Alvetex Publications - page 2
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.
71. Differentiation Patterns of Immortalized Human Meibomian Gland Epithelial Cells in Three-Dimensional Culture
Nagayoshi Asano; Ulrike Hampel; Fabian Garreis; Antje Schröder; Martin Schicht; Christian M. Hammer; Friedrich Paulsen
Investigative Ophthalmology & Visual Science, March 2018, Vol.59, 1343-1353. doi:10.1167/iovs.17-23266
Dong Hyeok Park, Hyeong Jin Jeon, Moon Jeong Kim, Xuan Don Nguyen, Karl Morten and Jeung Sang Go
Journal of Micromechanics and Microengineering (online 17 January 2018)
69. Paracrine interactions between mesenchymal stem cells and macrophages are regulated by 1,25-dihydroxyvitamin D3
Laura Saldaña, Gema Vallés, Fátima Bensiamar, Francisco José Mancebo, Eduardo García-Rey & Nuria Vilaboa
Scientific Reports 7, Article number: 14618 (2017)
68. Effect of_the Scaffold Microenvironment on Cell Polarizability and Capacitance Determined by Probabilistic Computations.
Pazmino Betancourt B, Florczyk S, Simon M, Juba D, Douglas JF, Keyrouz W, Bajcsy P, Lee C, Simon CG.
Biomed Mater. 2017 Oct 26.
Michel C, Miller CN, Küchler R, Brors B, Anderson MS, Kyewski B, Pinto S.
J Immunol. 2017 Oct 9. pii: ji1700203.
66. Autocrine and Paracrine Regulation of the Murine Skeleton by Osteocyte-Derived Parathyroid Hormone-Related Protein.
Ansari N, Ho PW, Crimeen-Irwin B, Poulton IJ, Brunt AR, Forwood MR, Divieti Pajevic P, Gooi JH, Martin TJ, Sims NA.
J Bone Miner Res. 2017 Sep 15.
S. Florczyk, M. Simon, D. Juba, S. Pine, S. Sarkar, D. Chen, P. Baker, S. Bodhak, A. Cardone, M. Brady, P. Bajcsy, C.G. Simon.
ACS Biomater. Sci. Eng. 2017 Aug 31.
In vivo, stem cells reside within an ECM niche that influences both their morphology and their function. In vitro, 3D biomaterials constitute a synthetic niche which can affect cell shape, and consequently, cell function. In this study, the authors used confocal laser microscopy to determine the 3D morphometrics of individual primary human bone marrow stromal cells cultured on eight different substrates representative of fibrous, porous, gel and planar geometries, with Alvetex Scaffold being selected as the sole example of 3D porous substrate. Both F-actin and nuclear 2D areas and 3D volumes were quantified, which revealed that quantification of 2D area alone tends to underestimate cell size when compared to 3D volume, due to differences in cell height between culture substrates. Actin metrics were more variable than nuclear ones, consistent with the greater dynamics of the actin cytoskeleton, but both showed similar groupings of the substrates, i.e. planar and gelled substrates being associated with flatter cells compared with porous and fibrous substrates, with Matrigel being unique in promoting a spheroid cell morphology.
These results clearly demonstrate how 3D culture within Alvetex Scaffold promote quantifiable changes in individual cell shape, most notably reducing the cellular and nuclear flattening characteristic of conventional 2D in vitro culture.
64. Galectin-1 from conditioned medium of three-dimensional culture of adipose-derived stem cells accelerates migration and proliferation of human keratinocytes and fibroblasts
M.H. Kim, W.H. Wu, J.H. Choi, J.H. Kim, J.H. Jun, Y. Ko and J.H. Lee, MD.
Wound Repair and Regeneration. 2017 Aug 30.
