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Jones B, Michou S, Chen T, Moreno-Betancur M, Kilpatrick N, Burgner D, Vannahme C, Silva M. Caries Detection in Primary Teeth Using Intraoral Scanners Featuring Fluorescence: Protocol for a Diagnostic Agreement Study. JMIR Res Protoc 2023; 12:e51578. [PMID: 38096003 PMCID: PMC10755660 DOI: 10.2196/51578] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/29/2023] [Accepted: 10/30/2023] [Indexed: 12/31/2023] Open
Abstract
BACKGROUND Digital methods that enable early caries identification can streamline data collection in research and optimize dental examinations for young children. Intraoral scanners are devices used for creating 3D models of teeth in dentistry and are being rapidly adopted into clinical workflows. Integrating fluorescence technology into scanner hardware can support early caries detection. However, the performance of caries detection methods using 3D models featuring color and fluorescence in primary teeth is unknown. OBJECTIVE This study aims to assess the diagnostic agreement between visual examination (VE), on-screen assessment of 3D models in approximate natural colors with and without fluorescence, and application of an automated caries scoring system to the 3D models with fluorescence for caries detection in primary teeth. METHODS The study sample will be drawn from eligible participants in a randomized controlled trial at the Royal Children's Hospital, Melbourne, Australia, where a dental assessment was conducted, including VE using the International Caries Detection and Assessment System (ICDAS) and intraoral scan using the TRIOS 4 (3Shape TRIOS A/S). Participant clinical records will be collected, and all records meeting eligibility criteria will be subject to an on-screen assessment of 3D models by 4 dental practitioners. First, all primary tooth surfaces will be examined for caries based on 3D geometry and color, using a merged ICDAS index. Second, the on-screen assessment of 3D models will include fluorescence, where caries will be classified using a merged ICDAS index that has been modified to incorporate fluorescence criteria. After 4 weeks, all examiners will repeat the on-screen assessment for all 3D models. Finally, an automated caries scoring system will be used to classify caries on primary occlusal surfaces. The agreement in the total number of caries detected per person between methods will be assessed using a Bland-Altman analysis and intraclass correlation coefficients. At a tooth surface level, agreement between methods will be estimated using multilevel models to account for the clustering of dental data. RESULTS Automated caries scoring of 3D models was completed as of October 2023, with the publication of results expected by July 2024. On-screen assessment has commenced, with the expected completion of scoring and data analysis by March 2024. Results will be disseminated by the end of 2024. CONCLUSIONS The study outcomes may inform new practices that use digital models to facilitate dental assessments. Novel approaches that enable remote dental examination without compromising the accuracy of VE have wide applications in the research environment, clinical practice, and the provision of teledentistry. TRIAL REGISTRATION Australian New Zealand Clinical Trials Registry ACTRN12622001237774; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=384632. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID) DERR1-10.2196/51578.
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Affiliation(s)
- Bree Jones
- Murdoch Children's Research Institute, Royal Children's Hospital, Darley, Australia
- Melbourne Dental School, University of Melbourne, Melbourne, Australia
| | - Stavroula Michou
- Department of Odontology, School of Dentistry, University of Copenhagen, Copenhagen, Denmark
- 3Shape TRIOS A/S, Copenhagen, Denmark
| | - Tong Chen
- Melbourne Dental School, University of Melbourne, Melbourne, Australia
- Clinical Epidemiology & Biostatistics Unit, Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Australia
| | - Margarita Moreno-Betancur
- Clinical Epidemiology & Biostatistics Unit, Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - Nicky Kilpatrick
- Murdoch Children's Research Institute, Royal Children's Hospital, Darley, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | - David Burgner
- Murdoch Children's Research Institute, Royal Children's Hospital, Darley, Australia
- Department of Paediatrics, University of Melbourne, Melbourne, Australia
| | | | - Mihiri Silva
- Murdoch Children's Research Institute, Royal Children's Hospital, Darley, Australia
- Melbourne Dental School, University of Melbourne, Melbourne, Australia
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Michou S, Lambach MS, Ntovas P, Benetti AR, Bakhshandeh A, Rahiotis C, Ekstrand KR, Vannahme C. Author Correction: Automated caries detection in vivo using a 3D intraoral scanner. Sci Rep 2022; 12:13240. [PMID: 35918530 PMCID: PMC9345875 DOI: 10.1038/s41598-022-17576-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Affiliation(s)
- Stavroula Michou
- Department of Odontology, University of Copenhagen, 2200, Copenhagen, Denmark. .,3Shape TRIOS A/S, 1060, Copenhagen, Denmark.
