Michael J. Crescenz Veterans Affairs Medical Center 4 articles published in JoVE Bioengineering Fabrication of Ti3C2 MXene Microelectrode Arrays for In Vivo Neural Recording Nicolette Driscoll1,2,3, Kathleen Maleski4,5, Andrew G. Richardson2,6, Brendan Murphy1,2,3, Babak Anasori4,5, Timothy H. Lucas2,6, Yury Gogotsi4,5, Flavia Vitale1,2,3,7,8 1Department of Bioengineering, University of Pennsylvania, 2Center for Neuroengineering and Therapeutics, University of Pennsylvania, 3Corporal Michael J. Crescenz Veterans Affairs Medical Center, 4Department of Materials Science and Engineering, Drexel University, 5A.J. Drexel Nanomaterials Institute, Drexel University, 6Department of Neurosurgery, University of Pennsylvania, 7Department of Neurology, University of Pennsylvania, 8Department of Physical Medicine and Rehabilitation We describe here a method for fabricating Ti3C2 MXene microelectrode arrays and utilizing them for in vivo neural recording. Behavior Using a Real-Time Locating System to Measure Walking Activity Associated with Wandering Behaviors Among Institutionalized Older Adults Mary E. Bowen1,2, William Kearns3, Jeremy R. Crenshaw4, Steven J. Stanhope4 1School of Nursing, University of Delaware, 2Corporeal Michael J. Crescenz VA Medical Center, 3Child and Family Studies, University of South Florida, 4Department of Kinesiology and Applied Physiology, University of Delaware This paper discusses the use of a continuous and objective real-time locating system to measure walking activity associated with wandering behaviors, focusing on older adults with cognitive impairment. Walking activity is measured by walking distance, sustained walking distance, and sustained gait speed. Also assessed are gait quality and balance ability. Bioengineering Three-dimensional Tissue Engineered Aligned Astrocyte Networks to Recapitulate Developmental Mechanisms and Facilitate Nervous System Regeneration Kritika S. Katiyar*1,2,3, Carla C. Winter*1,2,4, Wisberty J. Gordián-Vélez1,2,4, John C. O'Donnell1,2, Yeri J. Song1,5, Nicole S. Hernandez1,5, Laura A. Struzyna1,2,4, D. Kacy Cullen1,2,5 1Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, 2Center for Neurotrauma, Neurodegeneration & Restoration, Michael J. Crescenz Veterans Affairs Medical Center, 3School of Biomedical Engineering, Drexel University, 4Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, 5Neuroscience Graduate Group, Perelman School of Medicine, University of Pennsylvania We showcase the development of self-assembled, three-dimensional bundles of longitudinally aligned astrocytic somata and processes within a novel biomaterial encasement. These engineered "living scaffolds", exhibiting micron-scale diameter yet extending centimeters in length, may serve as test-beds to study neurodevelopmental mechanisms or facilitate neuroregeneration by directing neuronal migration and/or axonal pathfinding. Neuroscience Anatomically Inspired Three-dimensional Micro-tissue Engineered Neural Networks for Nervous System Reconstruction, Modulation, and Modeling Laura A. Struzyna*1,2,3, Dayo O. Adewole*1,2,3, Wisberty J. Gordián-Vélez1,2,3, Michael R. Grovola2,3, Justin C. Burrell2,3, Kritika S. Katiyar2,3,4, Dmitriy Petrov2,3, James P. Harris2,3, D. Kacy Cullen2,3 1Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, 2Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, 3Center for Neurotrauma, Neurodegeneration & Restoration, Michael J. Crescenz Veterans Affairs Medical Center, 4School of Biomedical Engineering, Drexel University This manuscript details the fabrication of micro-tissue engineered neural networks: three-dimensional micron-sized constructs comprised of long aligned axonal tracts spanning aggregated neuronal population(s) encased in a tubular hydrogel. These living scaffolds can serve as functional relays to reconstruct or modulate neural circuitry or as biofidelic test-beds mimicking gray-white matter neuroanatomy.