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Acute Effects Of Dopamine Agonist On Electrotaxis Of Zebrafish Larvae Inside A Microfluidic Device
Amir Reza Peimani, Second Year Master Student, York University
Zebrafish is an accessible model organism in behavioral screening[1],[2] and drug discovery[3]. Orientation[4] and escape[5] movement behaviors have been investigated using the zebrafish models. Movement is associated with the dopaminergic system of zebrafish in a way that less activity during night is observed due to low dopamine level[6]. However, studying zebrafish movement on a petri dish is qualitative and inaccurate[7],[8]. Microfluidic devices[9]–[12] have resolved these issues but they focus on neural imaging while suffering from disadvantages such as complexity, irreversibility, and lack of an accurate method to evoke movement and study it quantitatively. A novel and simple device that uses electric current (EC=3µA) to induce on-demand electrotaxis movement in zebrafish larvae is introduced. Electrotaxis was quantified based on orientation rate and movement speed of larvae towards the anode in a microchannel. A significant reduction in electrotaxis orientation was detected in zebrafishes at night. However, treating them with apomorphine (believed to increase dopamine level[6]) resulted in improved electrotaxis at low apomorphine doses while increasing the exposure dose resulted in a response rate decline in fishes. This device can be employed in chemical screening of dopaminergic neurons against dopamine agonists and antagonists using zebrafish as a robust model for neurodegenerative diseases.
Microfluidic Dissecting Chip for Chemical-Free Isolation of Larval Cells from C. elegans
Khaled Youssef, 1st year PhD student, Department of Mechanical Engineering, York University., York University, Lassonde School of Engineering
Model organisms such as C. elegans have many applications in biomedical research [1] due to their small size, rapid growth, body transparency, and amenability to high-throughput screening [2]. However, the tough and thick cuticle of C. elegans have hindered many attempts to isolate cells from worms for in-vitro studies. The current chemical-based methods [3-6] are not very successful in isolating low-abundance cells due to their toxic mitigation of cell viability while being expensive and time- and labor-intensive. To circumvent these problems, the unrivaled features of microfluidics were exploited to develop a novel C. elegans dissecting chip which is chemical-free, low-cost and time-efficient in isolating cells from worms. It consisted of a single-worm trap with a side dissection needle through which worms were longitudinally passed and mechanically lysed. Cells were extracted at the outlet and cultured off-chip for characterization of the chip. Using worms that express fluorescent tags at target neurons, these rare cells can be isolated by sorting the extracted cells using FACS [4]. Cell extraction with our device can be achieved within 1 hr at a fraction of the cost associated with conventional chemical-based methods. This microfluidic chip has a wide application in studies that require cells from C. elegans.
Microfluidic and 3D printing devices for cell patterning and tumor analysis
Liang Zhao, Associate Professor, Beijing University of Technology
Herein, we developed a 3D printed “LEGO”-like device to implement tumor cell migration and metastasis assay without any micro-fabrication process due to the easy configuration of 3D printing. This technology allows quantitative analysis on not only tumor cell migration at single cell level but also for tumor-stomatocyte interactions.
Microfluidic-assisted synthesis of nanomedicines in a low-cost microfluidic platform
Alvaro Jose Conde, Microfluidics Engineer, CNEA
We present applications of a low-cost microfluidic platform that uses laminated polymethylmethacrylate chips, peristaltic micropumps and LEGO® Mindstorms components for the generation of nanomedicines [1]. We have successfully encapsulated hydrophilic and hydrophobic compounds in liposomes with the advantages associated to microfluidic-assisted synthesis such as monodisperse size distributions, enhanced encapsulation efficiency and no need of size reduction steps. Microfluidic-generated liposomes containing oxaliplatin (an hydrophilic drug for cancer chemotherapy) had smaller size and better drug-to-lipid ratio when compared to traditional synthesis methods. Likewise, the same improvement of parameters was obtained in microfluidic-generated liposomes containing lactosyl carborane (an hydrophobic molecule used in boron neutron capture therapy). We have also synthetized nanoparticles containing siRNA-PEI (complexes used for gene therapy) that had smaller size and enhanced silencing capability when compared to traditional methods. The platform does not only allow for improvements in the nanomedicines parameters but also a significant reduction in processing times which is usually critical in research laboratories
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