| | | | - Panagiotis Ntovas
- School of Dentistry, National and Kapodistrian University of Athens, 11527, Athens, Greece
| | - Ana R Benetti
- Department of Odontology, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Azam Bakhshandeh
- Department of Odontology, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Christos Rahiotis
- School of Dentistry, National and Kapodistrian University of Athens, 11527, Athens, Greece
| | - Kim R Ekstrand
- Department of Odontology, University of Copenhagen, 2200, Copenhagen, Denmark
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Michou S, Lambach MS, Ntovas P, Benetti AR, Bakhshandeh A, Rahiotis C, Ekstrand KR, Vannahme C. Publisher Correction: Automated caries detection in vivo using a 3D intraoral scanner. Sci Rep 2021; 11:23951. [PMID: 34880272 PMCID: PMC8655065 DOI: 10.1038/s41598-021-01926-8] [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] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Stavroula Michou
- Department of Odontology, University of Copenhagen, 2200, Copenhagen, Denmark. .,3Shape TRIOS A/S, 1060, Copenhagen, Denmark.
| | | | - Panagiotis Ntovas
- School of Dentistry, National and Kapodistrian University of Athens, 11527, Athens, Greece
| | - Ana R Benetti
- Department of Odontology, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Azam Bakhshandeh
- Department of Odontology, University of Copenhagen, 2200, Copenhagen, Denmark
| | - Christos Rahiotis
- School of Dentistry, National and Kapodistrian University of Athens, 11527, Athens, Greece
| | - Kim R Ekstrand
- Department of Odontology, University of Copenhagen, 2200, Copenhagen, Denmark
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Michou S, Vannahme C, Bakhshandeh A, Ekstrand KR, Benetti AR. Intraoral scanner featuring transillumination for proximal caries detection. An in vitro validation study on permanent posterior teeth. J Dent 2021; 116:103841. [PMID: 34624420 DOI: 10.1016/j.jdent.2021.103841] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 08/02/2021] [Accepted: 09/29/2021] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVES To assess the validity of an intraoral scanner system featuring near-infrared (NIR) transillumination to aid the detection of proximal caries lesions, and to compare the diagnostic performance of this system with that of conventional caries detection methods and with that of an intraoral camera featuring NIR transillumination (DIAGNOcam). METHODS Ninety-five permanent posterior teeth were examined using a prototype tip functioning with TRIOS 4 intraoral scanner system (3Shape TRIOS A/S, Denmark) and emitting NIR light, DIAGNOcam, and visual and radiographic examination employing ICDAS criteria. One or two approximal surfaces per tooth, sound or with caries lesions at different stages, were examined (N1=158). Histological assessment was used as the reference standard. RESULTS All methods showed excellent intra-examiner reliability (κintra ≥0.80). Two independent examiners assessed the NIR images obtained with both devices. The first examiner, who obtained and assessed the images, showed improved diagnostic performance than the second examiner, who only had access to the images. The inter-examiner agreement between the two examiners assessing the NIR images was substantial (κinter 0.57-0.72). The intraoral scanner and DIAGNOcam showed similar diagnostic performance. Regarding initial caries lesions, the NIR image assessment resulted in equal or improved sensitivity (SE 0.50-0.89) compared to radiographic assessment (SE 0.49-0.51) and higher than visual examination (SE 0.28-0.39). Radiographic and NIR image assessment resulted in similar SE in detecting moderate-extensive dentin caries lesions (SE 0.59-0.70), while visual examination showed an inferior value (SE 0.30). CONCLUSIONS The intraoral scanner system featuring NIR transillumination and DIAGNOcam showed an overall good diagnostic performance. The conventional caries detection methods showed inferior sensitivity at initial caries lesion stages. CLINICAL SIGNIFICANCE Considering the promising diagnostic performance of the intraoral scanner featuring transillumination and the advantages offered by combining the NIR images with the 3D models of the teeth, this system has the potential to contribute towards more reliable caries detection and monitoring in clinical practice without the use of ionizing radiation.
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Affiliation(s)
- Stavroula Michou
- Dental Materials, Section for Oral Health, Society and Technology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark; Research and Development, 3Shape TRIOS A/S, 1060 Copenhagen K, Denmark.
| | | | - Azam Bakhshandeh
- Cariology and Oral Radiology, Section for Clinical Oral Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark.
| | - Kim R Ekstrand
- Cariology, Section for Clinical Oral Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark.
| | - Ana R Benetti
- Dental Materials, Section for Oral Health, Society and Technology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen N, Denmark.
