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Akbari A, Emamzadeh R, Nazari M, Brandstetter T, Rühe J. Enhancing protein delivery for tissue regeneration: Development of AGR2-loaded hydrogels with controlled release properties. Int J Biol Macromol 2024; 259:128846. [PMID: 38141714 DOI: 10.1016/j.ijbiomac.2023.128846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 12/12/2023] [Accepted: 12/14/2023] [Indexed: 12/25/2023]
Abstract
The growth factor Anterior Gradient 2 (AGR2) has been shown to have an effective role in tissue regeneration, but remained largely unexplored in localized tissue engineering applications. Alginate beads have been proven as safe carriers for protein encapsulation, but they suffer from fragility and uncontrolled protein release. For such alginate systems, little is known about how changes in concentrations and ion-crosslinking affect protein release and accumulation in 3-D matrices. To address these questions, an engineered interpenetrating polymer network (IPN) has been used to synthesize a novel hybrid system consisting of AGR2 loaded beads composed of calcium-crosslinked sodium alginate (SA) and carboxymethyl cellulose (CMC). These beads are embedded in films consisting of SA and polyvinyl alcohol (PVA), using a simple ion gelation technique. We assess protein release kinetics and accumulation within the hybrid system by varying polymer concentrations and cross-linking parameters. The IPN hybrid system maintains controlled release over two weeks, without an initial burst period. Through this approach efficicnt delivery of AGR2 is achieved which in turn effectively mediates cell migration and proliferation, resulting in excellent cell viability and complete wound closure. The described release system opens new perspectives in tissue engineering.
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Affiliation(s)
- Atefeh Akbari
- Department of Cell and Molecular Biology and Microbiology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan, Iran; Department of Microsystems Engineering, University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
| | - Rahman Emamzadeh
- Department of Cell and Molecular Biology and Microbiology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan, Iran.
| | - Mahboobeh Nazari
- Endocrine Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, Tehran, Iran; Nanobiotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran
| | - Thomas Brandstetter
- Department of Microsystems Engineering, University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
| | - Jürgen Rühe
- Department of Microsystems Engineering, University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany.
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2
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Alpsoy L, Sedeky AS, Rehbein U, Thedieck K, Brandstetter T, Rühe J. Particle ID: A Multiplexed Hydrogel Bead Platform for Biomedical Applications. ACS Appl Mater Interfaces 2023; 15:55346-55357. [PMID: 37982803 DOI: 10.1021/acsami.3c12122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2023]
Abstract
We present a new platform based on hydrogel beads for multiplex analysis that can be fabricated, barcoded, and functionalized in a single step using a simple microfluidic assembly and a photo-cross-linking process. The beads are generated in a two-phase flow fluidic system and photo-cross-linking of the polymer in the aqueous phase by C,H insertion cross-linking (CHic). The size and shape of the hydrogel particles can be controlled over a wide range by fluidic parameters. During the fabrication of the beads, they are barcoded by using physical and optical barcoding strategies. Magnetic beads and fluorescent particles, which allow identification of the production batch number, are added simultaneously as desired, resulting in complex, multifunctional beads in a one-step reaction. As an example of biofunctionalization, Borrelia antigens were immobilized on the beads. Serum samples that originated from infected and non-infected patients could be clearly distinguished, and the sensitivity was as good as or even better than ELISA, the state of the art in clinical diagnostics. The ease of the one-step production process and the wide range of barcoding parameters offer strong advantages for multiplexed analytics in the life sciences and medical diagnostics.
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Affiliation(s)
- Lokman Alpsoy
- Department of Microsystems Engineering (IMTEK), Chemistry & Physics of Interfaces, University of Freiburg, Freiburg im Breisgau 79110, Germany
- livMatS@FIT (Freiburg Center for Interactive Materials and Bioinspired Technologies), University of Freiburg, Freiburg 79110, Germany
| | - Abanoub Selim Sedeky
- Department of Microsystems Engineering (IMTEK), Chemistry & Physics of Interfaces, University of Freiburg, Freiburg im Breisgau 79110, Germany
| | - Ulrike Rehbein
- Institute of Biochemistry, Center of Chemistry and Biomedicine, University of Innsbruck, 6020 Innsbruck, Austria
| | - Kathrin Thedieck
- Institute of Biochemistry, Center of Chemistry and Biomedicine, University of Innsbruck, 6020 Innsbruck, Austria
- Freiburg Materials Research Center FMF, Albert-Ludwigs-University of Freiburg, 79104 Freiburg, Germany
- Department of Pediatrics, Section Systems Medicine of Metabolism and Signaling, University of Groningen, University Medical Center Groningen, Groningen 9700 RB, The Netherlands
| | - Thomas Brandstetter
- Department of Microsystems Engineering (IMTEK), Chemistry & Physics of Interfaces, University of Freiburg, Freiburg im Breisgau 79110, Germany
| | - Jürgen Rühe
- Department of Microsystems Engineering (IMTEK), Chemistry & Physics of Interfaces, University of Freiburg, Freiburg im Breisgau 79110, Germany
- livMatS@FIT (Freiburg Center for Interactive Materials and Bioinspired Technologies), University of Freiburg, Freiburg 79110, Germany
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3
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Luongo A, von Stockert AR, Scherag FD, Brandstetter T, Biesalski M, Rühe J. Controlling Fluorescent Readout in Paper-based Analytical Devices. ACS Biomater Sci Eng 2023; 9:6379-6389. [PMID: 37875260 PMCID: PMC10649804 DOI: 10.1021/acsbiomaterials.3c00736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 09/14/2023] [Indexed: 10/26/2023]
Abstract
Paper is an ideal candidate for the development of new disposable diagnostic devices because it is a low-cost material, allows transport of the liquid on the device by capillary action, and is environmentally friendly. Today, colorimetric analysis is most often used as a detection method for rapid tests (test strips or lateral flow devices) but usually gives only qualitative results and is limited by a relatively high detection threshold. Here, we describe studies using fluorescence as a readout tool for paper-based diagnostics. We study how the optical readout is affected by light transmission, scattering, and fluorescence as a function of paper characteristics such as thickness (grammage), water content, autofluorescence, and paper type/composition. We show that paper-based fluorescence analysis allows better optical readout compared to that of nitrocellulose, which is currently the material of choice in colorimetric assays. To reduce the loss of analyte molecules (e.g., proteins) due to adsorption to the paper surface, we coat the paper fibers with a protein-repellent hydrogel. For this purpose, we use hydrophilic copolymers consisting of N,N-dimethyl acrylamide and a benzophenone-based cross-linker, which are photochemically transformed into a fiber-attached polymer hydrogel on the paper fiber surfaces in situ. We show that the combination of fluorescence detection and the use of a protein-repellent coating enables sensitive paper-based analysis. Finally, the success of the strategy is demonstrated by using a simple LFD application as an example.
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Affiliation(s)
- Anna Luongo
- Laboratory
for Chemistry & Physics of Interfaces, Department of Microsystems
Engineering (IMTEK), Albert-Ludwigs-Universität
Freiburg, Freiburg 79110, Germany
- Freiburg
Institute for Interactive Materials and Bioinspired Technologies (FIT), Albert-Ludwigs-Universität Freiburg, Freiburg 79110, Germany
| | | | - Frank D. Scherag
- Laboratory
for Chemistry & Physics of Interfaces, Department of Microsystems
Engineering (IMTEK), Albert-Ludwigs-Universität
Freiburg, Freiburg 79110, Germany
- Freiburg
Institute for Interactive Materials and Bioinspired Technologies (FIT), Albert-Ludwigs-Universität Freiburg, Freiburg 79110, Germany
| | - Thomas Brandstetter
- Laboratory
for Chemistry & Physics of Interfaces, Department of Microsystems
Engineering (IMTEK), Albert-Ludwigs-Universität
Freiburg, Freiburg 79110, Germany
- Freiburg
Institute for Interactive Materials and Bioinspired Technologies (FIT), Albert-Ludwigs-Universität Freiburg, Freiburg 79110, Germany
| | - Markus Biesalski
- Macromolecular
Chemistry & Paper Chemistry, Technical
University of Darmstadt, Darmstadt 64287, Germany
| | - Jürgen Rühe
- Laboratory
for Chemistry & Physics of Interfaces, Department of Microsystems
Engineering (IMTEK), Albert-Ludwigs-Universität
Freiburg, Freiburg 79110, Germany
- Freiburg
Institute for Interactive Materials and Bioinspired Technologies (FIT), Albert-Ludwigs-Universität Freiburg, Freiburg 79110, Germany
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Reddy Banda S, Klapproth H, Smit N, Bednar S, Brandstetter T, Rühe J. An advanced and efficient asymmetric PCR method for microarray applications. Front Bioeng Biotechnol 2022; 10:1045154. [DOI: 10.3389/fbioe.2022.1045154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 11/09/2022] [Indexed: 12/02/2022] Open
Abstract
The sensitivity of a PCR based biochip assay relies on the efficiency of PCR amplicons in binding to the microarray spots. The essential factor determining the sensitivity is the amount of single stranded (ss) amplicons available for biochip hybridization. Asymmetric PCR can generate ss-amplicons depending on the ratio of primers used in the amplification process, but this process is often inefficient. We report a novel variant of PCR called the Asymmetric Exponential and Linear Amplification (AELA) which can overcome these issues and generate large amounts of single stranded amplicons. AELA-PCR introduces an amplification strategy that makes use of both exponential and linear amplification of the target nucleic acid. This is done by specifically designed primers and choice of adequate thermal profiles. In conventional PCR with a classical thermal profile, these specifically designed primers will work normally and contribute to an exponential increase of amplicons. A designed sequence extension of one of the primers and a very specific thermal profile, will result in a situation that the extended primer will be the only functional one for amplification, resulting in a linear phase of the amplification process. That is why during this step only one of the two strands of the target is amplified linearly and no longer exponentially. The result of the whole process is an amplification product enriched very strongly in one of the two single strands of the target. These adaptions in PCR are particularly favorable where the generation of ss-DNA/RNA is required. We demonstrate the higher biochip sensitivity of AELA-PCR compared to conventional amplification methods with an example of the Staphylococcus aureus detection on a DNA oligonucleotide microarray.
