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Maharjan S, Ma C, Singh B, Kang H, Orive G, Yao J, Shrike Zhang Y. Advanced 3D imaging and organoid bioprinting for biomedical research and therapeutic applications. Adv Drug Deliv Rev 2024; 208:115237. [PMID: 38447931 PMCID: PMC11031334 DOI: 10.1016/j.addr.2024.115237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/15/2024] [Accepted: 02/27/2024] [Indexed: 03/08/2024]
Abstract
Organoid cultures offer a valuable platform for studying organ-level biology, allowing for a closer mimicry of human physiology compared to traditional two-dimensional cell culture systems or non-primate animal models. While many organoid cultures use cell aggregates or decellularized extracellular matrices as scaffolds, they often lack precise biochemical and biophysical microenvironments. In contrast, three-dimensional (3D) bioprinting allows precise placement of organoids or spheroids, providing enhanced spatial control and facilitating the direct fusion for the formation of large-scale functional tissues in vitro. In addition, 3D bioprinting enables fine tuning of biochemical and biophysical cues to support organoid development and maturation. With advances in the organoid technology and its potential applications across diverse research fields such as cell biology, developmental biology, disease pathology, precision medicine, drug toxicology, and tissue engineering, organoid imaging has become a crucial aspect of physiological and pathological studies. This review highlights the recent advancements in imaging technologies that have significantly contributed to organoid research. Additionally, we discuss various bioprinting techniques, emphasizing their applications in organoid bioprinting. Integrating 3D imaging tools into a bioprinting platform allows real-time visualization while facilitating quality control, optimization, and comprehensive bioprinting assessment. Similarly, combining imaging technologies with organoid bioprinting can provide valuable insights into tissue formation, maturation, functions, and therapeutic responses. This approach not only improves the reproducibility of physiologically relevant tissues but also enhances understanding of complex biological processes. Thus, careful selection of bioprinting modalities, coupled with appropriate imaging techniques, holds the potential to create a versatile platform capable of addressing existing challenges and harnessing opportunities in these rapidly evolving fields.
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Affiliation(s)
- Sushila Maharjan
- Division of Engineering in Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA 02139, USA
| | - Chenshuo Ma
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
| | - Bibhor Singh
- Winthrop L. Chenery Upper Elementary School, Belmont, MA 02478, USA
| | - Heemin Kang
- Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea; College of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Gorka Orive
- NanoBioCel Research Group, School of Pharmacy, University of the Basque Country (UPV/EHU), Vitoria-Gasteiz, Spain; Bioaraba, NanoBioCel Research Group, Vitoria-Gasteiz, Spain; Biomedical Research Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN). Vitoria-Gasteiz, Spain; University Institute for Regenerative Medicine and Oral Implantology - UIRMI (UPV/EHU-Fundación Eduardo Anitua), Vitoria, 01007, Spain; Singapore Eye Research Institute, The Academia, 20 College Road, Discovery Tower, Singapore 169856, Singapore
| | - Junjie Yao
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA.
| | - Yu Shrike Zhang
- Division of Engineering in Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA 02139, USA.
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Fei K, Zhang J, Yuan J, Xiao P. Present Application and Perspectives of Organoid Imaging Technology. Bioengineering (Basel) 2022; 9:121. [PMID: 35324810 PMCID: PMC8945799 DOI: 10.3390/bioengineering9030121] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/23/2022] [Accepted: 03/13/2022] [Indexed: 11/18/2022] Open
Abstract
An organoid is a miniaturized and simplified in vitro model with a similar structure and function to a real organ. In recent years, the use of organoids has increased explosively in the field of growth and development, disease simulation, drug screening, cell therapy, etc. In order to obtain necessary information, such as morphological structure, cell function and dynamic signals, it is necessary and important to directly monitor the culture process of organoids. Among different detection technologies, imaging technology is a simple and convenient choice and can realize direct observation and quantitative research. In this review, the principle, advantages and disadvantages of imaging technologies that have been applied in organoids research are introduced. We also offer an overview of prospective technologies for organoid imaging. This review aims to help biologists find appropriate imaging techniques for different areas of organoid research, and also contribute to the development of organoid imaging systems.
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Affiliation(s)
| | | | - Jin Yuan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-Sen University, Guangzhou 510060, China; (K.F.); (J.Z.)
| | - Peng Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-Sen University, Guangzhou 510060, China; (K.F.); (J.Z.)
