title: Size control of calcium alginate beads containing living cells using micro-nozzle array.
abstract: Size-controlled small (i.e. less than 300 microm) polyelectrolyte complex gel beads are urgently desired for wide-spread application, including use in medical, pharmaceutical, and bioengineering fields. However, it was impossible to obtain smaller beads less than 300 microm with conventional apparatuses. We developed a novel microfluidics device that utilizes silicon micro-nozzle (MN) array, enabling to produce 50-200 microm calcium alginate beads with a narrow size distribution. Alginate aqueous solution was extruded through a precisely fabricated thin (30 microm x 30 microm) and short (500 microm) MN and was sheared by the viscous drag force of oil flow to form alginate droplets. Alginate droplets were immediately reacted with CaCl2 droplets at the downstream of oil flow to form calcium alginate gel beads. This device enabled us to successfully encapsulate living cells into 162 microm calcium alginate beads with maintaining viability, which was confirmed by the expression of marker protein.
authors.affiliation: Food Engineering Division, National Food Research Institute, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Sugiura
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Oda
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Izumida
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Aoyagi
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Satake
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ochiai
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Ohkohchi
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Nakajima
mesh_terms: D000464:Alginates / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D001709:Biotechnology / Q000295:instrumentation*; D002118:Calcium / Q000737:chemistry; D002122:Calcium Chloride / Q000737:chemistry; D002460:Cell Line; D048271:Chitosan / Q000737:chemistry; D004339:Drug Compounding; D020723:Glucuronic Acid / Q000737:chemistry*; D049452:Green Fluorescent Proteins / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010316:Particle Size
chemical_list: D000464:Alginates; D001672:Biocompatible Materials; D006603:Hexuronic Acids; D049452:Green Fluorescent Proteins; D020723:Glucuronic Acid; D048271:Chitosan; D002122:Calcium Chloride; D002118:Calcium