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PubMed1994

Inhibition of hemoglobin S polymerization by N-terminal band 3 peptides: new class of inhibitors: solubility studies.

Two synthetic peptides corresponding to the N-terminal amino acids (AA) of band 3 were designed to inhibit deoxyhemoglobin S (deoxy S) polymerization through two different mechanisms. Peptide I, an N:1-15AA fragment, was employed to bind to the 2,3-diphosphoglycerate (2,3-DPG) receptor locus of single deoxy S molecules with 5-7 AA extending internally and the remaining 10-8 AA projecting external to hemoglobin (Hb) S, thereby inhibiting polymerization by steric hindrance. Peptide II consisted of two N:1-8AA + K (lysine) sequences linked by a coupler through the lysine, and it was employed to bind to the 2,3-DPG loci of two deoxy S molecules, tethering them together to form "binary hemoglobin complexes" incapable of entering the polymer chains. Decreased polymerization would result from reduction in effective concentration of deoxy S. Binding of peptides to the 2,3-DPG receptor loci was demonstrated by a progressive rightward shift in the hemoglobin oxygen binding curves as a function of increasing peptide concentrations. Inhibition of deoxy S polymerization was studied by equilibrium solubility measurements of purified, stripped solutions of Hb S. Physiologically significant inhibition was demonstrated for both peptides with near-maximum increases in solubility achieved by Peptide II at 1:1 peptide:Hb S ratios. These peptides represent a new class of inhibitors of deoxy S polymerization.

Amino Acid Sequence↗
PubMed2006

Relationship between one-electron transition-metal reactivity and radical polymerization processes.

Controlled radical polymerization has come along in leaps and bounds following the development of efficient transition-metal catalysts for atom-transfer radical polymerization. Another type of controlled radical polymerization process, namely organometallic radical polymerization, uses the reversible formation of metal-carbon bonds. Metals are also implicated in catalytic chain transfer, a process that involves the abstraction of hydrogen atoms. This Minireview discusses the importance of one-electron transition-metal reactivity in metal-mediated controlled radical polymerization processes.

Journal Article↗
PubMed1991

A mixed-bed, multi-derivatization approach using polymeric reagents for derivatizations of amines in high performance liquid chromatographic detection.

Immobilized, polymeric reagents containing covalently attached tagging groups have been synthesized and reacted individually, off-line or on-line, pre-column in high performance liquid chromatographic (HPLC) detection. These reagents have also been combined into a single, mixed-bed reactor, useful for simultaneously preparing several derivatives from a single analyte, all at the same time. Each derivative possesses different chromatographic and detection properties, dependent on the nature of the original polymeric reagent containing the immobilized, tagging species. These particular reagents were designed to impart Ultraviolet/fluorescence, Ultraviolet/electrochemistry (oxidative/reductive or oxidative-hv-electrochemistry) to the final derivatives. Variations in the amounts/ratios of polymeric reagents contained in a single mixed-bed reactor will lead to varying ratios of the final derivatives. These can be predicted knowing the approximate reactivity of each polymeric reagent, percent derivatizations, and overall rates for each reagent towards a given substrate. In this first example of mixed-bed, polymeric reagents for improved derivatization approaches in chromatography, emphasis has been placed on simple amines or amine-like analytes. Multiple derivatives can be effectively used to improve the identification of an unknown analyte in a complex sample matrix, as well as to improve the detectability of that analyte. As one real world application, amphetamine in human urine was quantitated via on-line derivatizations with a mixed-bed reactor. With the least sampling work-up, the resulting sample solutions were directly injected into the on-line derivatization HPLC system for quantitation. The method was validated by single blind spiking experiments. The precision and accuracy were acceptable.

Amphetamine↗
PubMed2004

Steric and electronic effects in cyclic alkoxyamines--synthesis and applications as regulators for controlled/living radical polymerization.