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Combined TPEF and SHG Imaging for the Microstructural Characterization of Different Wood Species Used in Artworks. PHOTONICS 2022. [DOI: 10.3390/photonics9030170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The morphological and chemical conformation of wood microstructures is characteristic of individual species and strongly influences the macromechanical properties of the material, as well as its sensitivity to deterioration factors. Noninvasive techniques enabling the visualization of wood microstructures, while simultaneously providing compositional information, can significantly facilitate the analysis of wooden artworks for conservation purposes. In this paper, we present the application of combined two-photon excited fluorescence (TPEF) and second-harmonic generation (SHG) imaging as a versatile diagnostic tool for the microcharacterization of three hardwood species never analyzed by this method. Multimodal mapping of the molecular constituents based on the detected nonlinear signals provides useful information for studying the biological and biochemical deterioration of wood, opening a new field of application for a well-established and widely used imaging technology.
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Umezawa M, Sera T, Yokota H, Takematsu M, Morita M, Yeroslavsky G, Kamimura M, Soga K. Computed tomography for in vivo deep over-1000 nm near-infrared fluorescence imaging. JOURNAL OF BIOPHOTONICS 2020; 13:e202000071. [PMID: 32388908 DOI: 10.1002/jbio.202000071] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/30/2020] [Accepted: 05/04/2020] [Indexed: 06/11/2023]
Abstract
This study aims to develop a novel cross-sectional imaging of fluorescence in over-1000 nm near-infrared (OTN-NIR), which allows in vivo deep imaging, using computed tomography (CT) system. Cylindrical specimens of composite of OTN-NIR fluorophore, NaGdF4 co-doped with Yb3+ and Ho3+ (ex: 980 nm, em: 1150 nm), were embedded in cubic agar (10.5-12 mm) or in the peritoneal cavity of mice and placed on a rotatable stage. When the fluorescence from inside of the samples was serially captured from multiple angles, the images were disrupted by the reflection and refraction of emitted light on the sample-air interface. Immersing the sample into water filled in a rectangular bath suppressed the disruption at the interface and successfully reconstructed the position and concentration of OTN-NIR fluorophores on the cross-sectional images using a CT technique. This is promising as a novel three-dimensional imaging technique for OTN-NIR fluorescent image projections of small animals captured from multiple angles.
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Affiliation(s)
- Masakazu Umezawa
- Department of Materials Science and Technology, Faculty of Industrial Science and Technology, Tokyo University of Science, Tokyo, Japan
| | - Toshihiro Sera
- Department of Mechanical Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan
| | - Hideo Yokota
- Image Processing Team, RIKEN Center for Advanced Photonics, Saitama, Japan
| | - Maho Takematsu
- Department of Materials Science and Technology, Faculty of Industrial Science and Technology, Tokyo University of Science, Tokyo, Japan
| | - Masahiko Morita
- Image Processing Team, RIKEN Center for Advanced Photonics, Saitama, Japan
| | - Gil Yeroslavsky
- Imaging Frontier Center, Research Institute for Science and Technology, Tokyo University of Science, Chiba, Japan
| | - Masao Kamimura
- Department of Materials Science and Technology, Faculty of Industrial Science and Technology, Tokyo University of Science, Tokyo, Japan
- Imaging Frontier Center, Research Institute for Science and Technology, Tokyo University of Science, Chiba, Japan
| | - Kohei Soga
- Department of Materials Science and Technology, Faculty of Industrial Science and Technology, Tokyo University of Science, Tokyo, Japan
- Imaging Frontier Center, Research Institute for Science and Technology, Tokyo University of Science, Chiba, Japan
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Molitoris BA, Reilly ES. Quantifying Glomerular Filtration Rates in Acute Kidney Injury: A Requirement for Translational Success. Semin Nephrol 2017; 36:31-41. [PMID: 27085733 DOI: 10.1016/j.semnephrol.2016.01.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Acute kidney injury (AKI) remains a vexing clinical problem that results in unacceptably high patient mortality, development of chronic kidney disease, and accelerated progression to end-stage kidney disease. Although clinical risks factors for developing AKI have been identified, there is no reasonable surveillance technique to definitively and rapidly diagnose and determine the extent of severity of AKI in any patient. Because patient outcomes correlate with the extent of injury, and effective therapy likely requires early intervention, the ability to rapidly diagnose and stratify patients by their level of kidney injury is paramount for translational progress. Many groups are developing and characterizing optical measurement techniques using novel minimally invasive or noninvasive techniques that can quantify kidney function independent of serum or urinary measurements. The use of both one- and two-compartment models, as well as continuous monitoring, are being developed. This review documents the need for glomerular filtration rate measurement in AKI patients and discusses the approaches being taken to deliver this overdue technique that is necessary to help propel nephrology to individualization of care and therapeutic success.
