Browsing by Author "Calderon, Gisele A."

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    A 3D printable perfused hydrogel vascular model to assay ultrasound-induced permeability
    (Royal Society of Chemistry, 2022) Royse, Madison K.; Means, A. Kristen; Calderon, Gisele A.; Kinstlinger, Ian S.; He, Yufang; Durante, Marc R.; Procopio, Adam T.; Veiseh, Omid; Xu, Jun; Bioengineering
    The development of an in vitro model to study vascular permeability is vital for clinical applications such as the targeted delivery of therapeutics. This work demonstrates the use of a perfusion-based 3D printable hydrogel vascular model as an assessment for endothelial permeability and its barrier function. Aside from providing a platform that more closely mimics the dynamic vascular conditions in vivo, this model enables the real-time observation of changes in the endothelial monolayer during the application of ultrasound to investigate the downstream effect of ultrasound-induced permeability. We show an increase in the apparent permeability coefficient of a fluorescently labeled tracer molecule after ultrasound treatment via a custom MATLAB algorithm, which implemented advanced features such as edge detection and a dynamic region of interest, thus supporting the use of ultrasound as a non-invasive method to enhance vascular permeability for targeted drug therapies. Notably, live-cell imaging with VE-cadherin-GFP HUVECs provides some of the first real-time acquisitions of the dynamics of endothelial cell–cell junctions under the application of ultrasound in a 3D perfusable model. This model demonstrates potential as a new scalable platform to investigate ultrasound-assisted delivery of therapeutics across a cellular barrier that more accurately mimics the physiologic matrix and fluid dynamics.
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    Improved Angiogenesis in Response to Localized Delivery of Macrophage-Recruiting Molecules
    (Public Library of Science, 2015) Hsu, Chih-Wei; Poché, Ross A.; Saik, Jennifer E.; Ali, Saniya; Wang, Shang; Yosef, Nejla; Calderon, Gisele A.; Scott, Larry Jr.; Vadakkan, Tegy J.; Larina, Irina V.; West, Jennifer L.; Dickinson, Mary E.; Bioengineering
    Successful engineering of complex organs requires improved methods to promote rapid and stable vascularization of artificial tissue scaffolds. Toward this goal, tissue engineering strategies utilize the release of pro-angiogenic growth factors, alone or in combination, from biomaterials to induce angiogenesis. In this study we have used intravital microscopy to define key, dynamic cellular changes induced by the release of pro-angiogenic factors from polyethylene glycol diacrylate hydrogels transplanted in vivo. Our data show robust macrophage recruitment when the potent and synergistic angiogenic factors, PDGFBB and FGF2 were used as compared with VEGF alone and intravital imaging suggested roles for macrophages in endothelial tip cell migration and anastomosis, as well as pericyte-like behavior. Further data from in vivo experiments show that delivery of CSF1 with VEGF can dramatically improve the poor angiogenic response seen with VEGF alone. These studies show that incorporating macrophage-recruiting factors into the design of pro-angiogenic biomaterial scaffolds is a key strategy likely to be necessary for stable vascularization and survival of implanted artificial tissues.
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    Perfusable cell-laden matrices to guide patterning of vascularization in vivo
    (Royal Society of Chemistry, 2023) Parkhideh, Siavash; Calderon, Gisele A.; Janson, Kevin D.; Mukherjee, Sudip; Mai, A. Kristen; Doerfert, Michael D.; Yao, Zhuoran; Sazer, Daniel W.; Veiseh, Omid; Bioengineering
    The survival and function of transplanted tissue engineered constructs and organs require a functional vascular network. In the body, blood vessels are organized into distinct patterns that enable optimal nutrient delivery and oxygen exchange. Mimicking these same patterns in engineered tissue matrices is a critical challenge for cell and tissue transplantation. Here, we leverage bioprinting to assemble endothelial cells in to organized networks of large (>100 μm) diameter blood vessel grafts to enable spatial control of vessel formation in vivo. Acellular PEG/GelMA matrices with perfusable channels were bioprinted and laminar flow was confirmed within patterned channels, beneficial for channel endothelialization and consistent wall shear stress for endothelial maturation. Next, human umbilical vein endothelial cells (HUVECs) were seeded within the patterned channel and maintained under perfusion culture for multiple days, leading to cell–cell coordination within the construct in vitro. HUVEC and human mesenchymal stromal cells (hMSCs) were additionally added to bulk matrix to further stimulate anastomosis of our bioprinted vascular grafts in vivo. Among multiple candidate matrix designs, the greatest degree of biomaterial vascularization in vivo was seen within matrices fabricated with HUVECs and hMSCs encapsulated within the bulk matrix and HUVECs lining the walls of the patterned channels, dubbed design M-C_E. For this lead design, vasculature was detected within the endothelialized, perfusable matrix channels as early as two weeks and αSMA+ CD31+ vessels greater than 100 μm in diameter had formed by eight weeks, resulting in durable and mature vasculature. Notably, vascularization occurred within the endothelialized, bioprinted channels of the matrix, demonstrating the ability of bioprinted perfusable structures to guide vascularization patterns in vivo. The ability to influence vascular patterning in vivo can contribute to the future development of vascularized tissues and organs.