A list of Publications in Scientific Journals detailing research where Alvetex® has been used
The publications below are hosted on the websites of various scientific journals.
Imogen Smith, Marcus Haag, Christopher Ugbode, Daniel Tams, Marcus Rattray,
Stefan Przyborski, Angela Bithell, Benjamin J. Whalley
19 October 2015
J Neuroscience Letters
In this study, the authors characterise the morphological and electrophysiological features of embryonic mouse cortical neuroglial cells grown on 2D and in 3D Alvetex Scaffold.
Embryonic day 14 mouse cortical cells grown on punch-holed 6mm diameter Alvetex Scaffold discs for 14-21 days expressed GFAP and betaIII-tubulin, indicating the presence of both glial and neuronal cells. Although these markers were also present in 2D cultures, cell morphology was markedly different between 2D and 3D substrates, with more cell processes and less cell flattening being noted in Alvetex. Both 2D and 3D cells also exhibited spontaneous action potential firing, which responded adequately to the GABA and glutamate antagonists BMI and CNQX. A positive correlation was found between burst incidence and signal power in 2D cultures, while this was only true in BMI-treated Alvetex cultures. Although the rate of firing was less in 3D than in 2D, the authors speculated this might be due to the limited range of MEA recording.
These results highlight the profound effect of 3D cell culture on the morphology of individual cells, with functional consequences at the level of multicellular networks.
Schammim Ray Amith, Jodi Marie Wilkinson, Larry Fliegel
27 January 2016
J Biochimie Open 2 (2016) 16-23
This paper describes methods allowing the investigation of Na+/H+ exchanger isoform 1(NHE 1) function, which is of particular relevance to drug resistance in triple-negative breast cancers.
By promoting the general acidification of the extracellular environment, NHE1 activity results in increased degradation of extracellular matrix and facilitates cancer cell invasion. The authors used matrigel-coated Alvetex Scaffold in a 6-well insert format to assess whether the disruption of NHE1 expression in MDA-MB-231 cells would affect their invasive behaviour. After 7 days of Alvetex Scaffold 3D culture, MDA-MD-231 cells expressing wild-type NHE1 were present throughout the scaffold, as detected by histological staining of paraffin-embedded sections . NHE1-knock-out MDA-MB-23 cells, however, were predominantly present at the surface of the Alvetex Scaffold, with only occasional cells present within the depth of the substrate.
By taking advantage of the thickness of Alvetex Scaffold, this report presents a straightforward assay which enables scientists to study cell invasion through a substantial depth of 3D substrate.
(40.) Chondrogenic potential of human articular chondrocytes and skeletal stem cells: A comparative study
Siwei Li, Bram G Sengers, Richard OC Oreffo and Rahul S Tare
Journal of Biomaterials Applications
August 20, 2014
This study investigates the chondrogenic expression profiles of human articular chondrocytes (HACs) and differentiated human bone-marrow-derived mesenchymal stem cells (MSCs) in a bid to assess their utility as cell-based therapy for cartilage repair following injury or degeneration. Both HACs and MSCs were cultured in Alvetex scaffold presented as 12-well inserts in 12-well plates, and compared with more conventional scaffold-free pellet cultures. Although both Alvetex-grown and pellet-grown MSCs cultures exhibited a high level of Col10a1 expression, a marker of hypertrophic differentiation which is only present at low level in HACs, Alvetex-grown cultures also showed expression of the chondrogenic markers Sox9, Aggrecan and Col2a1 at levels similar to that seen in HACS. Pellet-grown cultures, by comparison, failed to express such high levels of the same chondrogenic markers. The authors speculated that the stiffness and the high porosity of Alvetex might have aided the improved MSCs chondrogenic differentiation by giving physical cues and allowing improved solutes transport.