The synthesis of new six- and seven-membered cyclic alkoxyamines bearing ethyl groups at the alpha-N position of the alkoxyamines is described. The key step in the synthesis of the sterically hindered six-membered cyclic alkoxyamines is a Wadsworth-Horner-Emmons olefination with bisphosphonate 1. The seven-membered cyclic alkoxyamines were prepared from the corresponding six-membered keto alkoxyamines by ring-enlargement with trimethylsilyl(TMS)-diazomethane. The use of the new alkoxyamines as regulators/initiators for radical polymerization is discussed. Efficient controlled and living polymerization of styrene and n-butyl acrylate was obtained with the six-membered tetraethyl alkoxyamine 13. Controlled polymerizations can be conducted even at 90 degrees C. In addition, alkoxyamine 13 can be used for the preparation of AB diblock and ABA triblock copolymers with narrow polydispersities. The influence of the replacement of methyl groups in the alpha-position of the N atom in cyclic alkoxyamines by larger ethyl groups on the styrene polymerization (reaction time, PDI, kinetics of the C-O bond homolysis) is discussed. In addition, thermal decomposition of the new alkoxyamines was studied. Furthermore, the synthesis of N,N-bissilylated alkoxyamines is described. The silylated alkoxyamines are not suitable as regulators/initiators for the controlled/living radical polymerization. The C-O bonds in silylated alkoxyamines are stronger than the C-O bonds in analogous N,N-dialkylated alkoxyamines. The experimental results are verified by calculations with Gaussian 98 (A. 9).

Journal Article↗
PubMed2005

Actin polymerization promotes the reversal of streaming in the apex of pollen tubes.

Actin polymerization is important in the control of pollen tube growth. Thus, treatment of pollen tubes with low concentrations of latrunculin B (Lat-B), which inhibits actin polymerization, permits streaming but reversibly blocks oscillatory growth. In the current study, we employ Jasplakinolide (Jas), a sponge cyclodepsipeptide that stabilizes actin microfilaments and promotes polymerization. Uniquely, Jas (2 microM) blocks streaming in the shank of the tube, but induces the formation of a toroidal-shaped domain in the swollen apex, of which longitudinal optical sections exhibit circles of motion. The polarity of this rotary motion is identical to that of reverse fountain motility in control pollen tubes, with the forward direction occurring at the edge of the cell and the rearward direction in the cell interior. Support for the idea that actin polymerization in the apical domain contributes to the formation of this rotary motility activity derives from the appearance therein of aggregates and flared cables of F-actin, using immunofluorescence, and by the reduction in G-actin as indicated with fluorescent DNAse. In addition, Jas reduces the tip-focused Ca2+ gradient. However, the alkaline band appears in the swollen apex and is spatially localized with the reverse fountain streaming activity. Taken together, our results support the idea that actin polymerization promotes reversal of streaming in the apex of the lily pollen tube.

Actin Cytoskeleton↗
PubMed1992

Thrombin, epidermal growth factor, and phorbol myristate acetate stimulate tubulin polymerization in quiescent cells: a potential link to mitogenesis.

Previous studies suggest that alterations in the microtubule (MT)-tubulin equilibrium during G0/G1 affect mitogenesis. To determine the effect of growth factors on the MT-tubulin equilibrium, we developed a radioactive monoclonal antibody binding assay (Ball et al.: J. Cell. Biol. 103:1033-1041, 1986). With this assay, 3H-Ab 1-1.1 binding to cytoskeletons in confluent populations of cultured cells is proportional to the number of tubulin subunits polymerized into MTs. We now show that purified alpha-thrombin increases 3H-Ab 1-1.1 binding to cytoskeletons of serum-arrested mouse embryo (ME) fibroblasts from 1.5- to 3-fold. This stimulation is dose-dependent and correlates with concentrations of thrombin required for initiation of DNA synthesis. Other mitogenic factors, epidermal growth factor (EGF) and phorbol 12-myristate 13-acetate (PMA), also stimulate MT polymerization. Addition of colchicine (0.3 microM) eight hours after growth factor addition, blocks stimulation of 3H-thymidine incorporation by thrombin, EGF, or PMA, suggesting that tubulin polymerization or subsequent events triggered by MT polymerization are required for cells to enter a proliferative cycle. Consistent with models for autoregulation of tubulin synthesis, thrombin, EGF, and PMA all increase tubulin synthesis 9 to 15 hr after growth factor addition, raising the possibility that the decrease in free tubulin and subsequent stimulation of tubulin synthesis is linked to progression of cells into a proliferative cycle. Colchicine addition to these cells also stimulates DNA synthesis, but colchicine-stimulated cells enter S phase 6 to 8 hr later than those stimulated by growth factors. This delayed stimulation may be related to the time required for degradation of tubulin-colchicine complexes below a critical level. These data suggest that regulation of cell proliferation may be linked to increased MT polymerization and the resulting decrease in free tubulin pools.