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Michou S, Benetti AR, Vannahme C, Hermannsson PG, Bakhshandeh A, Ekstrand KR. Development of a Fluorescence-Based Caries Scoring System for an Intraoral Scanner: An in vitro Study. Caries Res 2020; 54:324-335. [PMID: 33053552 DOI: 10.1159/000509925] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 07/04/2020] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES To develop an automated fluorescence-based caries scoring system for an intraoral scanner and totest the performance of the system compared to state-of-the-art methods. METHODS Seventy-three permanent posterior teeth were scanned with a three-dimensional (3D) intraoral scanner prototype which emitted light at 415 nm. An overlay representing the fluorescence signal from the tissue was mapped onto 3D models of the teeth. Multiple examination sites (n = 139) on the occlusal surfaces were chosen, and their red and green fluorescence signal components were extracted. These components were used to calculate 4 mathematical functions upon which a caries scoring system for the scanner prototype could be based. Visual-tactile (International Caries Detection and Assessment System, ICDAS), radiographic (ICDAS), and histological assessments were conducted on the same examination sites. RESULTS Most index tests showed significant correlation with histology. The strongest correlation was observed for the visual-tactile examination (rs = 0.80) followed by the scanner supported by the caries classification function that quantifies the overall fluorescence compared to sound surfaces (rs = 0.78). Additionally, this function resulted in the highest intra-examiner reliability (κ = 0.964), and the highest sum of sensitivity (SE) and specificity (SP) (sum SE-SP: 1.60-1.84) at the 2 histological levels where the comparison with visual-tactile assessment was possible (κ = 0.886, sum SE-SP = 1.57-1.81) and at the 3 out of 4 histological levels where the comparison with radiographic assessment was possible (κ = 0.911, sum SE-SP = 1.37-1.78); the only exception was for the lesions in the outer third of dentin, where the radiographic assessment showed the highest sum SE-SP (1.78). CONCLUSION A fluorescence-based caries scoring system was developed for the intraoral scanner showing promising performance compared to state-of-the-art caries detection methods. The intraoral scanner accompanied by an automated caries scoring system may improve objective caries detection and increase the efficiency and effectiveness of oral examinations. Furthermore, this device has the potential to support reliable monitoring of early caries lesions.
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Affiliation(s)
- Stavroula Michou
- Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark, .,3Shape TRIOS A/S, Copenhagen, Denmark,
| | - Ana Raquel Benetti
- Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | | | - Azam Bakhshandeh
- Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kim Rud Ekstrand
- Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Zhu X, Vannahme C, Højlund-Nielsen E, Mortensen NA, Kristensen A. Plasmonic colour laser printing. Nat Nanotechnol 2016; 11:325-9. [PMID: 26657786 DOI: 10.1038/nnano.2015.285] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 11/04/2015] [Indexed: 05/18/2023]
Abstract
Colour generation by plasmonic nanostructures and metasurfaces has several advantages over dye technology: reduced pixel area, sub-wavelength resolution and the production of bright and non-fading colours. However, plasmonic colour patterns need to be pre-designed and printed either by e-beam lithography (EBL) or focused ion beam (FIB), both expensive and not scalable processes that are not suitable for post-processing customization. Here we show a method of colour printing on nanoimprinted plasmonic metasurfaces using laser post-writing. Laser pulses induce transient local heat generation that leads to melting and reshaping of the imprinted nanostructures. Depending on the laser pulse energy density, different surface morphologies that support different plasmonic resonances leading to different colour appearances can be created. Using this technique we can print all primary colours with a speed of 1 ns per pixel, resolution up to 127,000 dots per inch (DPI) and power consumption down to 0.3 nJ per pixel.
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Affiliation(s)
- Xiaolong Zhu
- Department of Micro- and Nanotechnology, Technical University of Denmark, Kongens Lyngby DK-2800, Denmark
| | - Christoph Vannahme
- Department of Micro- and Nanotechnology, Technical University of Denmark, Kongens Lyngby DK-2800, Denmark
| | - Emil Højlund-Nielsen
- Department of Micro- and Nanotechnology, Technical University of Denmark, Kongens Lyngby DK-2800, Denmark
| | - N Asger Mortensen
- Department of Photonics Engineering, Technical University of Denmark, Kongens Lyngby DK-2800, Denmark
| | - Anders Kristensen
- Department of Micro- and Nanotechnology, Technical University of Denmark, Kongens Lyngby DK-2800, Denmark
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7
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Højlund-Nielsen E, Zhu X, Carstensen MS, Sørensen MK, Vannahme C, Asger Mortensen N, Kristensen A. Polarization-dependent aluminum metasurface operating at 450 nm. Opt Express 2015; 23:28829-28835. [PMID: 26561151 DOI: 10.1364/oe.23.028829] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We report on a polarization-dependent plasmonic aluminum-based high-density metasurface operating at blue wavelengths. The fabricated sub-wavelength structures, tailored in size and geometry, possess strong, localized, plasmonic resonances able to control linear polarization. Best performance is achieved by rotating an elongated rectangular structure of length 180 nm and width 110 nm inside a square lattice of period 250 nm. In the case of 45 degrees rotation of the structure with respect to the lattice, the normal-incidence reflectance drops around the resonance wavelength of 457 nm from about 60 percent to below 2 percent.
