Stationary nanoliter droplet array with a substrate of choice for single adherent/nonadherent cell incubation and analysis

Microfluidic water-in-oil droplets that serve as separate, chemically isolated compartments can be applied for single-cell analysis; however, to investigate encapsulated cells effectively over prolonged time periods, an array of droplets must remain stationary on a versatile substrate for optimal cell compatibility. We present here a platform of unique geometry and substrate versatility that generates a stationary nanodroplet array by using wells branching off a main microfluidic channel. These droplets are confined by multiple sides of a nanowell and are in direct contact with a biocompatible substrate of choice. The device is operated by a unique and reversed loading procedure that eliminates the need for fine pressure control or external tubing. Fluorocarbon oil isolates the droplets and provides soluble oxygen for the cells. By using this approach, the metabolic activity of single adherent cells was monitored continuously over time, and the concentration of viable pathogens in blood-derived samples was determined directly by measuring the number of colony-formed droplets. The method is simple to operate, requires a few microliters of reagent volume, is portable, is reusable, and allows for cell retrieval. This technology may be particularly useful for multiplexed assays for which prolonged and simultaneous visual inspection of many isolated single adherent or nonadherent cells is required.clos

Fabrication and Characterization of Autonomously Self-Healable and Stretchable Soft Microfluidics

In this paper, a novel self-healable and stretchable microfluidics system for next generation wearable lab-on-a-chip is presented. An imine-based precursor with various metal sources (Co(II), Fe(II), and Zn(II)) is used for the development of an intrinsically autonomous self-healing microfluidic device. Microfluidics fabrication is performed on the self-healing substrate layer using a mold transfer method. The mechanical properties of the resulting layer are evaluated using tensile strain pull testing. Microfluidic characteristics including fluid flow, wettability, leak, and fluorescence compatibility are investigated to understand its performance in classical microfluidic applications. The new microfluidic devices are also characterized using scanning-electron microscopy to evaluate the mold transfer capability. The self-healing microfluidics and the corresponding detailed fluidic characterization presented in this paper will open new opportunities for microfluidic lab on a chip development for various applications, especially in wearable electronics

Mapping the physiological and molecular markers of stress and SSRI antidepressant treatment in S100a10 corticostriatal neurons

In mood disorders, psychomotor and sensory abnormalities are prevalent, disabling, and intertwined with emotional and cognitive symptoms. Corticostriatal neurons in motor and somatosensory cortex are implicated in these symptoms, yet mechanisms of their vulnerability are unknown. Here, we demonstrate that S100a10 corticostriatal neurons exhibit distinct serotonin responses and have increased excitability, compared with S100a10-negative neurons. We reveal that prolonged social isolation disrupts the specific serotonin response which gets restored by chronic antidepressant treatment. We identify cell-type-specific transcriptional signatures in S100a10 neurons that contribute to serotonin responses and strongly associate with psychomotor and somatosensory function. Our studies provide a strong framework to understand the pathogenesis and create new avenues for the treatment of mood disorders