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PubMedDate not supplied

Absorbed dose comparison among commercial ionization chambers in polystyrene and acrylic phantoms.

Using the AAPM Task Group 21 protocol, photon and electron doses were compared in polystyrene and acrylic phantoms. The ionization chambers used were a Farmer graphite chamber, a PTW acrylic chamber, a homemade polystyrene chamber, and an Exradin air-equivalent chamber, all being of cylindrical type. A Memorial parallel-plate polystyrene chamber was also included. 60Co, 4-, 6-, and 18-MV x rays as well as 9- and 20-MeV electron beams were investigated.

Acrylates↗

PubMed2001

Papillomavirus microbicidal activities of high-molecular-weight cellulose sulfate, dextran sulfate, and polystyrene sulfonate.

The high-molecular-weight sulfated or sulfonated polysaccharides or polymers cellulose sulfate, dextran sulfate, and polystyrene sulfonate were tested for microbicidal activity against bovine papillomavirus type 1 (BPV-1) and human papillomavirus type 11 (HPV-11) and type 40 (HPV-40). In vitro assays included the BPV-1-induced focus-forming assay and transient infection of human A431 cells with HPVs. The compounds were tested for microbicidal activity directly by preincubation with virus prior to addition to cell cultures and indirectly by addition of virus to compound-treated cells and to virus-coated cells to test inactivation of the virus after virus-cell binding. The data indicated that all three compounds showed direct microbicidal activity with 50% effective concentrations between 10 to 100 microg/ml. These concentrations were nontoxic to cell cultures for both assays. When a clone of C127 cells was tested for microbicidal activity, approximately 10-fold-less compound was required to achieve a 50% reduction in BPV-1-induced foci than for the uncloned parental C127 cells. Pretreatment of cells with compound prior to addition of virus also demonstrated strong microbicidal activity with dextran sulfate and polystyrene sulfonate, but cellulose sulfate required several orders of magnitude more compound for virus inactivation. Polystyrene sulfonate prevented subsequent infection of HPV-11 after virus-cell binding, and this inactivation was observed up to 4 h after addition of virus. These data indicate that the polysulfated and polysulfonated compounds may be useful nontoxic microbicidal compounds that are active against a variety of sexually transmitted disease agents including papillomaviruses.

Animals↗

PubMed1992

Adhesion and proliferation of bovine aortic endothelial cells on monoamine- and diamine-containing polystyrene derivatives.

Adhesion and proliferation of bovine aortic endothelial cells on polystyrene derivatives having monoamine or diamine side chain was investigated focusing on the chemical structure of amino groups. Copolymers, SE8.5, is composed of polystyrene with 8.5 mol% of monoamine side chains, and SED8, which is with 8 mol% of diamine side chains, were estimated to contain almost the same amount of protonated amino groups in bulk composition at physiological pH (pH 7.4). There observed significant difference in cellular spreading of attached endothelial cells between these two types of copolymer surfaces. Spreading-% of attached cells on SED8 surfaces was approximately 1.6 times greater than that on SE8.5 6 h after seeding. This difference in cellular spreading influenced to subsequent cell growth. Cellular growth on each polymer surface was featured by parameter k, which corresponds to the 'rate constant' of cellular proliferation. While the k-value for SE8.5 decreased with decreasing seeding density as well as the case for polystyrene, SED8 maintained a high k-value even at low seeding density as 2 x 10(3) cells/cm2. These results suggest that cells may recognize the difference in the chemical structure of amine side chains of SE and SED copolymers.

Amines↗

PubMed1993

Synthesis and application of new microcarriers for animal cell culture. Part II: Application of polystyrene microcarriers.

In this work (Part II) the application of new polystyrene based microcarriers in cell culture technology is demonstrated. Carriers with a variety of surface modifications were tested as a growth support for cell line BHK 21. The growth behavior of the cells and cell to surface attachment were compared to Cytodex 3 (Pharmacia), which was used as a reference carrier. To select carriers with growth supporting surfaces, broad screening in petri dish experiments was carried out. Candidates with the highest growth rates were investigated in spinner flash experiments in further detail. Polystyrene carrier with a surface modification like triethylamine, maltamine or N-methylglucosamine were able to support growth as good or better as the reference carrier Cytodex 3. Economies of ingredients and ease in laboratory handling could make amine-modified polystyrenes a competitive alternative to currently commercially available microcarrier types.