(39.) Differentiation of a Human Neural Stem Cell Line on Three Dimensional Cultures, Analysis of MicroRNA and Putative Target Genes
Lara Stevanato, Caroline Hicks, John D. Sinden
Journal of Visualized Experiments (98), e52410,
The human neural stem cell line CTX0E03 is a therapeutically-relevant cell line currently undergoing clinical trials related to Stroke-induced conditions and this paper investigates the effect of 3D culture on the ability of this cell line to differentiate in vitro. The authors describe methods to culture and differentiate CXT0E03 cells on laminin-coated Alvetex scaffolds, as well as how to measure the length of axon processes stained with anti-beta3-tubulin antibodies and to perform RNA extraction followed by cDNA reverse transcription and real-time PCR of MiRNA targets. Their results demonstrate that significantly longer axon processes are obtained after both one week and three weeks of differentiation in Alvetex scaffolds compared to 2D. MiRNA expression changes indicative of cell differentiation are also detected earlier when the CTX0E03 cells are grown in Alvetex scaffolds compared to 2D. This study demonstrates the feasibility of high-quality imaging and RNA extraction from cultures grown in Alvetex scaffolds, as well as its beneficial effect on stem cell differentiation in vitro.
David S. Hill, Neil D.P. Robinson, Matthew P. Caley, Mei Chen, Edel A. O’Toole, Jane L. Armstrong, Stefan Przyborski, and Penny E. Lovat
September 1, 2015
Molecular Cancer Therapeutics
(37.) Dexamethasone-Mediated Activation of Fibronectin Matrix Assembly Reduces Dispersal of Primary Human Glioblastoma Cells
S Shannon, C Vaca, D Jia, I Entersz, et al.
PloS one, 2015
In this study, Shannon and colleagues report the effect of dexamethasone on the dispersal of primary human glioblastoma cells. They use a variety of modern molecular and cellular techniques to investigate this process, including the use of Alvetex Scaffold to assess the ex vivo dispersal of tumour cells. They provide a detailed method describing the seeding of the GFP-labelled tumour cells onto the scaffold and their subsequent culture for 48 hours to allow the cells to infiltrate the 3D structure of Alvetex and disperse. After two days, the scaffolds were mounted onto microscope slides and cover-slipped. Confocal microscopy was used to capture images at successive focal planes at 1 micron intervals to generate a z stack. Differential interference contrast (DIC) microscopy was used to analyse each z stack and measure the z-axis position of cells within the tissue scaffold. The results of the Alvetex Scaffold study are shown in Figure 6 and demonstrate that dexamethasone decreased the dispersal of tumour cells in an ex vivo 3D model. In summary, this paper provides a good example of where Alvetex technology has been applied to assess the action of a drug on tumour cell motility. This technique could be developed further to form a general assay to study tumour cell dispersal and be used to assess the action of drugs on specific tumour tissues ex vivo as part of an applications to personal medicine.
(36.) Two and three dimensional graphene substrates to magnify osteogenic differentiation of periodontal ligament stem cells
Han Xie, Tong Cao, José Viana Gomes, Antônio Hélio Castro Neto, Vinicius Rosa
Carbon 93, 2015
In this report the authors investigate the differentiation of periodontal ligament stem cells (PDLSCs) on graphene substrates. They test the growth of cells on two- and three-dimensional (3D) graphene supports and use Alvetex polystyrene scaffolds as an established control for 3D cell culture. With specific reference to the use of Alvetex, the investigators successfully demonstrate the 3D culture of PDLSCs and the application of a range of analytic methods to monitor cell behavior including: 1) using scanning electron microscopy they visualized cells growing on Alvetex Scaffold; 2) cell viability and proliferation were assessed using a conventional MTS assay; 3) induction of osteogenic differentiation was monitored by staining for alizarin red; 4) gene expression was measured by quantitative real time PCR. The paper provides a good illustration of the versatility of Alvetex technology and its compatibility with a range of conventional analytical methods.
Jordan M. Spatz, Marc N. Wein, Jonathan H. Gooi, Yili Qu, Jenna L. Garr, Shawn Liu, Kevin J. Barry, Yuhei Uda, Forest Lai, Christopher Dedic, Mercedes Balcells-Camps, Henry M. Kronenberg, Philip Babij, Paola Divieti Pajevic
JOURNAL OF BIOLOGICAL CHEMISTRY
JBC Papers in Press.