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8
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Hermannsson PG, Sørensen KT, Vannahme C, Smith CLC, Klein JJ, Russew MM, Grützner G, Kristensen A. All-polymer photonic crystal slab sensor. Opt Express 2015; 23:16529-16539. [PMID: 26191664 DOI: 10.1364/oe.23.016529] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
An all-polymer photonic crystal slab sensor is presented, and shown to exhibit narrow resonant reflection with a FWHM of less than 1 nm and a sensitivity of 31 nm/RIU when sensing media with refractive indices around that of water. This results in a detection limit of 4.5 × 10(-6) RIU when measured in conjunction with a spectrometer of 12 pm/pixel resolution. The device is a two-layer structure, composed of a low refractive index polymer with a periodically modulated surface height, covered with a smooth upper-surface high refractive index inorganic-organic hybrid polymer modified with ZrO2based nanoparticles. Furthermore, it is fabricated using inexpensive vacuum-less techniques involving only UV nanoreplication and polymer spin-casting, and is thus well suited for single-use biological and refractive index sensing applications.
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9
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Vannahme C, Sørensen KT, Gade C, Dufva M, Kristensen A. Refractometric monitoring of dissolution and fluid flow with distributed feedback dye laser sensor. Opt Express 2015; 23:6562-6568. [PMID: 25836874 DOI: 10.1364/oe.23.006562] [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] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Monitoring the dissolution of solid material in liquids and monitoring of fluid flow is of significant interest for applications in chemistry, food production, medicine, and especially in the fields of microfluidics and lab on a chip. Here, real-time refractometric monitoring of dissolution and fast fluid flow with DFB dye laser sensors with an optical imaging spectroscopy setup is presented. The dye laser sensors provide both low detection limits and high spatial resolution. It is demonstrated how the materials NaCl, sucrose, and bovine serum albumin show characteristic dissolution patterns. The unique feature of the presented method is a high frame rate of up to 20 Hz, which is proven to enable the monitoring of fast flow of a sucrose solution jet into pure water.
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10
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Krämmer S, Vannahme C, Smith CLC, Grossmann T, Jenne M, Schierle S, Jørgensen L, Chronakis IS, Kristensen A, Kalt H. Random-cavity lasing from electrospun polymer fiber networks. Adv Mater 2014; 26:8096-100. [PMID: 25358725 DOI: 10.1002/adma.201402995] [Citation(s) in RCA: 7] [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] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 09/22/2014] [Indexed: 05/16/2023]
Abstract
Lasing emission from random cavities formed in networks of electrospun Rhodamine-doped polymer fibers is presented. Spatially resolved spectroscopy and spectral analysis prove that the observed laser emission stems from individual ring resonators randomly distributed throughout the network. These electrospun fiber lasers represent a facile and straightforward configuration for developing novel photonic devices that may advantageously utilize the network morphology.
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Affiliation(s)
- Sarah Krämmer
- Institute of Applied Physics (APH), Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Str. 1, 76131, Karlsruhe, Germany
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11
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Smith CC, Thilsted AH, Garcia-Ortiz CE, Radko IP, Marie R, Jeppesen C, Vannahme C, Bozhevolnyi SI, Kristensen A. Efficient excitation of channel plasmons in tailored, UV-lithography-defined V-grooves. Nano Lett 2014; 14:1659-64. [PMID: 24524631 PMCID: PMC3964729 DOI: 10.1021/nl5002058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Indexed: 05/23/2023]
Abstract
We demonstrate the highly efficient (>50%) conversion of freely propagating light to channel plasmon-polaritons (CPPs) in gold V-groove waveguides using compact 1.6 μm long waveguide-termination coupling mirrors. Our straightforward fabrication process, involving UV-lithography and crystallographic silicon etching, forms the coupling mirrors innately and ensures exceptional-quality, wafer-scale device production. We tailor the V-shaped profiles by thermal silicon oxidation in order to shift initially wedge-located modes downward into the V-grooves, resulting in well-confined CPPs suitable for nanophotonic applications.