Animals↗

PubMed2006

Self-assembly of well-defined polyacrylamide-polystyrene copolymer on fibrillar clays via ultrasonic-assisted surface-initiated atom transfer radical polymerization.

Well-defined polyacrylamide-polystyrene copolymers were grafted from the fibrillar clay, attapulgite, by a four-step self-assembly process: (i) the gamma-aminopropyltriethoxyl silane was self-assembled onto the surfaces of the attapulgite; (ii) the surface amino groups were amidated with bromoacetylbromide; (iii) the bromo-acetamide modified attapulgite was used as macro-initiator for the surface-initiated atom transfer radical polymerization of styrene with the catalyst of the complex of 1,10-phenanthroline and Cu(I)Br; (iv) the polystyrene grafted attapulgite was then used as macroinitiator for the polymerization of acrylamide. The two steps of the surface-initiated atom transfer radical polymerizations were all conducted under ultrasonic irradiation at room temperature. The product, polyacrylamide-polystyrene copolymers grafted attapulgite, had been characterized with elemental analysis, Fourier transform infrared spectroscopy, Thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy, X-ray diffractometry, and transmission electron microscopy.

Acrylic Resins↗

PubMedDate not supplied

Sodium polystyrene sulfonate used to reduce the potassium content of a high-protein enteral formula: a quantitative analysis.

BACKGROUND: Sodium polystyrene sulfonate (Kayexalate) commonly is used in treating hyperkalemia. As a cation exchange resin, it also can be used to reduce the potassium content of enteral nutrition formulas. This study evaluates the use of Kayexalate to reduce potassium in one high-protein enteral formula and describes the quantitative analysis of the product. METHODS: Sodium polystyrene sulfonate and enteral formula were mixed into a slurry and allowed to settle, and then the supernatant was decanted off and tested as samples. Three sample concentrations were analyzed: a control not subjected to potassium reduction, 0.5 g of Kayexalate per mEq K+ sample, and a 1 g/mEq K+ sample. Of these samples, moisture, lipid, protein, carbohydrate, ash, and mineral content were obtained. RESULTS: Compared with the control, the percentage decrease of potassium ranged from 25% to 36%, depending on the concentration of Kayexalate. A significant increase of 324% in sodium concentration was found in the 1.0 g/mEq K+ sample. Although there was no change in magnesium content, a slight increase in phosphorus, iron, and zinc was evident. CONCLUSIONS: The treatment of an enteral formula with sodium polystyrene sulfonate significantly increases its sodium content, with a modest decrease in potassium content. Clinicians using this method in clinical practice should be aware of the increase in sodium content.

Cation Exchange Resins↗

PubMed2000

Effect of subminimal inhibitory concentrations of azithromycin on adherence of Pseudomonas aeruginosa to polystyrene.

Pseudomonas aeruginosa forms a bacterial biofilm by producing alginate when it adheres to mucosa or various medical devices. In this study, the effect of subminimal inhibitory concentrations (subMICs) of azithromycin (AZM) on the biofilm formation and in vitro adherence to polystyrene of 14 wild-type P. aeruginosa strains was studied. A total of 35 P. aeruginosa isolates from clinical specimens were used. Glycocalyx production was determined by the tube method, and bacterial adherence to the wells of flat bottom polystyrene tissue culture plates was estimated by the spectrophotometric method. Compared to the control, the adherence ability to polystyrene was inhibited by incubation with subMICs of AZM in a dose-dependent manner. These results support the findings of other investigators suggesting that AZM in subinhibitory concentrations may be useful in the prevention or treatment of biofilm-associated infections due to P. aeruginosa.

Anti-Bacterial Agents↗

PubMed2001

Oriented antibody immobilization to polystyrene macrocarriers for immunoassay modified with hydrazide derivatives of poly(meth)acrylic acid.

