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Non-destructive, continuous monitoring of biochemical, mechanical, and structural maturation in engineered tissue. Sci Rep 2022; 12:16227. [PMID: 36171228 PMCID: PMC9519952 DOI: 10.1038/s41598-022-18702-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 08/17/2022] [Indexed: 11/08/2022] Open
Abstract
Regulatory guidelines for tissue engineered products require stringent characterization during production and necessitate the development of novel, non-destructive methods to quantify key functional parameters for clinical translation. Traditional assessments of engineered tissues are destructive, expensive, and time consuming. Here, we introduce a non-destructive, inexpensive, and rapid sampling and analysis system that can continuously monitor the mechanical, biochemical, and structural properties of a single sample over extended periods of time. The label-free system combines the imaging modalities of fluorescent lifetime imaging and ultrasound backscatter microscopy through a fiber-based interface for sterile monitoring of tissue quality. We tested the multimodal system using tissue engineered articular cartilage as an experimental model. We identified strong correlations between optical and destructive testing. Combining FLIm and UBM results, we created a novel statistical model of tissue homogeneity that can be applied to tissue engineered constructs prior to implantation. Continuous monitoring of engineered tissues with this non-destructive system has the potential for in-process monitoring of tissue engineered products, reducing costs and improving quality controls in research, manufacturing, and clinical applications.
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Bielajew BJ, Hu JC, Athanasiou KA. Collagen: quantification, biomechanics, and role of minor subtypes in cartilage. NATURE REVIEWS. MATERIALS 2020; 5:730-747. [PMID: 33996147 PMCID: PMC8114887 DOI: 10.1038/s41578-020-0213-1] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/28/2020] [Indexed: 05/02/2023]
Abstract
Collagen is a ubiquitous biomaterial in vertebrate animals. Although each of its 28 subtypes contributes to the functions of many different tissues in the body, most studies on collagen or collagenous tissues have focussed on only one or two subtypes. With recent developments in analytical chemistry, especially mass spectrometry, significant advances have been made toward quantifying the different collagen subtypes in various tissues; however, high-throughput and low-cost methods for collagen subtype quantification do not yet exist. In this Review, we introduce the roles of collagen subtypes and crosslinks, and describe modern assays that enable a deep understanding of tissue physiology and disease states. Using cartilage as a model tissue, we describe the roles of major and minor collagen subtypes in detail; discuss known and unknown structure-function relationships; and show how tissue engineers may harness the functional characteristics of collagen to engineer robust neotissues.
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Affiliation(s)
- Benjamin J. Bielajew
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92617, USA
| | - Jerry C. Hu
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92617, USA
| | - Kyriacos A. Athanasiou
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA 92617, USA
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3
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Haudenschild AK, Sherlock BE, Zhou X, Hu JC, Leach JK, Marcu L, Athanasiou KA. Non-destructive detection of matrix stabilization correlates with enhanced mechanical properties of self-assembled articular cartilage. J Tissue Eng Regen Med 2019; 13:637-648. [PMID: 30770656 DOI: 10.1002/term.2824] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 12/05/2018] [Accepted: 02/13/2019] [Indexed: 11/10/2022]
Abstract
Tissue engineers rely on expensive, time-consuming, and destructive techniques to monitor the composition, microstructure, and function of engineered tissue equivalents. A non-destructive solution to monitor tissue quality and maturation would greatly reduce costs and accelerate the development of tissue-engineered products. The objectives of this study were to (a) determine whether matrix stabilization with exogenous lysyl oxidase-like protein-2 (LOXL2) with recombinant hyaluronan and proteoglycan link protein-1 (LINK) would result in increased compressive and tensile properties in self-assembled articular cartilage constructs, (b) evaluate whether label-free, non-destructive fluorescence lifetime imaging (FLIm) could be used to infer changes in both biochemical composition and biomechanical properties, (c) form quantitative relationships between destructive and non-destructive measurements to determine whether the strength of these correlations is sufficient to replace destructive testing methods, and (d) determine whether support vector machine (SVM) learning can predict LOXL2-induced collagen crosslinking. The combination of exogenous LOXL2 and LINK proteins created a synergistic 4.9-fold increase in collagen crosslinking density and an 8.3-fold increase in tensile strength as compared with control (CTL). Compressive relaxation modulus was increased 5.9-fold with addition of LOXL2 and 3.4-fold with combined treatments over CTL. FLIm parameters had strong and significant correlations with tensile properties (R2 = 0.82; p < 0.001) and compressive properties (R2 = 0.59; p < 0.001). SVM learning based on FLIm-derived parameters was capable of automating tissue maturation assessment with a discriminant ability of 98.4%. These results showed marked improvements in mechanical properties with matrix stabilization and suggest that FLIm-based tools have great potential for the non-destructive assessment of tissue-engineered cartilage.