Animals↗
PubMedDate not supplied

Is gravity on our way? The case of polyacrylamide gel polymerization.

Potential gravity-induced deformations of polyacrylamide matrices during gelling were investigated in two different initiator systems based on (i) photopolymerization with 100 microM methylene blue, 1 mM sodium toluene sulfinate (reducer) and 50 microM diphenyliodonium chloride (oxidizer) (photopolymerization) and (ii) chemical polymerization, utilizing the standard persulfate N,N,N',N'-tetramethylethylenediamine. In both systems, it is seen that convective flows are imprinted in the final gel structure above a critical gelling layer thickness, set at ca. 3 mm. In both systems, progressive increments of the solution density, from normodense (density = 1.0) up to isodense with the growing polymer chains (density = 1.3) do not inhibit the appearance of strong convective flows. However, gel inhomogeneities are completely abolished even in 10 mm gelling layers if polymerization is performed in presence of density gradients, notably of sucrose, from 0 to 20%, 0 to 40% and 0 to 60%. Even the shallower gradient (0-20% sucrose) is able to completely abolish convective flows in persulfate-driven polymerization. It is hypothesized that such disturbances are not created by sedimentation of the growing polymer chains in the gravitational field, but are produced by the reaction exothermality, which produces strong buoyancy-driven flows. It is additionally demonstrated that persulfate polymerization is sensitive to oxygen absorbed from the top liquid layers, which should be carefully protected by an overlay of organic solvent. Methylene blue-induced polymerization appears to offer a series of unique advantages over chemical initiation with persulfate.

Acrylic Resins↗
PubMed2004

Polymeric alkenoxy amino acid surfactants: III. Chiral separations of binaphthyl derivatives.

Micellar electrokinetic chromatography (MEKC) was investigated for the enantiomeric separations of three binaphthyl derivatives ((+/-)-1,1'-bi-(2-naphthol) (BOH), (+/-)-1,1'-binaphthyl-2,2'-diyl hydrogenphosphate (BNP), and (+/-)-1,1'-binaphthyl-2,2'-diamine (BNA)) using two recently synthesized chiral polymeric surfactants (polysodium N-undecenoxy carbonyl-L-leucinate (poly-L-SUCL) and polysodium N-undecenoxy carbonyl-L-isoleucinate (poly-L-SUCIL)) in our laboratory. Enantiomeric separation (resolution and selectivity) of the binaphthyl derivatives was influenced by polymerization concentration of the monomeric surfactant, pH, type and concentration of the background electrolyte (BGE) as well as concentration of the polymeric surfactant. Two BGEs (dibasic phosphate and Tris-borate) were compared for this study. The use of dibasic phosphate as BGE in poly-L-SUCL provides baseline resolution of (+/-) BOH and (+/-) BNP, however, no resolution and selectivity at all was observed for (+/-) BNA. A similar approach was adopted with Tris-borate-poly-L-SUCL system at fixed pH 10.1, which resulted in baseline resolution of all three binaphthyl derivatives. Although R(s) of binaphthyl derivatives was always higher and electroosmotic flow (EOF) was always lower using Tris-borate than with dibasic phosphate, the selectivity values for the two buffer systems did not differ significantly. In addition, it was found that poly-L-SUCL provided better enantiomeric resolution and selectivity for (+/-) BOH and (+/-) BNA, while poly-L-SUCIL provided enhanced enantiomeric resolution but similar enantioselectivity for (+/-) BNP. This indicates that the depth of analyte penetration into the palisade layer and the micellar core are responsible for chiral recognition of hydrophobic analyte (e.g., (+/-) BOH, and (+/-) BNA) whereas for moderately hydrophobic analyte (e.g., (+/-) BNP) interaction with the polar head group seems to dictate chiral recognition. Simultaneous enantioresolution of all three binaphthyl derivatives was possible in a single electrophoretic run using either poly-L-SUCL or poly-L-SUCIL. Further comparison of the two polymeric surfactants showed that poly-L-SUCL provided slightly longer analysis time than poly-L-SUCIL but the use of the former polymeric surfactant should be preferred due to its ability to provide complete baseline resolution and higher selectivity of all the three atropisomers with a wider chiral window.

