Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology (Biomater Artif Cell Immobil Biotechnol)

Publications in this journal

• Article: Evaluation of 90:10 poly(D,L-lactide-co-glycolide) microspheres containing norethisterone: drug release and biodegradation.

  Z Zhou, M Zhou, Z Shen, W Shen
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  ABSTRACT: Poly(D,L-lactide-co-glycolide) (PLG, 90:10) microspheres containing 20% norethisterone (NET) were prepared by solvent evaporation method. Microspheres in the size ranges of 65 to 100 microns were sterilized by irradiation and used for further study. In vitro release showed fairly constant release of NET from the above microspheres over more than 90 days. However, in vivo drug release determined by residual NET analysis after i.m. injection in rats indicated a faster release rate. About 95% of NET was released in a period of 45 days. At the dose of 80 mg of microspheres, vaginal estrus cycles were inhibited for 45 days compared to 27 days for the same dose of NET crystals in rats. Biodegradation of the microspheres was tested by direct measurement of molecular weight losses and SEM observation of morphological changes of the microspheres, which showed continuous erosion in the internal matrix of microspheres with the decrease of molecular weight of PLG until total collapse of microspheres, and biodegradation was faster in rats than in human serum at 37 degrees C in vitro. Total degradation of 90:10 PLG microspheres was less than 7 months in rats and more than 9 months in vitro.
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(4):475-86.
• Article: In vitro toxicity of biomaterials determined with cell density, total protein, cell cycle distribution and adenine nucleotides.

  A P Wieslander, M K Nordin, B Hansson, B Baldetorp, P T Kjellstrand
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  ABSTRACT: Inhibition of cell growth is the most commonly used endpoint for in vitro toxicity of biomaterials. The use of several different endpoints might however generate more information concerning the nature of the toxicity. Thus, we examined the toxicity of two biomaterials, Polyvinylchloride (PVC) and Polyoximethene (POM), with different selected endpoints. The influence of cell growth on these endpoints was also investigated. Water extracts from the polymeric materials were tested on the continuous cell line L-929. Cell density, total protein, total protein per cell, fraction of cells in G0/G1- or S-phase, the concentration of ATP, ADP and AMP were used as endpoints. The PVC material did not significantly influence any of these endpoints until after 72 hours of exposure and the main part of the toxicity at 72 hours was related to higher proliferation rate in control cultures. After the cells had been incubated for 8 hour with POM the main toxic effect was on the energy parameters. In conclusion the PVC material was less toxic than the POM material. Our results also implies that the choice of endpoint will influence the evaluation of cytotoxicity.
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(1):63-70.
• Article: Alpha-amylase immobilized on plastic supports: stabilities, pH and temperature profiles and kinetic parameters.

  M G Roig, A Slade, J F Kennedy
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  ABSTRACT: The covalent immobilization of alpha-amylase on new isocyanate, acid chloride and carboxylic acid--activated plastic supports shows the viability of such supports for immobilizing enzymes, especially those reacting with 1,6-diaminohexane and glutaraldehyde for producing side arms. The operational stability of immobilized alpha-amylase could be extended by crosslinking the enzyme or by extending the support's side arm (substrate concentration has no effect). Inactive immobilized alpha-amylase were unfolded and then refolded at elevated temperature, these supports were found to be essential in increasing the stability of the enzyme during refolding. The pH curves for the immobilized enzyme were in general found not to be shifted from the soluble enzyme's pH optimum, although one isocyanate plastic support derivative shifted the pH activity profile of alpha-amylase to a higher range by 1.5 pH units, probably due to reaction between the enzyme and the free anhydride groups existing on the support's surface. In all cases, the immobilized enzyme's temperature activity profiles were shifted to a lower temperature range when compared to the soluble enzyme. The immobilized alpha-amylase Michaelis constants increased and the the maximum rates and specific activities decreased when compared to the soluble enzyme kinetic parameters.
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(4):487-525.
• Article: In vitro and ex vivo evaluation of methotrexate removal by different sorbents haemoperfusion.

  R Giardino, M Fini, G Giavaresi, M Spighi, S Faenza, M Orlandi, M L Florio
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  ABSTRACT: The administration of high doses of Methotrexate (HDMTX) seems to be very effective in neoplastic treatment. Furthermore high doses of the drug could overcome the Methotrexate (MTX) resistance that it is possible to observe in some kind of cancers. To avoid several serious problems in the therapeutical application of HDMTX such as nephrotoxicity, hepatotoxicity and the difficulty to assess the right therapeutic range of the specific antagonist Leucovorin, a Haemoperfusion (HP) treatment could be very usefulL. In this study 3 anion exchange resins with different active group (trimethylammonium, dimethylethanolammonium and dimethylammina) and a spherical petroleum based charcoal were tested both in vitro and ex vivo to evaluate their capability to remove MTX. These results show a good strength and biocompatibility of the 4 sorbents and demonstrate the active group trimethylammonium resin as the most effective one.
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(4):447-54.
• Article: Theoretical modelling of the motion and deformation of capsules in shear flows.