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5
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Weber T, Metzler L, Fosso Tene PL, Brandstetter T, Rühe J. Single-Color Barcoding for Multiplexed Hydrogel Bead-Based Immunoassays. ACS Appl Mater Interfaces 2022; 14:25147-25154. [PMID: 35617151 PMCID: PMC9185679 DOI: 10.1021/acsami.2c04361] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 04/06/2022] [Indexed: 05/30/2023]
Abstract
Current developments in precision medicine require the simultaneous detection of an increasing number of biomarkers in heterogeneous, complex solutions, such as blood samples. To meet this need, immunoassays on barcoded hydrogel beads have been proposed, although the encoding and decoding of these barcodes is usually complex and/or resource-intensive. Herein, an efficient method for the fabrication of barcoded, functionalized hydrogel beads is presented. The hydrogel beads are generated using droplet-based microfluidics in combination with photochemically induced C-H insertion reactions, allowing photo-crosslinking, (bio-) functionalization, and barcode integration to be performed in a single step. The generated functionalized beads carry single-color barcodes consisting of green-fluorescent particles of different sizes and concentrations, allowing simple and simultaneous readout with a standard plate reader. As a test example, the performance of barcoded hydrogel beads (3 × 3 matrix) functionalized with capture molecules of interest (e.g., antigens) is investigated for the detection of Lyme-disease-specific antibodies in patient sera. The described barcoding strategy for hydrogel beads does not interfere with the bioanalytical process and captivates by its simplicity and versatility, making it an attractive candidate for multiplex bioanalytical processes.
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von Stockert AR, Luongo A, Langhans M, Brandstetter T, Rühe J, Meckel T, Biesalski M. Reducing Unspecific Protein Adsorption in Microfluidic Papers Using Fiber-Attached Polymer Hydrogels. Sensors (Basel) 2021; 21:s21196348. [PMID: 34640668 PMCID: PMC8512548 DOI: 10.3390/s21196348] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/17/2021] [Accepted: 09/18/2021] [Indexed: 12/24/2022]
Abstract
Microfluidic paper combines pump-free water transport at low cost with a high degree of sustainability, as well as good availability of the paper-forming cellulosic material, thus making it an attractive candidate for point-of-care (POC) analytics and diagnostics. Although a number of interesting demonstrators for such paper devices have been reported to date, a number of challenges still exist, which limit a successful transfer into marketable applications. A strong limitation in this respect is the (unspecific) adsorption of protein analytes to the paper fibers during the lateral flow assay. This interaction may significantly reduce the amount of analyte that reaches the detection zone of the microfluidic paper-based analytical device (µPAD), thereby reducing its overall sensitivity. Here, we introduce a novel approach on reducing the nonspecific adsorption of proteins to lab-made paper sheets for the use in µPADs. To this, cotton linter fibers in lab-formed additive-free paper sheets are modified with a surrounding thin hydrogel layer generated from photo-crosslinked, benzophenone functionalized copolymers based on poly-(oligo-ethylene glycol methacrylate) (POEGMA) and poly-dimethyl acrylamide (PDMAA). This, as we show in tests similar to lateral flow assays, significantly reduces unspecific binding of model proteins. Furthermore, by evaporating the transport fluid during the microfluidic run at the end of the paper strip through local heating, model proteins can almost quantitatively be accumulated in that zone. The possibility of complete, almost quantitative protein transport in a µPAD opens up new opportunities to significantly improve the signal-to-noise (S/N) ratio of paper-based lateral flow assays.
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Affiliation(s)
- Alexander Ritter von Stockert
- Laboratory of Macromolecular Chemistry and Paper Chemistry (MAP), Department of Chemistry, Technische Universität Darmstadt, 64287 Darmstadt, Germany; (A.R.v.S.); (M.L.); (T.M.)
| | - Anna Luongo
- Laboratory of Chemistry and Physics of Interfaces, Institute for Microsystems Technology, Technical Faculty, University of Freiburg, 79110 Freiburg, Germany; (A.L.); (T.B.)
| | - Markus Langhans
- Laboratory of Macromolecular Chemistry and Paper Chemistry (MAP), Department of Chemistry, Technische Universität Darmstadt, 64287 Darmstadt, Germany; (A.R.v.S.); (M.L.); (T.M.)
| | - Thomas Brandstetter
- Laboratory of Chemistry and Physics of Interfaces, Institute for Microsystems Technology, Technical Faculty, University of Freiburg, 79110 Freiburg, Germany; (A.L.); (T.B.)
| | - Jürgen Rühe
- Laboratory of Chemistry and Physics of Interfaces, Institute for Microsystems Technology, Technical Faculty, University of Freiburg, 79110 Freiburg, Germany; (A.L.); (T.B.)
- Correspondence: (J.R.); (M.B.)
| | - Tobias Meckel
- Laboratory of Macromolecular Chemistry and Paper Chemistry (MAP), Department of Chemistry, Technische Universität Darmstadt, 64287 Darmstadt, Germany; (A.R.v.S.); (M.L.); (T.M.)
| | - Markus Biesalski
- Laboratory of Macromolecular Chemistry and Paper Chemistry (MAP), Department of Chemistry, Technische Universität Darmstadt, 64287 Darmstadt, Germany; (A.R.v.S.); (M.L.); (T.M.)
- Correspondence: (J.R.); (M.B.)
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7
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Fosso Tene PL, Weltin A, Tritz F, Defeu Soufo HJ, Brandstetter T, Rühe J. Cryogel Monoliths for Analyte Enrichment by Capture and Release. Langmuir 2021; 37:11041-11048. [PMID: 34506153 DOI: 10.1021/acs.langmuir.1c01638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A platform based on cryogel monoliths in small capillaries, which allows very strong enrichment of an analyte through a capture and release process, is described. For their preparation, a photoreactive copolymer solution containing capture molecules of interest is filled into a capillary, frozen in, and then photochemically transformed into cryogel monoliths through C,H-insertion cross-linking reactions. As a test example, the platform is used for the preconcentration of dopamine from bovine serum albumin and urine samples through capture and release processes. During capture from a large volume and release into a smaller volume, the platform shows recovery rates up to 97% and allows up to a roughly 630-fold enrichment of the concentration of the analyte. The presented platform could be used as a disposable device for the purification and enrichment of a variety of cis-diol-containing samples.