Adipose-derived stem cells (ADSCs) are an easier-to-source alternative to bone marrow stem cells and are known to secrete factors that can promote angiogenesis and aid tissue repair. In this study, the authors investigated the effect of 3D culture of ADSCs in Alvetex Scaffold on the ability of ADSC-conditioned medium to promote proliferation and migration of HaCat keratinocytes and primary human dermal fibroblast (HDFs). Compared to ADSCs culture in 2D, the conditioned medium from Alvetex-cultured ADSCs contained greater amounts of ECM proteins that may improve cell-substrate adhesion (collagen I and collagen III), as well as growth factors and cytokines involved in wound healing (bFGF and IL-6). 3D-conditioned medium also contained factors not found in 2D-conditioned medium, notably TIMP-1, CHI3LI and Galectin-1, all of which have previously been shown to promote fibroblast proliferation. Compared to 2D-conditioned medium, 3D-conditioned medium increased the proliferation of HaCat keratinocytess and the migration of both HaCats and HDFs. Antibody-blocking of Galectin-1, but not CHI3LI, activity from the medium abrogated its effect on HaCat migration, supporting the role of Galectin-1 in the wound healing process.
These results demonstrate how three-dimensionality can promote the expression of functionally-important proteins and therefore the benefits of 3D culture for the study of paracrine signalling in co-culture models.
Ugbode CI, Smith I, Whalley BJ, Hirst WD, Rattray M.
J Neurochem. 2017 May 9. doi: 10.1111/jnc.14064.
Sonic HedgeHog (SHH) signalling is already known to reduce astrocyte reactivity after CNS injury in vivo. In this study, the authors used two SHH pathway agonists, purmorpharmine (Pur) and smoothened agonist (SAG) to characterise the effects of SHH signalling upon astrocytes grown in vitro in both conventional 2D and Alvetex 3D cultures, with a focus on neuroprotection. Following agonist treatment, primary astrocytes isolated from E15 mouse embryo cerebral cortices exhibited cell elongation, increased cell proliferation and decreased expression of the reactivity marker GFAP in 2D. In 2D astrocyte-neuron co-cultures, treatment with SAG resulted in a decrease in neuronal firing frequency, as determined by multi-electrode array (MEA). To better characterise this observation, astrocytes were cultured and pre-treated with SAG as a monoculture in a 3D Alvetex Scaffold insert, after which SAG was washed out and the Alvetex insert was suspended in a culture well already containing neurons grown in 2D. After allowing sufficient time for the astrocytes to condition the medium, the insert was removed and the neurons were treated with kainate to induce injury. Medium conditioning with SAG-treated astrocytes grown in 3D Alvetex inserts conferred cytotoxic protection upon the neurons, as assessed by MAP-2 expression levels. This experimental set-up illustrates the suitability of 3D Alvetex inserts for multi-phasic co-culture and for the in vitro characterisation of functionally-significant cell-cell interactions observed in vivo.
62. Dedifferentiation into blastomere-like cancer stem cells via formation of polyploid giant cancer cells.
Niu N, Mercado-Uribe I, Liu J.
Oncogene. 2017 Apr 24. doi: 10.1038/onc.2017.72.
In this study, the authors characterised polyploid giant cancer cells (PGCC) derived from mitosis-arrested ovarian cancer cell lines. When grown in 2D, PGCCs were capable of exhibiting stem cell characteristics, as evidenced by the expression of OCT4, SOX2 and NANOG and the loss of Xist expression. YAP, a critical factor in regulating the tumour-suppressor pathway, had a distinct nuclear localisation in PGCCs, which, when disrupted by the addition of dobutamine, prevented the differentiation of PGCCs into either endoderm or neural-like cells. Daughter cells arising from PGCCs by budding exhibited morphologies reminiscent of various cell lineages and differentiated when cultured in either chondrogenic, adipogenic or osteogenic medium, as indicated by positive staining for sulphate chondroitin, oil red O and osteogenin, respectively. In xenografts, tumours obtained from daughter cells where smaller and more heterogenous than those from un-arrested cancer cells, which mimics clinical observations post-chemotherapy in humans. When grown on Alvetex Scaffold, PGCCs remained at the surface of the substrate and exhibited an epithelial-like morphology, rather than invading into the substrate as seen with un-arrested cancer cells. Taken together, this study shows how the use of 2D, 3D and animal models can be combined to assess specific aspects of cell expression and behaviour to gain a more complete understanding of cancer cell regulation under chemotherapy.