BACKGROUND: Hydrophobic polystyrene is the most common material for solid phase immunoassay. Proteins are immobilized on polystyrene by passive adsorption, which often causes considerable denaturation. Biological macromolecules were found to better retain their functional activity when immobilized on hydrophilic materials. Polyacrylamide is a common material for solid-phase carriers of biological macromolecules, including immunoreagents used in affinity chromatography. New macroformats for immunoassay modified with activated polyacrylamide derivatives seem to be promising. RESULTS: New polymeric matrices for immunoassay in the form of 0.63-cm balls which contain hydrazide functional groups on hydrophilic polymer spacer arms at their surface shell are synthesized by modification of aldehyde-containing polystyrene balls with hydrazide derivatives of poly(meth)acrylic acid. The beads contain up to 0.31 micromol/cm2 active hydrazide groups accessible for covalent reaction with periodate-oxidized antibodies. The matrices obtained allow carrying out the oriented antibody immobilization, which increases the functional activity of immunosorbents. CONCLUSIONS: An efficient site-directed antibody immobilization on a macrosupport is realized. The polymer hydrophilic spacer arms are the most convenient and effective tools for oriented antibody coupling with molded materials. The suggested scheme can be used for the modification of any other solid supports containing electrophilic groups reacting with hydrazides.

Antibodies↗

PubMed1988

Evaluating glass, polystyrene, and polypropylene containers for semen collection and sperm washing.

The effects of glass, polystyrene, and polypropylene containers on semen parameters as measured by Cell Soft computer-assisted semen analysis and hypoosmotic swelling (HOS) tests were assessed in unwashed specimens and again after sperm washing and swim-up procedures. A superiority in unwashed specimens was observed in glass versus polystyrene concerning velocity, motility percentage, and HOS testing (p less than 0.01). Also, superiority of glass versus polystyrene was demonstrated for linearity and ALH (p less than 0.05). Glass was only superior to polypropylene in categories of motility and HOS testing (p less than 0.05 and p less than 0.01, respectively). There was no category in which plastic was statistically superior to glass in the unwashed specimens. Concerning washed and swim-up specimens, there were no semen parameters in which there was any superiority demonstrated of either glass or plastic. Unless some future proof that the differences in semen parameters demonstrated in this study have no clinical significance, these data suggest that the collection of semen samples for sperm analysis or therapeutic use should be performed in glass containers.

Glass↗

PubMed1979

Polystyrene embedding: a new method for light and electron microscopy.

Polystyrene embedments of histological specimens can be obtained with a solution of 1:14 polystyrene-toluene, 5% benzyl alcohol and 1% dibutyl phthalate, allowing the solvent to evaporate in polyethylene containers for 2-3 days at 58 C. The resulting blocks are easily cut into truncated pyramids, each containing a piece of tissue, which are then glued to a Plexiglas support. Drying is completed at 80 C for 20 hr. The pyramids can then be sectioned to produce thick sections with a steel knife or to produce semi- or ultrathin sections with a glass knife. A 10% paraldehyde solution is used to mount the light microscopy sections on a slide heated on a hot plate to 80 C; these can be treated with the same techniques used with paraffin sections. The results are of high quality. Semithin sections of tissues fixed for electron microscopy can be stained directly after mounting, or by a wider range of stains once the polystyrene has been removed by organic solvents. In electron microscopy, the ultrathin sections obtained with the usual techniques are highly electron beam-resistant and given acceptable results.

Animals↗

PubMed1993

Comparison of poly(DL-lactide-co-glycolide) and polystyrene microsphere targeting to intestinal M cells.