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Affiliation(s)
- Anne K Haudenschild
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA
| | - Benjamin E Sherlock
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA
| | - Xiangnan Zhou
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA
| | - Jerry C Hu
- Department of Biomedical Engineering, University of California Irvine, Irvine, CA, USA
| | - J Kent Leach
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA.,Department of Orthopaedic Surgery, University of California Davis Medical Center, Sacramento, CA, USA
| | - Laura Marcu
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA
| | - Kyriacos A Athanasiou
- Department of Biomedical Engineering, University of California Irvine, Irvine, CA, USA
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Mitra D, Fatakdawala H, Nguyen-Truong M, Creecy A, Nyman J, Marcu L, Leach JK. Detection of Pentosidine Cross-Links in Cell-Secreted Decellularized Matrices Using Time Resolved Fluorescence Spectroscopy. ACS Biomater Sci Eng 2017; 3:1944-1954. [PMID: 28944287 PMCID: PMC5604893 DOI: 10.1021/acsbiomaterials.6b00029] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Hyperglycemia-mediated, nonenzymatic collagen cross-links such as pentosidine (PENT) can have deleterious effects on cellular interactions with the extracellular matrix (ECM). Present techniques to quantify PENT are limited, motivating the need for improved methods to study the accumulation and contribution of PENT toward diabetic clinical challenges such as impaired bone healing. Current methods for studying PENT are destructive, laborious, and frequently employ oversimplified collagen films that lack the complexity of the native ECM. The primary goal of this study was to evaluate the capacity of time-resolved fluorescence spectroscopy (TRFS) to detect PENT in cell-secreted ECMs possessing enhanced compositional complexity. To demonstrate an application of this method, we assessed the response of human mesenchymal stem cells (MSCs) to cross-linked substrates to explore the role of detected PENT on osteogenic differentiation. We exposed MSC-secreted decellularized matrices (DMs) to 0.66 M ribose for 2 weeks and used TRFS to detect the accumulation of PENT. Ribose treatment resulted in a 30 nm blue shift in peak fluorescence emission and a significant decrease in average lifetime compared to that of control DMs (4.4 ± 0.3 ns vs 3.5 ± 0.09 ns). Evaluation of samples with high performance liquid chromatography (HPLC) confirmed that changes in observed fluorescence were due to PENT accumulation. A strong correlation was found between TRFS parameters and the HPLC measurement of PENT, validating the use of TRFS as an alternative method of PENT detection. Osteoblastic gene expression was significantly reduced in MSCs seeded on ribose DMs at days 7 and 14. However, no significant differences in calcium deposition were detected between control and ribose DMs. These data demonstrate the efficacy of nondestructive fluorescence spectroscopy to examine the formation of nonenzymatic collagen cross-links within biomimetic culture platforms and showcase one example where an improved biomimetic substrate can be used to probe cell-ECM interactions in the presence of collagen cross-links.
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Affiliation(s)
- Debika Mitra
- Department of Biomedical Engineering, University of California, Davis, California 95616, United States
| | - Hussain Fatakdawala
- Department of Biomedical Engineering, University of California, Davis, California 95616, United States
| | - Michael Nguyen-Truong
- Department of Biomedical Engineering, University of California, Davis, California 95616, United States
| | - Amy Creecy
- Department of Orthopaedic Surgery and Rehabilitation and Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Tennessee Valley Healthcare System, Department of Veterans Affairs, Nashville, Tennessee 37212, United States
| | - Jeffry Nyman
- Department of Orthopaedic Surgery and Rehabilitation and Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, United States
- Tennessee Valley Healthcare System, Department of Veterans Affairs, Nashville, Tennessee 37212, United States
| | - Laura Marcu
- Department of Biomedical Engineering, University of California, Davis, California 95616, United States
| | - J. Kent Leach
- Department of Biomedical Engineering, University of California, Davis, California 95616, United States
- Department of Orthopaedic Surgery, School of Medicine, University of California, Davis, Sacramento, California 95817, United States
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Zhang Y, Li DDU. Comment on 'A novel method for fast and robust estimation of fluorescence decay dynamics using constrained least-square deconvolution with Laguerre expansion'. Phys Med Biol 2017; 62:1632-1636. [PMID: 28145282 DOI: 10.1088/1361-6560/aa522f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This comment is to clarify that Poisson noise instead of Gaussian noise shall be included to assess the performances of least-squares deconvolution with Laguerre expansion (LSD-LE) for analysing fluorescence lifetime imaging data obtained from time-resolved systems. Moreover, we also corrected an equation in the paper. As the LSD-LE method is rapid and has the potential to be widely applied not only for diagnostic but for wider bioimaging applications, it is desirable to have precise noise models and equations.
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Affiliation(s)
- Yongliang Zhang
- Centre for Biophotonics, Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, Glasgow, Scotland, UK. College of Information Science & Electronic Engineering, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
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Mansour JM, Lee Z, Welter JF. Nondestructive Techniques to Evaluate the Characteristics and Development of Engineered Cartilage. Ann Biomed Eng 2016; 44:733-49. [PMID: 26817458 PMCID: PMC4792725 DOI: 10.1007/s10439-015-1535-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 12/12/2015] [Indexed: 12/16/2022]
Abstract
In this review, methods for evaluating the properties of tissue engineered (TE) cartilage are described. Many of these have been developed for evaluating properties of native and osteoarthritic articular cartilage. However, with the increasing interest in engineering cartilage, specialized methods are needed for nondestructive evaluation of tissue while it is developing and after it is implanted. Such methods are needed, in part, due to the large inter- and intra-donor variability in the performance of the cellular component of the tissue, which remains a barrier to delivering reliable TE cartilage for implantation. Using conventional destructive tests, such variability makes it near-impossible to predict the timing and outcome of the tissue engineering process at the level of a specific piece of engineered tissue and also makes it difficult to assess the impact of changing tissue engineering regimens. While it is clear that the true test of engineered cartilage is its performance after it is implanted, correlation of pre and post implantation properties determined non-destructively in vitro and/or in vivo with performance should lead to predictive methods to improve quality-control and to minimize the chances of implanting inferior tissue.
