Abstract
INTRODUCTION: To be clinically effective, engineered tissues should be mechanically stable with surgical compatibility and have a multiscale hierarchical organization resembling vascular tree. Apart from organization, hemodynamic parameters such as blood flow velocity, patency and vascular permeability are the important parameters which control the vascular structures to pass over remodeling and maturation phase [1]. However, how developing vascular network acquire hierarchical organization, what signals drive the organization, and what parameters are involved behind the scenes, remains poorly understood. Thisstudy reports the application of optical techniques, namely laser speckle contrast imaging (LSCI), laser Doppler perfusion imaging (LDPI) and monitoring (LDPM) and side-stream dark field imaging (SDF) [2] to explore and quantify theabovementioned hemodynamic parameters within developing chicken embryo.
METHODS: To follow how the vascular networks form around the yolk, fertilized chicken eggs were cracked on day 3 into a PDMS container. The imaging procedure of different techniques is listed below;1. Non-invasive (LSCI and LDPI): The embryo surface is illuminated by a uniform coherent light distribution and imaged viacameras.2. Invasive: (a) LDPM: Optical probe containing a pair of fibers to illuminate coherent light and detect Doppler shifted photonsis mounted on a vessel. (b) SDF: Optical probe including visible light emitting diodes (LEDs) and photodetector is mounted on the capillaries to imagethe dark field.
RESULTS: Both qualitative and quantitative assessment of spatiotemporal blood flow perfusion maps and RBCs velocity measurement were performed within macro- and microvascular structures. Results show that relative perfusion levels of individual blood vessels can be imaged with LSCI and LDPI in full-field with millimeter resolution. It can also be locally monitored in time domain using LDPM. Moreover, SDF helps to probe the formation of microcapillaries, and quantitatively measure the blood flow within the capillaries with micrometer resolution.
DISCUSSION & CONCLUSIONS: By developing an ex ovo chicken embryo system that is compatible with multiple imaging technologies, we have developed a powerful tool to better understand the processes of vascular organization and maturation. Next steps will focus on the perturbation of the vascular network using mechanical and chemical signals to study how these signals regulate the organization. This will provide crucial information to design mechanically stable organized vascular networks within engineered tissues.Acknowledgements:This work is supported by an ERC Consolidator Grant (724469) and NWO Dutch funding (14538).
References:[1] Le Noble F, et al. Development 2004;131(2):361-375[2] Nadort A, et al. Sci Rep 2016;6:25258
METHODS: To follow how the vascular networks form around the yolk, fertilized chicken eggs were cracked on day 3 into a PDMS container. The imaging procedure of different techniques is listed below;1. Non-invasive (LSCI and LDPI): The embryo surface is illuminated by a uniform coherent light distribution and imaged viacameras.2. Invasive: (a) LDPM: Optical probe containing a pair of fibers to illuminate coherent light and detect Doppler shifted photonsis mounted on a vessel. (b) SDF: Optical probe including visible light emitting diodes (LEDs) and photodetector is mounted on the capillaries to imagethe dark field.
RESULTS: Both qualitative and quantitative assessment of spatiotemporal blood flow perfusion maps and RBCs velocity measurement were performed within macro- and microvascular structures. Results show that relative perfusion levels of individual blood vessels can be imaged with LSCI and LDPI in full-field with millimeter resolution. It can also be locally monitored in time domain using LDPM. Moreover, SDF helps to probe the formation of microcapillaries, and quantitatively measure the blood flow within the capillaries with micrometer resolution.
DISCUSSION & CONCLUSIONS: By developing an ex ovo chicken embryo system that is compatible with multiple imaging technologies, we have developed a powerful tool to better understand the processes of vascular organization and maturation. Next steps will focus on the perturbation of the vascular network using mechanical and chemical signals to study how these signals regulate the organization. This will provide crucial information to design mechanically stable organized vascular networks within engineered tissues.Acknowledgements:This work is supported by an ERC Consolidator Grant (724469) and NWO Dutch funding (14538).
References:[1] Le Noble F, et al. Development 2004;131(2):361-375[2] Nadort A, et al. Sci Rep 2016;6:25258
Original language | English |
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Publication status | Unpublished - 18 Dec 2019 |
Event | TERMIS EU Chapter Conference 2023 - Manchester, United Kingdom Duration: 27 Mar 2023 → 30 Mar 2023 https://eu2023.termis.org/ |
Conference
Conference | TERMIS EU Chapter Conference 2023 |
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Country/Territory | United Kingdom |
City | Manchester |
Period | 27/03/23 → 30/03/23 |
Internet address |
Keywords
- Imaging
- Biomechanics
- Mechanotransduction
- Biophysical stimuli