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Affiliation(s)
- Bruce A Molitoris
- Division of Nephrology, Department of Medicine, Indiana Center for Biological Microscopy, Indiana University School of Medicine, Roudebush VA, Indianapolis, Indiana; FAST BioMedical, Indianapolis, Indiana.
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Grist SM, Nasseri SS, Poon T, Roskelley C, Cheung KC. On-chip clearing of arrays of 3-D cell cultures and micro-tissues. BIOMICROFLUIDICS 2016; 10:044107. [PMID: 27493703 PMCID: PMC4958101 DOI: 10.1063/1.4959031] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 07/06/2016] [Indexed: 05/16/2023]
Abstract
Three-dimensional (3-D) cell cultures are beneficial models for mimicking the complexities of in vivo tissues, especially in tumour studies where transport limitations can complicate response to cancer drugs. 3-D optical microscopy techniques are less involved than traditional embedding and sectioning, but are impeded by optical scattering properties of the tissues. Confocal and even two-photon microscopy limit sample imaging to approximately 100-200 μm depth, which is insufficient to image hypoxic spheroid cores. Optical clearing methods have permitted high-depth imaging of tissues without physical sectioning, but they are difficult to implement for smaller 3-D cultures due to sample loss in solution exchange. In this work, we demonstrate a microfluidic platform for high-throughput on-chip optical clearing of breast cancer spheroids using the SeeDB, Clear(T2), and ScaleSQ clearing methods. Although all three methods are able to effectively clear the spheroids, we find that SeeDB and ScaleSQ more effectively clear the sample than Clear(T2); however, SeeDB induces green autofluorescence while ScaleS causes sample expansion. Our unique on-chip implementation permits clearing arrays of 3-D cultures using perfusion while monitoring the 3-D cultures throughout the process, enabling visualization of the clearing endpoint as well as monitoring of transient changes that could induce image artefacts. Our microfluidic device is compatible with on-chip 3-D cell culture, permitting the use of on-chip clearing at the endpoint after monitoring the same spheroids during their culture. This on-chip method has the potential to improve readout from 3-D cultures, facilitating their use in cell-based assays for high-content drug screening and other applications.
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Affiliation(s)
- S M Grist
- Department of Electrical and Computer Engineering, The University of British Columbia , 2332 Main Mall, Vancouver, BC Canada V6T 1Z4
| | - S S Nasseri
- Department of Electrical and Computer Engineering, The University of British Columbia , 2332 Main Mall, Vancouver, BC Canada V6T 1Z4
| | - T Poon
- Department of Cellular and Physiological Sciences, The University of British Columbia , 2350 Health Sciences Mall, Vancouver, BC, Canada V6T 1Z3
| | - C Roskelley
- Department of Cellular and Physiological Sciences, The University of British Columbia , 2350 Health Sciences Mall, Vancouver, BC, Canada V6T 1Z3
| | - K C Cheung
- Department of Electrical and Computer Engineering, The University of British Columbia , 2332 Main Mall, Vancouver, BC Canada V6T 1Z4
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Tkaczyk AH, Tkaczyk ER, Norris TB, Takayama S. Microfluidic Droplet Consistency Monitoring and Cell Detection via Laser Excitation. J MECH MED BIOL 2011; 11:1-14. [PMID: 29755161 DOI: 10.1142/s0219519410003617] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Microfluidic droplets formed in emulsions are used in a variety of analytical techniques and hold great potential for future scientific and commercial applications. Our experiments merge quantitative quality engineering methods into the microdroplet field. We present a unique microdroplet generation and consistency monitoring system with laser optics excitation and detection. Our setup analyzes each droplet with sub-millisecond signal resolution and single photon accuracy, and is compatible with process control methods. To demonstrate the consistency of microdroplet generation over time, we measure and examine the mean frequency of aqueous plug-shaped droplet (microplug) formation in oil phase, as well as the mean length of plugs, and the interval between consecutive droplets. We also demonstrate the detection of cancer cells encapsulated within aqueous microdroplets in continuous oil phase flow. Two-channel optical monitoring allows for the simultaneous and independent inspection of both microdroplet generation and identification of green fluorescent protein-labelled cancer cells within the droplets. Increased accuracy and consistency are central to many established and developing microfluidic technologies. A systematic, quantitative approach as demonstrated with our experiments may be essential in the development of advanced microfluidic concepts that require exacting reproducibility and would greatly benefit from incorporated automated measurement techniques for process control.
