title: Low cost microfluidic cell culture array using normally closed valves for cytotoxicity assay.
abstract: A reusable low cost microfluidic cell culture array device (MCCAD) integrated with a six output concentration gradient generator (cGG) and 4×6 arrays of microchamber elements, addressed by a series of row and columnar pneumatically actuated normally closed (NC) microvalves was fabricated for cell-based screening of chemotherapeutic compounds. The poly(dimethylsiloxane) (PDMS) device consists of three layers: fluidic, control and membrane which are held by surface contact and made leak-proof by clamping pressure. The NC valves are actuated by a thick PDMS membrane that was created by a novel method based on the self-assembly of PDMS pre-polymer molecules over a denser calcium chloride solution. The membrane actuated the valves reliably and particulates such as alumina particles (3 µm) and MCF-7 cells (20-24 µm) (2×10(5) cells/mL) were flowed through the valves without causing blockage or leakage and consequently avoiding contamination of the different cell culture elements. The MCCAD was cast and assembled in a standard laboratory without specialist equipment and demonstrated for performing quantitative cell-based cytotoxicity assays of pyocyanine on human breast cancer (MCF-7) cells and assessed for toxic effect on human hepatocyte carcinoma (HepG2) cells as an indicator for liver injury. Then, the MCCAD was demonstrated for sequential drug combinatorial screening involving gradient generation of paclitaxel doses followed by treatment with aspirin doses on the viability of MCF-7 cells. The interaction between paclitaxel and aspirin was evaluated by using the Bliss independence predictive model and results showed reasonable agreement with the model. A robust, portable, easily fabricated and low cost device is therefore shown to conveniently carry out culturing of multiple cell lines for high throughput screening of anti-cancer compounds using minimal reagents.
authors.affiliation: School of Science and Engineering, Teesside University, Borough Road, Middlesbrough TS1 3BA, United Kingdom. Electronic address: godfrey.pasirayi@tees.ac.uk.
authors.forename: Godfrey
authors.initials: G
authors.lastname: Pasirayi
authors.affiliation: School of Science and Engineering, Teesside University, Borough Road, Middlesbrough TS1 3BA, United Kingdom.
authors.forename: Simon M
authors.initials: SM
authors.lastname: Scott
authors.affiliation: School of Science and Engineering, Teesside University, Borough Road, Middlesbrough TS1 3BA, United Kingdom.
authors.forename: Meez
authors.initials: M
authors.lastname: Islam
authors.affiliation: School of Science and Engineering, Teesside University, Borough Road, Middlesbrough TS1 3BA, United Kingdom.
authors.forename: Liam
authors.initials: L
authors.lastname: O'Hare
authors.affiliation: School of Science and Engineering, Teesside University, Borough Road, Middlesbrough TS1 3BA, United Kingdom.
authors.forename: Simon
authors.initials: S
authors.lastname: Bateson
authors.affiliation: Graduate Research School, Teesside University, Borough Road, Middlesbrough TS1 3BA, United Kingdom.
authors.forename: Zulfiqur
authors.initials: Z
authors.lastname: Ali
mesh_terms: D001241:Aspirin / Q000737:chemistry; D019149:Bioreactors; D002122:Calcium Chloride / Q000737:chemistry*; D002448:Cell Adhesion; D018929:Cell Culture Techniques / Q000295:instrumentation; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D015195:Drug Design; D004353:Drug Evaluation, Preclinical; D004359:Drug Therapy, Combination; D056945:Hep G2 Cells; D006801:Humans; D061986:MCF-7 Cells; D008567:Membranes, Artificial; D046210:Microfluidic Analytical Techniques / Q000191:economics / Q000379:methods*; D044085:Microfluidics; D017239:Paclitaxel / Q000737:chemistry; D011108:Polymers
chemical_list: D008567:Membranes, Artificial; D011108:Polymers; D002122:Calcium Chloride; D017239:Paclitaxel; D001241:Aspirin
keywords: Cell culture array; Combinatorial screening; Cytotoxicity assay; Microfluidic; Normally closed valve