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Bowers DT, Tanes ML, Das A, Lin Y, Keane NA, Neal RA, Ogle ME, Brayman KL, Fraser CL, Botchwey EA. Spatiotemporal oxygen sensing using dual emissive boron dye-polylactide nanofibers. ACS NANO 2014; 8:12080-91. [PMID: 25426706 PMCID: PMC4278692 DOI: 10.1021/nn504332j] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Oxygenation in tissue scaffolds continues to be a limiting factor in regenerative medicine despite efforts to induce neovascularization or to use oxygen-generating materials. Unfortunately, many established methods to measure oxygen concentration, such as using electrodes, require mechanical disturbance of the tissue structure. To address the need for scaffold-based oxygen concentration monitoring, a single-component, self-referenced oxygen sensor was made into nanofibers. Electrospinning process parameters were tuned to produce a biomaterial scaffold with specific morphological features. The ratio of an oxygen sensitive phosphorescence signal to an oxygen insensitive fluorescence signal was calculated at each image pixel to determine an oxygenation value. A single component boron dye-polymer conjugate was chosen for additional investigation due to improved resistance to degradation in aqueous media compared to a boron dye polymer blend. Standardization curves show that in fully supplemented media, the fibers are responsive to dissolved oxygen concentrations less than 15 ppm. Spatial (millimeters) and temporal (minutes) ratiometric gradients were observed in vitro radiating outward from the center of a dense adherent cell grouping on scaffolds. Sensor activation in ischemia and cell transplant models in vivo show oxygenation decreases on the scale of minutes. The nanofiber construct offers a robust approach to biomaterial scaffold oxygen sensing.
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Affiliation(s)
- Daniel T. Bowers
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Michael L. Tanes
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
| | - Anusuya Das
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
- Orthopaedic Surgery, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Yong Lin
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Nicole A. Keane
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Rebekah A. Neal
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Molly E. Ogle
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
| | - Kenneth L. Brayman
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
- Department of Surgery, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Cassandra L. Fraser
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Edward A. Botchwey
- Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, United States
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
- Address correspondence to
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Magnesium substitution in brushite cements for enhanced bone tissue regeneration. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2014; 43:403-10. [DOI: 10.1016/j.msec.2014.06.036] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 06/05/2014] [Accepted: 06/30/2014] [Indexed: 11/21/2022]
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Schmitz M, Rothe T, Kienle A. Evaluation of a spectrally resolved scattering microscope. BIOMEDICAL OPTICS EXPRESS 2011; 2:2665-2678. [PMID: 22091448 PMCID: PMC3184875 DOI: 10.1364/boe.2.002665] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 08/02/2011] [Accepted: 08/16/2011] [Indexed: 05/31/2023]
Abstract
A scattering microscope was developed to investigate single cells and biological microstructures by light scattering measurements. The spectrally resolved part of the setup and its validation are shown in detail. The analysis of light scattered by homogenous polystyrene spheres allows the determination of their diameters using Mie theory. The diameters of 150 single polystyrene spheres were determined by the spectrally resolved scattering microscope. In comparison, the same polystyrene suspension stock was investigated by a collimated transmission setup. Mean diameters and standard deviations of the size distribution were evaluated by both methods with a statistical error of less than 1nm. The systematic errors of both devices are in agreement within the measurement accuracy.
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Lu J, Wei J, Yan Y, Li H, Jia J, Wei S, Guo H, Xiao T, Liu C. Preparation and preliminary cytocompatibility of magnesium doped apatite cement with degradability for bone regeneration. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2011; 22:607-615. [PMID: 21258847 DOI: 10.1007/s10856-011-4228-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2010] [Accepted: 01/03/2011] [Indexed: 05/30/2023]
Abstract
In the present study, we fabricated magnesium doped apatite cement (md-AC) with rapid self-setting characteristic by adding the mixed powders of magnesium oxide and calcium dihydrogen phosphate (MO-CDP) into hydroxyapatite cement (HAC). The results revealed that the md-AC with 50 wt% MO-CDP could set within 6 min and the compression strength could reach 51 MPa after setting for 1 h, indicating that the md-AC had highly initial mechanical strength. The degradability of the md-AC in Tris-HCl solution increased with the increase of MO-CDP amount, and the weight loss ratio of md-AC with 50 wt% MO-CDP was 57.5 wt% after soaked for 12 weeks. Newly flake-like apatite could be deposited on the md-AC surfaces after soaked in simulated body fluid (SBF) for 7 days. Cell proliferation ratio of MG(63) cells on md-AC was obviously higher than that of HAC on days 4 and 7. The cells with normal phenotype spread well on the md-AC surfaces and attached intimately with the substrate, and alkaline phosphatase (ALP) activity of the cells on md-AC significantly improved compared with HAC on day 7. The results demonstrate that the md-AC has a good ability to support cell proliferation and differentiation, and indicate a good cytocompatibility.
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Affiliation(s)
- Jingxiong Lu
- Key Laboratory for Ultrafine Materials of Ministry of Education, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China.
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Georgakoudi I, Rice WL, Hronik-Tupaj M, Kaplan DL. Optical spectroscopy and imaging for the noninvasive evaluation of engineered tissues. TISSUE ENGINEERING PART B-REVIEWS 2009; 14:321-40. [PMID: 18844604 DOI: 10.1089/ten.teb.2008.0248] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Optical spectroscopy and imaging approaches offer the potential to noninvasively assess different aspects of the cellular, extracellular matrix, and scaffold components of engineered tissues. In addition, the combination of multiple imaging modalities within a single instrument is highly feasible, allowing acquisition of complementary information related to the structure, organization, biochemistry, and physiology of the sample. The ability to characterize and monitor the dynamic interactions that take place as engineered tissues develop promises to enhance our understanding of the interdependence of processes that ultimately leads to functional tissue outcomes. It is expected that this information will impact significantly upon our abilities to optimize the design of biomaterial scaffolds, bioreactors, and cell systems. Here, we review the principles and performance characteristics of the main methodologies that have been exploited thus far, and we present examples of corresponding tissue engineering studies.
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Affiliation(s)
- Irene Georgakoudi
- Biomedical Engineering Department, Tufts University, Medford, Massachusetts 02155, USA.
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