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Affiliation(s)
- Alan H Tkaczyk
- Department of Biomedical Engineering, University of Michigan, 2200 Bonisteel Blvd., Ann Arbor, MI 48109-2099, USA.,Department of Mechanical Engineering, University of Michigan, 2350 Hayward St., Ann Arbor, MI 48109-2125, USA
| | - Eric R Tkaczyk
- Center for Ultrafast Optical Science, Department of Electrical Engineering and Computer Science, University of Michigan, 2200 Bonisteel Blvd., Ann Arbor, MI 48109-2099, USA
| | - Theodore B Norris
- Center for Ultrafast Optical Science, Department of Electrical Engineering and Computer Science, University of Michigan, 2200 Bonisteel Blvd., Ann Arbor, MI 48109-2099, USA
| | - Shuichi Takayama
- Department of Biomedical Engineering, University of Michigan, 2200 Bonisteel Blvd., Ann Arbor, MI 48109-2099, USA
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8
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Canaria CA, Lansford R. Advanced optical imaging in living embryos. Cell Mol Life Sci 2010; 67:3489-97. [PMID: 20614161 PMCID: PMC2943067 DOI: 10.1007/s00018-010-0440-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2010] [Revised: 06/12/2010] [Accepted: 06/15/2010] [Indexed: 11/28/2022]
Abstract
Developmental biology investigations have evolved from static studies of embryo anatomy and into dynamic studies of the genetic and cellular mechanisms responsible for shaping the embryo anatomy. With the advancement of fluorescent protein fusions, the ability to visualize and comprehend how thousands to millions of cells interact with one another to form tissues and organs in three dimensions (xyz) over time (t) is just beginning to be realized and exploited. In this review, we explore recent advances utilizing confocal and multi-photon time-lapse microscopy to capture gene expression, cell behavior, and embryo development. From choosing the appropriate fluorophore, to labeling strategy, to experimental set-up, and data pipeline handling, this review covers the various aspects related to acquiring and analyzing multi-dimensional data sets. These innovative techniques in multi-dimensional imaging and analysis can be applied across a number of fields in time and space including protein dynamics to cell biology to morphogenesis.
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Affiliation(s)
- Christie A. Canaria
- California Institute of Technology, 1200 E. California Blvd, MC 139-74, Pasadena, CA 91125 USA
| | - Rusty Lansford
- California Institute of Technology, 1200 E. California Blvd, MC 139-74, Pasadena, CA 91125 USA
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9
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Campana M, Sarti A. Cell morphodynamics visualization from images of zebrafish embryogenesis. Comput Med Imaging Graph 2010; 34:394-403. [DOI: 10.1016/j.compmedimag.2010.01.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 12/09/2009] [Accepted: 01/27/2010] [Indexed: 11/29/2022]
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10
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Campana M, Maury B, Dutreix M, Peyriéras N, Sarti A. Methods toward in vivo measurement of zebrafish epithelial and deep cell proliferation. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2010; 98:103-117. [PMID: 19781805 DOI: 10.1016/j.cmpb.2009.08.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Revised: 07/23/2009] [Accepted: 08/24/2009] [Indexed: 05/28/2023]
Abstract
We present a strategy for automatic classification and density estimation of epithelial enveloping layer (EVL) and deep layer (DEL) cells, throughout zebrafish early embryonic stages. Automatic cells classification provides the bases to measure the variability of relevant parameters, such as cells density, in different classes of cells and is finalized to the estimation of effectiveness and selectivity of anticancer drug in vivo. We aim at approaching these measurements through epithelial/deep cells classification, epithelial area and thickness measurement, and density estimation from scattered points. Our procedure is based on Minimal Surfaces, Otsu clustering, Delaunay Triangulation, and Within-R cloud of points density estimation approaches. In this paper, we investigated whether the distance between nuclei and epithelial surface is sufficient to discriminate epithelial cells from deep cells. Comparisons of different density estimators, experimental results, and extensively accuracy measurements are included.