Wood C.L., Divieti Pajevic P., Gooi J.H.
Bone Reports. 2017 Jun 6:74-80. doi:10.1016/j.bonr.2017.02.007
In this study, the authors investigated the cross-talk between bone and muscle, and more specifically the effect of osteocyte-conditioned medium on myogenic differentiation. MLO-Y4 osteocytes were cultured in Alvetex scaffold in either static or perfused conditions, using the Alvetex perfusion plate, and the resulting conditioned medium was added to C2C12 myoblasts. A significant decrease in the number and length of myofibers was observed after 6 days of treatment with medium from either static or perfused cultures and the expression of several myogenic regulatory factors (eg. Myf5, Myogenin, Myh1) was also decreased. Several cytokines relevant to muscle formation were detected in the conditioned medium, with differential amounts of individual cytokines between static and perfused medium generally supporting a greater inhibitory activity of perfused conditioned medium, as exemplified by a decrease in IL-1β, IL-3, IL-4, IL-10, MIG and MIP-1a in perfused culture conditioned medium compared to its static culture equivalent.
These results demonstrate how Alvetex technologies can be successfully combined to provide several physiological cues in vitro, i.e. both three dimensionality and mechanical stimulation, with benefits to protein expression and the understanding of cell-cell interaction mechanisms.
Shannon S, Jia D, Entersz I, Beelen P, Yu M, Carcione C, Carcione J, Mahtabfar A, Vaca C, Weaver M, Shreiber D, Zahn JD, Liu L, Lin H, Foty RA.
BMC Cancer. 2017 Feb 10; 17(1):121. doi: 10.1186/s12885-017-3107-x.
Continuous dispersal of individual glioblastoma cells away from the main tumour mass is a challenge to the long-term efficacy of resection surgery.
In this study, the authors investigated the activity of the MEK inhibitor PD032901 on the growth and mechanical properties of hanging-drop aggregates generated from human primary glioblastoma cells, as well as on the actin organisation, detachment under shear stress and dispersal of individual cells. Of particular note, some of these aggregates were transferred on top of Alvetex scaffold that had been previously seeded with normal human astrocytes, and the ability of the aggregated glioblastoma cells to detach and disperse through the astrocyte culture was quantified by spinning disk confocal microscopy. In the absence of PD0325901, glioblastoma cells penetrated into the astrocyte-seeded scaffold for up to 30 microns deep in the space of 48h, and this was significantly reduced in the presence of the MEK inhibitor.
This study demonstrates how Alvetex 3D co-culture capabilities can further the applications of other 3D culture methods and enable the use of more complex in vitro models of cancer cell invasion through neighbouring tissue.
59. A robust and reproducible human pluripotent stem cell derived model of neurite outgrowth in a three-dimensional culture system and its application to study neurite inhibition.
Clarke KE, Tams DM, Henderson AP, Roger MF, Whiting A, Przyborski SA.
Neurochem Int. 2016 Dec 20. pii: S0197-0186(16)30507-1. doi: 10.1016/j.neuint.2016.12.009.