  D Barthes-Biesel
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  ABSTRACT: Mechanical models for capsules freely suspended in another liquid, are devised to predict the deformation, motion, breakup of one particle and also the rheological flow behaviour of a suspension. The capsule is filled with a newtonian liquid, and is surrounded by a thin deformable membrane having otherwise arbitrary mechanical properties. Initially spherical capsules in simple shear flow, are found to deform and orient with respect to streamlines, while their membrane is continuously rotating around the internal liquid. A dilute suspension of such capsules has a viscoelastic constitutive law which depends on the particle physical properties. It is then possible to use such models to interpret experiments in terms of the mean intrinsic properties of a capsule population.
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(3):359-73.
• Article: Alginate immobilized mammalian neurons: a potential tool to isolate new neuronal ligands.

  S Boisseau, C Tamponnet, C Poujeol, M Lièvremont, M Simonneau
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  ABSTRACT: We developed improved immobilization conditions which permitted (i) to immobilize neuroblastoma cells (N18) in calcium-alginate gel beads, (ii) to test the function of ionic channels using patch-clamp electrophysiological techniques and (iii) to quantitatively analyze ligand interactions with voltage-dependent sodium channels in neurons inside the beads. These results qualify this immobilization technique for the isolation and/or purification of ligands specific for neuronal cells.
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(3):421-6.
• Article: Bioencapsulation revisited.

  J E Saucedo, J N Barbotin
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  ABSTRACT: Methods to encapsulate biological materials are now widely used. Sometimes bioencapsulation is considered as a universal technique conducting to identical results independently on the biological material used. For instance, a similar behavior is frequently waited for different strains of immobilized microorganisms without taking into account substantial differences in its physiological and morphological characteristics. Often interactions with the matrix support are also neglected. Thus, some concepts developed throughout all these years working in bioencapsulation merits to be revisited.
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(3):383-9.
• Article: Effect of antigen-specific immunoadsorption on antibody kinetics in a rat model.

  R A Zeuner, R Béress, J O Schroeder, H H Euler
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  ABSTRACT: The investigation of antibody kinetics following antigen-specific immunoadsorption in alkaline phosphatase immunized rats revealed significantly lower antibody levels than in untreated controls over a follow-up period of 6 weeks. A rebounding antibody synthesis as a result of specific depletion was not observed. Non-adsorption of specific antiidiotypic antibodies may explain these findings.
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(2):199-211.
• Article: Genetically engineered E. coli cells containing K. aerogenes gene, microencapsulated in artificial cells for urea and ammonia removal.

  S Prakash, T M Chang
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  ABSTRACT: Microencapsulated genetically engineered E. coli cells can efficiently remove urea without any increase in the ammonia levels in the medium. A 100 mg. alginate encapsulated bacteria rapidly reduces urea in a 100 ml. solution. The original urea concentration 100.00 +/- 1.00 mg./dl. fell to 1.55 +/- 0.13 mg./dl. in 30 minutes. There was no increase in the ammonia in the reaction medium. Extrapolated results shows that urea depletion capacity of encapsulated bacteria is sufficient to remove urea during kidney failure. Using single pool model, 40 gm. of encapsulated genetically engineered E. coli can lower urea (100 mg./dl.) in 40 litres of the body water to 1.60 mg./dl. within 30 minutes. Also, 40.00 gm. bacteria can lower ammonia (758.00 microM/l), in 40 litres of body water, to 90.42 microM/l in 20 minutes. Further studies will be required for multi-compartmental models in the physiological conditions.
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(5):629-36.
• Article: X-ray photoelectron spectroscopy studies, surface tension measurements, immobilization of human serum albumin, human fibrinogen and human fibronectin onto ammonia plasma treated surfaces of biomaterials useful for cardiovascular implants and artificial cornea implants.