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Affiliation(s)
- Matteo Campana
- Department of Electronics, Computer Sciences and Systems, Bologna University, Bologna, Italy.
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Przybylo M, Borowik T, Langner M. Fluorescence Techniques for Determination of the Membrane Potentials in High Throughput Screening. J Fluoresc 2010; 20:1139-57. [DOI: 10.1007/s10895-010-0665-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Accepted: 04/05/2010] [Indexed: 01/14/2023]
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12
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Toro C, De Boni L, Yao S, Belfield KD, Hernández FE. Photophysical Characterization of a Highly Conjugated Bipyridyl-Based Dye Synthesized by a Unique Two-Step Approach. J Phys Chem B 2008; 112:12185-90. [DOI: 10.1021/jp804975a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Carlos Toro
- Department of Chemistry, University of Central Florida, P.O. Box 162366, Orlando, Florida 32816-2366
| | - Leonardo De Boni
- Department of Chemistry, University of Central Florida, P.O. Box 162366, Orlando, Florida 32816-2366
| | - Sheng Yao
- Department of Chemistry, University of Central Florida, P.O. Box 162366, Orlando, Florida 32816-2366
| | - Kevin D. Belfield
- Department of Chemistry, University of Central Florida, P.O. Box 162366, Orlando, Florida 32816-2366
| | - Florencio E. Hernández
- Department of Chemistry, University of Central Florida, P.O. Box 162366, Orlando, Florida 32816-2366
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Yao J, Zobeck KL, Lis JT, Webb WW. Imaging transcription dynamics at endogenous genes in living Drosophila tissues. Methods 2008; 45:233-41. [PMID: 18586105 DOI: 10.1016/j.ymeth.2008.06.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2008] [Accepted: 06/16/2008] [Indexed: 11/26/2022] Open
Abstract
How transcription of individual genes is regulated in a single, intact, three-dimensionally organized cell nucleus remains mysterious. Recently, live cell imaging has become an essential tool to dissect the in vivo mechanisms of gene transcription. It not only examines functions of transcription factors at their gene targets within the chromatin context, but it also provides a non-disruptive approach for observing the dynamics of a transcription cycle in real time. However, the identification of any endogenous gene loci and their associated transcription factors remains technically difficult. Here, we describe the method of imaging the transcriptional dynamics of heat shock genes in Drosophila polytene chromosomes in living salivary gland tissues by multiphoton microscopy (MPM). This method has provided the experimental capability to visualize the assembly and dynamics of individual transcription factors and regulators and to dissect their functions at their endogenous gene targets in living cells.
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Affiliation(s)
- Jie Yao
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA
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Affiliation(s)
- Norbert Hoffmann
- Laboratoire des Réactions Sélectives et Applications, UMR 6519 CNRS et Université de Reims Champagne-Ardenne, UFR Sciences, B.P. 1039, F-51687 Reims, Cedex 02, France
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Liu E, Treiser MD, Johnson PA, Patel P, Rege A, Kohn J, Moghe PV. Quantitative biorelevant profiling of material microstructure within 3D porous scaffolds via multiphoton fluorescence microscopy. J Biomed Mater Res B Appl Biomater 2007; 82:284-97. [PMID: 17238159 DOI: 10.1002/jbm.b.30732] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This study presents a novel approach, based on fluorescence multiphoton microscopy (MPM), to image and quantitatively characterize the microstructure and cell-substrate interactions within microporous scaffold substrates fabricated from synthetic biodegradable polymers. Using fluorescently dyed scaffolds fabricated from poly(DTE carbonate)/poly(DTO carbonate) blends of varying porosity and complementary green fluorescent protein-engineered fibroblasts, we reconstructed the three-dimensional distribution of the microporous and macroporous regions in 3D scaffolds, as well as cellular morphological patterns. The porosity, pore size and distribution, strut size, pore interconnectivity, and orientation of both macroscale and microscale pores of 3D scaffolds were effectively quantified and validated using complementary imaging techniques. Compared to other scaffold characterizing techniques such as confocal imaging and scanning electron microscopy (SEM), MPM enables the acquisition of images from scaffold thicknesses greater than a hundred microns with high signal-to-noise ratio, reduced bulk photobleaching, and the elimination of the need for deconvolution. In our study, the morphology and cytoskeletal organization of cells within the scaffold interior could be tracked with high resolution within the limits of penetration of MPM. Thus, MPM affords a promising integrated platform for imaging cell-material interactions within the interior of polymeric biomaterials.
