In this paper, we present a microfluidic platform for the continuous generation of stable, monodisperse lipid vesicles 20-110 lm in diameter. Our approach utilizes a microfluidic flow-focusing droplet generation design to control the vesicle size by altering the system's fluid flow rates to generate vesicles with narrow size distribution. Double emulsions are first produced in consecutive flow-focusing channel geometries and lipid membranes are then formed through a controlled solvent extraction process. Since no strong solvents are used in the process, our method allows for the safe encapsulation and manipulation of an assortment of biological entities, including cells, proteins, and nucleic acids. The vesicles generated by this method are stable and have a shelf life of at least 3 months. Here, we demonstrate the cell-free in vitro synthesis of proteins within lipid vesicles as an initial step towards the development of an artificial cell.

We report the development of a microfluidic array device for continuous-exchange, cell-free protein synthesis. The advantages of protein expression in the microfluidic array include (1) the potential to achieve high-throughput protein expression, matching the throughput of gene discovery; (2) more than 2 orders of magnitude reduction in reagent consumption, decreasing the cost of protein synthesis; and (3) the possibility to integrate with detection for rapid protein analysis, eliminating the need to harvest proteins. The device consists of an array of units, and each unit can be used for production of an individual protein. The unit comprises a tray chamber for in vitro protein expression and a well chamber as a nutrient reservoir. The tray is nested in the well, and they are separated by a dialysis membrane and connected through a microfluidic connection that provides a means to supply nutrients and remove the reaction byproducts. The device is demonstrated by synthesis of green fluorescent protein, chloramphenicol acetyl-transferase, and luciferase. Protein expression in the device lasts 5-10 times longer and the production yield is 13-22 times higher than in a microcentrifuge tube. In addition, we studied the effects of the operation temperature and hydrostatic flow on the protein production yield.

Parkinson's disease currently affects millions of people worldwide and is steadily increasing. Many symptoms are associated with this disease, including rest tremor, bradykinesia, stiffness or rigidity of the extremities and postural instability. No cure is currently available for Parkinson's disease patients; instead most medications are for treatment of symptoms. This treatment depends on the quantification of these symptoms such as hand tremor. This work proposes a new system for mobile phone applications. The system is based on measuring the acceleration from the Parkinson's disease patient's hand using a mobile cell phone accelerometer. Recordings from 21 Parkinson's disease patients and 21 healthy subjects were used. These recordings were analysed using a two level wavelet packet analysis and features were extracted forming a feature vector of 12 elements. The features extracted from the 42 subjects were classified using a neural networks classifier. The results obtained showed an accuracy of 95% and a Kappa coefficient of 90%. These results indicate that a cell phone accelerometer can accurately detect and record rest tremor in Parkinson's disease patients.

We report in vitro (cell-free) protein expression in a microfluidic device using passive pumping. The polystyrene device contains 192 microchannels, each of which is connected to two wells positioned in a 384-well microplate format. A larger droplet of an expression solution was placed at one well of each channel while a smaller droplet of a nutrient solution was at the other well. Protein expression took place in the larger droplet and we found the expression yield in the expression solution is enhanced due to the replenishment of the nutrient solution supplied by passive pumping via the channel. The pumping pressure was generated from the difference in the surface tension between two different sized droplets at the two wells. We demonstrated expression of luciferase in the device and the expression yield was measured using luminescence assay. Different experimental conditions were investigated to achieve maximum protein yield with the least amount of reagents. Protein expression yields were found to be dependent on the amount of the nutrient solution pumped, independent of the amount of the expression solution within the experimental conditions studied. A higher feeding frequency or delivery rate of the nutrient solution resulted in higher protein expression yield. The work demonstrated the feasibility of using the microchannel array for protein expression with the following advantages: (1) simultaneous production of the same protein with different conditions to optimize the expression process; (2) simultaneous production of different proteins for high-throughput protein expression with high yield; (3) low reagent cost due to the fact that it consumes 125-800 times less than the amount used in a protein expression instrument commercially available.

We describe a miniaturized fluid array device for high-throughput cell-free protein synthesis (CFPS), aiming to match the throughput and scale of gene discovery. Current practice of using E. coli cells for production of recombinant proteins is difficult and cost-prohibitive to implement in a high-throughput format. As more and more new genes are being identified, there is a considerable need to have high-throughput methods to produce a large number of proteins for studying structures and functions of the corresponding genes. The device consists of 96 units and each unit is for expression of one protein; thus up to 96 proteins can be produced simultaneously. The function of the fluid array was demonstrated by expression of a variety of proteins, with more than two orders of magnitude reduction in reagent consumption compared with a commercially available CFPS instrument. The protein expression yield in the device was up to 87 times higher for β-glucoronidase than that in a conventional microplate. The concentration of β-galactosidase expressed in the device was determined at 5.5 μg/μL. The feasibility of using the device for drug screening was demonstrated by measuring the inhibitory effects of mock drug compounds on synthesized β-lactamase without the need for harvesting proteins, which enabled us to reduce the analysis time from days to hours.