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Affiliation(s)
- Patrick L Fosso Tene
- Chemistry & Physics of Interfaces, Department of Microsystems Engineering - IMTEK, University of Freiburg, 79110 Freiburg, Germany
| | - Andreas Weltin
- Laboratory for Sensors, Department of Microsystems Engineering - IMTEK, University of Freiburg, 79110 Freiburg, Germany
| | - Florian Tritz
- Chemistry & Physics of Interfaces, Department of Microsystems Engineering - IMTEK, University of Freiburg, 79110 Freiburg, Germany
| | - Herve J Defeu Soufo
- Division of Infectious Diseases, University Medical Center Freiburg, 79106 Freiburg, Germany
| | - Thomas Brandstetter
- Chemistry & Physics of Interfaces, Department of Microsystems Engineering - IMTEK, University of Freiburg, 79110 Freiburg, Germany
| | - Jürgen Rühe
- Chemistry & Physics of Interfaces, Department of Microsystems Engineering - IMTEK, University of Freiburg, 79110 Freiburg, Germany
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8
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Fosso Tene PL, Stumpf A, Zinggeler M, Reuck V, Malik A, Weigel W, Müller M, Kneusel R, Brandstetter T, Rühe J. Linear Cryogel Arrays: On the Fast Track for Borreliosis Detection. Anal Chem 2021; 93:12426-12433. [PMID: 34470214 DOI: 10.1021/acs.analchem.1c02561] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The detection of IgG/IgM antibodies is a crucial tool for the diagnosis of infectious diseases as they give specific information such as the stage of infection or when it approximately occurred. In this work, a linear cryogel array (LCA) technology is described for the detection of IgG and IgM antibodies, indicative of a borreliosis infection in human sera. The LCA consists of a transparent capillary filled with functionalized cryogel compartments. For the generation of these cryogel arrays, solutions containing a photo-copolymer and the appropriate antigens are sucked into a surface-modified glass capillary. The solution compartments are separated from each other through air pockets. After freezing the solutions, a photo-induced cross-linking process is performed, through which the solutions are transformed into cryogel compartments, covalently attached to the capillary walls. We show that the LCA technology allows the simultaneous detection of IgG and IgM antibodies via a sandwich immunoassay in sera from Borrelia-infected patients within 1 h for sample sizes of only 12 μL. A study with sera from 42 patients conducted with the LCAs and referenced - depending on the source of the sera - to a commercial line immunoassay and a chemiluminescent immunoassay, which are currently widely used for Lyme disease screening, demonstrates the diagnostic potential of the approach.
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Affiliation(s)
- Patrick L Fosso Tene
- Chemistry & Physics of Interfaces, Department of Microsystems Engineering-IMTEK, University of Freiburg, 79110 Freiburg, Germany
| | - Anne Stumpf
- Chemistry & Physics of Interfaces, Department of Microsystems Engineering-IMTEK, University of Freiburg, 79110 Freiburg, Germany
| | - Marc Zinggeler
- Chemistry & Physics of Interfaces, Department of Microsystems Engineering-IMTEK, University of Freiburg, 79110 Freiburg, Germany
| | | | - Arif Malik
- MicroDiscovery GmbH, 10405 Berlin, Germany
| | | | | | | | - Thomas Brandstetter
- Chemistry & Physics of Interfaces, Department of Microsystems Engineering-IMTEK, University of Freiburg, 79110 Freiburg, Germany
| | - Jürgen Rühe
- Chemistry & Physics of Interfaces, Department of Microsystems Engineering-IMTEK, University of Freiburg, 79110 Freiburg, Germany
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9
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Schölch S, Schäfer JL, Meckel T, Brandstetter T, Biesalski M, Rühe J. Diazo-Based Copolymers for the Wet Strength Improvement of Paper Based on Thermally Induced CH-Insertion Cross-Linking. Biomacromolecules 2021; 22:2864-2873. [PMID: 34126012 DOI: 10.1021/acs.biomac.1c00249] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
We present an alternative to commonly used, but from an environmental point of view, problematic wet strength agents, which are usually added to paper to prevent a loss of mechanical stability and finally disintegrate when they get into contact with water. To this end, diazoester-containing copolymers are generated, which are coated onto paper and by heating to 110-160 °C for short periods of time become activated and form carbene intermediates, which undergo a CH-insertion cross-linking reaction. The process leads to a simultaneous cross-linking of the polymer and its attachment to the cellulose substrate. The immobilization process of copolymers consisting of a hydrophilic matrix based on N,N-dimethylacrylamide and a diazoester-based comonomer to a cellulose model surface and to laboratory-engineered, fibrous paper substrates is investigated as a function of time, temperature, and cross-linker composition. The distribution of the polymer in the fiber network is studied using confocal fluorescence microscopy. Finally, the tensile properties of modified wet and dry eucalyptus sulfate papers are measured to demonstrate the strong effect of the thermally cross-linked copolymers on the wet strength of paper substrates. Initial experiments show that the tensile indices of the modified and wetted paper samples are up to 50 times higher compared to the values measured for unmodified samples. When dry and wet papers coated with the above-described wetting agents are compared, relative wet strengths of over 30% are observed.
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Affiliation(s)
- Simon Schölch
- Department of Microsystems Engineering (IMTEK), Laboratory for Chemistry & Physics of Interfaces, Albert-Ludwigs-Universität Freiburg, Georges-Köhler-Allee 103, Freiburg 79110, Germany.,Freiburg Institute for Interactive Materials and Bioinspired Technologies (FIT), Albert-Ludwigs-Universität Freiburg, Georges-Köhler-Allee 105, Freiburg 79110, Germany
| | - Jan-Lukas Schäfer
- Makromolekulare Chemie und Papierchemie, Technische Universität Darmstadt, Alarich-Weiss-Straße 8, Darmstadt 64287, Germany
| | - Tobias Meckel
- Makromolekulare Chemie und Papierchemie, Technische Universität Darmstadt, Alarich-Weiss-Straße 8, Darmstadt 64287, Germany
| | - Thomas Brandstetter
- Department of Microsystems Engineering (IMTEK), Laboratory for Chemistry & Physics of Interfaces, Albert-Ludwigs-Universität Freiburg, Georges-Köhler-Allee 103, Freiburg 79110, Germany
| | - Markus Biesalski
- Makromolekulare Chemie und Papierchemie, Technische Universität Darmstadt, Alarich-Weiss-Straße 8, Darmstadt 64287, Germany
| | - Jürgen Rühe
- Department of Microsystems Engineering (IMTEK), Laboratory for Chemistry & Physics of Interfaces, Albert-Ludwigs-Universität Freiburg, Georges-Köhler-Allee 103, Freiburg 79110, Germany.,Freiburg Institute for Interactive Materials and Bioinspired Technologies (FIT), Albert-Ludwigs-Universität Freiburg, Georges-Köhler-Allee 105, Freiburg 79110, Germany
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10
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Straub AJ, Scherag FD, Kim HI, Steiner MS, Brandstetter T, Rühe J. "CHicable" and "Clickable" Copolymers for Network Formation and Surface Modification. Langmuir 2021; 37:6510-6520. [PMID: 34003660 DOI: 10.1021/acs.langmuir.1c00669] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
In this study, we present the generation of novel, multifunctional polymer networks through a combination of C,H-insertion cross-linking (CHic) and click chemistry. To this, copolymers consisting of hydrophilic N,N-dimethylacrylamide as matrix component and repeat units containing azide moieties, as well as benzophenone or anthraquinone groups, are generated. The benzophenone or anthraquinone groups allow photo-cross-linking, surface attachment or covalent immobilization of adjacent (bio)molecules through CHic reactions. The azide moieties either can react with available alkynes through conventional click reactions or can be activated to form nitrenes, which can also undergo CHic reactions. By choosing appropriate reaction conditions, the same polymer can be used to follow very different reaction paths, opening up a plethora of choices for the generation of functional polymer networks. In the exemplary presented case ("CHic-Click"), irradiation of the copolymers with UV-A light (λirr = 365 nm) leads to cross-linking (network formation) and surface attachment simultaneously. The azide units remain intact during this cross-linking step, and alkyne-modified (bio)molecules can be bound through click reactions. Biofunctionalization of the polymer network with alkynylated streptavidin, followed by application of biotin-conjugated antibody and a model analyte, highlights the potential of these surface architectures as a toolbox which can be adapted for diverse bioanalytical applications.
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Affiliation(s)
- Alexander J Straub
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
| | - Frank D Scherag
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
| | - Hye In Kim
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
| | - Mark-Steven Steiner
- Microcoat Biotechnologie GmbH, Am Neuland 3, 82347 Bernried am Starnberger See, Germany
| | - Thomas Brandstetter
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
| | - Jürgen Rühe
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
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11
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Metzler L, Rehbein U, Schönberg JN, Brandstetter T, Thedieck K, Rühe J. Breaking the Interface: Efficient Extraction of Magnetic Beads from Nanoliter Droplets for Automated Sequential Immunoassays. Anal Chem 2020; 92:10283-10290. [PMID: 32501674 DOI: 10.1021/acs.analchem.0c00187] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Droplet-based microfluidic systems offer a high potential for miniaturization and automation. Therefore, they are becoming an increasingly important tool in analytical chemistry, biosciences, and medicine. Heterogeneous assays commonly utilize magnetic beads as a solid phase. However, the sensitivity of state of the art microfluidic systems is limited by the high bead concentrations required for efficient extraction across the water-oil interface. Furthermore, current systems suffer from a lack of technical solutions for sequential measurements of multiple samples, limiting their throughput and capacity for automation. Taking advantage of the different wetting properties of hydrophilic and hydrophobic areas in the channels, we improve the extraction efficiency of magnetic beads from aqueous nanoliter-sized droplets by 2 orders of magnitude to the low μg/mL range. Furthermore, the introduction of a switchable magnetic trap enables repetitive capture and release of magnetic particles for sequential analysis of multiple samples, enhancing the throughput. In comparison to conventional ELISA-based sandwich immunoassays on microtiter plates, our microfluidic setup offers a 25-50-fold reduction of sample and reagent consumption with up to 50 technical replicates per sample. The enhanced sensitivity and throughput of this system open avenues for the development of automated detection of biomolecules at the nanoliter scale.
