Researcher(s)
- Jenna Taylor, Mechanical Engineering, University of Delaware
Faculty Mentor(s)
- Jason Gleghorn, Biomedical Engineering, University of Delaware
Abstract
The development of complex 3D biological structures require an intact perfused vascular network. This vascular network is integral to the advancement of studying disease processes and predicting potential pharmaceutical treatment strategies in vitro [1]. Vascular networks provide nutrients and oxygen while transporting waste away from the surrounding tissue. Absent perfused vasculature, engineered tissues often develop a necrotic core due to the limitations of passive diffusion in providing tissue with metabolic necessities [2]. This limits their development, growth, and effective usefulness as mature organotypic in vitro models. We created a system to parallelize multiple vascularized hydrogel constructs into a sealed configuration that allows leak-free perfusion through a self-assembled microvascular network anastomosed with deterministically patterned 3D vessels encapsulated within a collagen-I hydrogel ECM. This system enables the vascular networks to develop in their own specialized media formulations and timescale as independent tissue constructs. The device consists of a polydimethylsiloxane (PDMS) molded microfluidic device [3] placed inside of an acrylic “cassette” that creates sealed fluidic channels when clamped against the PDMS device. The thickness of the cassette base was optimized to allow for in-situ imaging as well as to ensure a seal is formed between the acrylic and the PDMS. The three-piece laser-cut acrylic cassette includes a base bonded to a spacer, and lid with luer lock fittings positioned over the media reservoirs in the PDMS device providing a fluidic interface with a pump. Continuous perfusion through the tissue vascular networks without leakage was tested for up to 72 hours at 1.25 µL/min. No disruption of the ECM was observed over the duration of the experiment. These results demonstrate that this system provides continuous perfusion of the vascular network and anastomosed microvasculature within the ECM of the tissue constructs.
References
[1] H. A. Strobel, S. M. Moss, and J. B. Hoying, “Methods for vascularization and perfusion of tissue organoids,” vol. 33, no. 3, pp. 437–450, Mar. 2022, doi: 10.1007/s00335-022-09951-2. [Online]. Available: https://pubmed.ncbi.nlm.nih.gov/35333952/
[2] J. T. Morgan, J. Shirazi, E. M. Comber, C. Eschenburg, and J. P. Gleghorn, “Fabrication of centimeter-scale and geometrically arbitrary vascular networks using in vitro self-assembly,” vol. 189, pp. 37–47, 2019, doi: 10.1016/j.biomaterials.2018.10.021.
[3] J. Shirazi, J. T. Morgan, E. M. Comber, and J. P. Gleghorn, “Generation and morphological quantification of large scale, three-dimensional, self-assembled vascular networks,” vol. 6, pp. 1907–1918, 2019, doi: 10.1016/j.mex.2019.08.006.