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Affiliation(s)
- Cameron
L. C. Smith
- Department
of Micro- and Nanotechnology, Technical
University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Anil H. Thilsted
- Department
of Micro- and Nanotechnology, Technical
University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Cesar E. Garcia-Ortiz
- Institute
of Technology and Innovation (ITI), University
of Southern Denmark, DK-5230 Odense M, Denmark
| | - Ilya P. Radko
- Institute
of Technology and Innovation (ITI), University
of Southern Denmark, DK-5230 Odense M, Denmark
| | - Rodolphe Marie
- Department
of Micro- and Nanotechnology, Technical
University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Claus Jeppesen
- Department
of Photonics Engineering, Technical University
of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Christoph Vannahme
- Department
of Micro- and Nanotechnology, Technical
University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Sergey I. Bozhevolnyi
- Institute
of Technology and Innovation (ITI), University
of Southern Denmark, DK-5230 Odense M, Denmark
| | - Anders Kristensen
- Department
of Micro- and Nanotechnology, Technical
University of Denmark, DK-2800 Kongens Lyngby, Denmark
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Liu X, Prinz S, Besser H, Pfleging W, Wissmann M, Vannahme C, Guttmann M, Mappes T, Koeber S, Koos C, Lemmer U. Organic semiconductor distributed feedback laser pixels for lab-on-a-chip applications fabricated by laser-assisted replication. Faraday Discuss 2014; 174:153-64. [DOI: 10.1039/c4fd00077c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The integration of organic semiconductor distributed feedback (DFB) laser sources into all-polymer chips is promising for biomedical or chemical analysis. However, the fabrication of DFB corrugations is often expensive and time-consuming. Here, we apply the method of laser-assisted replication using a near-infrared diode laser beam to efficiently fabricate inexpensive poly(methyl methacrylate) (PMMA) chips with spatially localized organic DFB laser pixels. This time-saving fabrication process enables a pre-defined positioning of nanoscale corrugations on the chip and a simultaneous generation of nanoscale gratings for organic edge-emitting laser pixels next to microscale waveguide structures. A single chip of size 30 mm × 30 mm can be processed within 5 min. Laser-assisted replication allows for the subsequent addition of further nanostructures without a negative impact on the existing photonic components. The minimum replication area can be defined as being as small as the diode laser beam focus spot size. To complete the fabrication process, we encapsulate the chip in PMMA using laser transmission welding.
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Affiliation(s)
- Xin Liu
- Light Technology Institute (LTI)
- Karlsruhe Institute of Technology
- 76131 Karlsruhe, Germany
- Institute of Microstructure Technology (IMT)
- Karlsruhe Institute of Technology
| | - Stephan Prinz
- Light Technology Institute (LTI)
- Karlsruhe Institute of Technology
- 76131 Karlsruhe, Germany
| | - Heino Besser
- Institute for Applied Materials - Applied Materials Physics (IAM-AWP)
- Karlsruhe Institute of Technology
- 76344 Eggenstein-Leopoldshafen, Germany
- Karlsruhe Nano Micro Facility
- 76344 Eggenstein-Leopoldshafen, Germany
| | - Wilhelm Pfleging
- Institute for Applied Materials - Applied Materials Physics (IAM-AWP)
- Karlsruhe Institute of Technology
- 76344 Eggenstein-Leopoldshafen, Germany
- Karlsruhe Nano Micro Facility
- 76344 Eggenstein-Leopoldshafen, Germany
| | - Markus Wissmann
- Institute of Microstructure Technology (IMT)
- Karlsruhe Institute of Technology
- 76344 Eggenstein-Leopoldshafen, Germany
- Karlsruhe Nano Micro Facility
- 76344 Eggenstein-Leopoldshafen, Germany
| | - Christoph Vannahme
- Institute of Microstructure Technology (IMT)
- Karlsruhe Institute of Technology
- 76344 Eggenstein-Leopoldshafen, Germany
- Light Technology Institute (LTI)
- Karlsruhe Institute of Technology
| | - Markus Guttmann
- Institute of Microstructure Technology (IMT)
- Karlsruhe Institute of Technology
- 76344 Eggenstein-Leopoldshafen, Germany
- Karlsruhe Nano Micro Facility
- 76344 Eggenstein-Leopoldshafen, Germany
| | - Timo Mappes
- Institute of Microstructure Technology (IMT)
- Karlsruhe Institute of Technology
- 76344 Eggenstein-Leopoldshafen, Germany
| | - Sebastian Koeber
- Institute of Microstructure Technology (IMT)
- Karlsruhe Institute of Technology
- 76344 Eggenstein-Leopoldshafen, Germany
- Institute of Photonics and Quantum Electronics (IPQ)
- Karlsruhe Institute of Technology
| | - Christian Koos
- Institute of Microstructure Technology (IMT)
- Karlsruhe Institute of Technology
- 76344 Eggenstein-Leopoldshafen, Germany
- Institute of Photonics and Quantum Electronics (IPQ)
- Karlsruhe Institute of Technology
| | - Uli Lemmer
- Light Technology Institute (LTI)
- Karlsruhe Institute of Technology
- 76131 Karlsruhe, Germany
- Institute of Microstructure Technology (IMT)
- Karlsruhe Institute of Technology
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13
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Liu X, Klinkhammer S, Wang Z, Wienhold T, Vannahme C, Jakobs PJ, Bacher A, Muslija A, Mappes T, Lemmer U. Pump spot size dependent lasing threshold in organic semiconductor DFB lasers fabricated via nanograting transfer. Opt Express 2013; 21:27697-27706. [PMID: 24514287 DOI: 10.1364/oe.21.027697] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Optically excited organic semiconductor distributed feedback (DFB) lasers enable efficient lasing in the visible spectrum. Here, we report on the rapid and parallel fabrication of DFB lasers via transferring a nanograting structure from a flexible mold onto an unstructured film of the organic gain material. This geometrically well-defined structure allows for a systematic investigation of the laser threshold behavior. The laser thresholds for these devices show a strong dependence on the pump spot diameter. This experimental finding is in good qualitative agreement with calculations based on coupled-wave theory. With further investigations on various DFB laser geometries prepared by different routes and based on different organic gain materials, we found that these findings are quite general. This is important for the comparison of threshold values of various devices characterized under different excitation areas.