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Affiliation(s)
- Er Liu
- Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey 08854, USA
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16
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Niesner R, Peker B, Schlüsche P, Gericke KH, Hoffmann C, Hahne D, Müller-Goymann C. 3D-resolved investigation of the pH gradient in artificial skin constructs by means of fluorescence lifetime imaging. Pharm Res 2005; 22:1079-87. [PMID: 16028008 DOI: 10.1007/s11095-005-5304-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2005] [Accepted: 04/14/2005] [Indexed: 10/25/2022]
Abstract
PURPOSE The development of substitutes for the human skin, e.g., artificial skin constructs (ASCs), is of particular importance for pharmaceutical and dermatologic research because they represent economical test samples for the validation of new drugs. In this regard, it is essential for the skin substitutes to be reliable models of the genuine skin, i.e., to have similar morphology and functionality. Particularly important is the barrier function, i.e., the selective permeability of the skin, which is strongly related to the epidermal pH gradient. Because the pH significantly influences the permeation profile of ionizable drugs such as nonsteroidal anti-inflammatory drugs, it is of major importance to quantitatively measure the epidermal pH gradient of the ASC and compare it to that of genuine skin. METHODS Using three-dimensional fluorescence lifetime imaging combined with two-photon scanning microscopy, we measured with submicron resolution the three-dimensional pH gradient in the epidermis of ASCs stained with 2',7'-bis-(2-carboxyethyl)-5/6-carboxyfluorescein. RESULTS Similar to genuine skin, the surface of the artificial epidermis has an acidic character (pH 5.9), whereas in the deeper layers the pH increases up to 7.0. Moreover, the pH gradient differs in the cell interior (maximally 7.2) and in the intercellular matrix (maximally 6.6). Apart from the similitude of the pH distribution, the genuine and the artificial skin prove to have similar morphologies and to be characterized by similar distributions of the refractive index. CONCLUSIONS Artificial skin is a reliable model of genuine human skin, e.g., in permeability studies, because it is characterized by a similar pH gradient, a similar morphology, and a similar distribution of the refractive index to that of genuine skin.
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Affiliation(s)
- Raluca Niesner
- Institute for Physical and Theoretical Chemistry, Technical University, Braunschweig, Germany.
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Xie A, Liu B, Hall JE, Barron SL, Higgins DA. Self-assembled photoactive polyelectrolyte/perylene-diimide composites. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:4149-4155. [PMID: 15835987 DOI: 10.1021/la0471700] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A new class of polyelectrolyte-surfactant (PE-surf) composites having potential applications as thin film organic semiconductors is introduced. These materials are comprised of cationic asymmetrically substituted perylene diimides and oppositely charged poly(acrylate) polyanions. Thin films of the composite materials are prepared by mixing and drop casting aqueous solutions of the two precursors onto appropriate substrates. The resulting materials yield photovoltages of >140 mV for approximately equal to 0.6 W/cm(2) illumination intensities, when incorporated in p-n heterojunction devices. Solution-phase spectra obtained from the PE-surf complexes exhibit excimer-like emission and evidence for formation of weakly coupled aggregates in the ground state. Wide-angle X-ray scattering data show the composite films are locally amorphous, while small-angle X-ray data are consistent with a mixture of polymorphic structures that incorporate planar PE-surf bilayers of 3.9-nm repeat distances. Images obtained by conventional far-field light microscopy and multiphoton-excited fluorescence microscopy (MPEFM) indicate that the films are heterogeneous, incorporating submicrometer sized clusters dispersed among much thinner film regions that also incorporate dye. Polarization-dependent MPEFM studies prove the clusters are semiorganized, yielding order parameters (s and P(4)) of 0.09 and 0.01 for in-plane alignment of the chromophores, consistent with a relatively high degree of disorder.