  R Sipehia
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  ABSTRACT: XPS studies of untreated and ammonia plasma treated surfaces of PTFE, ePTFE, Dacron, P(HEMA), PMMA, Silastic and PS were carried out. Ammonia plasma treatment caused significant changes in the surface composition. The curve-fitting results confirmed the incorporation of nitrogen and oxygen in the form of functional groups such as C-N, C=O, C-O, Si-N, Si-OH etc. Increases in the values of surface tension occurred. The surface tension of plasma treated surfaces varied between 44-48 erg/cm2 with the exception of Dacron which became wettable. Enhanced immobilization of human albumin on plasma treated surfaces was achieved. When washed with 0.2% Tween in buffer, these albuminated surfaces were found to be stable compared to control samples. Increased immobilization of human fibrinogen was also observed. The ammonia plasma treated surfaces showed high binding properties and retention for human fibronectin. Ionic interaction between proteins solution and plasma treated surfaces may be cause of the increase attachment of these biological molecules.
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(5):647-58.
• Article: Immobilization of aminoacylase in polyethyleneimine stabilized calcium alginate beads for L-phenylalanine production.

  P M Lee, K H Lee, Y S Siaw
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  ABSTRACT: Aminoacylase I (E.C.3.5.1.14) was immobilized by entrapment in calcium alginate beads coated with polyethyleneimine for the production of L-phenylalanine by the hydrolysis of a racemic mixture of N-acetyl-DL-phenylalanine. The operational stability in terms of batch operation and continuous reaction in packed-bed bioreactor were studied. Kinetic constants, Km and Vmax values of free and immobilized enzymes were studied. Polyethyleneimine treatment was found to enhance the operational stability of the enzyme though its activity was substantially reduced. When polyethyleneimine-coated calcium alginate beads were packed into packed bed bioreactor, it was stable for at least 25 days under continuous operation without appreciable loss of activity.
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(4):563-70.
• Article: Release of chemicals from polyurethane foam in the Même breast implant.

  J N Daka, A S Chawla
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  ABSTRACT: Samples of polyurethane (PU) foam from the Même breast implant were incubated at 37 degrees C in either 0.3-3.0 N sodium hydroxide (NaOH) solutions, normal saline, or methanol. The chemicals released were analyzed by gas chromatography (GC), gas chromatography/mass spectrometry (GC/MS), and Fourier-transform infra-red (FT-IR) spectroscopy. The surfaces of the treated and untreated foam samples were studied by scanning electron microscopy (SEM). The NaOH solutions hydrolysed the foam, releasing toluene diamine (TDA). Incubating the foam in methanol washed out trace quantities of anti-oxidant, 2,4-dimethyl-6-t-butylphenol (DBP). When the foam was incubated in normal saline at 37 degrees C no TDA was detectable but another compound with a mass ion of 173 was detected. Further GC/MS studies confirmed that this compound was polyol, one of the reagents used to manufacture the PU foam. Repeatedly incubating or washing the foam in normal saline or methanol eliminated the release of polyol. SEM studies of the foam samples before and after incubation experiments, showed no evidence of polymer degradation. These findings indicated that polyol was present in the PU foam only as an impurity or residue and did not originate from the breakdown of the foam itself.
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(1):23-46.
• Article: Principles of immunapheresis and specific elimination of plasma components.

  R Spaethe, A du Moulin, F Bieber, W Böhm
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  ABSTRACT: In summary the therapeutic use of affinity chromatography, the immunapheresis with LDL-Therasorb columns, Baxter, has been shown to be a safe, specific and efficacious extracorporeal treatment. Following GMP rules LDL-Therasorb is produced in a constant quality. Beyond the treatment of hypercholesterolemia the versatility of antibodies opens this technology to the treatment of other diseases.
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(2):239-51.
• Article: Combined dialysis and plasma-exchange in acute renal failure.

  N E Montemurro, A Di Maggio, P Strippoli, F Coviello, F Godino, G Miloro, A Scatizzi
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  ABSTRACT: Combined use of plasma-exchange and dialysis therapy in 3 different cases of acute renal failure is presented. The first is a case of acute renal failure due to rhabdomyolysis caused by hemlock poisoning. Plasma-exchange was effective in improving the signs of rhabdomyolysis and renal failure. The second is a case of acute renal failure in an IgG-kappa myeloma. After 9 sessions of plasma-exchange, performed simultaneously with CAPD, a significant fall in the plasma and urine light chains levels was obtained. After the recovery of normal renal function, CAPD was prosecuted to remove light chains. The last is a case of acute renal failure in a patient with a mesangiocapillary nephritis and a high level of circulating immune complexes (CIC). He underwent steroid therapy and daily sessions of hemodialysis, followed by plasma-exchange, which permitted a fall of the CIC level, until a normal renal function was achieved. In conclusion, plasma-exchange combined with dialysis, is an useful tool for the management of acute renal failure caused by toxic proteins.
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(2):283-7.
• Article: STM of glow-discharge treated surfaces.