In this study, the authors present a novel 3D model which enables the investigation of neurite outgrowth in vitro, by culturing neurospheres derived from pluripotent stem cells onto Alvetex Scaffold inserts. Stem cells were differentiated with the synthetic retinoid EC23 in 2D, as evidenced by decreased expression of the pluripotency markers SSEA3, Nanog and Oct-4, as well as increased expression of the neuronal differentiation markers A2B5 and Pax6 and of the mature neuronal protein NF-H. Differentiated neurospheres were also transferred onto the top surface of Alvetex scaffold inserts. Only a small minority of individual cells within the neurospheres migrated into the scaffold while neurites extended throughout the material. Neurites could be tracked using various techniques and their length and number extending through the 3D material could be quantified from imaging beneath the scaffold membrane. In experiments where U-118 MG glioma cells were co-cultured in the scaffold prior to neurosphere transfer, 3D neurite extension into the scaffold was drastically halted. Such suppression of neurite outgrowth was consistent with the detectable expression of inhibitory CSPGs expressed by U-118 MG cells grown in Alvetex Scaffold. This inhibitory effect could be rescued by addition of the ROCK inhibitor Y-27632.
These results demonstrate that Alvetex 3D Cell Culture technology can further the use and complexity of established differentiation in vitro models. The technology can be developed to replicate aspects of certain neuropathological disorders, allowing the more convenient acquisition of functional endpoints for testing drug candidates.
58. Synthesis of Near-Infrared Fluorescent Two-Photon-Absorbing Fluorenyl Benzothiadiazole and Benzoselenadiazole Derivatives.
Sheng Yao, Bosung Kim, Xiling Yue, Maria Y. Colon Gomez, Mykhailo V. Bondar, and Kevin D. Belfield.
ACS Omega, 2016, 1 (6), pp 1149–1156. DOI: 10.1021/acsomega.6b00289
Although two-photon fluorescence microscopy (2PFM) is already widely used to image ex-vivo tissue up to several millimetres depths, its potential use for microscopy-aided clinical surgery is currently untapped.
In this study, the authors synthesised four bis-thienylbenzothiadiazole chromophores and assessed their performance as candidate near-infrared (NIR) dyes for 2PFM. Their absorption/fluorescence spectra and quantum yields were found to be roughly constant in toluene, tetrahydrofuran and methylene chloride, suggesting that the dyes might also maintain their properties in aqueous solvents, i.e. in a biologically-relevant environment. Out of the four candidates, the one exhibiting the highest figure of merit was encapsulated in Pluronic micelles and added to 3T3 fibroblast grown in both 2D and Alvetex 3D substrate, whereby fluorescence was maintained and could be imaged up to a depth of 100 microns in Alvetex using confocal microscopy.
This study demonstrate the utility of Alvetex substrate for early studies destined to be applied in living tissues.
Natividad Gomez-Roman, Katrina Stevenson, Lesley Gilmour, Graham Hamilton and Anthony J Chalmers
Neuro Oncology (2016) First published online: August 30, 2016. doi: 10.1093/neuonc/now164
In this study, the authors utilised Alvetex 3D cell culture technology to develop models of glioblastoma that would better recapitulate the in vivo behaviour of this common type of brain tumor. Although 2D models of glioblastoma already exist, they are unable to accurately predict drug sensitivity in vivo, which greatly impairs efforts to bring about new therapeutic agents. Cell lines derived from patient resections were grown in stem-cell promoting medium on either ECM-coated 2D plates or in ECM-coated Alvetex. Alvetex-grown cells exhibited a differential gene expression profile, notably in members of the EGFR and VEGF pathways and stem cell markers. They responded to presence of VEGF by an increase in proliferation and to withdrawal of VEGF by increased differentiation, which is consistent with the hypothesised role of VEGF in maintaining a stem cell character in vivo and is relevant to cancer treatment as drug resistance is thought to be associated with cancer stem-like cells. Also in accordance with in vivo data and in opposition to results from 2D cultures, cells grown in 3D in Alvetex were not radiosensitised by erlotinib treatment but were radiosensitised by either bevacizumab or temozolomide. Finally, upon injection into mice to assess tumorigenicity, cells from 3D cultures resulted in a greater number of symptomatic mice. Taken together, these results give strong evidence that Alvetex 3D culture models are better able to predict cell responses to therapeutic candidates before pre-clinical and clinical in vivo testing than current 2D models, with great potential benefit to cancer research and ultimately human health.