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Affiliation(s)
- Lukas Metzler
- Department of Microsystems Engineering, Chemistry & Physics of Interfaces, Albert-Ludwigs-Universität Freiburg, 79110 Freiburg im Breisgau, Baden-Württemberg, Germany
| | - Ulrike Rehbein
- Department of Neuroscience, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany.,Laboratory of Pediatrics, Section Systems Medicine of Metabolism and Signaling, University of Groningen, University Medical Center Groningen, 9713 AV, Groningen, The Netherlands
| | - Jan-Niklas Schönberg
- Department of Microsystems Engineering, Chemistry & Physics of Interfaces, Albert-Ludwigs-Universität Freiburg, 79110 Freiburg im Breisgau, Baden-Württemberg, Germany
| | - Thomas Brandstetter
- Department of Microsystems Engineering, Chemistry & Physics of Interfaces, Albert-Ludwigs-Universität Freiburg, 79110 Freiburg im Breisgau, Baden-Württemberg, Germany
| | - Kathrin Thedieck
- Department of Neuroscience, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Germany.,Laboratory of Pediatrics, Section Systems Medicine of Metabolism and Signaling, University of Groningen, University Medical Center Groningen, 9713 AV, Groningen, The Netherlands.,Institute of Biochemistry and Center for Molecular Biosciences Innsbruck, University of Innsbruck, 6020 Innsbruck, Austria
| | - Jürgen Rühe
- Department of Microsystems Engineering, Chemistry & Physics of Interfaces, Albert-Ludwigs-Universität Freiburg, 79110 Freiburg im Breisgau, Baden-Württemberg, Germany
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12
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Stumpf A, Brandstetter T, Hübner J, Rühe J. Hydrogel based protein biochip for parallel detection of biomarkers for diagnosis of a Systemic Inflammatory Response Syndrome (SIRS) in human serum. PLoS One 2019; 14:e0225525. [PMID: 31790441 PMCID: PMC6886838 DOI: 10.1371/journal.pone.0225525] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 11/06/2019] [Indexed: 11/18/2022] Open
Abstract
The Systemic Inflammatory Response Syndrome (SIRS), a sepsis related inflammatory state, is a self-defense mechanism against specific and nonspecific stimuli. The six most extensively studied inflammatory biomarkers for the clinical diagnosis of SIRS are interleukin 4 (hIL-4), interleukin 6 (hIL-6), interleukin 10 (hIL-10), tumor necrosis factor alpha (hTNF-α), interferon gamma (hIFN-γ) and procalcitonin (hPCT). These biomarkers are naturally present (but usually only at low concentration) in SIRS infected patients [1, 2] and thus the development of a highly sensitive detection method is of major clinical interest. However, the existing analytical techniques are lacking in required analytical sensitivity and parallel determination of these biomarkers. We developed a fast, easy and cost-efficient protein microarray biochip where the capture molecules are attached on hydrogel spots, enabling SIRS diagnosis by parallel detection of these six clinically relevant biomarkers with a sample volume of 25 μl. With our hydrogel based protein microarray biochip we achieved a limit of detection for hIL-4 of 75.2 pg/ml, for hIL-6 of 45.1 pg/ml, for hIL-10 of 71.5 pg/ml, for hTNF-α of 56.7 pg/ml, for IFN-γ of 46.4 pg/ml and for hPCT of 1.1 ng/ml in spiked human serum demonstrating sufficient sensitivity for clinical usage. Additionally, we demonstrated successful detection of two relevant SIRS biomarkers in clinical patient samples with a turnaround time of the complete analysis from sample-to-answer in less than 200 minutes.
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Affiliation(s)
- Anne Stumpf
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee, Freiburg, Germany
| | - Thomas Brandstetter
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee, Freiburg, Germany
| | - Johannes Hübner
- Division of Pediatric Infectious Diseases, Dr. von Hauner Children's Hospital, Ludwig Maximilian's University, Munich, Germany, Lindwurmstr, Munich, Germany
| | - Jürgen Rühe
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee, Freiburg, Germany
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Vitunskaite M, He Y, Brandstetter T, Janicke H. Smart cities and cyber security: Are we there yet?A comparative study on the role of standards, third party risk management and security ownership. Comput Secur 2019. [DOI: 10.1016/j.cose.2019.02.009] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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14
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Szell T, Dressler FF, Goelz H, Bluemel B, Miernik A, Brandstetter T, Scherag F, Schoeb DS. In Vitro Effects of a Novel Coating Agent on Bacterial Biofilm Development on Ureteral Stents. J Endourol 2019; 33:225-231. [PMID: 30458115 DOI: 10.1089/end.2018.0616] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Affiliation(s)
- Tamas Szell
- Department of Urology, Faculty of Medicine, Medical Center–University of Freiburg, Freiburg, Germany
| | - Franz Friedrich Dressler
- Department of Urology, Faculty of Medicine, Medical Center–University of Freiburg, Freiburg, Germany
| | - Hanna Goelz
- Institute of Medical Microbiology and Hygiene, Faculty of Medicine, Medical Center–University of Freiburg, Freiburg, Germany
| | - Benjamin Bluemel
- Institute of Medical Microbiology and Hygiene, Faculty of Medicine, Medical Center–University of Freiburg, Freiburg, Germany
| | - Arkadiusz Miernik
- Department of Urology, Faculty of Medicine, Medical Center–University of Freiburg, Freiburg, Germany
| | - Thomas Brandstetter
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany
| | - Frank Scherag
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany
| | - Dominik Stefan Schoeb
- Department of Urology, Faculty of Medicine, Medical Center–University of Freiburg, Freiburg, Germany
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Szell T, Dressler FF, Goelz H, Bluemel B, Miernik A, Brandstetter T, Scherag F, Schoeb DS. Response to Tailly and Van Haute: In Vitro Effects of a Novel Coating Agent on Bacterial Biofilm Development on Ureteral Stent by Schoeb et al. (From: Tailly T, Van Haute C. J Endourol 2019;33:232–233; DOI: 10.1089/end.2018.0907). J Endourol 2019; 33:234. [DOI: 10.1089/end.2019.29052.tsz] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Tamas Szell
- Department of Urology, Medical Center – University of Freiburg, Freiburg, Germany
| | | | - Hanna Goelz
- Institute for Microbiology and Hygiene, Medical Center – University of Freiburg, Freiburg, Germany
| | - Benjamin Bluemel
- Institute for Microbiology and Hygiene, Medical Center – University of Freiburg, Freiburg, Germany
| | - Arkadiusz Miernik
- Department of Urology, Medical Center – University of Freiburg, Freiburg, Germany
| | - Thomas Brandstetter
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany
| | - Frank Scherag
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany
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Zinggeler M, Brandstetter T, Rühe J. Biophysical Insights on the Enrichment of Cancer Cells from Whole Blood by (Affinity) Filtration. Sci Rep 2019; 9:1246. [PMID: 30718672 PMCID: PMC6362249 DOI: 10.1038/s41598-018-37541-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 11/22/2018] [Indexed: 12/31/2022] Open
Abstract
Circulating tumor cells (CTCs) play a key role during the metastatic process of human cancers and their reliable detection and characterization could enable new and effective ways of cancer diagnosis, monitoring and treatment. However, due to their ultralow concentration in patient blood, the CTCs must first be enriched before such analysis can be performed. Classical microfiltration is an important and widely used method for the mechanical enrichment of CTCs. This method exploits that CTCs are generally larger than the accompanying blood cells, however, does not differentiate the cells in other ways. In an affinity filtration, selectivity is added by functionalizing the membrane with specific antibodies against a CTC-characteristic surface protein such as the epithelial cell adhesion molecule (EpCAM). A common shortcoming of both filtration approaches is that there is still a poor understanding of the enrichment process and the systems developed so far are frequently operated under non-optimized conditions. To address this, systematic filtration experiments are performed in this work using the EpCAM+ cell line MCF-7 as CTC-model and standard track-etched membranes modified with or without antibodies against EpCAM. The influences of the key filtration parameters time and applied pressure are studied and it is found that in all cases the extent of cell recovery is limited by a lysis process which occurs on the membrane surface. Counterintuitively, it is found that filtration at rather high pressures is advantageous to ensure high recovery rates. To describe the pressure-induced lysis process a biophysical model is developed. This model allows the determination of optimum filtration conditions to achieve both high cancer cell recovery and large blood sample throughput. It is demonstrated that this way practically 100% of spiked cancer cells can be recovered from milliliters of undiluted whole blood within seconds.
