title: Multicellular tumor spheroid formation in duplex microcapsules for analysis of chemosensitivity.
abstract: Multicellular tumor spheroids (MTS) are gaining increased recognition as valuable tools and key elements in anticancer drug discovery and tumor therapy test programs. However, the lack of reproducible and uniform MTS sizes is a major problem for pharmaceutical assays. Here, we show the usefulness of duplex microcapsules with a Ca-alginate gel membrane as a platform for producing MTS with a highly homogeneous size distribution. HeLa cells were enclosed with 86.9% viability within the microcapsules. The enclosed cells grew and formed MTS with the same size as the cavity of the microcapsules by arresting their growth with the microcapsule membrane. The cells in the resultant MTS had a higher proportion in G(0)/G(1) phase (71.2%) than 2-D cultured cells in the stationary phase (64.3%) or those in MTS formed on a non-adherent surface (65.3%) (P < 0.01). Furthermore, the cells in MTS formed within microcapsules showed higher tolerance to mitomycin C (1-1000 nM) and gemcitabine (4.5-4500 nM) than 2-D cultured cells (P < 0.01). In addition, the expression of MDR1, MCT1, HIF-1α, and GRP78 mRNA was 2.9-, 3.2-, 3.8-, and 5.5-fold higher, respectively, than those in 2-D cultured cells (P < 0.04). Cryopreserved encapsulated cells in the microcapsules showed 80.5% viability and formed MTS with a comparable tolerance of 100 and 1000 nM mitomycin C to those that were not cryopreserved (P > 0.09). These findings suggest the duplex microcapsule may be a promising tool for producing MTS for pharmaceutical applications.
authors.affiliation: Division of Chemical Engineering, Department of Materials Science and Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Japan. sakai@cheng.es.osaka-u.ac.jp
authors.forename: Shinji
authors.initials: S
authors.lastname: Sakai
authors.forename: Kazuya
authors.initials: K
authors.lastname: Inamoto
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Shinji
authors.initials: S
authors.lastname: Tanaka
authors.forename: Shigeki
authors.initials: S
authors.lastname: Arii
authors.forename: Masahito
authors.initials: M
authors.lastname: Taya
mesh_terms: D000464:Alginates; D002214:Capsules / Q000737:chemistry; D018929:Cell Culture Techniques; D002453:Cell Cycle / Q000502:physiology; D015925:Cryopreservation; D000091342:Endoplasmic Reticulum Chaperone BiP; D020723:Glucuronic Acid; D006367:HeLa Cells; D006603:Hexuronic Acids; D006801:Humans; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018874:Spheroids, Cellular / Q000166:cytology*
chemical_list: D000464:Alginates; D002214:Capsules; D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D006603:Hexuronic Acids; D020723:Glucuronic Acid