Scherr AL, Gdynia G, Salou M, Radhakrishnan P, Duglova K, Heller A, Keim S, Kautz N, Jassowicz A, Elssner C, He YW, Jaeger D, Heikenwalder M, Schneider M, Weber A, Roth W, Schulze-Bergkamen H, Koehler BC.
Cell Death Dis. 2016 Aug 18; 7(8):e2342. doi: 10.1038/cddis.2016.233.
This study highlights the role of the anti-apoptotic protein Bcl-xL in the incidence and treatment of colorectal cancer (CRC). After demonstrating using human CRC tissue and mouse knock-out mutants that Bcl-xL is upregulated in CRC and that its absence results in fewer tumor lesions, the authors cultured HT29 cells in Alvetex Scaffold and exposed them to ABT-737, a BH3 mimetic which competitively binds both Bcl-xL and Bcl-2. IHC-stained sections of the Alvetex-grown cultures revealed a greater amount of PARP cleavage and LDH medium activity in ABT-373-treated cells compared to untreated controls, although numbers of Ki67-expressing cells were unchanged. Crucially, when the authors repeated this ABT-737 treatment in human ex vivo CRC lesions slices, similar results were observed. This study demonstrates that data obtained using Alvetex can be replicated in human samples and that Alvetex 3D cell culture technology is therefore a physiologically-relevant model to study human disease in vitro.
Simkova D, Kharaishvili G, Korinkova G, Ozdian T, Suchánková-Kleplová T, Soukup T, Krupka M, Galandakova A, Dzubak P, Janikova M, Navratil J, Kahounova Z, Soucek K, Bouchal J.
Oncotarget. 2016 Jul 7. doi: 10.18632/oncotarget.10471.
Asporin, an aspartic acid-rich protein belonging to the small leucine-rich proteoglycan family, is involved in the development and pathogenesis of cartilage and bone tissues, thanks to its ability to bind both calcium and collagen types I and II, leading to ECM mineralisation. Although high expression of asporin is also detected in a number of cancers (eg. breast, lung, ovary, GI) and correlates with increased invasiveness in vitro, its relation to prognosis seems largely dependent on stage and subtype. In this report, the authors investigated the role of asporin on breast cancer cell invasion in a number of 3D matrices, including Alvetex Scaffold. Both human breast carcinoma Hs578T cells and human primary cancer-associated fibroblasts exhibited up-regulated asporin protein expression when grown in Alvetex Scaffold compared to 2D. Neither was asporin up-regulated in Hs578T cells grown in collagen gels, leading the authors to speculate that the stiffness of Alvetex Scaffold better mimics the physical environment of solid tumours.
Manghera M, Ferguson-Parry J, Douville RN
Neurobiol Dis. 2016 Oct;94:226-36. doi: 10.1016/j.nbd.2016.06.017.
This study investigates the interplay of human endogenous retrovirus-K (ERVK) and TAR DNA binding protein 43 (TDP-43), a regulator of RNA processing and protein homeostasis, in amyotrophic lateral sclerosis (ALS). The authors specifically compared astrocytes to neurons in vitro and detected differences in aggregation and clearance of ERVK/TDP-43 granules between both cell types. RenCell CX cells, grown and differentiated into neurons using the Alvetex Scaffold 12-well plate format, consistently expressed ERVK-reverse transcriptase, regardless of treatment with TNF-a and/or MG132 proteasome inhibitor, as shown by confocal microscopy. These results highlight differences in the robustness of protein degradation pathways in different CNS cell types and their potential sensitivity to protein-aggregation diseases.
53. Influence of Matrices on 3D-Cultured Prostate Cancer Cells’ Drug Response and Expression of Drug-Action Associated Proteins.
Edmondson R, Adcock AF, Yang L.
PLoS One. 2016 Jun 28;11(6):e0158116. doi: 10.1371/journal.pone.0158116.