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Affiliation(s)
- Joseph M Mansour
- Departments of Mechanical and Aerospace Engineering, Case Western Reserve University, 2123 Martin Luther King Jr. Drive, Glennan Building Room 616A, Cleveland, OH, 44106, USA.
| | - Zhenghong Lee
- Radiology and Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Jean F Welter
- Biology (Skeletal Research Center), Case Western Reserve University, Cleveland, OH, USA
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Fatakdawala H, Griffiths LG, Humphrey S, Marcu L. Time-resolved fluorescence spectroscopy and ultrasound backscatter microscopy for nondestructive evaluation of vascular grafts. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:080503. [PMID: 25147960 PMCID: PMC4407666 DOI: 10.1117/1.jbo.19.8.080503] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2014] [Revised: 07/28/2014] [Accepted: 08/01/2014] [Indexed: 06/03/2023]
Abstract
Quantitative and qualitative evaluations of structure and composition are important in monitoring development of engineered vascular tissue both in vitro and in vivo. Destructive techniques are an obstacle for performing time-lapse analyses from a single sample or animal. This study demonstrates the ability of time-resolved fluorescence spectroscopy (TRFS) and ultrasound backscatter microscopy (UBM), as nondestructive and synergistic techniques, for compositional and morphological analyses of tissue grafts, respectively. UBM images and integrated backscatter coefficients demonstrate the ability to visualize and quantify postimplantation changes in vascular graft biomaterials such as loss of the external elastic lamina and intimal/medial thickening over the grafted region as well as graft integration with the surrounding tissue. TRFS results show significant changes in spectra, average lifetime, and fluorescence decay parameters owing to changes in collagen, elastin, and cellular content between normal and grafted tissue regions. These results lay the foundation for the application of a catheter-based technique for in vivo evaluation of vascular grafts using TRFS and UBM.
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Affiliation(s)
- Hussain Fatakdawala
- University of California Davis, Department of Biomedical Engineering, 451 East Health Sciences Drive, Davis, California 95616, United States
| | - Leigh G. Griffiths
- University of California Davis, Department of Medicine and Epidemiology, VM2 Building, Davis, California 95618, United States
| | - Sterling Humphrey
- University of California Davis, Department of Surgery, 2221 Stockton Boulevard, Sacramento, California 95817, United States
| | - Laura Marcu
- University of California Davis, Department of Biomedical Engineering, 451 East Health Sciences Drive, Davis, California 95616, United States
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Ma D, Bec J, Yankelevich DR, Gorpas D, Fatakdawala H, Marcu L. Rotational multispectral fluorescence lifetime imaging and intravascular ultrasound: bimodal system for intravascular applications. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:066004. [PMID: 24898604 PMCID: PMC4045254 DOI: 10.1117/1.jbo.19.6.066004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 05/05/2014] [Accepted: 05/06/2014] [Indexed: 05/24/2023]
Abstract
We report the development and validation of a hybrid intravascular diagnostic system combining multispectral fluorescence lifetime imaging (FLIm) and intravascular ultrasound (IVUS) for cardiovascular imaging applications. A prototype FLIm system based on fluorescence pulse sampling technique providing information on artery biochemical composition was integrated with a commercial IVUS system providing information on artery morphology. A customized 3-Fr bimodal catheter combining a rotational side-view fiberoptic and a 40-MHz IVUS transducer was constructed for sequential helical scanning (rotation and pullback) of tubular structures. Validation of this bimodal approach was conducted in pig heart coronary arteries. Spatial resolution, fluorescence detection efficiency, pulse broadening effect, and lifetime measurement variability of the FLIm system were systematically evaluated. Current results show that this system is capable of temporarily resolving the fluorescence emission simultaneously in multiple spectral channels in a single pullback sequence. Accurate measurements of fluorescence decay characteristics from arterial segments can be obtained rapidly (e.g., 20 mm in 5 s), and accurate co-registration of fluorescence and ultrasound features can be achieved. The current finding demonstrates the compatibility of FLIm instrumentation with in vivo clinical investigations and its potential to complement conventional IVUS during catheterization procedures.
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Affiliation(s)
- Dinglong Ma
- University of California, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616
| | - Julien Bec
- University of California, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616
| | - Diego R. Yankelevich
- University of California, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616
- University of California, Department of Electrical Engineering, 3101 Kemper Hall, Davis, California 95616
| | - Dimitris Gorpas
- University of California, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616
| | - Hussain Fatakdawala
- University of California, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616
| | - Laura Marcu
- University of California, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616
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Qi W, Li R, Ma T, Kirk Shung K, Zhou Q, Chen Z. Confocal acoustic radiation force optical coherence elastography using a ring ultrasonic transducer. APPLIED PHYSICS LETTERS 2014; 104:123702. [PMID: 24737920 PMCID: PMC3971820 DOI: 10.1063/1.4869562] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 03/13/2014] [Indexed: 05/17/2023]
Abstract
We designed and developed a confocal acoustic radiation force optical coherence elastography system. A ring ultrasound transducer was used to achieve reflection mode excitation and generate an oscillating acoustic radiation force in order to generate displacements within the tissue, which were detected using the phase-resolved optical coherence elastography method. Both phantom and human tissue tests indicate that this system is able to sense the stiffness difference of samples and quantitatively map the elastic property of materials. Our confocal setup promises a great potential for point by point elastic imaging in vivo and differentiation of diseased tissues from normal tissue.