The interaction of poly(DL-lactide-co-glycolide) (PLG) and polystyrene microspheres with the follicle-associated epithelium (FAE) of rabbit Peyer's patches was compared. Binding by PLG microspheres to the FAE was an order of magnitude lower than that of polystyrene microspheres of equivalent size (0.5-0.6 microns diameter). Although PLG microspheres are not selectively targeted to the M cell surface, as is the case with polystyrene microspheres, a high proportion of those that bind to M cells are transcytosed, resulting in the transepithelial delivery of 1.5 x 10(4) PLG microspheres/mm2 FAE. This represents the first direct demonstration of transepithelial delivery of PLG microspheres by M cells, which is crucial to the potential use of such vehicles for the oral delivery of drugs and vaccines. As native PLG microspheres are not optimally targeted to the M cell surface, there is scope for the further improvement of their efficacy by surface modifications.

Animals↗

PubMed1990

The enhanced attachment and growth of endothelial cells on anhydrous ammonia gaseous plasma modified surfaces of polystyrene and poly(tetrafluoroethylene).

Anhydrous ammonia gaseous plasma technique was used for the surface modification of polystyrene petri dishes and poly(tetrafluoroethylene) (PTFE) membranes. Amino groups were added onto surfaces by exposing them to ammonia plasma. Plasma modified polymeric surfaces and control polymeric surfaces were seeded with bovine pulmonary artery endothelial cells (EC). It was found that attachment of EC to control polystyrene surface was negligible. On the plasma modified polystyrene surface, there was improved attachment and growth of EC. At 96 hours, plasma modified surfaces yielded an order of 3 magnitudes more cells compared to those on control. Twenty four hours after seeding the cells, the percentage of EC attachment to control PTFE surfaces and modified surfaces were found to be about 36% and 92% respectively.

Ammonia↗

PubMed1989

Blood modeling using polystyrene microspheres.

The steady flow viscosity at shear rates 0 to 120 sec-1 and dynamic viscoelasticity at frequencies 0.02 to 0.8 Hz were determined for aqueous suspensions of uniform polystyrene microspheres of 1.0 micron diameter. Rheological properties of the microsphere suspensions were Newtonian for particle concentrations up to 32%. By introducing dextran and calcium chloride into the particle suspensions, non-Newtonian behavior was produced similar to that observed for human blood. The cooperative effects of dextran and calcium ions promoted aggregation of particles at a concentration as low as 12%. Thus, a suspension of uniform sized spherical polystyrene particles in aqueous solution of dextran may be made to mimic blood by controlling the surface charge on the polystyrene spheres using addition of calcium ions to the medium.

Blood↗

PubMed1987

Effectiveness of detergents in blocking nonspecific binding of IgG in the enzyme-linked immunosorbent assay (ELISA) depends upon the type of polystyrene used.

Since nonspecific binding of immunoglobulins to polystyrene is a major factor in the nonspecific reactions observed in the ELISA, we studied the effect of a nonionic detergent (Tween-20) on the binding of human IgG to polystyrene. Pretreatment of polystyrene with detergent did not provide a permanent barrier to adsorption of IgG, because washing with water completely removed the blocking ability of detergents from low-binding plates, but only partially removed the blocking power from high-binding plates. On high-binding plates, human IgG molecules suspended in detergent solution attached to the plastic surface, an effect not seen with low-binding plates. Consequently, the binding power of the plastic that is used greatly affects the ability of nonionic detergents to prevent nonspecific binding of immunoglobulins.

Animals↗

PubMed1980

Adhesion of human and chicken red blood cells to polystyrene: influence of electrolyte and polyethylene glycol concentration.

Adhesion of glutaraldehyde-fixed human red blood cells (RBC) to polystyrene was measured as a function of concentration of mono-, di-, and trivalent cations. The effectiveness for preventing adhesion was trivalent > divalent > monovalent. Adhesion increased with ionic strength but no specificity of cations in a particular valency group was observed. Adhesion as a function of NaCl concentration was not affected by temperature between 1 degrees C and 22 degrees C but decreased in 150 mM NaCl above pH 6. Chicken RBC and neuraminidase-treated human RBC were more adhesive than untreated human RBC in NaCl. In 150 mM NaCl, adhesion of human RBC decreased in the presence of hemolyzate or polyethylene glycols (mol. wt. 10,000-300,000). These results support the hypothesis that RBC adhesion to polystyrene occurs in the primary minimum of the potential energy of interaction and is governed by attractive London-Van der Waals and repulsive electrostatic forces. The implications were applied to study of hemagglutination of RBC with lectin and lectin-labeled gold granules in polystyrene microplates.

