Optically characterizing collagen gels made with different cell types

David Levitz, Niloy Choudhury, Keri Vartanian, Monica Hinds, Stephen R. Hanson, Steven Jacques

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

The ability of optical imaging techniques such as optical coherence tomography (OCT) to non-destructively characterize tissue-engineered constructs has generated enormous interest recently. Collagen gels are 3D structures that represent a simple common model of many engineered tissues that contain 2 primary scatterers: collagen and cells. We are testing the ability of OCT data to characterize the remodeling of such collagen-based constructs by 3 different types of cells: vascular smooth muscle cells (SMCs), endothelial cells (ECs), and osteoblasts (OBs). Collagen gels were prepared with SMCs, ECs, and OBs with a seeding density of 1×106 cells/ml; additionally, acellular controls were also prepared. The disk-shaped constructs were allowed to remodel in the incubator for 5 days, with OCT imaging occurring on days 1 and 5. From the OCT data, the attenuation and reflectivity were evaluated by fitting the data to a theoretical model that relates the tissue optical properties (scattering coefficient and anisotropy factor) and imaging conditions to the OCT signal. The degree of gel compaction was determined from the volume of the culture medium that feeds the constructs. We found that gel compaction (relative to the acellular control) occurred in the SMC constructs, but not in the OB or EC constructs. The optical property data showed that at day 5 the SMC constructs had an overall higher reflectivity (lower g) relative to day 1, whereas there was no obvious change in reflectivity of the EC, OB constructs and acellular controls relative to day 1. Moreover, there was a difference in the attenuation of the OB constructs on day 5 relative to day 1, but not in the other constructs. The apparent decrease in anisotropy observed in the SMC constructs, but not in the OB and EC constructs and acellular controls, suggests that OCT is sensitive to the remodeling of the collagen matrix that accompanies gel compaction, and can offer highly localized information on the construct microstructure. The apparent increase in the scattering coefficient of the OB constructs is believed to be caused by a higher rate of proliferation by these cell types relative to the others. Overall, these results suggest that the optical properties of collagen gels contain information on both cell number and collagen gel microstructure.

Original languageEnglish (US)
Title of host publicationProgress in Biomedical Optics and Imaging - Proceedings of SPIE
Volume7179
DOIs
StatePublished - 2009
EventOptics in Tissue Engineering and Regenerative Medicine III - San Jose, CA, United States
Duration: Jan 24 2009Jan 24 2009

Other

OtherOptics in Tissue Engineering and Regenerative Medicine III
CountryUnited States
CitySan Jose, CA
Period1/24/091/24/09

Fingerprint

Collagen
Osteoblasts
osteoblasts
Optical Coherence Tomography
collagens
Smooth muscle Cells
Optical tomography
Endothelial Cells
smooth muscle
muscle cells
Endothelial cells
Gels
gels
Muscle
tomography
Cell
cells
Compaction
Reflectivity
Optical Properties

Keywords

  • Anisotropy
  • Cells
  • Collagen
  • Optical coherence tomography
  • Optical properties
  • Scattering
  • Tissue engineering

ASJC Scopus subject areas

  • Applied Mathematics
  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

Levitz, D., Choudhury, N., Vartanian, K., Hinds, M., Hanson, S. R., & Jacques, S. (2009). Optically characterizing collagen gels made with different cell types. In Progress in Biomedical Optics and Imaging - Proceedings of SPIE (Vol. 7179). [717905] https://doi.org/10.1117/12.809687

Optically characterizing collagen gels made with different cell types. / Levitz, David; Choudhury, Niloy; Vartanian, Keri; Hinds, Monica; Hanson, Stephen R.; Jacques, Steven.

Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Vol. 7179 2009. 717905.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Levitz, D, Choudhury, N, Vartanian, K, Hinds, M, Hanson, SR & Jacques, S 2009, Optically characterizing collagen gels made with different cell types. in Progress in Biomedical Optics and Imaging - Proceedings of SPIE. vol. 7179, 717905, Optics in Tissue Engineering and Regenerative Medicine III, San Jose, CA, United States, 1/24/09. https://doi.org/10.1117/12.809687
Levitz D, Choudhury N, Vartanian K, Hinds M, Hanson SR, Jacques S. Optically characterizing collagen gels made with different cell types. In Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Vol. 7179. 2009. 717905 https://doi.org/10.1117/12.809687
Levitz, David ; Choudhury, Niloy ; Vartanian, Keri ; Hinds, Monica ; Hanson, Stephen R. ; Jacques, Steven. / Optically characterizing collagen gels made with different cell types. Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Vol. 7179 2009.
@inproceedings{ab7d318f9e4545faa5af587e799a3671,
title = "Optically characterizing collagen gels made with different cell types",
abstract = "The ability of optical imaging techniques such as optical coherence tomography (OCT) to non-destructively characterize tissue-engineered constructs has generated enormous interest recently. Collagen gels are 3D structures that represent a simple common model of many engineered tissues that contain 2 primary scatterers: collagen and cells. We are testing the ability of OCT data to characterize the remodeling of such collagen-based constructs by 3 different types of cells: vascular smooth muscle cells (SMCs), endothelial cells (ECs), and osteoblasts (OBs). Collagen gels were prepared with SMCs, ECs, and OBs with a seeding density of 1×106 cells/ml; additionally, acellular controls were also prepared. The disk-shaped constructs were allowed to remodel in the incubator for 5 days, with OCT imaging occurring on days 1 and 5. From the OCT data, the attenuation and reflectivity were evaluated by fitting the data to a theoretical model that relates the tissue optical properties (scattering coefficient and anisotropy factor) and imaging conditions to the OCT signal. The degree of gel compaction was determined from the volume of the culture medium that feeds the constructs. We found that gel compaction (relative to the acellular control) occurred in the SMC constructs, but not in the OB or EC constructs. The optical property data showed that at day 5 the SMC constructs had an overall higher reflectivity (lower g) relative to day 1, whereas there was no obvious change in reflectivity of the EC, OB constructs and acellular controls relative to day 1. Moreover, there was a difference in the attenuation of the OB constructs on day 5 relative to day 1, but not in the other constructs. The apparent decrease in anisotropy observed in the SMC constructs, but not in the OB and EC constructs and acellular controls, suggests that OCT is sensitive to the remodeling of the collagen matrix that accompanies gel compaction, and can offer highly localized information on the construct microstructure. The apparent increase in the scattering coefficient of the OB constructs is believed to be caused by a higher rate of proliferation by these cell types relative to the others. Overall, these results suggest that the optical properties of collagen gels contain information on both cell number and collagen gel microstructure.",
keywords = "Anisotropy, Cells, Collagen, Optical coherence tomography, Optical properties, Scattering, Tissue engineering",
author = "David Levitz and Niloy Choudhury and Keri Vartanian and Monica Hinds and Hanson, {Stephen R.} and Steven Jacques",
year = "2009",
doi = "10.1117/12.809687",
language = "English (US)",
volume = "7179",
booktitle = "Progress in Biomedical Optics and Imaging - Proceedings of SPIE",

}

TY - GEN

T1 - Optically characterizing collagen gels made with different cell types

AU - Levitz, David

AU - Choudhury, Niloy

AU - Vartanian, Keri

AU - Hinds, Monica

AU - Hanson, Stephen R.