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Affiliation(s)
- Wenjuan Qi
- Beckman Laser Institute, University of California, Irvine, 1002 Health Sciences Road East, Irvine, California 92612, USA ; Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, USA
| | - Rui Li
- Beckman Laser Institute, University of California, Irvine, 1002 Health Sciences Road East, Irvine, California 92612, USA
| | - Teng Ma
- Department of Biomedical Engineering, NIH Ultrasonic Transducer Resource Center, University of Southern California, Los Angeles, California 90089, USA
| | - K Kirk Shung
- Department of Biomedical Engineering, NIH Ultrasonic Transducer Resource Center, University of Southern California, Los Angeles, California 90089, USA
| | - Qifa Zhou
- Department of Biomedical Engineering, NIH Ultrasonic Transducer Resource Center, University of Southern California, Los Angeles, California 90089, USA
| | - Zhongping Chen
- Beckman Laser Institute, University of California, Irvine, 1002 Health Sciences Road East, Irvine, California 92612, USA ; Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, California 92697, USA ; Department of Biomedical Engineering, University of California, Irvine, Irvine, California 92697, USA
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Yankelevich D, González JE, Cudney RS, Ríos LA, Marcu L. Development of a new pulsed source for photoacoustic imaging based on aperiodically poled lithium niobate. BIOMEDICAL OPTICS EXPRESS 2014; 5:468-473. [PMID: 24575341 PMCID: PMC3920877 DOI: 10.1364/boe.5.000468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 12/20/2013] [Accepted: 01/07/2014] [Indexed: 06/03/2023]
Abstract
We present the development of a source of deep-red radiation for photoacoustic imaging. This source, which is based on two cascaded wavelength conversion processes in aperiodically poled lithium niobate, emits 10 nanosecond pulses of over 500 µJ at 710 nm. Photoacoustic images were obtained from phantoms designed to mimic the optical and acoustic properties of oral tissue. Results indicate this device is a viable source of optical pulses for photoacoustic applications.
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Affiliation(s)
- Diego Yankelevich
- Department of Electrical and Computer Engineering, University of California, 3101 Kemper Hall, Davis, California, 95616, USA
- Department of Biomedical Engineering, University of California, 451 Health Sciences Drive, Davis, California, 95616, USA
| | - J. E. González
- Department of Optics, Centro de Investigación Científica y Educación Superior de Ensenada, Ensenada 22880, Mexico
| | - Roger S. Cudney
- Department of Optics, Centro de Investigación Científica y Educación Superior de Ensenada, Ensenada 22880, Mexico
| | - Luis A. Ríos
- Department of Optics, Centro de Investigación Científica y Educación Superior de Ensenada, Ensenada 22880, Mexico
| | - Laura Marcu
- Department of Electrical and Computer Engineering, University of California, 3101 Kemper Hall, Davis, California, 95616, USA
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Lam M, Chaudhari AJ, Sun Y, Zhou F, Dobbie A, Gandour-Edwards RF, Tinling SP, Farwell DG, Monsky WL, Shung KK, Marcu L. Ultrasound backscatter microscopy for imaging of oral carcinoma. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2013; 32:1789-97. [PMID: 24065260 PMCID: PMC3835773 DOI: 10.7863/ultra.32.10.1789] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
OBJECTIVES Ultrasound backscatter microscopy (UBM), or ultrasound biomicroscopy, is a noninvasive, label-free, and ionizing radiation-free technique allowing high-resolution 3-dimensional structural imaging. The goal of this study was to evaluate UBM for resolving anatomic features associated with squamous cell carcinoma of the oral cavity. METHODS The study was conducted in a hamster buccal pouch model. A carcinogen was topically applied to cheeks of 14 golden Syrian hamsters. Six additional hamsters served as healthy controls. A high-frequency (41 MHz, 6-mm focal depth, lateral and axial resolutions of 65 and 37 μm, respectively) UBM system was used for scanning the oral cavity after 14 weeks of carcinogen application. Histologic analyses were conducted on scanned regions. RESULTS The histologic structure of buccal tissue and microvasculature networks could be visualized from the UBM images. Epithelial and mucosal hypertrophy and neoplastic changes were identified in animals subjected to the carcinogen. In animals with invasive squamous cell carcinoma, lesion development and destruction of the structural integrity of tissue layers were noted. CONCLUSIONS In this pilot study, UBM generated sufficient contrast for morphologic features associated with oral carcinoma compared to healthy tissue. This modality may present a practical technique for detection of oral neoplasms that is potentially translatable to humans.
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Affiliation(s)
- Matthew Lam
- Department of Radiology, University of California Davis School of Medicine, 4860 Y St, Suite 3100, Sacramento, CA 95817.