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14
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Abstract
Single-mode second order distributed feedback (DFB) lasers of riboflavin (vitamin B2) doped gelatine films on nanostructured low refractive index material are demonstrated. Manufacturing is based on a simple UV nanoimprint and spin-coating. Emission wavelengths of 543 nm and 562 nm for two different grating periods are reported.
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Affiliation(s)
- Christoph Vannahme
- Department of Micro and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345B, 2800 Kongens Lyngby, Denmark.
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15
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Wienhold T, Breithaupt F, Vannahme C, Christiansen MB, Dörfler W, Kristensen A, Mappes T. Diffusion driven optofluidic dye lasers encapsulated into polymer chips. Lab Chip 2012; 12:3734-3739. [PMID: 22820609 DOI: 10.1039/c2lc40494j] [Citation(s) in RCA: 3] [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: 06/01/2023]
Abstract
Lab-on-a-chip systems made of polymers are promising for the integration of active optical elements, enabling e.g. on-chip excitation of fluorescent markers or spectroscopy. In this work we present diffusion operation of tunable optofluidic dye lasers in a polymer foil. We demonstrate that these first order distributed feedback lasers can be operated for more than 90 min at a pulse repetition rate of 2 Hz without fluidic pumping. Ultra-high output pulse energies of more than 10 μJ and laser thresholds of 2 μJ are achieved for resonator lengths of 3 mm. By introducing comparatively large on-chip dye solution reservoirs, the required exchange of dye molecules is accomplished solely by diffusion. Polymer chips the size of a microscope cover slip (18 × 18 mm(2)) were fabricated in batches on a wafer using a commercially available polymer (TOPAS(®) Cyclic Olefin Copolymer). Thermal imprinting of micro- and nanoscale structures into 100 μm foils simultaneously defines photonic resonators, liquid-core waveguides, and fluidic reservoirs. Subsequently, the fluidic structures are sealed with another 220 μm foil by thermal bonding. Tunability of laser output wavelengths over a spectral range of 24 nm on a single chip is accomplished by varying the laser grating period in steps of 2 nm. Low-cost manufacturing suitable for mass production, wide laser tunability, ultra-high output pulse energies, and long operation times without external fluidic pumping make these on-chip lasers suitable for a wide range of lab-on-a-chip applications, e.g. on-chip spectroscopy, biosensing, excitation of fluorescent markers, or surface enhanced Raman spectroscopy (SERS).
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Affiliation(s)
- Tobias Wienhold
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), 76128, Karlsruhe, Germany.
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Klinkhammer S, Liu X, Huska K, Shen Y, Vanderheiden S, Valouch S, Vannahme C, Bräse S, Mappes T, Lemmer U. Continuously tunable solution-processed organic semiconductor DFB lasers pumped by laser diode. Opt Express 2012; 20:6357-6364. [PMID: 22418517 DOI: 10.1364/oe.20.006357] [Citation(s) in RCA: 13] [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] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The fabrication and characterization of continuously tunable, solution-processed distributed feedback (DFB) lasers in the visible regime is reported. Continuous thin film thickness gradients were achieved by means of horizontal dipping of several conjugated polymer and blended small molecule solutions on cm-scale surface gratings of different periods. We report optically pumped continuously tunable laser emission of 13 nm in the blue, 16 nm in the green and 19 nm in the red spectral region on a single chip respectively. Tuning behavior can be described with the Bragg-equation and the measured thickness profile. The laser threshold is low enough that inexpensive laser diodes can be used as pump sources.
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Affiliation(s)
- Sönke Klinkhammer
- Light Technology Institute (LTI), Karlsruhe Institute of Technology (KIT), 76128 Karlsruhe, Germany
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Grossmann T, Klinkhammer S, Hauser M, Floess D, Beck T, Vannahme C, Mappes T, Lemmer U, Kalt H. Strongly confined, low-threshold laser modes in organic semiconductor microgoblets. Opt Express 2011; 19:10009-10016. [PMID: 21643259 DOI: 10.1364/oe.19.010009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We investigate lasing from high-Q, polymeric goblet-type microcavities covered by an organic semiconductor gain layer. We analyze the optical modes in the high-Q cavities using finite element simulations and present a numerical method to determine the cutoff thickness of the gain layer above which the whispering gallery modes are strongly confined in this layer. Fabricated devices show reduced lasing thresholds for increasing gain layer thicknesses, which can be explained by a higher filling factor of the optical modes in the gain layer. Furthermore, reduced lasing threshold is accompanied by a red-shift of the laser emission.