Alkenes↗
PubMed2004

Effects of the initial temperature of acrylic bone cement liquid monomer on the properties of the stem-cement interface and cement polymerization.

It has been shown that preheating the femoral stem prior to insertion minimizes interfacial porosity at the stem-cement interface. In this study, the effects of methylmethacrylate monomer temperature prior to mixing on the properties of stem-cement interface and cement polymerization were evaluated for 4 degrees C, room temperature, and 37 degrees C using a test model and cementing techniques that simulated a clinical situation. The nature and extent of interfacial porosity of stem-cement interface was quantified, the static shear strength of the stem-cement interface determined, and the time and temperature of polymerization at the cement-bone interface were measured. Compared to RT monomer, preheating monomer to 37 degrees C produced higher polymerization temperatures and greater initial interfacial shear strength with an unchanged amount of interfacial porosity. Precooling monomer to 4 degrees C produced lower polymerization temperatures and decreased initial interfacial shear strength, with the amount of interfacial porosity unchanged compared to the RT group. Although clinical techniques of preheating or precooling bone cement have some effects on the properties of the stem-cement interface and cement polymerization, they do not appear to enhance implant fixation.

Chromium↗
PubMed2004

Probing the origins and control of shrinkage stress in dental resin composites. II. Novel method of simultaneous measurement of polymerization shrinkage stress and conversion.

This study probes the interrelationships between polymerization shrinkage stress development and the polymerization progress with a novel experimental technique. This technique is capable of real time, simultaneous measurement of double-bond conversion and shrinkage stress with the use of a noninvasive near-infrared fiber-optic system, along with a cantilever beam-based tensometer. The results from both filled and unfilled bis-GMA/TEGDMA (70:30 mass ratio) systems showed that the shrinkage stress buildup was concentrated in the latter stages of polymerization, with its dramatic increase linked to the asymptotic approach of conversion to its limiting value. The monotonic increase of shrinkage stress with conversion in the vitrified state is attributed to the dramatic increase of the sample's elastic modulus during the vitrification stage and a certain amount of cooling stress as the sample cools down from the temperature rise caused by the exothermic polymerization and light absorption. Excellent reproducibility of both the polymerization kinetics assessment and the shrinkage stress measurement has been achieved.

Biocompatible Materials↗
PubMed2006

Effect of irradiation mode on polymerization of dental composite resins.

Many researchers have sought to reduce the polymerization shrinkage in composite resins. Controlling the irradiation light seems practical because the polymerization process initiates with light by activating the photoinitiators. The present study evaluated the effect of irradiation mode on microhardness and polymerization shrinkage of composite resins. Three different irradiation modes, STD, EXP, and MED, were taken under 40-s exposure condition. As results, the irradiation mode significantly affected the microhardness difference. However, in all products, the microhardness difference between the STD and MED modes was less than 10%. In all irradiation modes, microhardness was linearly correlated with the filler content of the tested specimens. The effect of mode on the difference of the polymerization shrinkage was not uniform even though the shrinkage values decreased following the order of the STD > EXP > MED mode. An inverse correlation was found between filler content and polymerization shrinkage in all irradiation modes and specimen thicknesses. In spite of the statistical significance of the irradiation modes on the difference of the measured values, their numeric difference was not great. Especially, compared with the STD and MED mode, the exponentially increasing light (EXP mode) produced no noticeable difference except for a delayed shrinkage process.

Composite Resins↗
PubMed1994

Microtubular protein in its polymerized or nonpolymerized states differentially modulates in vitro and intracellular fluxes catalyzed by enzymes of carbon metabolism.