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Affiliation(s)
- Marc Zinggeler
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Koehler-Allee 103, 79110, Freiburg, Germany
| | - Thomas Brandstetter
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Koehler-Allee 103, 79110, Freiburg, Germany
| | - Jürgen Rühe
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Koehler-Allee 103, 79110, Freiburg, Germany.
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17
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Schönberg JN, Zinggeler M, Fosso P, Brandstetter T, Rühe J. One-Step Photochemical Generation of Biofunctionalized Hydrogel Particles via Two-Phase Flow. ACS Appl Mater Interfaces 2018; 10:39411-39416. [PMID: 30375846 DOI: 10.1021/acsami.8b11757] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Biofunctional hydrogel particles have become increasingly popular in medical diagnostics; however, their generation is time-consuming and typically requires several process steps. We report on a new method for the simple, fast, and reproducible one-step generation of monodisperse hydrogel particles equipped with biofunctional molecules such as proteins or DNA. Key to the approach is the simultaneous photo cross-linking of the polymer chains and covalent binding of proteins or DNA through a C,H insertion reaction inside aqueous plug compartments that are produced via microfluidics. The strong performance in biological binding assays of the functionalized particles is demonstrated.
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Affiliation(s)
- Jan-Niklas Schönberg
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering , University of Freiburg , Georges-Koehler-Allee 103 , Freiburg 79110 , Germany
| | - Marc Zinggeler
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering , University of Freiburg , Georges-Koehler-Allee 103 , Freiburg 79110 , Germany
| | - Patrick Fosso
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering , University of Freiburg , Georges-Koehler-Allee 103 , Freiburg 79110 , Germany
| | - Thomas Brandstetter
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering , University of Freiburg , Georges-Koehler-Allee 103 , Freiburg 79110 , Germany
| | - Jürgen Rühe
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering , University of Freiburg , Georges-Koehler-Allee 103 , Freiburg 79110 , Germany
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18
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Scherag FD, Mader A, Zinggeler M, Birsner N, Kneusel RE, Brandstetter T, Rühe J. Blocking-Free and Substrate-Independent Serological Microarray Immunoassays. Biomacromolecules 2018; 19:4641-4649. [DOI: 10.1021/acs.biomac.8b01334] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Frank D. Scherag
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
| | - Andreas Mader
- Scienion AG, Volmerstrasse 7b, 12489 Berlin, Germany
| | - Marc Zinggeler
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
| | - Nicole Birsner
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
| | | | - Thomas Brandstetter
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
| | - Jürgen Rühe
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
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19
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Scherag FD, Brandstetter T, Rühe J. Geometrically enhanced sensor surfaces for the selective capture of cell-like particles in a laminar flow field. Biomicrofluidics 2018; 12:014116. [PMID: 30867852 PMCID: PMC6404926 DOI: 10.1063/1.5017714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 01/22/2018] [Indexed: 06/09/2023]
Abstract
Medical wires inserted into the blood stream of patients offer an attractive perspective to capture rare cells such as circulating tumor cells in vivo. A major challenge in such systems is to achieve an efficient interaction of the desired cells with the sensing surface and avoid those cells that simply flow by the wire without any contact while floating in a laminar flow field at some small distance to the sensor surface. We describe a new strategy to increase the interaction of cells or cell-like particles to such wire-shaped sensor surfaces both from an experimental and a theoretical point of view. For model experiments, we use cell-like particles that are flowing past the profile wire in a blood-like liquid stream. In the fluid dynamics simulations, this sensor is inserted into small capillaries. The influence of geometry and orientation of the wire with respect to the surrounding capillary onto the capture behavior is studied. Parameters, such as wire diameter, profile shape, wire torsion, and orientation of it with respect to the liquid stream, induce in some cases quite strong crossflows. These crossflows enhance the contact probability compared to a straight line wire of the same length by factors of up to about 80. A general model connecting the wire geometry with the crossflow intensity and the particle capture behavior is developed. Particle capture experiments demonstrate that the identified geometric factors can improve the capture of cell-like particles in laminar fluid flows and enhance the performance of such cell sensors.
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Affiliation(s)
- Frank D Scherag
- Department of Microsystems Engineering, University of Freiburg, Freiburg im Breisgau, Baden-Württemberg 79110, Germany
| | - Thomas Brandstetter
- Department of Microsystems Engineering, University of Freiburg, Freiburg im Breisgau, Baden-Württemberg 79110, Germany
| | - Jürgen Rühe
- Department of Microsystems Engineering, University of Freiburg, Freiburg im Breisgau, Baden-Württemberg 79110, Germany
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20
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Zinggeler M, Fosso PL, Hao Y, Brandstetter T, Rühe J. Preparation of Linear Cryogel Arrays as a Microfluidic Platform for Immunochromatographic Assays. Anal Chem 2017; 89:5697-5701. [PMID: 28530809 DOI: 10.1021/acs.analchem.7b01182] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We describe a new microfluidic platform to perform immunochromatographic assays. The platform consists of a linear assembly of small, porous cryogel monoliths functionalized with various biomolecules. The cryogels are anchored in an optically transparent capillary, which serves as the microfluidic carrier. This assembly enables fluid flow by capillary action and simple optical detection. Using an in situ preparation method, individual compartments are generated from small plugs of polymer solutions that are transformed into small individually functionalized cryogel monoliths through a photoinduced cross-linking reaction. In the same reaction step, the monoliths are firmly anchored to the surface of the capillary. As proof-of-concept, a prototype platform is successfully used for the detection of the inflammatory marker interleukin 6 via a sandwich immunoassay. We observe excellent assay performance metrics that include high sensitivity, good linearity, and low variation. We also demonstrate fluid transport solely by passive means, which is a critical attribute for point-of-care diagnostics.
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Affiliation(s)
- Marc Zinggeler
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering, University of Freiburg , Georges-Koehler-Allee 103, 79110 Freiburg, Germany
| | - Patrick L Fosso
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering, University of Freiburg , Georges-Koehler-Allee 103, 79110 Freiburg, Germany
| | - Yan Hao
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering, University of Freiburg , Georges-Koehler-Allee 103, 79110 Freiburg, Germany
| | - Thomas Brandstetter
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering, University of Freiburg , Georges-Koehler-Allee 103, 79110 Freiburg, Germany
| | - Jürgen Rühe
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering, University of Freiburg , Georges-Koehler-Allee 103, 79110 Freiburg, Germany
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21
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Zinggeler M, Schönberg JN, Fosso PL, Brandstetter T, Rühe J. Functional Cryogel Microstructures Prepared by Light-Induced Cross-Linking of a Photoreactive Copolymer. ACS Appl Mater Interfaces 2017; 9:12165-12170. [PMID: 28357863 DOI: 10.1021/acsami.7b01232] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A novel, highly efficient method for the preparation of functional, microstructured and surface-attached cryogels is described. Photoinduced C,H-insertion reactions are used to generate cryogels in a single, rapid photo-cross-linking process. To this end, solutions containing both a photoreactive copolymer and the (bio)molecules to be immobilized are placed on a polymeric substrate followed by freezing and a short UV exposure. This strategy combines photolithography and cryogel formation allowing for a simultaneous generation and (bio)functionalization of cryogels in a single reaction step. To demonstrate the potential of the generated materials for bioanalytical applications, we successfully prepared DNA and protein cryogel microarrays.
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Affiliation(s)
- Marc Zinggeler
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering, University of Freiburg , Georges-Koehler-Allee 103, 79110 Freiburg, Germany
| | - Jan-Niklas Schönberg
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering, University of Freiburg , Georges-Koehler-Allee 103, 79110 Freiburg, Germany
| | - Patrick L Fosso
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering, University of Freiburg , Georges-Koehler-Allee 103, 79110 Freiburg, Germany
| | - Thomas Brandstetter
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering, University of Freiburg , Georges-Koehler-Allee 103, 79110 Freiburg, Germany
| | - Jürgen Rühe
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering, University of Freiburg , Georges-Koehler-Allee 103, 79110 Freiburg, Germany
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22
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Scherag FD, Niestroj-Pahl R, Krusekopf S, Lücke K, Brandstetter T, Rühe J. Highly Selective Capture Surfaces on Medical Wires for Fishing Tumor Cells in Whole Blood. Anal Chem 2017; 89:1846-1854. [PMID: 28208267 DOI: 10.1021/acs.analchem.6b04219] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The detection of circulating tumor cells (CTCs) in the blood of cancer patients is a challenging task. CTCs are, especially at the early stages of cancer development, extremely rare cells hidden in a vast background of regular blood cells. We describe a new strategy for the isolation of CTCs from whole blood. The key component is a medical wire coated with a multilayer assembly that allows highly specific capture of EpCAM (epithelial cell adhesion molecule) positive CTCs from blood. The assembly is generated in a layer-by-layer fashion through photochemically induced C,H insertion reactions and consists of a protective layer, which shields the contacting solution from the metal, a protein resistant layer, which prevents nonspecific interactions with proteins and a layer containing the EpCAM antibodies. In vitro experiments show that these surfaces can capture tumor cells from whole blood with enrichment factors (specifically vs nonspecifically bound cells) of up to about 3000 compared to the number of leucocytes in the blood. The purity of the isolated cells is greater than 90%. After "fishing" them from the blood, the cells, still bound to the wire, can be genetically analyzed. This demonstrates that this strategy might prove useful for next generation sequencing.
