title: Optimization of the formation of embedded multicellular spheroids of MCF-7 cells: How to reliably produce a biomimetic 3D model.
abstract: To obtain a multicellular MCF-7 spheroid model to mimic the three-dimensional (3D) of tumors, the microwell liquid overlay (A) and hanging-drop/agar (B) methods were first compared for their technical parameters. Then a method for embedding spheroids within collagen was optimized. For method A, centrifugation assisted cells form irregular aggregates but not spheroids. For method B, an extended sedimentation period of over 24 h for cell suspensions and increased viscosity of the culture medium using methylcellulose were necessary to harvest a dense and regular cell spheroid. When the number was less than 5000 cells/drop, embedded spheroids showed no tight cores and higher viability than the unembedded. However, above 5000 cells/drop, cellular viability of embedded spheroids was not significantly different from unembedded spheroids and cells invading through the collagen were in a sun-burst pattern with tight cores. Propidium Iodide staining indicated that spheroids had necrotic cores. The doxorubicin cytotoxicity demonstrated that spheroids were less susceptible to DOX than their monolayer cells. A reliable and reproducible method for embedding spheroids using the hanging-drop/agarose method within collagen is described herein. The cell culture model can be used to guide experimental manipulation of 3D cell cultures and to evaluate anticancer drug efficacy.
authors.affiliation: Department of Pharmaceutics, China Pharmaceutical University, Nanjing, 210009, PR China.
authors.forename: Wenli
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Pharmaceutics, China Pharmaceutical University, Nanjing, 210009, PR China.
authors.forename: Caibin
authors.initials: C
authors.lastname: Li
authors.affiliation: Auckland Cancer Society Research Centre, University of Auckland, Private Bag 92019, Auckland, New Zealand.
authors.forename: Bruce C
authors.initials: BC
authors.lastname: Baguley
authors.affiliation: Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing, 210009, PR China.
authors.forename: Fang
authors.initials: F
authors.lastname: Zhou
authors.affiliation: Department of Pharmaceutics, China Pharmaceutical University, Nanjing, 210009, PR China.
authors.forename: Weisai
authors.initials: W
authors.lastname: Zhou
authors.affiliation: School of Pharmacy, University of Auckland, Private Bag 92019, Auckland, New Zealand.
authors.forename: John P
authors.initials: JP
authors.lastname: Shaw
authors.affiliation: Department of Pharmaceutics, China Pharmaceutical University, Nanjing, 210009, PR China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wang
authors.affiliation: School of Pharmacy, University of Auckland, Private Bag 92019, Auckland, New Zealand. Electronic address: z.wu@auckland.ac.nz.
authors.forename: Zimei
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Department of Pharmaceutics, China Pharmaceutical University, Nanjing, 210009, PR China. Electronic address: liujianpingljp@hotmail.com.
authors.forename: Jianping
authors.initials: J
authors.lastname: Liu
mesh_terms: D032701:Biomimetics / Q000379:methods*; D018929:Cell Culture Techniques / Q000379:methods*; D002470:Cell Survival / Q000187:drug effects; D004317:Doxorubicin / Q000494:pharmacology; D005260:Female; D006801:Humans; D061986:MCF-7 Cells; D018874:Spheroids, Cellular / Q000166:cytology* / Q000378:metabolism
chemical_list: D004317:Doxorubicin
keywords: Collagen gels; Hanging drop; Liquid overlay; MCF-7 cells; Multicellular spheroids