The fluxes through HK/G6PDH and PK/LDH coupled-enzymatic reactions were quantified in the presence of physiological concentrations (1-15 microM) of polymerized or non-polymerized microtubular protein (MTP) from rat brain and in a permeabilized yeast cell system. In vitro enzymatic fluxes were increased by either polymerized or nonpolymerized brain MTP mainly in the lower range of MTP concentration. At fixed MTP concentrations in the flux stimulatory range of HK/G6PDH (1 mg/ml MTP) or PK/LDH (0.4 mg/ml MTP), a hyperbolic and sigmoidal response to NADP and PEP, respectively, was detected. That dependence varied according to the polymeric status of MTP. The specificity of the phenomenon observed in vitro, was tested for the PK/LDH and HK/G6PDH enzymatic couples in the presence of neutral polymers such as glycogen (< or = 10 mg/ml), poly(ethylene glycol) (up to 10% w/w) or G-actin (< or = 1 mg/ml). In permeabilized Saccharomyces cerevisiae cells, the PK-catalyzed flux was sensitive to microtubule disruption by nocodazole (15 micrograms/ml). The HK/G6PDH system was not affected by nocodazole showing values of kinetic parameters close to those obtained in vitro in the presence of polymerized brain MTP. Indirect immunofluorescence with specific antibodies against tubulin allowed to confirm the microtubules disruption in the presence of nocodazole in permeabilized yeast cells under the same conditions in which enzymes were assayed intracellularly. The experimental evidence is in agreement with the observed phenomenon of increase in fluxes in the enzymatic reactions assayed to be specifically induced by MTP either in vitro or in situ. The results presented are discussed in terms of the assembly of large supramolecular structures as a supraregulatory mechanism of synchronization of systemic cellular processes such as metabolic fluxes.

Actins↗
PubMed1993

Differential regulation of actin polymerization following activation of resting T lymphocytes from young and aged mice.

Actin polymerization accompanies receptor-mediated responses and is correlated with motility-related events. In T lymphocytes, there is a lateral redistribution of surface receptors into caps and aggregation of actin-myosin in cytoplasmic subcaps, and these are impaired in T cells from aged individuals. This study documents marked changes in age-related cytoskeletal actin filament function which may account for the reduced motility. Basal levels of filamentous actin (F-actin) are significantly higher in purified G(o) T cells from aged C57BL/6 mice, due to a preferential increase in the CD8+ subpopulation. Following activation of the resting T cells with Concanavalin A (Con A), F-actin depolymerized in cells from young mice for 2 min, followed by rapid polymerization, reaching a plateau 200% above resting levels. In cells from 15-17-month-old mice, an attenuated depolymerization phase was seen for 45 sec, followed by little polymerization. No depolymerization or polymerization phases occurred in cells from aged mice. Phorbol 12 myristate 13-acetate (PMA), which activates protein kinase C (PKC), bypassing receptor mediated signals, induced actin polymerization to 57% of the levels of that after Con A stimulation in cells from both young and old animals and partially eliminated the differences in actin filament assembly due to age. Perturbation of the cytoskeleton with cytochalasin E (CE) potentiated proliferation of Con A-stimulated T cells from aged mice but did not completely restore the deficit attributed to immunosenescence. The results show an age-related impairment of cytoskeletal functions and suggest that differences in early signal transduction events contribute to the decrements in surface receptor motility and subsequent proliferation of T lymphocytes from older individuals.

Actin Cytoskeleton↗
PubMed1992

Actin polymerization contributes to neutrophil chemotactic dysfunction following thermal injury.

The agent(s) and mechanism(s) responsible for suppression of neutrophil chemotaxis in association with major thermal injury have not been identified. We have proposed that the reduced random motility characterizing patients' cells may contribute to their generalized chemotactic dysfunction. Here we report that actin polymerization may be responsible for the loss of neutrophil motility associated with major thermal injury. Using a fluorescent ligand specific for polymerized or filamentous actin (NBD-phallacidin) in conjunction with flow cytometry, we have discovered that peripheral blood and exudate neutrophils from patients with major thermal injury contain increased levels of actin in a stably polymerized form. Because cyclic polymerization and depolymerization of actin is essential to cell motility, we suggest that actin polymerization may contribute in a major way to the attenuation of neutrophil random and chemotactic functions induced by major thermal injury.

Actin Cytoskeleton↗
PubMed1979

Interaction of hepatitis B surface antigen with polymerized human serum albumin.

HBsAg binds to a solid-phase adsorbent consisting of polymerized human serum albumin (HSA) on glass particles. Both AD and AY antigenic subtypes of hepatitis B surface antigen (HBsAg) display this interaction. In either case, the binding to polymerized HSA is reduced in the presence of human serum, suggesting significant attachment of serum components at the locations on HBsAg particles where polymerized HSA binds. The temperature dependence of the interaction goes through a maximum above room temperature, in contrast to the increasing reaction with temperature of the HBsAg--anti-HBs antibody system. The interaction between HBsAg and polymerized HSA is discussed in relation to previous findings of HSA polymers and anti-polymerized albumin antibodies in hepatic patients. A mechanism for production of an autoimmune, antialbumin antibody condition, in association with hepatitis B virus infection is proposed.