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Affiliation(s)
- Frank D Scherag
- Department of Microsystems Engineering, University of Freiburg , Georges-Köhler-Allee 103, D-79110 Freiburg, Germany
| | | | | | - Klaus Lücke
- GILUPI GmbH , Hermannswerder 20a, 14473 Potsdam, Germany
| | - Thomas Brandstetter
- Department of Microsystems Engineering, University of Freiburg , Georges-Köhler-Allee 103, D-79110 Freiburg, Germany
| | - Jürgen Rühe
- Department of Microsystems Engineering, University of Freiburg , Georges-Köhler-Allee 103, D-79110 Freiburg, Germany
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23
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Burger J, Rath C, Woehrle J, Meyer PA, Ben Ammar N, Kilb N, Brandstetter T, Pröll F, Proll G, Urban G, Roth G. Low-Volume Label-Free Detection of Molecule-Protein Interactions on Microarrays by Imaging Reflectometric Interferometry. SLAS Technol 2016; 22:437-446. [PMID: 27418371 DOI: 10.1177/2211068216657512] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
This system allows the high-throughput protein interaction analysis on microarrays. We apply the interference technology 1λ-imaging reflectometric interferometry (iRIf) as a label-free detection method and create microfluidic flow cells in microscope slide format for low reagent consumption and lab work compatibility. By now, most prominent for imaging label-free interaction analyses on microarrays are imaging surface plasmon resonance (SPR) methods, quartz crystal microbalance, or biolayer interferometry. SPR is sensitive against temperature drifts and suffers from plasmon crosstalk, and all systems lack array size (maximum 96 spots). Our detection system is robust against temperature drifts. Microarrays are analyzed with a spatial resolution of 7 µm and time resolution of ≤50 fps. System sensitivity is competitive, with random noise of <5 × 10-5 and baseline drift of <3 × 10-6. Currently available spotting technologies limit array sizes to ~4 spots/mm2 (1080 spots/array); our detection system would allow ~40 spots/mm2 (10,800 spots/array). The microfluidic flow cells consist of structured PDMS inlays sealed by versatilely coated glass slides immobilizing the microarray. The injection protocol determines reagent volumes, priming rates, and flow cell temperatures for up to 44 reagents; volumes of ≤300 µL are validated. The system is validated physically by the biotinylated bovine serum albumin streptavidin assay and biochemically by thrombin aptamer interaction analysis, resulting in a KD of ~100 nM.
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Affiliation(s)
- Juergen Burger
- 1 Laboratory for Microarray Copying, Centre for Biological Systems Analysis (ZBSA), University of Freiburg, Freiburg, Germany
| | - Christin Rath
- 1 Laboratory for Microarray Copying, Centre for Biological Systems Analysis (ZBSA), University of Freiburg, Freiburg, Germany.,2 Institute for Biology III, Biology, University of Freiburg, Freiburg, Germany
| | - Johannes Woehrle
- 1 Laboratory for Microarray Copying, Centre for Biological Systems Analysis (ZBSA), University of Freiburg, Freiburg, Germany
| | - Philipp A Meyer
- 1 Laboratory for Microarray Copying, Centre for Biological Systems Analysis (ZBSA), University of Freiburg, Freiburg, Germany
| | - Nessim Ben Ammar
- 1 Laboratory for Microarray Copying, Centre for Biological Systems Analysis (ZBSA), University of Freiburg, Freiburg, Germany
| | - Normann Kilb
- 1 Laboratory for Microarray Copying, Centre for Biological Systems Analysis (ZBSA), University of Freiburg, Freiburg, Germany.,2 Institute for Biology III, Biology, University of Freiburg, Freiburg, Germany
| | | | | | | | - Gerald Urban
- 5 Laboratory for Sensors, IMTEK, University of Freiburg, Freiburg, Germany
| | - Guenter Roth
- 1 Laboratory for Microarray Copying, Centre for Biological Systems Analysis (ZBSA), University of Freiburg, Freiburg, Germany.,2 Institute for Biology III, Biology, University of Freiburg, Freiburg, Germany.,6 BIOSS-Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
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Yodmongkol S, Sutapun B, Praphanphoj V, Srikhirin T, Brandstetter T, Rühe J. Fabrication of protein microarrays for alpha fetoprotein detection by using a rapid photo-immobilization process. Sensing and Bio-Sensing Research 2016. [DOI: 10.1016/j.sbsr.2016.01.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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Klapproth H, Bednar S, Baader J, Lehmann M, Freund I, Brandstetter T, Rühe J. Development of a multi-analyte CMOS sensor for point-of-care testing. Sensing and Bio-Sensing Research 2015. [DOI: 10.1016/j.sbsr.2015.08.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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Abstract
Two-phase flow systems are increasingly popular for miniaturized, high-throughput performance of analytical or chemical reactions. In this contribution, we extend a previously described method that allows to increase the range of applications of heterogeneous reactions in two-phase flow, i.e., reactions that rely on isolation and purification of the compound of interest for downstream analysis. Our concept is based on liquid plugs, which serve as miniaturized compartments for the analytical reactions. Purification of the target compound is achieved by extracting the analyte from the aqueous compartments using magnetic beads as solid carriers. In the present paper, we elucidate the influence of parameters such as the polarity of the liquid/liquid and solid/liquid interfaces, the magnetic forces and the fluidic conditions onto the extraction performance. The conditions for reliable extraction and purification of the target compounds are determined. Furthermore, we investigate how to facilitate breaking of the plugs through reduction of the surface tension of the solid/liquid interface. When a lower surface tension is employed, a smaller number of beads is required for the extraction process, which implies a higher sensitivity of the device. In addition, we generate channels with different surface chemistries, which are able to manipulate the flow of the two immiscible liquids. We describe a very simple way to generate such devices and show that we can achieve a transition from segmented flow of plugs to a side-by side flow of the two immiscible liquids, a key requirement for the purification of the compounds.
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Affiliation(s)
- Martin Rendl
- Laboratory for Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg , Georges-Köhler-Allee 103, D-79110 Freiburg, Germany
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Rendl M, Brandstetter T, Rühe J. Time-Resolved Analysis of Biological Reactions Based on Heterogeneous Assays in Liquid Plugs of Nanoliter Volume. Anal Chem 2013; 85:9469-77. [DOI: 10.1021/ac401752j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Martin Rendl
- Laboratory
for Chemistry and Physics
of Interfaces, Department of Microsystems Engineering
(IMTEK), University of Freiburg, Georges-Köhler-Allee 103, D-79110 Freiburg, Germany
| | - Thomas Brandstetter
- Laboratory
for Chemistry and Physics
of Interfaces, Department of Microsystems Engineering
(IMTEK), University of Freiburg, Georges-Köhler-Allee 103, D-79110 Freiburg, Germany
| | - Jürgen Rühe
- Laboratory
for Chemistry and Physics
of Interfaces, Department of Microsystems Engineering
(IMTEK), University of Freiburg, Georges-Köhler-Allee 103, D-79110 Freiburg, Germany
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Brandstetter T, Wessely C. [Einleitung: Mobilis in mobili]. Ber Wiss 2013; 36:119-127. [PMID: 33008223 DOI: 10.1002/bewi.201301632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Affiliation(s)
| | - Christina Wessely
- Humboldt Universität zu Berlin, Institut für Geschichtswissenschaften/Lehrstuhl für Wissenschaftsgeschichte, Friedrichstraße 191-193, D-10117 Berlin
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Moschallski M, Evers A, Brandstetter T, Rühe J. Sensitivity of microarray based immunoassays using surface-attached hydrogels. Anal Chim Acta 2013; 781:72-9. [DOI: 10.1016/j.aca.2013.04.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 03/28/2013] [Accepted: 04/01/2013] [Indexed: 12/19/2022]
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Abstract
The aim of this article is to show how, and in which context, astrobiological reasoning was employed before the establishment of astrobiology as a scientific discipline. By way of an example, I will discuss a popular science book published in 1931 by the Hungarian journalist Desiderius Papp. The author claims that this book represents an innovation in astrobiological reasoning, as it draws on contemporary biological research to conduct thought experiments, thereby coming up with concrete forms of possible extraterrestrial life. One of the most interesting of these forms was crystalline life. After a short overview on the history of this concept, this article will show how Papp drew on recent research by Otto Lehmann on liquid crystals to convey the idea that life may be based on other elements than carbon. The author concludes by arguing that popular science did not only make specialist knowledge accessible to a general public but also served to probe the limits of knowledge and point toward the situatedness of established categories and definitions.