Published on May 7, 2015
(34.) Targeting ADAM-17 with an inhibitory monoclonal antibody has antitumour effects in triple negative breast cancer cells
F Caiazza, P M McGowan, M Mullooly, A Murray, N Synnott, N O’Donovan, L Flanagan, C J Tape, G Murphy, J Crown and M J Duffy
British Journal of Cancer, 8 April 2015
This paper describes an investigation into the action of an inhibitory cross-domain humanized monoclonal antibody known as D1(A12) targeting the matrix metalloproteinase, ADAM-17, in cultured human triple negative breast cancer cells. To create a more biologically relevant in vitro model, the authors have used Alvetex Scaffold to support three dimensional (3D) of the cancer cells. A selection of triple negative breast cancer cell lines were grown on Alvetex for up to 7 days. Data for the cell lines HCC1143 and HCC1937 are shown in the main paper. The investigators visualized the gross distribution and density of cells on Alvetex using Neutral Red staining. Treatment by the inhibitory antibody resulted in a noticeable reduction in Neutral Red staining that was quantified using ImageJ software. Discs of Alvetex stained by Neutral Red were subsequently fixed and processed for histological analysis. The structure of individual 3D cultured cancer cells was visualized by conventional haematoxylin and eosin (H&E) staining. This paper provides a good demonstration of how Alvetex technology can be used to support 3D growth of tumour cells during treatment with anti-cancer agents. It also uses alternative methods to visualize the 3D cultures.
(33.) Human neural stem cell-derived cultures in three-dimensional substrates form spontaneously functional neuronal networks
Imogen Smith, Vasco Silveirinha, Jason L. Stein, Luis de la Torre-Ubieta, Jonathan A. Farrimond, Elizabeth M. Williamson and Benjamin J. Whalley
JOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE
Published online: 25 Feb 2015
This paper demonstrates the use of the Alvetex platform to culture 3D differentiated human neural stem cells. The cells formed spontaneously active, functional neuronal networks which were not seen in an otherwise comparable 2D culture system. The 3D neural networks responded reproducibly to pharmacological treatments revealing functional glutamatergic synapses. Further imaging analysis revealed a neuronal and glial population, where markers of maturity were apparent in the former. Microrarray analysis of the cultures of the 3D and 2D neuronal cultures showed substantial differences in the gene expression profile of genes coding for neuronal function, extracellular matrix and cytoskeleton.
The authors conclude that culturing differentiated neural stem cells in Alvetex offer significant advantages over conventional 2D culture including cost savings and enhanced physiological relevance for pharmacological and toxicological assay used by neuroscientists.
James Jenkins, Ruslan I. Dmitriev, Karl Morten, Kieran W. McDermott, Dmitri B. Papkovsky
Acta Biomaterialia 2015
Published 31 January 2015
Alvetex porous membrane scaffolds are widely used materials for three-dimensional cell cultures and tissue models. Additional functional modification of such scaffolds can potentially extend their use and operational performance. In this paper Alvetex microporous polystyrene-based scaffolds were impregnated with a phosphorescent O2-sensitive dye PtTFPP, optimized for live cell fluorescence microscopy and characteristics for the stable and robust response to pO2 in phosphorescence enabling imaging of O2 distribution in 3D cell cultures. The modified scaffolds possessed high brightness, convenient spectral intensity and lifetime imaging modes (>twofold response over 21/0% O2). They are suitable for prolonged use under standard culturing conditions without affecting cell viability, and for multi-parametric imaging analysis of cultured cells and tissue samples. The coated Alvetex membranes were cultured with cancer cells (HCT116), multicellular aggregates (PC12) and rat brain slices and showed that they can inform on tissue oxygenation at different depths and cell densities, changes in respiration activity, viability and responses to drug treatment. Using this method multiplexed with staining of dead cells (CellTox Green) and active mitochondria (TMRM), we demonstrated that decreased O2 (20–24 µM) in scaffold corresponds to highest expression of tyrosine hydroxylase in PC12 cells. Such hypoxia is also beneficial for action of hypoxia-specific anti-cancer drug tirapazamine (TPZ). Thus, oxygen sensitive alvetex scaffolds allow for better control of conditions in 3D tissue cultures, and are useful for a broad range of biomaterials and physiological studies.
