Microfibers have received much attention due to their promise for creating flexible and highly relevant tissue models for use in biomedical applications such as 3D cell culture, tissue modeling, and clinical treatments. A generated tissue or implanted material should mimic the natural microenvironment in terms of structural and mechanical properties as well as cell adhesion, differentiation, and growth rate. Therefore, the mechanical and biological properties of the fibers are of importance. This paper briefly introduces common fiber fabrication approaches, provides examples of polymers used in biomedical applications, and then reviews the methods applied to modify the mechanical and biological properties of fibers fabricated using different approaches for creating a highly controlled microenvironment for cell culturing. It is shown that microfibers are a highly tunable and versatile tool with great promise for creating 3D cell cultures with specific properties.

In this study, we examine the influence of university-based education on students' entrepreneurial capabilities. While the prevalence of entrepreneurship education is dramatically increasing worldwide, the education that business and engineering students receive throughout their academic experience wields a direct influence on several entrepreneurial capabilities. The purpose of this study is to measure these educational influences on three specific entrepreneurial capabilities-networking skill, proactiveness, and self-confidence. Moreover, we aim to raise awareness for faculty and students in these various programs as they form networks and optimize the knowledge obtained throughout their education. We test the hypotheses using data collected from 927 university students. Advice for policy makers, university students, and their respective educational departments is further discussed.

We report a study on two methods that enable spatial control and induced cavitation on targeted microbubbles (MBs). Cavitation is known to be present in many situations throughout nature. This phenomena has been proven to have the energy to erode alloys, like steel, in propellers and turbines. It is recently theorized that cavitation occurs inside the skull during a traumatic-brain injury (TBI) situation. Controlled cavitation methods could help better understand TBIs and explain how neurons respond at moments of trauma. Both of our approaches involve an ultrasonic transducer and bio-compatible Polycaprolactone (PCL) microfibers. These methods are reproducible as well as affordable, providing more control and efficiency compared to previous techniques found in literature. We specifically model three-dimensional spatial control of individual MBs using a 1.6 MHz transducer. Using a 100 kHz transducer, we also illustrate induced cavitation on an individual MB that is adhered to the surface of a PCL microfiber. The goal of future studies will involve characterization of neuronal response to cavitation and seek to unmask its linkage with TBIs.

While 3D cell cultures continue to grow in complexity and physiological relevance, more work must be done to reach the full potential of a real-time cell sensing system that is able to match the macro-and microenvironments of target tissues. 1D and 2D real-time sensors have been reliably created utilizing micro-and nano-electrodes, or planar electrodes, respectively. [1] This work furthers the cause by using biocompatible, graphene-laden microfibers as cellular constructs, which can be used in conjunction with 3D micro-electrode arrays for a highly complex real-time sensing system to analyze electrical cellto-cell communication that occurs within the brain. Additionally, this study works toward the important task of identifying genetic changes caused by manufacturing, and contrasting this against the effects of long-term encapsulation in four genes that are important to neural health, such as, tyrosine hydroxylase (TH), tubulin beta 3 class 3 (TUBB-3), interleukin 1 beta (IL-1β), and tumor necrosis factor alfa (TNF-α). Identifying the effects of manufacturing has been neglected in previous works, [2] and thus the current work provides a crucial understanding of the implications of using 3D cell cultures for tissue modeling.Hydrogels, with their high water content and the ease of diffusion across their borders, are ideal candidates for applications wherein the spatiotemporal properties of the cells must be controlled for long-term observation. [3] In particular, microfibers are well-suited for this purpose, as their higher surface-to-volume ratio expedites the diffusion of nutrients and waste across the cell border, while allowing for highly complex and specific scaffold geometries. [4,2,3b,3e,5] Cell-laden microfibers can be created in a number of different ways, including wetspinning/extrusion; [6] however, microfluidics provides unmatched control over the size, shape, and degredation rates of the resulting microfibers, while still allowing for all potential cell-safe gelation methods. [4,3h,7] In this way, a cell suspension might be mixed with a prepolymer solution before polymerization or gelation, thereby resulting in Engineering conductive 3D cell scaffoldings offer advantages toward the creation of physiologically relevant platforms with integrated real-time sensing capabilities. Dopaminergic neural cells are encapsulated into graphene-laden alginate microfibers using a microfluidic approach, which is unmatched for creating highly-tunable microfibers. Incorporating graphene increases the conductivity of the alginate microfibers by 148%, creating a similar conductivity to native brain tissue. The cell encapsulation procedure has an efficiency of 50%, and of those cells, ≈30% remain for the entire 6-day observation period. To understand how the microfluidic encapsulation affects cell genetics, tyrosine hydroxylase, tubulin beta 3 class 3, interleukin 1 beta, and tumor necrosis factor alfa are analyzed primarily with real-time reverse transcription-quantitative polymerase chain reaction and secondarily wi...

Reactive astrocytes are known to play a vital role in the overall response of the brain during a traumatic brain injury (TBI). Modern studies have speculated the existence of cavitation in the skull during a TBI, which has alarming potential to cause detrimental damage. Previous studies have confirmed the upregulation of various harmful genes in neurodegenerative diseases. Studying the longitudinal presence of these harmful genes in response to cavitation allows for optimized understanding of and treatment methods for cavitation exposure. We seek to characterize the longitudinal genetic expression levels that astrocytes exhibit after exposure to cavitation and further elucidate the startling presence of cranial cavitation. We have designed a system to induce cavitation on targeted microbubbles. Astrocytic expression levels of various common genes, like TNFα, IL-1β, and NOS1, that have been documented in TBI studies are our target of interest. Results summarize specific gene trends from 1 h to 48 h after cavitation. Our data conclude that maximum expression is not consistently exhibited immediately after cavitation exposure and most genes have individualized genetic trends. IL-1β shows a decreasing expression over 48 h, and TNFα shows upregulation until the 6 h time point but then begins to decrease in expression. The upregulation of NOS1 has been documented in neurodegenerative diseases, like Alzheimer’s and Parkinson’s disease. This study has shown a consistent upregulation in NOS1 expression from 0 h to 48 h. These results postulate a possible linkage between cavitation damage and neurodegenerative diseases. This analysis also provides novelty in optimizing treatments for the astrocytic function after TBI and legitimizing the concern of cranial cavitation existence.