title: Nanoliter scale microbioreactor array for quantitative cell biology.
abstract: A nanoliter scale microbioreactor array was designed for multiplexed quantitative cell biology. An addressable 8 x 8 array of three nanoliter chambers was demonstrated for observing the serum response of HeLa human cancer cells in 64 parallel cultures. The individual culture unit was designed with a "C" shaped ring that effectively decoupled the central cell growth regions from the outer fluid transport channels. The chamber layout mimics physiological tissue conditions by implementing an outer channel for convective "blood" flow that feeds cells through diffusion into the low shear "interstitial" space. The 2 microm opening at the base of the "C" ring established a differential fluidic resistance up to 3 orders of magnitude greater than the fluid transport channel within a single mold microfluidic device. Three-dimensional (3D) finite element simulation were used to predict fluid transport properties based on chamber dimensions and verified experimentally. The microbioreactor array provided a continuous flow culture environment with a Peclet number (0.02) and shear stress (0.01 Pa) that approximated in vivo tissue conditions without limiting mass transport (10 s nutrient turnover). This microfluidic design overcomes the major problems encountered in multiplexing nanoliter culture environments by enabling uniform cell loading, eliminating shear, and pressure stresses on cultured cells, providing stable control of fluidic addressing, and permitting continuous on-chip optical monitoring.
authors.affiliation: Department of Bioengineering, Biomolecular Nanotechnology Center, Berkeley Sensor and Actuator Center, University of California, Berkeley, 485 Evans Hall, 94720-1762, USA.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Lee
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Hung
authors.forename: Vivek M
authors.initials: VM
authors.lastname: Rao
authors.forename: Luke P
authors.initials: LP
authors.lastname: Lee
mesh_terms: D019149:Bioreactors; D018929:Cell Culture Techniques; D002468:Cell Physiological Phenomena; D049109:Cell Proliferation; D003198:Computer Simulation; D003470:Culture Media; D006367:HeLa Cells; D006801:Humans; D046210:Microfluidic Analytical Techniques; D044085:Microfluidics; D036103:Nanotechnology; D020411:Oligonucleotide Array Sequence Analysis
chemical_list: D003470:Culture Media