Sevim Yildiz Arslan, Yanni Yu, Joanne E. Burdette, Mary Ellen Pavone, Thomas J. Hope, Teresa K. Woodruff, J. Julie Kim
Published 30 Jan 2015
The endocervix plays an important role in conception and protection from pathogens. It is sensitive to changing concentrations of the sex hormones and alters the consistency of the mucus it secretes in response to these signals. This article reports on the development of a novel three dimensional (3D) model of human endocervix comprising both epithelial cells and stromal cells. Cells derived from primary sources were first explanted in conventional cultured and then seeded onto Alvetex Scaffold membranes and maintained for up to 28 days. Suspensions of two million cells were seeded into each 12-well insert containing Alvetex Scaffold. The cells remained viable and formed 3D cultures composed of epithelial and stromal cells that were treated with estradiol or progesterone over the growth period. Treatment by the hormones resulted in increased cell growth and proliferation. Cells expressed the expected repertoire of hormone receptors and produced both neutral and acid mucins. The article demonstrates the compatibility of Alvetex technology to support an endocervical 3D in vitro model that reacts to changing hormonal conditions. Alvetex Scaffold was further shown to be compatible with standard analytical assays such as cell viability, immunocytochemistry and histochemical methods. In summary, the paper describes a robust and novel human 3D culture model of the endocervix which showed physiological responses to menstrual hormones.
(30.) Imaging oxygen in neural cell and tissue models by means of anionic cell-permeable phosphorescent nanoparticles
Ruslan I. Dmitriev, Sergey M. Borisov, Alina V. Kondrashina, Janelle M. P. Pakan, Ujval Anilkumar, Jochen H. M. Prehn, Alexander V. Zhdanov, Kieran W. McDermott, Ingo Klimant, Dmitri B. Papkovsky
Cellular and Molecular Life Sciences (2015) 72:367–381
Published January 2015
Cell-permeable phosphorescent probes enable the study of cell and tissue oxygenation, bioenergetics, metabolism, and pathological states such as stroke and hypoxia. A number of such probes have been described in recent years, the majority consisting of cationic small molecule and nanoparticle structures. While these probes continue to advance, adequate staining for the study of certain cell types using live imaging techniques remains elusive; this is particularly true for neural cells. Here we introduce the novel anionic probe PA2 for the analysis of neural cells and neural tissues. PA2 efficiently stains rat brain slices and permits detailed O2 imaging experiments. In this study, brain slices were prepared and maintained as viable preparations on alvetex scaffolds. Analysis revealed age-dependent staining patterns for PA2 and a highly heterogeneous distribution of O2 in tissues, which we relate to the localisation of specific progenitor cell populations. Overall, these anionic probes are useful for sensing oxygen levels in various cells and tissues, particularly in neural cells, and facilitate high-resolution imaging of O2 in 3D tissue models supported on Alvetex membranes.
Christa MacDonald, David Benjamin Finlay, Anower Jabed, Michelle Glass, E. Scott Graham
Journal of Neuroscience Methods
Published 30 December 2014
In this study, the authors present a new method to generate biological samples that can be used as controls for in situ hybridisation (ISH) studies. Currently, ISH is limited due to inefficient probe penetration and loss of sample during preparation. In this paper researchers describe a novel approach using Alvetex Scaffold to create 3D tissue-like structures suitable for sectioning on a cryostat. These samples can subsequently be used as material for positive controls to verify gene expression by ISH. Cells are first transfected with the gene of interest, then cultured in 3D on Alvetex Scaffold, samples are then fixed, embedded and sectioned, and subsequently prepared for ISH using the riboprobe of interest. Sectioning increases probe penetration and further enhances the opportunity for good hybridisation. The authors demonstrated this technique using HEK cells transfected with CB1 and NeuN to optimise hybridisation stringency conditions. These conditions were then applied to samples of brain tissue analysed by ISH. This method can be adapted to generate positive controls for ISH for any gene of interest and it is especially useful where access to precious tissue is limited. In relation to Alvetex, this method further demonstrates the versatility of the material and its broad range of applications.
Gema Vallésa, Fátima Bensiamara, Lara Crespoa, Manuel Arruebob, Nuria Vilaboaa, Laura Saldañaa
Published online October 28, 2014
Valles and colleagues report on the role of the physical microenvironment in the modulation of signalling between mesenchymal stem cells and macrophages. Three dimensional culture of mesenchymal stem cells in Alvetex Scaffold stimulates the secretion of anti-inflammatory molecules that have a differential effect on co-cultured macrophages compared to cells grown in conventional cell culture on flat two dimensional substrates. The role of specific factors involved in this signalling process, namely IL-6 and MCP-1, was identified using immunological inhibition. In effect, the local inflammatory environment provided in 3D co-cultures induces a decrease in monocyte migration compared conventional monolayer cultures. These data highlight the importance of the three dimensional topography of the microenvironment in the regulation of paracrine factors and soluble-factor guided communication between two different cell populations.
