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Gade PS, Robertson AM, Chuang CY. Multiphoton Imaging of Collagen, Elastin, and Calcification in Intact Soft-Tissue Samples. CURRENT PROTOCOLS IN CYTOMETRY 2019; 87:e51. [PMID: 30379412 PMCID: PMC6314890 DOI: 10.1002/cpcy.51] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Multiphoton-induced second-harmonic generation and two-photon excitation enable imaging of collagen and elastin fibers at micron-level resolution to depths of hundreds of microns, without the use of exogenous stains. These attributes can be leveraged for quantitative analysis of the 3D architecture of collagen and elastin fibers within intact, soft tissue specimens such as the artery and bladder wall. This architecture influences the function of intramural cells and also plays a primary role in determining tissue passive mechanical properties. Calcification deposition in soft tissues is a highly prevalent pathology in both older and diseased populations that can alter tissue properties. In this unit, we provide a protocol for simultaneous multiphoton microscopy (MPM) imaging and analysis of 3D collagen and elastin structures with calcification, which is effective for fixed and fresh intact samples. We also provide an associated micro-CT protocol to identify regions of interest in the samples as a means to target the MPM imaging. © 2018 by John Wiley & Sons, Inc.
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Affiliation(s)
- Piyusha S. Gade
- Department of Bioengineerin, University of Pittsburgh Pittsburgh, PA
| | - Anne M. Robertson
- Department of Bioengineerin, University of Pittsburgh Pittsburgh, PA
- Department of Mechanical Engineering and Materials Science, University of Pittsburgh Pittsburgh, PA
| | - Chih-Yuan Chuang
- Department of Mechanical Engineering and Materials Science, University of Pittsburgh Pittsburgh, PA
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Jiang B, Suen R, Wang JJ, Zhang ZJ, Wertheim JA, Ameer GA. Vascular scaffolds with enhanced antioxidant activity inhibit graft calcification. Biomaterials 2017; 144:166-175. [PMID: 28841463 DOI: 10.1016/j.biomaterials.2017.08.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 08/08/2017] [Accepted: 08/13/2017] [Indexed: 10/19/2022]
Abstract
There is a need for off-the-shelf, small-diameter vascular grafts that are safe and exhibit high long-term patency. Decellularized tissues can potentially be used as vascular grafts; however, thrombogenic and unpredictable remodeling properties such as intimal hyperplasia and calcification are concerns that hinder their clinical use. The objective of this study was to investigate the long-term function and remodeling of extracellular matrix (ECM)-based vascular grafts composited with antioxidant poly(1, 8-octamethylene-citrate-co-cysteine) (POCC) with or without immobilized heparin. Rat aortas were decellularized to create the following vascular grafts: 1) ECM hybridized with POCC (Poly-ECM), 2) Poly-ECM subsequently functionalized with heparin (Poly-ECM-Hep), and 3) non-modified vascular ECM. Grafts were evaluated as interposition grafts in the abdominal aorta of adult rats at three months. All grafts displayed antioxidant activity, were patent, and exhibited minimal intramural cell infiltration with varying degrees of calcification. Areas of calcification co-localized with osteochondrogenic differentiation of vascular smooth muscle cells, lipid peroxidation, oxidized DNA damage, and cell apoptosis, suggesting an important role for oxidative stress in the calcification of grafts. The extent of calcification within grafts was inversely proportional to their antioxidant activity: Poly-ECM-Hep > ECM > Poly-ECM. The incorporation of antioxidants into vascular grafts may be a viable strategy to inhibit degenerative changes.
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Affiliation(s)
- Bin Jiang
- Biomedical Engineering Department, Northwestern University, Evanston, IL, 60208, USA; Comprehensive Transplant Center, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA; Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA; Center for Advanced Regenerative Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Rachel Suen
- Weinberg College of Arts and Sciences, Northwestern University, Evanston, IL, 60208, USA
| | - Jiao-Jing Wang
- Comprehensive Transplant Center, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA; Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Zheng J Zhang
- Comprehensive Transplant Center, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA; Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Jason A Wertheim
- Biomedical Engineering Department, Northwestern University, Evanston, IL, 60208, USA; Comprehensive Transplant Center, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA; Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA; Department of Surgery, Jesse Brown VA Medical Center, Chicago, IL, 60612, USA; Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, 60208, USA; Simpson Querrey Institute, Northwestern University, Chicago, IL, 60611, USA; Center for Advanced Regenerative Engineering, Northwestern University, Evanston, IL, 60208, USA.
| | - Guillermo A Ameer
- Biomedical Engineering Department, Northwestern University, Evanston, IL, 60208, USA; Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA; Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, 60208, USA; Simpson Querrey Institute, Northwestern University, Chicago, IL, 60611, USA; Center for Advanced Regenerative Engineering, Northwestern University, Evanston, IL, 60208, USA.
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