@article{pozdin_erb_downey_rivera_daniele_2021, title={Monitoring of random microvessel network formation by in-line sensing of flow rates: A numerical and in vitro investigation}, volume={331}, ISSN={["1873-3069"]}, DOI={10.1016/j.sna.2021.112970}, abstractNote={The directed or de novo formation of microvasculature in engineered tissue constructs is essential for accurately replicating physiological function. A limiting factor of a system relying on spontaneous microvessel formation is the inability to precisely quantify the development of the microvascular network and control fluid moving through formed vessels. Herein, we report a strategy to monitor the dynamic formation of microscale fluid networks, which can be translated to the monitoring of microvasculature development in engineered tissue constructs. The non-invasive, non-destructive monitoring and characterization of the fluid network is achieved via in-line sensing of fluid flow rate and correlating this measurement to the hydrodynamic resistance of the fluid network to model the progression of microvessel formation and connectivity. Computational fluid dynamics, equivalent circuit, and experimental models were compared, which simulated multi-generational branching or splitting microvessel networks. The networks simulated vessels with varying cross-sectional area, up to 16 branching vessels, and microvessel network volume ranging from ˜20−30 mm3. In all models, the increasing degree of network complexity and volume corresponded to a decrease in jumper flow-rate measured; however, vessel cross-section also impacted the measured jumper flow rate, i.e. at low vessel height (<200 μm) response was dominated by increased network volume and at higher vessel height (>200 μm) the response was dominated by resistance of narrow channels. An approximately 2% error was exhibited between the models, which was attributed to variation in the geometry of the fabricated models and illustrates the potential to precisely and non-destructively monitor microvessel network development and volumetric changes.}, journal={SENSORS AND ACTUATORS A-PHYSICAL}, author={Pozdin, Vladimir A. and Erb, Patrick D. and Downey, McKenna and Rivera, Kristina R. and Daniele, Michael}, year={2021}, month={Nov} }
 @misc{hunter_akbar_bhansali_daniele_erb_johnson_liu_miller_oralkan_hesketh_et al._2020, title={Editors' Choice-Critical Review-A Critical Review of Solid State Gas Sensors}, volume={167}, ISSN={["1945-7111"]}, DOI={10.1149/1945-7111/ab729c}, abstractNote={Solid state gas sensors are a core enabling technology to a range of measurement applications including industrial, safety, and environmental monitoring. The technology associated with solid-state gas sensors has evolved in recent years with advances in materials, and improvements in processing and miniaturization. In this review, we examine the state-of-the-art of solid state gas sensors with the goal of understanding the core technology and approaches, various sensor design methods to provide targeted functionality, and future prospects in the field. The structure, detection mechanism, and sensing properties of several types of solid state gas sensors will be discussed. In particular, electrochemical cells (solid and liquid), impedance/resistance based sensors (metal oxide, polymer, and carbon based structures), and mechanical sensing structures (resonators, cantilevers, and acoustic wave devices) as well as sensor arrays and supporting technologies, are described. Development areas for this field includes increased control of material properties for improved sensor response and durability, increased integration and miniaturization, and new material systems, including nano-materials and nano-structures, to address shortcomings of existing solid state gas sensors.}, number={3}, journal={JOURNAL OF THE ELECTROCHEMICAL SOCIETY}, author={Hunter, Gary W. and Akbar, Sheikh and Bhansali, Shekhar and Daniele, Michael and Erb, Patrick D. and Johnson, Kevin and Liu, Chung-Chiun and Miller, Derek and Oralkan, Omer and Hesketh, Peter J. and et al.}, year={2020}, month={Feb} }
 @article{rivera_pozdin_young_erb_wisniewski_magness_daniele_2019, title={Integrated phosphorescence-based photonic biosensor (iPOB) for monitoring oxygen levels in 3D cell culture systems}, volume={123}, ISSN={["1873-4235"]}, DOI={10.1016/j.bios.2018.07.035}, abstractNote={Physiological processes, such as respiration, circulation, digestion, and many pathologies alter oxygen concentration in the blood and tissue. When designing culture systems to recapitulate the in vivo oxygen environment, it is important to integrate systems for monitoring and controlling oxygen concentration. Herein, we report the design and engineering of a system to remotely monitor and control oxygen concentration inside a device for 3D cell culture. We integrate a photonic oxygen biosensor into the 3D tissue scaffold and regulate oxygen concentration via the control of purging gas flow. The integrated phosphorescence-based oxygen biosensor employs the quenching of palladium-benzoporphyrin by molecular oxygen to transduce the local oxygen concentration in the 3D tissue scaffold. The system is validated by testing the effects of normoxic and hypoxic culture conditions on healthy and tumorigenic breast epithelial cells, MCF-10A cells and BT474 cells, respectively. Under hypoxic conditions, both cell types exhibited upregulation of downstream target genes for the hypoxia marker gene, hypoxia-inducible factor 1α (HIF1A). Lastly, by monitoring the real-time fluctuation of oxygen concentration, we illustrated the formation of hypoxic culture conditions due to limited diffusion of oxygen through 3D tissue scaffolds.}, journal={BIOSENSORS & BIOELECTRONICS}, author={Rivera, Kristina R. and Pozdin, Vladimir A. and Young, Ashlyn T. and Erb, Patrick D. and Wisniewski, Natalie A. and Magness, Scott T. and Daniele, Michael}, year={2019}, month={Jan}, pages={131–140} }