AU - Jacques, Steven

PY - 2009

Y1 - 2009

N2 - The ability of optical imaging techniques such as optical coherence tomography (OCT) to non-destructively characterize tissue-engineered constructs has generated enormous interest recently. Collagen gels are 3D structures that represent a simple common model of many engineered tissues that contain 2 primary scatterers: collagen and cells. We are testing the ability of OCT data to characterize the remodeling of such collagen-based constructs by 3 different types of cells: vascular smooth muscle cells (SMCs), endothelial cells (ECs), and osteoblasts (OBs). Collagen gels were prepared with SMCs, ECs, and OBs with a seeding density of 1×106 cells/ml; additionally, acellular controls were also prepared. The disk-shaped constructs were allowed to remodel in the incubator for 5 days, with OCT imaging occurring on days 1 and 5. From the OCT data, the attenuation and reflectivity were evaluated by fitting the data to a theoretical model that relates the tissue optical properties (scattering coefficient and anisotropy factor) and imaging conditions to the OCT signal. The degree of gel compaction was determined from the volume of the culture medium that feeds the constructs. We found that gel compaction (relative to the acellular control) occurred in the SMC constructs, but not in the OB or EC constructs. The optical property data showed that at day 5 the SMC constructs had an overall higher reflectivity (lower g) relative to day 1, whereas there was no obvious change in reflectivity of the EC, OB constructs and acellular controls relative to day 1. Moreover, there was a difference in the attenuation of the OB constructs on day 5 relative to day 1, but not in the other constructs. The apparent decrease in anisotropy observed in the SMC constructs, but not in the OB and EC constructs and acellular controls, suggests that OCT is sensitive to the remodeling of the collagen matrix that accompanies gel compaction, and can offer highly localized information on the construct microstructure. The apparent increase in the scattering coefficient of the OB constructs is believed to be caused by a higher rate of proliferation by these cell types relative to the others. Overall, these results suggest that the optical properties of collagen gels contain information on both cell number and collagen gel microstructure.

AB - The ability of optical imaging techniques such as optical coherence tomography (OCT) to non-destructively characterize tissue-engineered constructs has generated enormous interest recently. Collagen gels are 3D structures that represent a simple common model of many engineered tissues that contain 2 primary scatterers: collagen and cells. We are testing the ability of OCT data to characterize the remodeling of such collagen-based constructs by 3 different types of cells: vascular smooth muscle cells (SMCs), endothelial cells (ECs), and osteoblasts (OBs). Collagen gels were prepared with SMCs, ECs, and OBs with a seeding density of 1×106 cells/ml; additionally, acellular controls were also prepared. The disk-shaped constructs were allowed to remodel in the incubator for 5 days, with OCT imaging occurring on days 1 and 5. From the OCT data, the attenuation and reflectivity were evaluated by fitting the data to a theoretical model that relates the tissue optical properties (scattering coefficient and anisotropy factor) and imaging conditions to the OCT signal. The degree of gel compaction was determined from the volume of the culture medium that feeds the constructs. We found that gel compaction (relative to the acellular control) occurred in the SMC constructs, but not in the OB or EC constructs. The optical property data showed that at day 5 the SMC constructs had an overall higher reflectivity (lower g) relative to day 1, whereas there was no obvious change in reflectivity of the EC, OB constructs and acellular controls relative to day 1. Moreover, there was a difference in the attenuation of the OB constructs on day 5 relative to day 1, but not in the other constructs. The apparent decrease in anisotropy observed in the SMC constructs, but not in the OB and EC constructs and acellular controls, suggests that OCT is sensitive to the remodeling of the collagen matrix that accompanies gel compaction, and can offer highly localized information on the construct microstructure. The apparent increase in the scattering coefficient of the OB constructs is believed to be caused by a higher rate of proliferation by these cell types relative to the others. Overall, these results suggest that the optical properties of collagen gels contain information on both cell number and collagen gel microstructure.

KW - Anisotropy

KW - Cells

KW - Collagen

KW - Optical coherence tomography

KW - Optical properties

KW - Scattering

KW - Tissue engineering

UR - http://www.scopus.com/inward/record.url?scp=65949090065&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=65949090065&partnerID=8YFLogxK

U2 - 10.1117/12.809687

DO - 10.1117/12.809687

M3 - Conference contribution

AN - SCOPUS:65949090065

VL - 7179

BT - Progress in Biomedical Optics and Imaging - Proceedings of SPIE

ER -