(27.) Pan-Bcl-2 Inhibitor Obatoclax Delays Cell Cycle Progression and Blocks Migration of Colorectal Cancer Cells
Bruno Christian Koehler, Anna-Lena Scherr, Stephan Lorenz, Christin Elssner, Nicole Kautz, Stefan Welte, Dirk Jaeger, Toni Urbanik, Henning Schulze-Bergkamen
PLoS ONE 9(9): e106571.
Published September 05, 2014
(26.) Morphology and functions of astrocytes cultured on water-repellent fractal tripalmitin surfaces
Wei-wei Hu, Zhe Wang, Shan-shan Zhang, Lei Jiang, Jing Zhang, Xiangnan Zhang, Qun-fang Lei, Hyun-Joo Park, Wen-jun Fang, Zhong Chen
Published 2 June 2014
Note: Hu and colleagues present work that describes the development and application of water-repellent fractal tripalmitin surfaces upon which they cultured primary rat astrocytes. Cells grown on these substrates form a more three dimensional in vivo-like phenotype. Such cell architecture was confirmed in comparison to the cells growing on Alvetex® Scaffold. In this case, Alvetex Scaffold was used as a form of positive control to create a three dimensional micro-environment in which the astrocytes could form in vivo-like morphologies. When cultured on Alvetex Scaffold, the astrocytes developed a more sophisticated structure: they formed more numerous and longer processes, they developed numerous filopodia extensions, and they increased cell-to-cell interactions. The paper also demonstrates the use of confocal microscopy to image the GFAP-immunostained astrocytes growing in Alvetex Scaffold.
(25.) The role of high cell density in the promotion of neuroendocrine transdifferentiation of prostate cancer cells
Molecular Cancer 2014, 13:113
Published: 20 May 2014
(24.) The effects of microRNAs on human neural stem cell differentiation in two- and three-dimensional cultures
Lara Stevanato and John D Sinden
Stem Cell Research & Therapy 2014, 5:49
Published: 11 April 2014
Ruslan I. Dmitriev, Alina V. Kondrashina, Klaus Koren, Ingo Klimant, Alexander V. Zhdanov, Janelle M. P. Pakan, Kieran W. McDermott and Dmitri B. Papkovsky
Biomaterials Science (28 Jan 2014)
(22.) Beyond Cell Death – Antiapoptotic Bcl-2 Proteins Regulate Migration and Invasion of Colorectal Cancer Cells In Vitro
Bruno Christian Koehler, Anna-Lena Scherr, Stephan Lorenz, Toni Urbanik, Nicole Kautz, Christin Elssner, Stefan Welte, Justo Lorenzo Bermejo, Dirk Jäger, Henning Schulze-Bergkamen
Public Library of Science.
PLoS ONE 8(10): e76446.
Published: October 3, 2013
(21.) Effect of PEG Surface Conformation on Anticancer Activity and Blood Circulation of Nanoemulsions Loaded with Tocotrienol-Rich Fraction of Palm Oil
Alaadin Alayoubi, Saeed Alqahtani, Amal Kaddoumi, Sami Nazzal
The AAPS Journal (August 2013)
(20.) Overlapping gene coexpression patterns in human medullary thymic epithelial cells generate self-antigen diversity
Sheena Pinto, Chloé Michela, Hannah Schmidt-Glenewinkel, Nathalie Harder, Karl Rohr, Stefan Wild,
Benedikt Brorse, and Bruno Kyewskia,
PNAS. 26 August 2013. doi: 10.1073
Ruchi Sharma, Safia Z. Barakzai, Sarah E. Taylor, F. Xavier Donadeu
Journal of Tissue Engineering and Regenerative Medicine.
First published online 30 July 2013. doi: 10.1002/term.1788
(18.) Targeting of Beta Adrenergic Receptors Results in Therapeutic Efficacy against Models of Hemangioendothelioma and Angiosarcoma
Jessica M. Stiles, Clarissa Amaya, Steven Rains, Dolores Diaz, Robert Pham, James Battiste, Jaime F. Modiano, Victor Kokta, Laura E. Boucheron, Dianne C. Mitchell, Brad A. Bryan
Public Library of Science.
March 2013 | Volume 8 | Issue 3 | e60021
PLoS ONE 8(3): e60021.