Antibody Specificity↗
PubMed1994

Detection of enterovirus-specific total and polymeric IgA antibodies in serum using a synthetic peptide or heated virion antigen in ELISA.

The presence of enterovirus-specific total and polymeric IgA antibodies was assessed in serum from different groups of patients and healthy controls by indirect ELISA using heated virions and synthetic peptide, both enteroviral broad reactive antigens. Total IgA antibody response against a synthetic peptide, representing an enterovirus group-common epitope, was detected in 52% of the patients with an acute enterovirus infection and in 12% of the patients with other infections (P = 0.02). We also found a significant difference (P = 0.005) in the prevalence of peptide IgA antibodies between serum samples collected from blood donors during summer (20%), the prevalent season of enterovirus infections, and winter (6%). A polymeric IgA activity against the peptide was detected in only three patients with an enterovirus infection. In contrast, when a heated coxsackie B5 (coxB5) virus antigen was used, the prevalence of total serum IgA antibodies was not significantly different between patients with an acute enterovirus infection and patients with other infections (71% vs. 53% respectively; P = 0.3). Also no difference was found between the two groups of blood donors (47% in summer vs. 51% in winter; P = 0.7). However, the prevalence of serum polymeric IgA antibodies against coxsackie B5 antigen was significantly greater (P = 0.02) in patients with an acute enterovirus infection (57%) than in patients with other infections (18%). These findings suggest that the presence (18%). These findings suggest that the presence of total peptide-IgA or of polymeric coxsackie B5-IgA in serum is a specific marker of acute enterovirus infection. Finally, we show that the total peptide-IgA- and polymeric coxsackie B5-ELISAs may have a diagnostic value for the serodiagnosis of enterovirus infections when they are used in combination with enteroviral IgG-ELISA.

Amino Acid Sequence↗
PubMed1989

Enhancement of physical properties of resin restorative materials by laser polymerization.

A study was conducted to compare the compressive strength, diametral tensile strength, transverse flexural strength, and flexural modulus of a microfilled and a small particle composite resin restorative material following argon laser and conventional visible light polymerization techniques. All physical properties examined in this study were enhanced by laser polymerization. The diametral tensile strength of both types of restorative materials was significantly greater following laser polymerization, as were the transverse flexural strength and the flexural modulus of the microfilled resin restorative material. Additionally, these results were obtained with a laser polymerization time that was one-fourth that used for visible light activation. It was concluded that the argon laser is a potentially advantageous means of initiating the polymerization of dental composite resin restorations.

Acrylic Resins↗
PubMed2004

Polypyrrole thin films formed by admicellar polymerization support the osteogenic differentiation of mesenchymal stem cells.

The objective of this study was to evaluate the attachment, proliferation, and differentiation of rat mesenchymal stem cells (MSC) toward the osteoblastic phenotype seeded on polypyrrole (PPy) thin films made by admicellar polymerization. Three different concentrations of pyrrole (Py) monomer (20, 35, and 50 x 10(-3) M) were used with the PPy films deposited on tissue culture polystyrene dishes (TCP). Regular TCP dishes and PPy polymerized on TCP by chemical polymerization without surfactant using 5 x 10(-3) M Py, were used as controls. Rat MSC were seeded on these surfaces and cultured for up to 20 d in osteogenic media. Surface topography was characterized by atomic force microscopy, X-ray photoelectron spectroscopy, and static contact angle. Cell attachment, proliferation, alkaline phosphatase (ALP) activity, and calcium content were measured to evaluate the ability of MSC to adhere and differentiate on PPy-coated TCP. Increased monomer concentrations resulted in PPy films of increased thickness and surface roughness. PPy films generated by different monomer concentrations induced drastically different cellular events. A wide spectrum of cell attachment characteristics (from excellent cell attachment to the complete inability to adhere) were obtained by varying the monomer concentration from 20 m to 50 x 10(-3) M. In particular the 20 x 10(-3) M PPy thin films demonstrated superior induction of MSC osteogenicity, which was comparable to standard TCP dishes, unlike PPy films of similar thickness prepared by chemical polymerization without surfactant. Adhesion of mesenchymal stem cells on tissue culture plates (TCP) coated with polypyrrole thin films made by admicellar polymerization.

Alkaline Phosphatase↗