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Sun Y, Xie H, Liu J, Lam M, Chaudhari AJ, Zhou F, Bec J, Yankelevich DR, Dobbie A, Tinling SL, Gandour-Edwards RF, Monsky WL, Gregory Farwell D, Marcu L. In vivo validation of a bimodal technique combining time-resolved fluorescence spectroscopy and ultrasonic backscatter microscopy for diagnosis of oral carcinoma. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:116003. [PMID: 23117798 PMCID: PMC3484195 DOI: 10.1117/1.jbo.17.11.116003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 09/19/2012] [Accepted: 09/24/2012] [Indexed: 05/29/2023]
Abstract
Tissue diagnostic features generated by a bimodal technique integrating scanning time-resolved fluorescence spectroscopy (TRFS) and ultrasonic backscatter microscopy (UBM) are investigated in an in vivo hamster oral carcinoma model. Tissue fluorescence is excited by a pulsed nitrogen laser and spectrally and temporally resolved using a set of filters/dichroic mirrors and a fast digitizer, respectively. A 41-MHz focused transducer (37-μm axial, 65-μm lateral resolution) is used for UBM scanning. Representative lesions of the different stages of carcinogenesis show that fluorescence characteristics complement ultrasonic features, and both correlate with histological findings. These results demonstrate that TRFS-UBM provide a wealth of co-registered, complementary data concerning tissue composition and structure as it relates to disease status. The direct co-registration of the TRFS data (sensitive to surface molecular changes) with the UBM data (sensitive to cross-sectional structural changes and depth of tumor invasion) is expected to play an important role in pre-operative diagnosis and intra-operative determination of tumor margins.
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Affiliation(s)
- Yang Sun
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616
| | - Hongtao Xie
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616
| | - Jing Liu
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616
| | - Matthew Lam
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616
| | - Abhijit J. Chaudhari
- University of California, Davis, School of Medicine, Department of Radiology, 4860 Y Street, Sacramento, California 95817
| | - Feifei Zhou
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616
| | - Julien Bec
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616
| | - Diego R. Yankelevich
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616
| | - Allison Dobbie
- University of California, Davis, Department of Head and Neck Oncology, Skull Base Surgery, 2521 Stockton Boulevard, Suite 7200, Sacramento, California 95817
| | - Steven L. Tinling
- University of California, Davis, Department of Head and Neck Oncology, Skull Base Surgery, 2521 Stockton Boulevard, Suite 7200, Sacramento, California 95817
| | - Regina F. Gandour-Edwards
- University of California, Davis, Department of Pathology & Laboratory Medicine, 4400 V Street, Sacramento, California 95817
| | - Wayne L. Monsky
- University of California, Davis, School of Medicine, Department of Radiology, 4860 Y Street, Sacramento, California 95817
| | - D. Gregory Farwell
- University of California, Davis, Department of Head and Neck Oncology, Skull Base Surgery, 2521 Stockton Boulevard, Suite 7200, Sacramento, California 95817
| | - Laura Marcu
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616
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13
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Qiu W, Chen Y, Li X, Yu Y, Cheng WF, Tsang FK, Zhou Q, Shung KK, Dai J, Sun L. An open system for intravascular ultrasound imaging. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2012; 59:2201-9. [PMID: 23143570 PMCID: PMC3760234 DOI: 10.1109/tuffc.2012.2446] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Visualization of the blood vessels can provide valuable morphological information for diagnosis and therapy strategies for cardiovascular disease. Intravascular ultrasound (IVUS) is able to delineate internal structures of vessel wall with fine spatial resolution. However, the developed IVUS is insufficient to identify the fibrous cap thickness and tissue composition of atherosclerotic lesions. Novel imaging strategies have been proposed, such as increasing the center frequency of ultrasound or using a modulated excitation technique to improve the accuracy of diagnosis. Dual-mode tomography combining IVUS with optical tomography has also been developed to determine tissue morphology and characteristics. The implementation of these new imaging methods requires an open system that allows users to customize the system for various studies. This paper presents the development of an IVUS system that has open structures to support various imaging strategies. The system design is based on electronic components and printed circuit board, and provides reconfigurable hardware implementation, programmable image processing algorithms, flexible imaging control, and raw RF data acquisition. In addition, the proposed IVUS system utilized a miniaturized ultrasound transducer constructed using PMNPT single crystal for better piezoelectric constant and electromechanical coupling coefficient than traditional lead zirconate titanate (PZT) ceramics. Testing results showed that the IVUS system could offer a minimum detectable signal of 25 μV, allowing a 51 dB dynamic range at 47 dB gain, with a frequency range from 20 to 80 MHz. Finally, phantom imaging, in vitro IVUS vessel imaging, and multimodality imaging with photoacoustics were conducted to demonstrate the performance of the open system.
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Affiliation(s)
- Weibao Qiu
- Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Yan Chen
- Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Xiang Li
- National Institutes of Health Resource Center for Medical Ultrasonic Transducer Technology and Department of Biomedical Engineering, University of Southern California, Los Angeles, CA
| | - Yanyan Yu
- Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Wang Fai Cheng
- Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Fu Keung Tsang
- Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Qifa Zhou
- National Institutes of Health Resource Center for Medical Ultrasonic Transducer Technology and Department of Biomedical Engineering, University of Southern California, Los Angeles, CA
| | - K. Kirk Shung
- National Institutes of Health Resource Center for Medical Ultrasonic Transducer Technology and Department of Biomedical Engineering, University of Southern California, Los Angeles, CA
| | - Jiyan Dai
- Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Lei Sun
- Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong SAR, China ()
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14
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Marcu L, Hartl BA. Fluorescence Lifetime Spectroscopy and Imaging in Neurosurgery. IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS : A PUBLICATION OF THE IEEE LASERS AND ELECTRO-OPTICS SOCIETY 2012; 18:1465-1477. [PMID: 28053498 PMCID: PMC5205025 DOI: 10.1109/jstqe.2012.2185823] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Clinical outcome of patients diagnosed with primary brain tumor has been correlated with the extent of surgical resection. In treating this disease, the neurosurgeon must balance between an aggressive, radical resection and minimizing the loss of healthy, functionally significant brain tissue. Numerous intra-operative methodologies and technological approaches have been explored as a means to improve the accuracy of surgical resection. This paper presents an overview of current conventional techniques and new emerging technologies with potential to impact the area of image-guided surgery of brain tumors. Emphasis is placed on techniques based on endogenous fluorescence lifetime contrast and their potential for intraoperative diagnosis of brain tumors.