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Rendl M, Bönisch A, Mader A, Schuh K, Prucker O, Brandstetter T, Rühe J. Simple one-step process for immobilization of biomolecules on polymer substrates based on surface-attached polymer networks. Langmuir 2011; 27:6116-23. [PMID: 21491877 DOI: 10.1021/la1050833] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
For the miniaturization of biological assays, especially for the fabrication of microarrays, immobilization of biomolecules at the surfaces of the chips is the decisive factor. Accordingly, a variety of binding techniques have been developed over the years to immobilize DNA or proteins onto such substrates. Most of them require rather complex fabrication processes and sophisticated surface chemistry. Here, a comparatively simple immobilization technique is presented, which is based on the local generation of small spots of surface attached polymer networks. Immobilization is achieved in a one-step procedure: probe molecules are mixed with a photoactive copolymer in aqueous buffer, spotted onto a solid support, and cross-linked as well as bound to the substrate during brief flood exposure to UV light. The described procedure permits spatially confined surface functionalization and allows reliable binding of biological species to conventional substrates such as glass microscope slides as well as various types of plastic substrates with comparable performance. The latter also permits immobilization on structured, thermoformed substrates resulting in an all-plastic biochip platform, which is simple and cheap and seems to be promising for a variety of microdiagnostic applications.
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Affiliation(s)
- Martin Rendl
- Chemistry and Physics of Interfaces, Department of Microsystems Engineering (IMTEK), University of Freiburg, Georges-Köhler-Allee 103, D-79110 Freiburg, Germany
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Riehle U, Mader A, Brandstetter T, Ruhe J, zur Hausen A, Stickeler E. Nucleic acid sequence-based amplification in formalin-fixed and paraffin-embedded breast-cancer tissues. J Clin Pathol 2010; 63:1071-6. [DOI: 10.1136/jcp.2010.078766] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Mader A, Riehle U, Brandstetter T, Stickeler E, zur Hausen A, Rühe J. Microarray-based amplification and detection of RNA by nucleic acid sequence based amplification. Anal Bioanal Chem 2010; 397:3533-41. [PMID: 20596698 DOI: 10.1007/s00216-010-3892-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Revised: 05/21/2010] [Accepted: 05/29/2010] [Indexed: 11/25/2022]
Abstract
Nucleic acid sequence based amplification (NASBA) is a versatile in vitro nucleic acid amplification method. In this work, RNA amplification and labeling by NASBA and microarray analysis are combined in a one-step process. The NASBA reaction is performed in direct contact with capture probes. These probes are bound to surface-attached hydrogel spots generated at the chip surfaces by using a simple printing and UV irradiation process. Five gene expression and SNP parameters with known relevance in breast cancer diagnostics were chosen to demonstrate that multiplex NASBA-on-microarray analysis is possible. A minimum amount of 10 pg of total RNA was shown to be sufficient for the detection of the reference parameter RPS18, which demonstrates that the detection limit of the microarray-based NASBA assays theoretically allows single-cell assays to be performed.
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Affiliation(s)
- Andreas Mader
- Institute of Pathology, Freiburg University Medical Center, Breisacher Strasse 115a, 79106 Freiburg, Germany
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Neumann T, Bonham AJ, Dame G, Berchtold B, Brandstetter T, Rühe J. Temperature and Time-Resolved Total Internal Reflectance Fluorescence Analysis of Reusable DNA Hydrogel Chips. Anal Chem 2010; 82:6124-31. [DOI: 10.1021/ac1008578] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Thorsten Neumann
- University of Freiburg – IMTEK, Department of Microsystems Engineering, Laboratory for Chemistry and Physics of Interfaces, Georges-Koehler-Allee 103, D-79110 Freiburg, Germany, University of California Santa Barbara, Department of Chemistry and Biochemistry, Santa Barbara, California 93106, and University of California, Berkeley Bioengineering Department, 306 Stanley Hall, Berkeley, California 94720-1762
| | - Andrew J. Bonham
- University of Freiburg – IMTEK, Department of Microsystems Engineering, Laboratory for Chemistry and Physics of Interfaces, Georges-Koehler-Allee 103, D-79110 Freiburg, Germany, University of California Santa Barbara, Department of Chemistry and Biochemistry, Santa Barbara, California 93106, and University of California, Berkeley Bioengineering Department, 306 Stanley Hall, Berkeley, California 94720-1762
| | - Gregory Dame
- University of Freiburg – IMTEK, Department of Microsystems Engineering, Laboratory for Chemistry and Physics of Interfaces, Georges-Koehler-Allee 103, D-79110 Freiburg, Germany, University of California Santa Barbara, Department of Chemistry and Biochemistry, Santa Barbara, California 93106, and University of California, Berkeley Bioengineering Department, 306 Stanley Hall, Berkeley, California 94720-1762
| | - Bernd Berchtold
- University of Freiburg – IMTEK, Department of Microsystems Engineering, Laboratory for Chemistry and Physics of Interfaces, Georges-Koehler-Allee 103, D-79110 Freiburg, Germany, University of California Santa Barbara, Department of Chemistry and Biochemistry, Santa Barbara, California 93106, and University of California, Berkeley Bioengineering Department, 306 Stanley Hall, Berkeley, California 94720-1762
| | - Thomas Brandstetter
- University of Freiburg – IMTEK, Department of Microsystems Engineering, Laboratory for Chemistry and Physics of Interfaces, Georges-Koehler-Allee 103, D-79110 Freiburg, Germany, University of California Santa Barbara, Department of Chemistry and Biochemistry, Santa Barbara, California 93106, and University of California, Berkeley Bioengineering Department, 306 Stanley Hall, Berkeley, California 94720-1762
| | - Jürgen Rühe
- University of Freiburg – IMTEK, Department of Microsystems Engineering, Laboratory for Chemistry and Physics of Interfaces, Georges-Koehler-Allee 103, D-79110 Freiburg, Germany, University of California Santa Barbara, Department of Chemistry and Biochemistry, Santa Barbara, California 93106, and University of California, Berkeley Bioengineering Department, 306 Stanley Hall, Berkeley, California 94720-1762
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Meinhold-Heerlein I, Ninci E, Ikenberg H, Brandstetter T, Ihling C, Schwenk I, Straub A, Schmitt B, Bettendorf H, Iggo R, Bauknecht T. Evaluation of methods to detect p53 mutations in ovarian cancer. Oncology 2001; 60:176-88. [PMID: 11244334 DOI: 10.1159/000055316] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
OBJECTIVE The p53 status is increasingly regarded as a marker predictive of response to particular cancer therapies, but for this approach it is self-evident that the p53 status must be determined correctly. METHODS We have tested ovarian cancers with single-strand conformation polymorphism analysis (SSCP), immunohistochemical staining with DO-1 anti-p53 antibody (IHC), and yeast p53 functional assay (FASAY). RESULTS These techniques commonly used to detect p53 mutations showed important differences in their sensitivity. Of 53 tumors tested with three indirect techniques, 27 (50%), 33 (62%) and 41 (77%) were positive by SSCP, IHC, and FASAY, respectively. In a subset of 32 tumors strongly suspected of containing mutations, 25 (78%), 26 (81%), 29 (91%) and 30 (94%) were positive by SSCP, immunostaining, DNA sequencing and yeast assay, respectively. CONCLUSIONS Under comparable routine conditions, the FASAY reached the highest sensitivity. Since no single technique detected all mutations, we recommend the use of at least two different techniques in situations where the p53 status will affect patient management.
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Brandstetter T, Ninci E, Bettendorf H, Perewusnyk G, Stolte J, Herchenbach D, Sellin D, Wagner E, Köchli OR, Bauknecht T. Granulocyte colony-stimulating factor (G-CSF) receptor gene expression of ovarian carcinoma does not correlate with G-CSF caused cell proliferation. Cancer 2001; 91:1372-83. [PMID: 11283939 DOI: 10.1002/1097-0142(20010401)91:7<1372::aid-cncr1141>3.0.co;2-e] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Recombinant human granulocyte colony-stimulating factor (rhG-CSF) is a growth factor commonly used to avoid leukopenia after chemotherapy. Endogenous G-CSF is produced by macrophages and granulocytes that infiltrate tumors. It has been reported that rhG-CSF stimulates the proliferation of several cell lines as well as bladder carcinoma cells. Conversely, in some hematopoietic cell lines such as U-937, WEHI-3B, and K-562 no effect or in some cases a differentiation pattern was found. Moreover, the role of rhG-CSF on the proliferation of solid tumors is not well understood. METHODS In this study, 10 ovarian carcinoma biopsies were characterized for the presence of G-CSF and G-CSF receptor by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemical analysis. Proliferation was analyzed by ATP viability assays. RESULTS Performing RT-PCR, these biopsies and four ovarian carcinoma cell lines were analyzed for endogenous G-CSF production, which was found in some biopsies and in all cell lines. Despite the presence of the G-CSF receptor in all biopsies and cell lines, no proliferation was found after rhG-CSF incubation of the cell lines or the tumor samples for 3 and for 6 days, respectively. CONCLUSIONS Summarizing the authors' in vitro studies, rhG-CSF does not affect the proliferation of ovarian carcinoma cells in vitro.
