title: Fabrication of uniform-sized poly-ɛ-caprolactone microspheres and their applications in human embryonic stem cell culture.
abstract: The generation of liquefied poly-ɛ-caprolactone (PCL) droplets by means of a microfluidic device results in uniform-sized microspheres, which are validated as microcarriers for human embryonic stem cell culture. Formed droplet size and size distribution, as well as the resulting PCL microsphere size, are correlated with the viscosity and flow rate ratio of the dispersed (Q d) and continuous (Q c) phases. PCL in dichloromethane increases its viscosity with concentration and molecular weight. Higher viscosity and Q d/Q c lead to the formation of larger droplets, within two observed formation modes: dripping and jetting. At low viscosity of dispersed phase and Q d/Q c, the microfluidic device is operated in dripping mode, which generates droplets and microspheres with greater size uniformity. Solutions with lower molecular weight PCL have lower viscosity, resulting in a wider concentration range for the dripping mode. When coated with extracellular matrix (ECM) proteins, the fabricated PCL microspheres are demonstrated capable of supporting the expansion of human embryonic stem cells.
authors.affiliation: A*STAR (Agency for Science, Technology and Research), Institute of Materials Research and Engineering, 2 Fusionopolis Way, Innovis, #08-03, Singapore, 138634, Singapore.
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.affiliation: A*STAR (Agency for Science, Technology and Research), Bioprocessing Technology Institute, 20 Biopolis Way, #06-01, Singapore, 138668, Singapore.
authors.forename: Alan Tin-Lun
authors.initials: AT
authors.lastname: Lam
authors.affiliation: A*STAR (Agency for Science, Technology and Research), Institute of Materials Research and Engineering, 2 Fusionopolis Way, Innovis, #08-03, Singapore, 138634, Singapore.
authors.forename: Jessica Pei Wen
authors.initials: JP
authors.lastname: Toh
authors.affiliation: A*STAR (Agency for Science, Technology and Research), Bioprocessing Technology Institute, 20 Biopolis Way, #06-01, Singapore, 138668, Singapore.
authors.forename: Shaul
authors.initials: S
authors.lastname: Reuveny
authors.affiliation: A*STAR (Agency for Science, Technology and Research), Bioprocessing Technology Institute, 20 Biopolis Way, #06-01, Singapore, 138668, Singapore.
authors.forename: Steve Kah-Weng
authors.initials: SK
authors.lastname: Oh
authors.affiliation: A*STAR (Agency for Science, Technology and Research), Institute of Materials Research and Engineering, 2 Fusionopolis Way, Innovis, #08-03, Singapore, 138634, Singapore. w-birch@imre.a-star.edu.sg.
authors.forename: William R
authors.initials: WR
authors.lastname: Birch
mesh_terms: D002448:Cell Adhesion; D049109:Cell Proliferation; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D016326:Extracellular Matrix Proteins / Q000737:chemistry; D000066449:Human Embryonic Stem Cells / Q000166:cytology*; D006801:Humans; D008863:Microspheres; D008970:Molecular Weight; D010316:Particle Size; D011091:Polyesters / Q000737:chemistry*; D014783:Viscosity
chemical_list: D020099:Coated Materials, Biocompatible; D016326:Extracellular Matrix Proteins; D011091:Polyesters; C016240:polycaprolactone
keywords: Human embryonic stem cells; Microcarriers; Microfluidics; Poly-ɛ-caprolactone; Polymer microspheres