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Affiliation(s)
- Laura Marcu
- University of California, Davis, Davis, CA 95616 USA
| | - Brad A Hartl
- University of California, Davis, Davis, CA 95616 USA
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15
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Xie H, Bec J, Liu J, Sun Y, Lam M, Yankelevich DR, Marcu L. Multispectral scanning time-resolved fluorescence spectroscopy (TRFS) technique for intravascular diagnosis. BIOMEDICAL OPTICS EXPRESS 2012; 3:1521-33. [PMID: 22808425 PMCID: PMC3395478 DOI: 10.1364/boe.3.001521] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Revised: 05/25/2012] [Accepted: 05/25/2012] [Indexed: 05/09/2023]
Abstract
This study describes a scanning time-resolved fluorescence spectroscopy (TRFS) system designed to continuously acquire fluorescence emission and to reconstruct fluorescence lifetime images (FLIM) from a luminal surface by using a catheter-based optical probe with rotary joint and pull-back device. The ability of the system to temporally and spectrally resolve the fluorescence emission from tissue was validated using standard dyes and tissue phantoms (e.g., ex vivo pig aorta phantom). Current results demonstrate that this system is capable to reliably resolve the fluorescence emission of multiple fluorophores located in the lumen; and suggest its potential for intravascular detection of distinct biochemical features of atherosclerotic plaques.
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Affiliation(s)
- Hongtao Xie
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, CA 95616, USA
| | - Julien Bec
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, CA 95616, USA
| | - Jing Liu
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, CA 95616, USA
| | - Yang Sun
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, CA 95616, USA
| | - Matthew Lam
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, CA 95616, USA
| | - Diego R. Yankelevich
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, CA 95616, USA
| | - Laura Marcu
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, CA 95616, USA
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16
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Zhang Y, Gao G, Chan HLW, Dai J, Wang Y, Hao J. Piezo-phototronic effect-induced dual-mode light and ultrasound emissions from ZnS:Mn/PMN-PT thin-film structures. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2012; 24:1729-1735. [PMID: 22396325 DOI: 10.1002/adma.201104584] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 01/19/2012] [Indexed: 05/31/2023]
Abstract
Electric-field-controllable luminescence of a ZnS:Mn/PMN-PT system is demonstrated. The light-emission of ZnS:Mn is caused by the piezoelectric potential, resulting from the converse piezoelectric effect of the PMN-PT substrate. Simultaneous generation of light and ultrasound waves is observed in this single system, which offers great potential to develop a dual-modal source combing light and ultrasonic waves for various applications.
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Affiliation(s)
- Yang Zhang
- Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, PR China
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17
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Marcu L. Fluorescence lifetime techniques in medical applications. Ann Biomed Eng 2012; 40:304-31. [PMID: 22273730 PMCID: PMC3368954 DOI: 10.1007/s10439-011-0495-y] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Accepted: 12/17/2011] [Indexed: 12/20/2022]
Abstract
This article presents an overview of time-resolved (lifetime) fluorescence techniques used in biomedical diagnostics. In particular, we review the development of time-resolved fluorescence spectroscopy (TRFS) and fluorescence lifetime imaging (FLIM) instrumentation and associated methodologies which allow in vivo characterization and diagnosis of biological tissues. Emphasis is placed on the translational research potential of these techniques and on evaluating whether intrinsic fluorescence signals provide useful contrast for the diagnosis of human diseases including cancer (gastrointestinal tract, lung, head and neck, and brain), skin and eye diseases, and atherosclerotic cardiovascular disease.
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Affiliation(s)
- Laura Marcu
- Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, USA.
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18
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Liu J, Sun Y, Qi J, Marcu L. A novel method for fast and robust estimation of fluorescence decay dynamics using constrained least-squares deconvolution with Laguerre expansion. Phys Med Biol 2012; 57:843-65. [PMID: 22290334 DOI: 10.1088/0031-9155/57/4/843] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We report a novel method for estimating fluorescence impulse response function (fIRF) from noise-corrupted time-domain fluorescence measurements of biological tissue. This method is based on the use of high-order Laguerre basis functions and a constrained least-squares approach that addresses the problem of overfitting due to increased model complexity. The new method was extensively evaluated on fluorescence data from simulation, fluorescent standard dyes, ex vivo tissue samples of atherosclerotic plaques and in vivo oral carcinoma. Current results demonstrate that this method allows for rapid and accurate deconvolution of multiple channel fluorescence decays without adaptively adjusting the Laguerre scale parameter. The appropriate choice of the scale parameter is essential for accurate estimation of the fIRF. The method described here is anticipated to play an important role in the development of computational techniques for real-time analysis of time-resolved fluorescence data from biological tissues and to support the advancement of fluorescence lifetime instrumentation for biomedical diagnostics by providing a means for on-line robust analysis of fluorescence decay.