  A Oral, A I Serbetci, R Elliatioglu, E Piskin
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  ABSTRACT: As a model surface, graphite slides were treated by pure nitrogen gas plasma for different periods (15 sec-5 min). These samples were kept in air or under argon atmosphere in sealed holders. STM images were obtained at constant current mode. Results showed that both the number and the size of clusters formed by plasma deposition increased with exposure time.
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(4):469-73.
• Article: Synthesis and interactions with blood of polyetherurethaneurea/polypeptide block copolymers.

  Y Ito, K Miyashita, T Kashiwagi, Y Imanishi
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  ABSTRACT: Polyurethane/polypeptide block copolymers were synthesized. Infrared spectroscopy and differential scanning calorimetry revealed that in the block copolymers both segments undergo phase-mixing, while in polyurethane/polypeptide blend both components undergo phase-separation. Contact angle measurement showed that in the block copolymers polyurethane segments tended to appear on the membrane surface, whereas in polyurethane/polypeptide blend polypeptide components appeared on the membrane surface. In vitro nonthrombogenicity of the block copolymers was similar to that of homopolymers or polymer blends, though adhesion and deformation of platelets were suppressed on the block copolymer membranes.
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(4):571-80.
• Article: Hemoperfusion and liver disease.

  G Visco, R Giannuzzi, M G Paglia, U Visco Comandini
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  ABSTRACT: After first adventurous attempts to apply perfusion techniques to the treatment of liver diseases, more extensive experiences have been acquired in the last twenty years, not only in acute hepatic failure but also in some chronic liver diseases (mainly in CAH:chronic active hepatitis, and in primary biliary cirrhosis) and in a severe complication of them, that is cryoglobulinemia. Some experiences on this field that are found in literature, using both plasma exchange and hemoperfusion, are reviewed and some personal data are reported: 15 patients with acute viral liver failure (survival rate: 33%) and 5 patients with a CAH-linked (3 viral and 2 autoimmune) cryoglobulinemia, in whom a good control of the disease parameters was obtained.
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(2):265-81.
• Article: Effect of high concentration perflubron emulsion on platelet function.

  D J Smith, T A Lane
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  ABSTRACT: Perfluorocarbon (PFC) and lipid emulsions (eg. Fluosol, Intralipid,) containing phospholipid have been reported to modify platelet function after intravenous infusion. Platelet activation might be responsible for the generation of mediators responsible for PFC-induced side effects. In view of this, we investigated the effect of a highly concentrated perfluorocarbon emulsion, containing 90% (w/v) perfluorooctylbromide (perflubron,;PFOB), on porcine and human platelet activation and function. We measured both (1) stimulated ex-vivo porcine platelet aggregation pre and post infusion of either perflubron or control (vehicle only) emulsions and (2) stimulated in vitro human platelet calcium flux in the presence of perflubron emulsion or control emulsions. Platelet aggregation stimulated by collagen, ADP or arachadonic acid (AA) was inhibited in ex-vivo porcine platelets following infusion of perflubron emulsion at a dose of 3 ml/kg (0.2 ml/kg/min). Inhibition was dose-dependent and was decreased when the dose of perflubron emulsion was reduced to 1.0 or 0.3 ml/kg. Infusion of saline or "vehicle" emulsions had little or no effect on stimulated ex-vivo pig platelet aggregation. Fluosol infusion was associated with inconsistant inhibition of platelet aggregation. A23187- or AA-stimulated calcium flux of human platelets in vitro was inhibited in the presence of 1% (v/v) perflubron emulsion. Similar effects were seen with Fluosol, or Intralipid. This inhibition was agonist dose-dependent.(ABSTRACT TRUNCATED AT 250 WORDS)
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(2):173-81.
• Article: Plasmapheresis in acute Guillain-Barre' syndrome.

  M Morosetti, C Meloni, L Meschini, M Taccone-Gallucci, S Di Giulio, G Bernardi, C Casciani
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(2):213-9.
• Article: "Venous hemofiltration associated with loco-regional chemotherapy in the treatment of patients with liver neoplasm".

  G Amicucci, G Porzio, U Giammaria, F De Meo, S Acitelli, F Ciocca, G Carta
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  ABSTRACT: In order to evaluate the possibility to administer high FUDR doses, 52 patients with liver metastases were treated with loco-regional chemotherapy associated with venous hemofiltration. The clinical and pharmacological results of this approach are discussed.
  Biomaterials, artificial cells, and immobilization biotechnology: official journal of the International Society for Artificial Cells and Immobilization Biotechnology 02/1993; 21(2):231-7.