 @misc{rivera_yokus_erb_pozdin_daniele_2019, title={Measuring and regulating oxygen levels in microphysiological systems: design, material, and sensor considerations}, volume={144}, ISSN={["1364-5528"]}, DOI={10.1039/c8an02201a}, abstractNote={Quantifying and regulating oxygen in a microphysiological models can be achievedviaan array of technologies, and is an essential component of recapitulating tissue-specific microenvironments.}, number={10}, journal={ANALYST}, author={Rivera, Kristina R. and Yokus, Murat A. and Erb, Patrick D. and Pozdin, Vladimir A. and Daniele, Michael}, year={2019}, month={May}, pages={3190–3215} }
 @misc{young_rivera_erb_daniele_2019, title={Monitoring of Microphysiological Systems: Integrating Sensors and Real-Time Data Analysis toward Autonomous Decision-Making}, volume={4}, ISSN={["2379-3694"]}, DOI={10.1021/acssensors.8b01549}, abstractNote={Microphysiological systems replicate human organ function and are promising technologies for discovery of translatable biomarkers, pharmaceuticals, and regenerative therapies. Because microphysiological systems require complex microscale anatomical structures and heterogeneous cell populations, a major challenge remains to manufacture and operate these products with reproducible and standardized function. In this Perspective, three stages of microphysiological system monitoring, including process, development, and function, are assessed. The unique features and remaining technical challenges for the required sensors are discussed. Monitoring of microphysiological systems requires nondestructive, continuous biosensors and imaging techniques. With such tools, the extent of cellular and tissue development, as well as function, can be autonomously determined and optimized by correlating physical and chemical sensor outputs with markers of physiological performance. Ultimately, data fusion and analyses across process, development, and function monitors can be implemented to adopt microphysiological systems for broad research and commercial applications.}, number={6}, journal={ACS SENSORS}, author={Young, Ashlyn T. and Rivera, Kristina R. and Erb, Patrick D. and Daniele, Michael A.}, year={2019}, month={Jun}, pages={1454–1464} }
 @article{su_huang_daniele_hensley_young_tang_allen_vandergriff_erb_ligler_et al._2018, title={Cardiac Stem Cell Patch Integrated with Microengineered Blood Vessels Promotes Cardiomyocyte Proliferation and Neovascularization after Acute Myocardial Infarction}, volume={10}, ISSN={["1944-8252"]}, DOI={10.1021/acsami.8b13571}, abstractNote={Cardiac stem cell (CSC) therapy has shown preclinical and clinical evidence for ischemic heart repair but is limited by low cellular engraftment and survival after transplantation. Previous versions of the cardiac patch strategy improve stem cell engraftment and encourage repair of cardiac tissue. However, cardiac patches that can enhance cardiomyogenesis and angiogenesis at the injured site remain elusive. Therapies that target cardiomyocyte proliferation and new blood vessel formation hold great potential for the protection against acute myocardial infarction (MI). Here, we report a new strategy for creating a vascularized cardiac patch in a facile and modular fashion by leveraging microfluidic hydrodynamic focusing to construct the biomimetic microvessels (BMVs) that include human umbilical vein endothelial cells (HUVECs) lining the luminal surface and then encapsulating the BMVs in a fibrin gel spiked with human CSCs. We show that the endothelialized BMVs mimicked the natural architecture and function of capillaries and that the resultant vascularized cardiac patch (BMV-CSC patch) exhibited equivalent release of paracrine factors compared to those of coculture of genuine human CSCs and HUVECs after 7 days of in vitro culture. In a rat model of acute MI, the BMV-CSC patch therapy induced profound mitotic activities of cardiomyocytes in the peri-infarct region 4 weeks post-treatment. A significant increase in myocardial capillary density was noted in the infarcted hearts that received BMV-CSC patch treatment compared to the infarcted hearts treated with conventional CSC patches. The striking therapeutic benefits and the fast and facile fabrication of the BMV-CSC patch make it promising for practical applications. Our findings suggest that the BMV-CSC patch strategy may open up new possibilities for the treatment of ischemic heart injury.}, number={39}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Su, Teng and Huang, Ke and Daniele, Michael A. and Hensley, Michael Taylor and Young, Ashlyn T. and Tang, Junnan and Allen, Tyler A. and Vandergriff, Adam C. and Erb, Patrick D. and Ligler, Frances S. and et al.}, year={2018}, month={Oct}, pages={33088–33096} }