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Affiliation(s)
- Jing Liu
- Department of Biomedical Engineering, University of California, Davis, CA 95616, USA
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19
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Sun Y, Responte D, Xie H, Liu J, Fatakdawala H, Hu J, Athanasiou KA, Marcu L. Nondestructive evaluation of tissue engineered articular cartilage using time-resolved fluorescence spectroscopy and ultrasound backscatter microscopy. Tissue Eng Part C Methods 2012; 18:215-26. [PMID: 22010819 DOI: 10.1089/ten.tec.2011.0343] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The goal of this study is to evaluate the ability of a bimodal technique integrating time-resolved fluorescence spectroscopy (TRFS) and ultrasound backscatter microscopy (UBM) for nondestructive detection of changes in the biochemical, structural, and mechanical properties of self-assembled engineered articular cartilage constructs. The cartilage constructs were treated with three chemical agents (collagenase, chondroitinase-ABC, and ribose) to induce changes in biochemical content (collagen and glycosaminoglycan [GAG]) of matured constructs (4 weeks); and to subsequently alter the mechanical properties of the construct. The biochemical changes were evaluated using TRFS. The microstructure and the thickness of the engineered cartilage samples were characterized by UBM. The optical and ultrasound results were validated against those acquired via conventional techniques including collagen and GAG quantification and measurement of construct stiffness. Current results demonstrated that a set of optical parameters (e.g., average fluorescence lifetime and decay constants) showed significant correlation (p<0.05) with biochemical and mechanical data. The high-resolution ultrasound images provided complementary cross-section information of the cartilage samples morphology. Therefore, the technique was capable of nondestructively evaluating the composition of extracellular matrix and the microstructure of engineered tissue, demonstrating great potential as an alternative to traditional destructive assays.
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Affiliation(s)
- Yang Sun
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA
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20
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Sun Y, Chaudhari AJ, Lam M, Xie H, Yankelevich DR, Phipps J, Liu J, Fishbein MC, Cannata JM, Shung KK, Marcu L. Multimodal characterization of compositional, structural and functional features of human atherosclerotic plaques. BIOMEDICAL OPTICS EXPRESS 2011; 2:2288-98. [PMID: 21833365 PMCID: PMC3149526 DOI: 10.1364/boe.2.002288] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 07/14/2011] [Accepted: 07/14/2011] [Indexed: 05/22/2023]
Abstract
Detection of atherosclerotic plaque vulnerability has critical clinical implications for avoiding sudden death in patients with high risk of plaque rupture. We report on multimodality imaging of ex-vivo human carotid plaque samples using a system that integrates fluorescence lifetime imaging (FLIM), ultrasonic backscatter microscopy (UBM), and photoacoustic imaging (PAI). Biochemical composition is differentiated with a high temporal resolution and sensitivity at the surface of the plaque by the FLIM subsystem. 3D microanatomy of the whole plaque is reconstructed by the UBM. Functional imaging associated with optical absorption contrast is evaluated from the PAI component. Simultaneous recordings of the optical, ultrasonic, and photoacoustic data present a wealth of complementary information concerning the plaque composition, structure, and function that are related to plaque vulnerability. This approach is expected to improve our ability to study atherosclerotic plaques. The multimodal system presented here can be translated into a catheter based intraluminal system for future clinical studies.
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Affiliation(s)
- Yang Sun
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616, USA
| | - Abhijit J. Chaudhari
- University of California, Davis School of Medicine, Department of Radiology, 4860 Y Street, Sacramento, California 95817, USA
| | - Matthew Lam
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616, USA
| | - Hongtao Xie
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616, USA
| | - Diego R. Yankelevich
- University of California, Davis, Department of Electrical and Computer Engineering, One shields Avenue, Davis, California 95616, USA
| | - Jennifer Phipps
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616, USA
| | - Jing Liu
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616, USA
| | - Michael C. Fishbein
- University of California, Los Angeles, Department of Pathology, 10833 Le Conte Ave, Los Angeles, California 90095, USA
| | - Jonathan M. Cannata
- University of Southern California, Department of Biomedical Engineering, 1042 Downey way, DRB 140, Los Angeles, California 90089, USA
| | - K. Kirk Shung
- University of Southern California, Department of Biomedical Engineering, 1042 Downey way, DRB 140, Los Angeles, California 90089, USA
| | - Laura Marcu
- University of California, Davis, Department of Biomedical Engineering, 451 Health Sciences Drive, Davis, California 95616, USA
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21
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Sun Y, Sun Y, Stephens D, Xie H, Phipps J, Saroufeem R, Southard J, Elson DS, Marcu L. Dynamic tissue analysis using time- and wavelength-resolved fluorescence spectroscopy for atherosclerosis diagnosis. OPTICS EXPRESS 2011; 19:3890-901. [PMID: 21369214 PMCID: PMC3368314 DOI: 10.1364/oe.19.003890] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 01/19/2011] [Accepted: 02/08/2011] [Indexed: 05/20/2023]
Abstract
Simultaneous time- and wavelength-resolved fluorescence spectroscopy (STWRFS) was developed and tested for the dynamic characterization of atherosclerotic tissue ex vivo and arterial vessels in vivo. Autofluorescence, induced by a 337 nm, 700 ps pulsed laser, was split to three wavelength sub-bands using dichroic filters, with each sub-band coupled into a different length of optical fiber for temporal separation. STWRFS allows for fast recording/analysis (few microseconds) of time-resolved fluorescence emission in these sub-bands and rapid scanning. Distinct compositions of excised human atherosclerotic aorta were clearly discriminated over scanning lengths of several centimeters based on fluorescence lifetime and the intensity ratio between 390 and 452 nm. Operation of STWRFS blood flow was further validated in pig femoral arteries in vivo using a single-fiber probe integrated with an ultrasound imaging catheter. Current results demonstrate the potential of STWRFS as a tool for real-time optical characterization of arterial tissue composition and for atherosclerosis research and diagnosis.