Animals↗

PubMedDate not supplied

Hematochezia associated with the use of hypertonic sodium polystyrene sulfonate enemas in premature infants.

The onset of hematochezia with the use of sodium polystyrene sulfonate enemas in an index case prompted us to review our experience with the use of such enemas in neonates. Sodium polystyrene sulfonate enemas were used in 20 of 2317 patients. Of these 20 patients, four (20%) had evidence of hematochezia temporally related to the use of the enemas. No episodes of such bleeding occurred in infants who were older than 29 weeks of gestation or larger than 1250 gm birth weight. In one case an autopsy performed within 2 days of the enemas showed extensive vascular congestion within the mucosa and submucosa with focal areas of hemorrhage. Approximately 20% sorbitol (1098 mOsm/L) was the vehicle for suspension of the sodium polystyrene sulfonate. On the basis of evidence regarding similar morbidities in adults, we are concerned that the hyperosmolar suspending agent, sorbitol, may be the cause of such pathologic conditions in the colon of susceptible infants.

Colon↗

PubMed1994

[Interaction of platelets with an artificial polystyrene surface under flow conditions: comparative study versus collagen].

PURPOSE: Platelets are known to interact with artificial surfaces, which leads to thrombosis that in turn may hamper repairing surgery. In order to evaluate such interaction, platelet adhesiveness on a polystyrene surface (Thermanox) was studied in an in vitro perfusion model. MATERIAL AND METHODS: Anticoagulated human blood was recirculated through a plain perfusion chamber containing fragments of the material under study, uncovered and covered with collagen. The studies were performed at a shearing coefficiente of 800 s-1 and with different timing. Additional blood samples were incubated with an anti- GPIIb-IIIa antibody. Platelet deposition on the perfused material was morphometrically evaluated with a computerized system of image analysis. RESULTS: The values attained, expressed as percent surface covered by platelets over the uncovered polystyrene surface, at 2, 5, 10 and 20 minutes, were, respectively, as follows: 10.4% +/- 1.83%, 27.04% +/- 2.32%, 36.04% +/- 3.09% and 61.48% +/- 8.86%; for the collagen-covered material these figures were: 35.2% +/- 1.3%, 47.8% +/- 4.2%, 71.7% +/- 2.4% and 73% +/- 3.2%, for similar timing (n = 7 for each group). CONCLUSIONS: The perfusion method proved useful for evaluating the interaction of platelets with artificial surfaces. These data show their polystyrene surfaces have high reactivity toward platelets and confirm that GPIIb-IIIa plays an important role in this reactivity.

Blood Platelets↗

PubMed2005

Alkylchlorotins grafted to cross-linked polystyrene beads by a -(CH2)n- spacer (n=4, 6, 11): selective, clean and recyclable catalysts for transesterification reactions.

Insoluble polystyrene grafted compounds of the type (P-H)(1-t){P-(CH2)n SnBu(p)Cl(3-p)}(t), (P-H)(1-t){P-(CH2)n SnBuO}(t) and (P-H)(1-t)[{P-(CH2)n SnBuCl}2O](t/2), in which (P-H) is a cross-linked polystyrene; n=4, 6, and 11; p=0 and 1; and t the degree of functionalisation, were synthesised from Amberlite XE-305, a polystyrene cross-linked with divinylbenzene. The compounds were characterised by using elemental analysis, and IR, Raman, solid-state 117Sn NMR, and 1H and 119Sn high-resolution MAS NMR spectroscopy. The influence of the spacer length and the tin functionality on the catalytic activity of these compounds, as well as their recycling ability, was assessed in the transesterification reaction of ethyl acetate with various alcohols. These studies showed significant differences in the activity of the catalysts interpreted in terms of changes in the mobility of the catalytic centres. Some of the supported catalysts could be recycled at least seven times without noticeable loss of activity. The residual tin content in the reaction products was found to be as low as 3 ppm.

Journal Article↗