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Affiliation(s)
- Tobias Grossmann
- Institute of Applied Physics, Karlsruhe Institute of Technology, 76128 Karlsruhe, Germany.
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Vannahme C, Klinkhammer S, Lemmer U, Mappes T. Plastic lab-on-a-chip for fluorescence excitation with integrated organic semiconductor lasers. Opt Express 2011; 19:8179-86. [PMID: 21643068 DOI: 10.1364/oe.19.008179] [Citation(s) in RCA: 14] [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] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Laser light excitation of fluorescent markers offers highly sensitive and specific analysis for bio-medical or chemical analysis. To profit from these advantages for applications in the field or at the point-of-care, a plastic lab-on-a-chip with integrated organic semiconductor lasers is presented here. First order distributed feedback lasers based on the organic semiconductor tris(8-hydroxyquinoline) aluminum (Alq3) doped with the laser dye 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyril)-4H-pyrane (DCM), deep ultraviolet induced waveguides, and a nanostructured microfluidic channel are integrated into a poly(methyl methacrylate) (PMMA) substrate. A simple and parallel fabrication process is used comprising thermal imprint, DUV exposure, evaporation of the laser material, and sealing by thermal bonding. The excitation of two fluorescent marker model systems including labeled antibodies with light emitted by integrated lasers is demonstrated.
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Affiliation(s)
- Christoph Vannahme
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
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Vannahme C, Klinkhammer S, Christiansen MB, Kolew A, Kristensen A, Lemmer U, Mappes T. All-polymer organic semiconductor laser chips: parallel fabrication and encapsulation. Opt Express 2010; 18:24881-24887. [PMID: 21164833 DOI: 10.1364/oe.18.024881] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Organic semiconductor lasers are of particular interest as tunable visible laser light sources. For bringing those to market encapsulation is needed to ensure practicable lifetimes. Additionally, fabrication technologies suitable for mass production must be used. We introduce all-polymer chips comprising encapsulated distributed feedback organic semiconductor lasers. Several chips are fabricated in parallel by thermal nanoimprint of the feedback grating on 4″ wafer scale out of poly(methyl methacrylate) (PMMA) and cyclic olefin copolymer (COC). The lasers consisting of the organic semiconductor tris(8-hydroxyquinoline) aluminum (Alq3) doped with the laser dye 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyril)-4H-pyrane (DCM) are hermetically sealed by thermally bonding a polymer lid. The organic thin film is placed in a basin within the substrate and is not in direct contact to the lid. Thus, the spectral properties of the lasers are unmodified in comparison to unencapsulated lasers. Grating periods of 378 nm to 428 nm in steps of 10 nm result in lasing at wavelengths of 622 nm to 685 nm. The operational lifetime of the lasers expressed in number of pulses is improved 11-fold (PMMA) and 3-fold (COC) in comparison to unencapsulated PMMA devices.
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Affiliation(s)
- Christoph Vannahme
- Institute for Microstructure Technology, Karlsruhe Institute of Technology, 76128 Karlsruhe, Germany.
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Schelb M, Vannahme C, Welle A, Lenhert S, Ross B, Mappes T. Fluorescence excitation on monolithically integrated all-polymer chips. J Biomed Opt 2010; 15:041517. [PMID: 20799795 DOI: 10.1117/1.3446672] [Citation(s) in RCA: 4] [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: 05/29/2023]
Abstract
All-polymer chips with integrated optical waveguides and microfluidic channels were built as a platform for fluorescence excitation of biological samples. Their functionality has been shown for four cases: (i) fluorescence of labeled phospholipids inside a microfluidic channel, (ii) fluorescence of stained cells inside a microfluidic channel, (iii) fluorescence of labeled phospholipids on top of a polymer waveguide, and (iv) fluorescence of stained cells on top of a polymer waveguide.
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Affiliation(s)
- Mauno Schelb
- Karlsruhe Institute of Technology, Institut fur Mikrostrukturtechnik, Karlsruhe, Germany.