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Affiliation(s)
- Yinghua Sun
- Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, USA
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22
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Fite BZ, Decaris M, Sun Y, Sun Y, Lam A, Ho CKL, Leach JK, Marcu L. Noninvasive multimodal evaluation of bioengineered cartilage constructs combining time-resolved fluorescence and ultrasound imaging. Tissue Eng Part C Methods 2011; 17:495-504. [PMID: 21303258 DOI: 10.1089/ten.tec.2010.0368] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
A multimodal diagnostic system that integrates time-resolved fluorescence spectroscopy, fluorescence lifetime imaging microscopy, and ultrasound backscatter microscopy is evaluated here as a potential tool for assessing changes in engineered tissue composition and microstructure nondestructively and noninvasively. The development of techniques capable of monitoring the quality of engineered tissue, determined by extracellular matrix (ECM) content, before implantation would alleviate the need for destructive assays over multiple time points and advance the widespread development and clinical application of engineered tissues. Using a prototype system combining time-resolved fluorescence spectroscopy, FLIM, and UBM, we measured changes in ECM content occurring during chondrogenic differentiation of equine adipose stem cells on 3D biodegradable matrices. The optical and ultrasound results were validated against those acquired via conventional techniques, including collagen II immunohistochemistry, picrosirius red staining, and measurement of construct stiffness. Current results confirm the ability of this multimodal approach to follow the progression of tissue maturation along the chondrogenic lineage by monitoring ECM production (namely, collagen type II) and by detecting resulting changes in mechanical properties of tissue constructs. Although this study was directed toward monitoring chondrogenic tissue maturation, these data demonstrate the feasibility of this approach for multiple applications toward engineering other tissues, including bone and vascular grafts.
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Affiliation(s)
- Brett Z Fite
- Department of Biomedical Engineering, University of California, Davis, California 95616, USA
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23
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Sun Y, Stephens DN, Park J, Sun Y, Marcu L, Cannata JM, Shung KK. Development of a Multi-modal Tissue Diagnostic System Combining High Frequency Ultrasound and Photoacoustic Imaging with Lifetime Fluorescence Spectroscopy. PROCEEDINGS. IEEE ULTRASONICS SYMPOSIUM 2008:570-573. [PMID: 21894259 PMCID: PMC3164263 DOI: 10.1109/ultsym.2008.0137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
We report the development and validate a multi-modal tissue diagnostic technology, which combines three complementary techniques into one system including ultrasound backscatter microscopy (UBM), photoacoustic imaging (PAI), and time-resolved laser-induced fluorescence spectroscopy (TR-LIFS). UBM enables the reconstruction of the tissue microanatomy. PAI maps the optical absorption heterogeneity of the tissue associated with structure information and has the potential to provide functional imaging of the tissue. Examination of the UBM and PAI images allows for localization of regions of interest for TR-LIFS evaluation of the tissue composition. The hybrid probe consists of a single element ring transducer with concentric fiber optics for multi-modal data acquisition. Validation and characterization of the multi-modal system and ultrasonic, photoacoustic, and spectroscopic data coregistration were conducted in a physical phantom with properties of ultrasound scattering, optical absorption, and fluorescence. The UBM system with the 41 MHz ring transducer can reach the axial and lateral resolution of 30 and 65 μm, respectively. The PAI system with 532 nm excitation light from a Nd:YAG laser shows great contrast for the distribution of optical absorbers. The TR-LIFS system records the fluorescence decay with the time resolution of ~300 ps and a high sensitivity of nM concentration range. Biological phantom constructed with different types of tissues (tendon and fat) was used to demonstrate the complementary information provided by the three modalities. Fluorescence spectra and lifetimes were compared to differentiate chemical composition of tissues at the regions of interest determined by the coregistered high resolution UBM and PAI image. Current results demonstrate that the fusion of these techniques enables sequentially detection of functional, morphological, and compositional features of biological tissue, suggesting potential applications in diagnosis of tumors and atherosclerotic plaques.
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Affiliation(s)
- Yang Sun
- Biomedical Engineering, University of California, Davis, Davis, CA
| | | | - Jesung Park
- Biomedical Engineering, University of California, Davis, Davis, CA
| | - Yinghua Sun
- Biomedical Engineering, University of California, Davis, Davis, CA
| | - Laura Marcu
- Biomedical Engineering, University of California, Davis, Davis, CA
| | | | - K. Kirk Shung
- Biomedical Engineering, University of Southern California, Los Angeles, CA
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