 0.5-1.0. In H-USD of this region, polyurethane which contributes to mechanical properties formed continuous domain and heparinized polymer which contributes to antithrombogenicity formed uniformly dispersed microdomain. The mechanical durability and elasticity of H-USD of this region (coated with polyurethane) were excellent.View full abstractDownload PDF (1928K) -
Toshiaki TAKAMATSU, Noriko MUTAGUCHI, Eiichi FUKADA, Hiroshi MATSUMOTO1979 Volume 36 Issue 4 Pages 231-239
Published: April 25, 1979
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSAdsorption of water, saline, ringer and heparin solutions on tubes and sheets of expanded poly (tetrafiuoroethylene) (EPTFE) were determined after the specimens were shaked repeatedly in these solutions at room temperature. The saturated value of adsorption increased with the increase of the length of internodal fibrils (pore size) observed by electron microscope. When the fibril length was about 6μm, saturated value of adsorption of water was only about 0.2wt%, and EPTFE showed the antithrombogenecity. The contact angle of water on EPTFE decreased with the shaking treatment and the increase of adsorption of water. The EPTFE tubes, immersed first in aqueous solutions of ethyl alcohol with different concentrations and then in water, saline, ringer and heparin solutions, were implanted to the superior vena cava of dogs. The thrombosis on the inner surface of the tubes observed one week after implantation increased with the increase of the adsorption of solutions. Adsorbed alcohol seems to have promoted the clotting of blood.View full abstractDownload PDF (2271K) -
Masahiro TAMURA, Tadashi URAGAMI, Mizuho SUGIHARA1979 Volume 36 Issue 4 Pages 241-247
Published: April 25, 1979
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSTo study hemoperfusion for artificial kidneys, the adsorption characteristics of anisotropic regenerated cellulose membranes which immobilized activated charcoal were investigated under various conditions. The regenerated cellulose membranes were prepared by hydrolyzing cellulose acetate membranes obtained from a system of cellulose acetate, acetone, formamide, and activated charcoal. The adsorption characteristics were influenced remarkably by the acetone/formamide ratio, the amount of activated charcoal, the solvent evaporation period, temperature in evaporation process, and the temperature of gelation medium. The optimum composition of the casting mixture was cellulose acetate: acetone: formamide=13.0: 43.5: 43.5 (wt%); this mixture also contained 7.5g of activated charcoal per 100g of the casting solution. The adsorption characteristics were dependent on the both temperatures of solvent evaporation process and of gelation medium: 7°C, was superior to 25°C. When a mixture of albumin and disodium phenoltetrabromophthalein sulfonate (BSP) was used as feed solution, only BSP was adsorbed and albumin was completely excluded. Repeated treatment with boiling water had advantages, e. g., the removal of casting solvents remained in the membranes and the steriling of this membrane.View full abstractDownload PDF (1172K) -
Shuzo YAMASHITA, Shiro NAGATA, Koichi TAKAKURA1979 Volume 36 Issue 4 Pages 249-256
Published: April 25, 1979
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSEthylene-vinyl alcohol (EVA) copolymer membranes prepared by wet coagulation process were investigated for hemodialysis. Various casting solvents and precipitant (water) were tested. The system of dimethyl sulfoxide (solvent) and water (precipitant) was found to be most favorable for making hemodialysis membranes. The membrane properties were considerably influenced by the casting conditions, such as coagulation temperature and polymer concentrations. This membranes cast at a low temperature were characterized by their excellent permeability for water and a middle molecular weight substance, such as vitamine B12. Electron microscope revealed a micro-porous structure in which a number of particles having an average diameter of 1, 000 to 2, 000Å were bonded with one another.View full abstractDownload PDF (2169K) -
Yasuji OHTSUKA, Yoshiaki HIRABAYASHI, Junichi MASUBUCHI, Norio KANEKO1979 Volume 36 Issue 4 Pages 257-264
Published: April 25, 1979