Although 2D cell-based assays have been a very useful and widespread model for drug toxicity testing in the pharmaceutical industry, the growing realisation of their limitations is leading to an increasing interest in 3D assays. However, commercially-available 3D in vitro assays vary greatly in their chemical and physical characteristics, potentially leading to model-specific changes in cell behaviour and drug response. In this report, the authors investigated the effects of three such 3D models, i.e. two basement-membrane gelling agents and Alvetex Scaffold 96-well plate format, on the morphology, proliferation and drug sensitivity of the LNCaP and DU145 prostate cancer cell lines. The results highlighted several model-specific, cell-specific and drug-specific differences between 2D and 3D models. While both gelling agents gave mostly similar results throughout, cells grown in Alvetex Scaffold exhibited cell-specific morphology, as well as drug sensitivity and protein expression profiles that could not consistently be matched to either the gelling agents or the 2D set-up. This report exemplifies the uniqueness of Alvetex Scaffold, which provides three-dimensionality of culture without the diffusional encumbrance or chemical signalling of a gelling system.
52. Structural Analysis of Three-dimensional Human Neural Tissue derived from Induced Pluripotent Stem Cells.
Patrick Terrence Brooks, Mikkel Aabech Rasmussen and Poul Hyttel.
J Stem Cell Res Ther 2016, 6:4 http://dx.doi.org/10.4172/2157-7633.1000337
In this study, the authors have characterised a 3D in vitro model of neural differentiation utilising human iPSCs grown on Alvetex. After an initial period of differentiation into neuroepithelial sheets on 2D conventional plastic using BMP and TGFβ inhibitors, the cultures were transferred onto laminin-coated Alvetex Scaffold inserts and maintained in hypoxic conditions (5% O2) for up to one month. The neural tissue equivalent obtained grew several hundred microns thick within and above the scaffold. In-depth morphological characterisation by confocal microscopy revealed neural tube-like structures (NTLS) formation within the tissue mass, with SOX2 and Ki67 positive neural stem cells concentrated at the edge of the NTLS lumen, while neuroprogenitor cells and radiating glial-like cells were found at the NTLS periphery. Other neural markers, such as βIII-tubulin and Tau, were more widely expressed throughout the tissue construct, with MAP2 being expressed preferentially in cells growing on the underside of the scaffold. TEM imaging further confirmed the high cohesion and maturity of the cultures, with clear example of tight junctions, basal bodies and primary cilia.
This model of extended neural differentiation demonstrate how the Alvetex insert format can enable the long-term differentiation of tissue constructs in vitro. This is of benefit not only in providing the research community with a more in vivo-like model of neural development, but could also be of use as a test of the differentiation capacity of iPSC lines.
Ugbode CI, Hirst WD, Rattray M.
Neurochem Res. 2016 Aug; 41(8):1857-67. doi: 10.1007/s11064-016-1911-3. Epub 2016 Apr 21.
This study investigates the effect of in vitro culture conditions on the marker expression profile of astrocytes and how well the resulting cells approximate astrocytes in vivo. In vitro astrocytes were obtained from either embryonic or postnatal mouse brain tissue and grown on both 2D glass coverslips and 3D Alvetex inserts coated with poly-L-ornithine. Using western blotting and qPCR to examine the expression levels of markers of astrocytic character (GLAST, GS, SMC3, NG2) and of reactive gliosis associated with CNS injury (GFAP, GLT-1, LCN2, Serpina3n, Cx43), the authors demonstrated that, although postnatal astrocytes only show very few differences between 2D and 3D, embryonic astrocytes grown in 3D exhibit lower levels of GFAP, GLAST, LCN2, serpina3n and Cx43, supporting the conclusion that culture in Alvetex can lead to astrocytes adopting a phenotype more representative of uninjured CNS tissue. These results highlights one of the advantages of using Alvetex 3D cell culture technology over conventional 2D culture to construct physiologically-relevant in vitro models.