There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Micromachining technology was used to prepare chemical analysis systems on glass chips (1 centimeter by 2 centimeters or larger) that utilize electroosmotic pumping to drive fluid flow and electrophoretic separation to distinguish sample components. Capillaries 1 to 10 centimeters long etched in the glass (cross section, 10 micrometers by 30 micrometers) allow for capillary electrophoresis-based separations of amino acids with up to 75,000 theoretical plates in about 15 seconds, and separations of about 600 plates can be effected within 4 seconds. Sample treatment steps within a manifold of intersecting capillaries were demonstrated for a simple sample dilution process. Manipulation of the applied voltages controlled the directions of fluid flow within the manifold. The principles demonstrated in this study can be used to develop a miniaturized system for sample handling and separation with no moving parts.

Micromachining a miniaturized capillary electrophoresis-based chemical analysis system on a chip

Introduction to Nanotechnology

Structure–property relationships between material properties and stem cell behaviour are investigated using high-throughput methods. The data identify the optimal substrates within a range of different polymeric surfaces to support the growth and self-renewal of human embryonic stem cells from fully dissociated single cells.

Combinatorial Development of Biomaterials for Clonal Growth of Human Pluripotent Stem Cells

Electrically–transduced sensors, with their simplicity and compatibility with standard electronic technologies, produce signals that can be efficiently acquired, processed, stored, and analyzed. Two dimensional (2D) nanomaterials, including graphene, phosphorene (BP), transition metal dichalcogenides (TMDCs), and others, have proven to be attractive for the fabrication of high–performance electrically-transduced chemical sensors due to their remarkable electronic and physical properties originating from their 2D structure. This review highlights the advances in electrically-transduced chemical sensing that rely on 2D materials. The structural components of such sensors are described, and the underlying operating principles for different types of architectures are discussed. The structural features, electronic properties, and surface chemistry of 2D nanostructures that dictate their sensing performance are reviewed. Key advances in the application of 2D materials, from both a historical and analytical pers...

Electrically-Transduced Chemical Sensors Based on Two-Dimensional Nanomaterials

Microfluidic cell cultures are ideally positioned to become the next generation of in vitro diagnostic tools for biomedical research, where key biological processes such as cell signalling and dynamic cell-to-cell interactions can be reliably analysed under reproducible physiological cell culture conditions. In the last decade, a large number of microfluidic cell analysis systems have been developed for a variety of applications including drug target optimization, drug screening and toxicological testing. More recently, advanced in vitro microfluidic cell culture systems have emerged that are capable of replicating the complex three-dimensional architectures of tissues and organs and thus represent valid biological models for investigating the mechanism and function of human tissue structures, as well as studying the onset and progression of diseases such as cancer. In this review, we present the most important developments in single-cell, 2D and 3D microfluidic cell culture systems for studying cell-to-cell interactions published over the last 6 years, with a focus on cancer research and immunotherapy, vascular models and neuroscience. In addition, the current technological development of microdevices with more advanced physiological cell microenvironments that integrate multiple organ models, namely, the so-called body-, human- and multi-organ-on-a-chip, is reviewed.

/pdf/recent-advances-in-microfluidic-technologies-for-cell-to-2lqoaazv2z.pdf

Recent advances in microfluidic technologies for cell-to-cell interaction studies

In this study we have investigated a photosensitive thermoset (OSTEMER 322-40) as a complementary material to readily fabricate complex multi-layered microdevices for applications in life science. Simple, versatile and robust fabrication of multifunctional microfluidics is becoming increasingly important for the development of customized tissue-, organ- and body-on-a-chip systems capable of mimicking tissue interfaces and biological barriers. In the present work key material properties including optical properties, vapor permeability, hydrophilicity and biocompatibility are evaluated for cell-based assays using fibroblasts, endothelial cells and mesenchymal stem cells. The excellent bonding strength of the OSTEMER thermoset to flexible fluoropolymer (FEP) sheets and poly(dimethylsiloxane) (PDMS) membranes further allows for the fabrication of integrated microfluidic components such as membrane-based microdegassers, microvalves and micropumps. We demonstrate the application of multi-layered, membrane-integrated microdevices that consist of up to seven layers and three membranes that specially confine and separate vascular cells from the epithelial barrier and 3D tissue structures.

Multi-layered, membrane-integrated microfluidics based on replica molding of a thiol–ene epoxy thermoset for organ-on-a-chip applications

The human placenta plays a crucial role as the interface between mother and fetus. It represents a unique tissue that undergoes morphological as well as functional changes on the cellular and tissue level throughout pregnancy. To better understand how the placenta works, a variety of techniques has been developed to re-create this complex physiological barrier in vitro. However, due to the low availability of freshly isolated primary cells, choriocarcinoma cell lines remain the usual suspects as in vitro models for placental research. Here, we present a comparative study on the functional aspects of the choriocarcinoma cell lines BeWo, JAR and Jeg-3, as well as the first trimester trophoblast cell line ACH-3P as placental in vitro barrier models for endocrine and transport studies. Functional assays including tight junction immunostaining, sodium fluorescein retardation, trans epithelial resistance, glucose transport, hormone secretion as well as size-dependent polystyrene nanoparticle transport were performed using the four cell types to evaluate key functional parameters of each cell line to act a relevant in vitro placental barrier model.

/pdf/a-comparative-study-of-five-physiological-key-parameters-1tiesgzbsy.pdf

A comparative study of five physiological key parameters between four different human trophoblast-derived cell lines

Tomorrow today: organ-on-a-chip advances towards clinically relevant pharmaceutical and medical in vitro models

https://www.mdpi.com/2079-6374/9/3/110/pdf

Mario Rothbauer

Papers

Recent advances in microfluidic technologies for cell-to-cell interaction studies

Multi-layered, membrane-integrated microfluidics based on replica molding of a thiol–ene epoxy thermoset for organ-on-a-chip applications

A comparative study of five physiological key parameters between four different human trophoblast-derived cell lines

Tomorrow today: organ-on-a-chip advances towards clinically relevant pharmaceutical and medical in vitro models

Latest Trends in Biosensing for Microphysiological Organs-on-a-Chip and Body-on-a-Chip Systems