Open-access and multi-directional electroosmotic flow chip for positioning heterotypic cells

Research on Optimization Model of Multisource Traffic Information Collection Combination Based on Genetic Algorithm

In order to reduce the excessive use of multisource traffic information collection system, a multisource traffic information collection combination optimization mode is proposed based on genetic algorithm in this paper. This model is mainly used to analyze the traffic management data in the city. According to the collected data information, the characteristics of the traffic equipment can be effectively analyzed. Basing on the market demand and supply relationship, the multisource traffic information collection combination optimization model is used to complete the reorganization and optimization of the traffic information in this paper, to acquire the main convolution feature variables of the model. The data information combination processing is performed according to the acquired feature variables, and the genetic algorithm is used to adjust the multisource traffic information. During the process of information fusion data analysis, the multisource traffic information clustering and fuzzy constraint control can be performed effectively to realize the optimization of the team's traffic information collection combination. Finally, the simulation results show that the method proposed in this paper is more accurate in realizing the optimization process of multisource traffic information collection and combination and has a better degree of information fusion.

On-site processing of single chromosomal DNA molecules using optically driven microtools on a microfluidic workbench

We developed optically driven microtools for processing single biomolecules using a microfluidic workbench composed of a microfluidic platform that functions under an optical microscope. The optically driven microtools have enzymes immobilized on their surfaces, which catalyze chemical reactions for molecular processing in a confined space. Optical manipulation of the microtools enables them to be integrated with a microfluidic device for controlling the position, orientation, shape of the target sample. Here, we describe the immobilization of enzymes on the surface of microtools, the microfluidics workbench, including its microtool storage and sample positioning functions, and the use of this system for on-site cutting of single chromosomal DNA molecules. We fabricated microtools by UV lithography with SU-8 and selected ozone treatments for immobilizing enzymes. The microfluidic workbench has tool-stock chambers for tool storage and micropillars to trap and extend single chromosomal DNA molecules. The DNA cutting enzymes DNaseI and DNaseII were immobilized on microtools that were manipulated using optical tweezers. The DNaseI tool shows reliable cutting for on-site processing. This pinpoint processing provides an approach for analyzing chromosomal DNA at the single-molecule level. The flexibility of the microtool design allows for processing of various samples, including biomolecules and single cells.

Cell pairing and polyethylene glycol (PEG)-mediated cell fusion using two-step centrifugation-assisted single-cell trapping (CAScT)

Here a convenient and effective strategy of two-step centrifugation-assisted single-cell trapping (CAScT) based on an addressable truncated cone-shaped microwell array (TCMA) chip is developed for cell pairing. We describe the operation principles of the method and demonstrate its compatibility with polyethylene glycol (PEG)-mediated cell fusion. Compared with other methods, most of which rely on sophisticated devices and bulky subsidiary equipment, our method is more convenient and exhibits better or comparable performance. Using this method, up to around 6000 heterotypic cell pairs can be formed and addressed within a small area of 1 cm2. The paired cells are then treated with fusogenic PEG for cell fusion. Compared with traditional protocols, cell fusion using this approach is well defined with better control, which leads to an improved yield of heterotypic binucleated hybrids. Furthermore, we demonstrate the capability of our device for long-term cell culture and cell harvesting.

Heterotypic cell pair co-culturing on patterned microarrays

We present a pair-wise co-culturing technique that creates large numbers of heterotypic cell pairs in patterned arrays. Lithographic patterning produces arrays with thousands of traps, each designed to accommodate only two cells and confine them at these sites for co-culturing. Two variants are introduced: a random seeding method that sediments a mixture of two cell types onto the array, and an approach that incorporates ferromagnetic thin films into the arrays and attracts cells that have been attached to ferromagnetic nanowires to the array sites through dipole interactions. The array technique includes the utilization of custom image analysis software that extracts data from multi-channel fluorescence images and records information about the cells in every trap, enabling the acquisition of accurate, high-statistics data. The applicability of the technique was demonstrated in experiments examining proliferation rates in pairs of bovine pulmonary artery endothelial and smooth muscle cells. Results demonstrated that heterotypic interactions favored smooth muscle cell proliferation while disfavoring endothelial cell proliferation. This is one example of a variety of cell-cell interactions that could be probed with this method.

Droplet-based microfluidic device for multiple-droplet clustering

We present a multiple-droplet clustering device that can perform sequential droplet trapping and storing. Shape-dependent droplet manipulation in forward and backward flows has been incorporated to achieve high trapping and storing efficiency in a 10 × 12 array of clustering structures (e.g., storing well, storing chamber, trapping well, and guiding track). In the forward flow, flattened droplets are trapped in each trapping well. In the backward flow, the trapped droplets are released from the trapping well and follow the guiding tracks to their corresponding storing wells. The guided droplets float up out of the confining channel to the super stratum of the storing chamber due to interfacial energy and buoyancy effects. This forward/backward flow-based trapping/storing process can be repeated several times to cluster droplets with different contents and samples in the storing chambers. We expect that the proposed platform will be a valuable tool to study complex droplet-based reactions in clustered droplets.