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSMembranes for hemodialysis were prepared by casting the following graft copolymer latexes in air of 65% relative humidity at 20°C: (A) mixtures of acrylonitrile (AN) and methylacrylate (MA) (MA/AN (wt/wt) =0.1-2.0) were graft-copolymerized onto poly (vinyl alcohol) (PVA) in aqueous solution using ceric ammonium nitrate. (B) mixtures of AN, MA and acrylamide (AAm) (AN/MA (wt/wt) =3.0, AAm variable) were graft copolymerized onto PVA by the similar procedure to the case A. The membranes obtained from (A) had good mechanical properties in wet state, and comparable permeabilities of solutes in aqueous solution to those of Cuprophane. The membranes obtained from (B) had well-ballanced composition of hydrophilic and hydrophobic components, and exhibited good mechanical properties in wet state and permeabilities of solutes in aqueous solution superior to those of Cuprophane (PT-150).View full abstractDownload PDF (1941K) -
Shuntaro HOSAKA, Yuichi MORI, Hideki KENJO, Hiroshi TANZAWA, Takayuki ...1979 Volume 36 Issue 4 Pages 265-271
Published: April 25, 1979
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSA hydrogel of high water content was applied for the soft contact lens capable of being worn continuously. The hydrogels prepared in this study contain methyl methacrylate units as hydrophobic component and N-viny1-2-pyrrolidone units as hydrophilic component. Oxygen permeability and tensile strength of the hydrogels were measured at 52% 90% water content. From the both properties mentioned above and the reported values of oxygen uptake by front surface of human cornea, it is anticipated that the contact lens of about 70% water content and 0.15 mm thickness can be worn continuously in sleep. In clinical tests, 69 myopic patients wore continuously the contact lenses of 70% water content and 0.15-0.20mm thickness at the center, without any symptom of hypoxia at the cornea for 1-25 months. On the other hand, several cases among the 78 aphakic patients were suspected of hypoxia at the corneas. They wore the contact lenses of the same material but of 0.50-0.60 mm center thickness continuously for the same period as the above.View full abstractDownload PDF (1308K) -
Kiyotaka FURUSAWA, Tetsuro IMAIKE, Yoko OHTA, Yoshio SUDA, Keishiro TS ...1979 Volume 36 Issue 4 Pages 273-278
Published: April 25, 1979
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSA new evaluation method for the biocompatibility of polymeric materials was devised using the proliferation of BHK-21 Clone-13 cells. BHK cells cultured on a cover glass are brought in contact with the surface of a polymer and the growth of cells on the surface is examined. The method is simple and will be useful as an auxiliary to an implantation test. Growth rates and protein contents of cells were investigated for polyacrylates and segmented polyurethanes. Good proliferation was obtained on the surface of poly (methyl methacrylate) and an abnormal one on poly (2-hydroxyethyl methacrylate). For segmented polyurethanes, good proliferation was obtained on the polymers extended with ethylenediamine and poor proliferation on the polymers extended with hydrazine.View full abstractDownload PDF (1806K) -
Nobuo NAKABAYASHI, Eiichi MASUHARA, Seinosuke NAKAGAWA, Shozo KOSHIKAW ...1979 Volume 36 Issue 4 Pages 279-286
Published: April 25, 1979
Released on J-STAGE: February 26, 2010
JOURNAL FREE ACCESSCoating processes of coconut and pitch base spherical activated charcoal (CAC and PAC) with poly (2-hydroxyethyl methacrylate) (poly-HEMA) were studied to make good adsorbent suitable for direct hemoperfusion (DHP). Improvement of blood compatibility and prevention of microparticle release were the main purpose of encapsulation. Decrease of the activity must be minimized by coating. Encapsulation of activated charcoal (AC) with the monomer (HEMA), prepolymerized HEMA or purified poly-HEMA, in 95% ethanol solution was evaluated by comparing the creatinine adsorption rates of the coated AC. PAC coated with 1-% poly-HEMA solution adsorbed creatinine as quickly as the oiginal AC. Microparticle release from AC was completely prevented by double coating with 0.1 and 1% poly-HEMA solution and 12-time washings. Permeation resistance of coated layer against rather high molecular weight solutes was observed but the amounts of solutes adsorbed by the coated charcoal during a period of 2 h were nearly the same as those done by the uncoated one. It is suggested that pressure drop in a 200ml column containing double-coated PAC and platelet counts at the inlet and outlet did not change throughout the 2 h DHP in in vivo studies. The poly-HEMA-coated PAC can be a promising adsorbent for metabolites and poisons in living bodies and is readily introduced into the clinical application.View full abstractDownload PDF (1467K)
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