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Affiliation(s)
- T Brandstetter
- Department of Biology II, University of Freiburg, Freiburg Germany.
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38
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Abstract
Recombinant human granulocyte colony-stimulating factor (rhG-CSF) is clinically used to overcome neutropenic periods during chemotherapy. In vitro studies using cell lines as a model system have recently suggested that G-CSF can promote ovarian cancer growth. The objective of this work is to determine whether tumor cells express G-CSF-receptors (G-CSFR). A set of ovarian tumor biopsies and ovarian cancer cell lines was analyzed by RT-PCR, immunohistochemistry and immunofluorescence. The presence of a 276 bp-amplicon (exon 8-10) obtained by RT-PCR showed that 12 out of 16 ovarian tumor biopsies and two out of four ovarian cancer cell lines expressed G-CSFR-mRNA. G-CSFR-protein was detected in tumor cells of the 12 biopsies that also contained G-CSFR-mRNA. A second 409 bp-amplicon (exon 17) obtained by RT-PCR from the variable C-terminal cytoplasmic region of G-CSFR could be amplified only in four out of 16 biopsies and in none of the ovarian cancer cell lines studied. The results presented here indicate that G-CSFR is frequently expressed in ovarian cancer cells. Moreover, the failure of RT-PCR amplification of the 409 bp-amplicon in samples that express G-CSFR-mRNA suggests that C-terminal truncated receptor forms are also expressed.
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Affiliation(s)
- E. B. Ninci
- Klinik für Tumorbiologie, Freiburg, and Department of Obstetrics and Gynecology, University of Freiburg, Freiburg, Germany;The Burnham Institute, J. Reed Laboratory, La Jolla, California, USA;Practice for Pathology, VS-Schwenningen, and Department of Obstetrics and Gynecology, University of Bonn, Bonn-Venusberg, Germany
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Keck C, Rajabi Z, Pfeifer K, Bettendorf H, Brandstetter T, Breckwoldt M. Expression of interleukin-6 and interleukin-6 receptors in human granulosa lutein cells. Mol Hum Reprod 1998; 4:1071-6. [PMID: 9835360 DOI: 10.1093/molehr/4.11.1071] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Cytokines are important regulators of reproductive functions. Significant amounts of interleukin-6 (IL-6) have been detected in the serum and ascites of patients with ovarian hyperstimulation syndrome (OHSS). These findings suggest the involvement of IL-6 as a mediator in the pathogenesis of OHSS. This study was performed to analyse IL-6 and IL-6 receptor (IL-6-R) expression in human granulosa lutein cells (GC). GC were cultured after isolation from follicular fluid. IL-6 concentrations in follicular fluid and serum from individual patients and GC supernatants were measured by enzyme-linked immunosorbent assay. We found detectable concentrations of IL-6 in serum and follicular fluid of all patients. Expression of IL-6 in GC was shown immunocytochemically. IL-6 mRNA was detected in GC by in-situ hybridization. Gene expression for IL-6 and IL-6-R in GC was demonstrated using reverse transcription-polymerase chain reaction. IL-6 significantly inhibited human chorionic gonadotrophin (HCG)-induced progesterone secretion of GC. The results of our study suggest that IL-6 is expressed in HGC and that this cytokine is able to modulate GC function via its specific receptor. This is the first report that describes the precence of IL-6-R in human granulosa lutein cells.
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Meinhold-Heerlein I, Brandstetter T, Kommoss F, Bettendorf H, Hagedorn M, Bauknecht T. Localization of cytokeratin 10 mRNA in human epidermis using nonradioactive in situ hybridization as a routine method. Arch Dermatol Res 1998; 290:286-8. [PMID: 9681682 DOI: 10.1007/s004030050306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- I Meinhold-Heerlein
- Department of Gynecology and Obstetrics, School of Medicine, University of Freiburg, Germany.
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Brandstetter T, Ninci E, Keck C, Bauknecht T, Breckwoldt M. Bedeutung des Rezeptors und der Signaltransduktion des Granulozyten-Kolonie-stimulierenden Faktors (G-CSF) beim Ovarialkarzinom. Geburtshilfe Frauenheilkd 1998. [DOI: 10.1055/s-2007-1022145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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42
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Abstract
The ovarian adenocarcinoma cell line HEY was used as an in vitro model to study the influence of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on epithelial tumours such as ovarian cancer. Serum-starved cells were treated with rhG-CSF in a time- and dose-dependent manner. Cell proliferation, measured as cell division and DNA synthesis, was stimulated about 40% by rhG-CSF. After harvesting, cells were examined for the presence of G-CSF receptor (FACS analysis and RT-PCR), as well as for expression of genes involved in mitogen signalling (ERKs, JNKs) and early gene expression (c-jun). rhG-CSF affected mitogen-activated pathways and was receptor-mediated if the G-CSF receptor was present. After rhG-CSF induction, Janus N-terminal kinases (JNK 1 and 2) were simultaneously increased in the cytosol, up to 30-fold as measured by Western blotting), whereas ERK 1 and 2 accumulated maximally by 2.5-fold 1 hr after rhG-CSF induction. c-Jun was up-regulated strongly by this cytokine at the translational level. Our data suggest that rhG-CSF affects genes involved in mitogen signalling and early gene expression in solid tumours. We also noted the presence of G-CSF receptor on ovarian cancer cell lines.
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Affiliation(s)
- T Brandstetter
- Department of Obstetrics and Gynaecology, University Hospital, Freiburg, Germany.
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Spinner DM, Brandstetter T, Kiechle-Schwarz M, Du Bois A, Angel P, Bauknecht T. c-jun expression and growth stimulation in human ovarian carcinoma cell lines following exposure to cytokines. Int J Cancer 1995; 63:423-7. [PMID: 7591243 DOI: 10.1002/ijc.2910630321] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We evaluated the effects of recombinant human G-CSF, rhGM-CSF, rhM-CSF and rhIL-1 alpha on proliferation and regulation of c-jun gene expression in 4 human ovarian-carcinoma (HOC) cell lines, NIH:OVCAR-3, SK-OV-3, HEY and BG-1, and in one primary ovarian tumor in vitro. The cytokines were administered in concentrations of 0.1 U/ml to 1000 U/ml. Cell growth was measured by crystal-violet- and thiazolyl-blue(MTT)-based cell counts. c-jun transcripts were measured by the solution hybridization/RNAse protection assay. RhM-CSF and rhGM-CSF showed no growth stimulation of any of the 5 cell lines tested. Results from exposure to rhG-CSF were different. The cell lines NIH:OVCAR-3, SK-OV-3, BG-1 and the primary ovarian tumor showed no proliferative response. A 2- to 3-fold increase in proliferation was observed in the HEY HOC cell line. rhIL-1 alpha led to growth stimulation in the BG-1 cell line, but showed an inhibitory effect in the NIH:OVCAR-3 cells. No effects of rhIL-1 alpha were observed in the remaining 2 cell lines nor in the primary ovarian tumor. Growth stimulation was accompanied by an increase in c-jun expression in the HEY cell line, and the BG-1 cell line. No alterations in c-jun expression were observed in the remaining 3 cell lines. Our results indicate that rhG-CSF or rhIL-1 alpha influence cell proliferation in 2 out of 5 human ovarian-tumor cell lines, accompanied by an increase in c-jun expression.
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Affiliation(s)
- D M Spinner
- Department of Obstetrics and Gynecology, University of Freiburg, Germany
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Lazzati M, Casagrande V, Brandstetter T. [Hypo-hypervitaminosis of oral significance]. Attual Dent 1990; 6:26-30. [PMID: 2393526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- M Lazzati
- Reparto di odontoiatria, Ospedale Multizonale di Varese
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Lazzati M, Brandstetter T, Casagrande V, Cucciati S, Pradella R, Mezzetti MG. [Dentist and emergency medicine]. Attual Dent 1989; 5:11-3. [PMID: 2640831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Lazzati M, Carloni L, Raso M, Brandstetter T. [Deciduous dentition and orthognathodontic prevention 1]. Prev Assist Dent 1989; 15:11-6. [PMID: 2517641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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