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Affiliation(s)
- Aifang Xie
- Department of Chemistry, Kansas State University, Manhattan, KS 66506, USA
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Chandrasekharan N, Gonzales B, Cullum BM. Non-resonant multiphoton photoacoustic spectroscopy for noninvasive subsurface chemical diagnostics. APPLIED SPECTROSCOPY 2004; 58:1325-1333. [PMID: 15606938 DOI: 10.1366/0003702042475565] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This paper describes the development and validation of a novel noninvasive spectroscopic subsurface chemical detection technique, non-resonant multiphoton photoacoustic spectroscopy (NMPPAS). In this technique, non-resonant multiphoton excitation is used to provide subsurface excitation of chemical constituents in a sample followed by the subsequent detection of an acoustic signal using a piezoelectric transducer. Because NMPPAS relies on non-radiative relaxation of the absorbing species, it is capable of monitoring both fluorescent and non-fluorescent species. Moreover, since the majority of the energy imparted to most molecules upon the absorption of light is released through non-radiative pathways, sensitive measurements of even fluorescent molecules can be performed. In this paper, demonstration of proof-of-principle of this novel technique has been shown using test samples of common fluorescent dyes and biomarkers including rhodamine 6G, tryptophan, and NADH in solution and gelatin tissue phantoms. From these studies, it was found that detection limits of these chromophores are in the subnanomolar concentration regime. In addition, preliminary results on excised tumor and healthy tissue samples have demonstrated significant differences between the tumorous and non-tumorous tissues at 740 nm and 950 nm wavelengths. From this work, it was found that NMPPAS has a great deal of potential for subsurface chemical diagnostics in the field of biomedical research.
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Affiliation(s)
- Nirmala Chandrasekharan
- Department of Chemistry and Biochemistry, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250, USA
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Affiliation(s)
- Andrew C Millard
- Department of Physiology, Center for Biomedical Imaging Technology, University of Connecticut Health Center, Farmington, Connecticut 06030, USA
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Two-photon excitation microscopy. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s1076-5670(03)80016-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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21
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Ruffins SW, Jacobs RE, Fraser SE. Towards a Tralfamadorian view of the embryo: multidimensional imaging of development. Curr Opin Neurobiol 2002; 12:580-6. [PMID: 12367639 DOI: 10.1016/s0959-4388(02)00366-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Biological problems such as embryonic development require tools to follow cell and tissue movements as well as the distribution of active genes. A variety of emerging imaging techniques offer the capability of fully rendering the three-dimensional structure of the embryo, and some offer the possibility of following changes directly over time. The data sets that result offer both new insights and new challenges. A framework of digital atlases will soon offer the integration of different imaging modalities and permit users to interact with multidimensional data sets.
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Affiliation(s)
- Seth W Ruffins
- Biological Imaging Center, Beckman Institute and Division of Biology, California Institute of Technology, Pasadena, California 91125, USA
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Abstract
Alzheimer disease (AD) is an illness that can only be diagnosed with certainty with postmortem examination of brain tissue. Tissue samples from afflicted patients show neuronal loss, neurofibrillary tangles (NFTs), and amyloid-beta plaques. An imaging technique that permitted in vivo detection of NFTs or amyloid-beta plaques would be extremely valuable. For example, chronic imaging of senile plaques would provide a readout of the efficacy of experimental therapeutics aimed at removing these neuropathologic lesions. This review discusses the available techniques for imaging amyloid-beta deposits in the intact brain, including magnetic resonance imaging, positron emission tomography, single photon emission computed tomography, and multiphoton microscopy. A variety of agents that target amyloid-beta deposits specifically have been developed using one or several of these imaging modalities. The difficulty in developing these tools lies in the need for the agents to cross the blood-brain barrier while recognizing amyloid-beta with high sensitivity and specificity. This review describes the progress in developing reagents suitable for in vivo imaging of senile plaques.
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Affiliation(s)
- Brian J Bacskai
- Alzheimer Research Unit, Massachusetts General Hospital, Charlestown 02129, USA
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Mellado M, Martínez-A C, Rodríguez-Frade JM. Analysis of G-protein-coupled receptor dimerization following chemokine signaling. Methods 2002; 27:349-57. [PMID: 12217651 DOI: 10.1016/s1046-2023(02)00093-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
An abundance of information has been generated in recent decades on the signaling events triggered through G-protein-coupled receptors (GPCRs). Nonetheless, the structural changes at the cell surface that provoke receptor activation are only now beginning to be understood. It is becoming clear that receptors are not isolated entities that are activated following ligand binding, but that they interact with other molecules already present or recruited to the vicinity, which results in a wide variety of new signaling possibilities. Understanding receptor interactions with relatives and/or friends on the cell surface is thus critical. The most important point is to determine which of these interactions are "casual" and which give rise to functional consequences.
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Affiliation(s)
- Mario Mellado
- Department of Immunology and Oncology, Centro Nacional de Biotecnologi;a, CSIC-Universidad Autónoma de Madrid, Campus de Cantoblanco, Spain
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