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Abstract
First order distributed feedback optofluidic dye lasers embedded in a 350 microm thick TOPAS((R)) foil are demonstrated. They are designed in order to give high output pulse energies. Microfluidic channels and first order distributed feedback gratings are fabricated in parallel by thermal nanoimprint into a 100 microm foil. The channels are closed by thermal bonding with a 250 microm thick foil and filled with 5.10(-3) mol/l Pyrromethene 597 in benzyl alcohol. The fluid forms a liquid core single mode slab waveguide of 1.6 microm height on a nanostructured grating area of 0.5 x 0.5 mm(2). This results in a large gain volume. Two grating periods of 185 nm and 190 nm yield single mode laser light emission at 566 nm and 581 nm respectively. High emitted pulse energies of more than 1 microJ are reported. Stable operation for more than 25 min at 10 Hz pulse repetition rate is achieved.
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Affiliation(s)
- Christoph Vannahme
- Institute for Microstructure Technology, Karlsruhe Institute of Technology, 76128 Karlsruhe, Germany.
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Lenhert S, Brinkmann F, Laue T, Walheim S, Vannahme C, Klinkhammer S, Xu M, Sekula S, Mappes T, Schimmel T, Fuchs H. Lipid multilayer gratings. Nat Nanotechnol 2010; 5:275-9. [PMID: 20190751 DOI: 10.1038/nnano.2010.17] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Accepted: 01/22/2010] [Indexed: 05/07/2023]
Abstract
The interaction of electromagnetic waves with matter can be controlled by structuring the matter on the scale of the wavelength of light, and various photonic components have been made by structuring materials using top-down or bottom-up approaches. Dip-pen nanolithography is a scanning-probe-based fabrication technique that can be used to deposit materials on surfaces with high resolution and, when carried out in parallel, with high throughput. Here, we show that lyotropic optical diffraction gratings--composed of biofunctional lipid multilayers with controllable heights between approximately 5 and 100 nm--can be fabricated by lipid dip-pen nanolithography. Multiple materials can be simultaneously written into arbitrary patterns on pre-structured surfaces to generate complex structures and devices, allowing nanostructures to be interfaced by combinations of top-down and bottom-up fabrication methods. We also show that fluid and biocompatible lipid multilayer gratings allow label-free and specific detection of lipid-protein interactions in solution. This biosensing capability takes advantage of the adhesion properties of the phospholipid superstructures and the changes in the size and shape of the grating elements that take place in response to analyte binding.
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Affiliation(s)
- Steven Lenhert
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany.
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Sohler W, Hu H, Ricken R, Quiring V, Vannahme C, Herrmann H, Büchter D, Reza S, Grundkötter W, Orlov S, Suche H, Nouroozi R, Min Y. Integrated Optical Devices in Lithium Niobate. ACTA ACUST UNITED AC 2008. [DOI: 10.1364/opn.19.1.000024] [Citation(s) in RCA: 155] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Vannahme C, Schübel S, Herud M, Gösling S, Hülsmann H, Paulsson M, Hartmann U, Maurer P. Molecular cloning of testican-2: defining a novel calcium-binding proteoglycan family expressed in brain. J Neurochem 1999; 73:12-20. [PMID: 10386950 DOI: 10.1046/j.1471-4159.1999.0730012.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [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: 11/20/2022]
Abstract
We have screened a human cDNA library using an expressed sequence tag related to the BM-40/secreted protein, acidic and rich in cysteine (SPARC)/osteonectin family of proteins and isolated a novel cDNA. It encodes a protein precursor of 424 amino acids that consists of a signal peptide, a follistatin-like domain, a Ca2+-binding domain, a thyroglobulin-like domain, and a C-terminal region with two putative glycosaminoglycan attachment sites. The protein is homologous to testican-1 and was termed testican-2. Testican-1 is a proteoglycan originally isolated from human seminal plasma that is also expressed in brain. Northern blot hybridization of testican-2 showed a 6.1-kb mRNA expressed mainly in CNS but also found in lung and testis. A widespread expression in multiple neuronal cell types in olfactory bulb, cerebral cortex, thalamus, hippocampus, cerebellum, and medulla was detected by in situ hybridization. A recombinant fragment consisting of the Ca2+-binding EF-hand domain and the thyroglobulin-like domain of testican-2 showed a reversible Ca2+-dependent conformational change in circular dichroism studies. Testican-1 and -2 form a novel Ca2+-binding proteoglycan family built of modular domains with the potential to participate in diverse steps of neurogenesis.
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Affiliation(s)
- C Vannahme
- Institute for Biochemistry II, Medical Faculty, University of Cologne, Germany
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Abstract
The extracellular calcium-binding (EC) module of human testican (115 residues) was obtained in native form by recombinant production in mammalian cell culture and thus shown to represent an independently folding domain. This module showed a large loss in alpha-helix upon calcium depletion. Apparently only one of the two EF hands binds calcium, with a moderate affinity (Kd =68 microM) about 100-fold lower than in the homologous BM-40 protein. No clear evidence was obtained for collagen binding, indicating that EC modules found in different proteins may not share similar functions.
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Affiliation(s)
- E Kohfeldt
- Max-Planck-Institut für Biochemie, Martinsried, Germany
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