(17.) Characterization of liver specific functions of upcyte® hepatocytes grown in 3D and co-cultured with upcyte® endothelial cells
C Dähn, N Hewitt, D Maltman, G Talas, S Przyborski, S Heinz, A Nörenberg, K Scheller, J Braspenning
Z Gastroenterol, 2012; 50 – P2_05
(16.) The autophagy-associated factors DRAM1 and p62 regulate cell migration and invasion in glioblastoma stem cells
S Galavotti, S Bartesaghi, D Faccenda, M Shaked-Rabi, S Sanzone, A McEvoy, D Dinsdale, F Condorelli, S Brandner, M Campanella, R Grose, C Jones, P Salomoni
(15.) Generation of proliferating human hepatocytes using upcyte® technology: characterisation and applications in induction and cytotoxicity assays
Alexandra Burkard, Caroline Dähn, Stefan Heinz, Anne Zutavern, Vera Sonntag-Buck, Daniel Maltman, Stefan Przyborski, Nicola J. Hewitt, and Joris Braspenning
(14.) Generation of proliferating human hepatocytes using upcyte® technology: characterisation and applications in induction and cytotoxicity assays
Alexandra Burkard1, Caroline Dähn, Stefan Heinz, Anne Zutavern, Vera Sonntag-Buck, Daniel Maltman, Stefan Przyborski, Nicola J. Hewitt, Joris Braspenning
General Xenobiochemistry, October 2012, Vol. 42, No. 10 , Pages 939-956
(13.) Rat primary hepatocytes show enhanced performance and sensitivity to acetaminophen during three-dimensional culture on a polystyrene scaffold designed for routine use.
Schutte, M., Fox. B., Baradez, M., Devonshire, A., Minguez., J., Bokhari. M., Przyborski. S., Marshall. D., (2011)
Assay and Drug Development Technologies
Neofytou. E.A., Chang. E., Patlola. B., Joubert. L.M., Rajadas. J., Gambhir. S.S., Cheng. Z., Robbins. R.C., Beygui. R.E., (2011)
Journal Biomedical Materials Research Part A
Rajan. N., Elliott. R., Clewes. O., Mackay. A., Reis-Filho. J.S., Burn. J., Langtry. J., Sieber-Blum. M., Lord. C.J., Ashworth. A., (2011)
Knight, E., Murray, B., Carnachan, R., Przyborski, S.A., (2011).
Methods in Molecular Biology, 695, 323-40.
(9.) Developments in three dimensional cell culture technology aimed at improving the accuracy of in vitro analyses.
Maltman, D., Przyborski, S.A., (2010)
Biochemical Society Transactions, 38(4), 1072-5
Carnachan, R.J., Bokhari, M., Maatta, A., Cameron, N.R., Przyborski, S.A. (2008).
American Chemical Society, Division of Polymer Chemistry, 49, 418-419.
(6.) Culture of HepG2 liver cells on three dimensional polystyrene scaffolds enhances cell structure and function during toxicological challenge.
Bokhari, M., Carnachan, R., Cameron, N.R., Przyborski, S.A. (2007).
Journal of Anatomy, 211, 567-76.
(6.) Effect of synthesis parameters on emulsion-templated porous polymer formation and evaluation for 3D cell culture scaffolds.
Bokhari, M., Carnachan, R., Przyborski, S.A., Cameron, N.R. (2007).
Journal of Materials Chemistry, 17, 4088-4094.
Bokhari, M., Carnachan, R., Cameron, N.R., Przyborski, S.A. (2007).
Biochemical and Biophysical Research Communications, 354, 1095-1100.
Carnachan, R.J., Bokhari, M., Przyborski, S.A., Cameron, N.R. (2006).
Soft Matter, 2, 608-616.
Barbetta, A., Carnachan, R.J., Smith, K.H., Zhao, C., Cameron, N.R., Kataky, R., Hayman, M., Przyborski, S.A., Swan, M. (2005).
Macromolecular Symposia, 226, 203-211.
Hayman, M.W., Smith, K.H., Cameron, N.R., Przyborski, S.A. (2005).
Journal of Biochemical and Biophysical Methods, 62, 231-240.
Hayman, M.W., Smith, K.H., Cameron, N.R., Przyborski, S.A. (2004).
Biochemical and Biophysical Research Communications, 314, 483-488.