title: Multifactorial Experimental Design to Optimize the Anti-Inflammatory and Proangiogenic Potential of Mesenchymal Stem Cell Spheroids.
abstract: Mesenchymal stem cell therapies promote wound healing by manipulating the local environment to enhance the function of host cells. Aggregation of mesenchymal stem cells (MSCs) into three-dimensional spheroids increases cell survival and augments their anti-inflammatory and proangiogenic potential, yet there is no consensus on the preferred conditions for maximizing spheroid function in this application. The objective of this study was to optimize conditions for forming MSC spheroids that simultaneously enhance their anti-inflammatory and proangiogenic nature. We applied a design of experiments (DOE) approach to determine the interaction between three input variables (number of cells per spheroid, oxygen tension, and inflammatory stimulus) on MSC spheroids by quantifying secretion of prostaglandin E2(PGE2) and vascular endothelial growth factor (VEGF), two potent molecules in the MSC secretome. DOE results revealed that MSC spheroids formed with 40,000 cells per spheroid in 1% oxygen with an inflammatory stimulus (Spheroid 1) would exhibit enhanced PGE2and VEGF production versus those formed with 10,000 cells per spheroid in 21% oxygen with no inflammatory stimulus (Spheroid 2). Compared to Spheroid 2, Spheroid 1 produced fivefold more PGE2and fourfold more VEGF, providing the opportunity to simultaneously upregulate the secretion of these factors from the same spheroid. The spheroids induced macrophage polarization, sprout formation with endothelial cells, and keratinocyte migration in a human skin equivalent model-demonstrating efficacy on three key cell types that are dysfunctional in chronic non-healing wounds. We conclude that DOE-based analysis effectively identifies optimal culture conditions to enhance the anti-inflammatory and proangiogenic potential of MSC spheroids. Stem Cells 2017;35:1493-1504.
authors.affiliation: Department of Biomedical Engineering, University of California Davis, Davis, California, USA.
authors.forename: Kaitlin C
authors.initials: KC
authors.lastname: Murphy
authors.affiliation: Department of Biomedical Engineering, University of California Davis, Davis, California, USA.
authors.forename: Jacklyn
authors.initials: J
authors.lastname: Whitehead
authors.affiliation: Department of Biomedical Engineering, University of California Davis, Davis, California, USA.
authors.forename: Patrick C
authors.initials: PC
authors.lastname: Falahee
authors.affiliation: Department of Biomedical Engineering, University of California Davis, Davis, California, USA.
authors.forename: Dejie
authors.initials: D
authors.lastname: Zhou
authors.affiliation: Department of Biomedical Engineering, University of California Davis, Davis, California, USA.
authors.forename: Scott I
authors.initials: SI
authors.lastname: Simon
authors.affiliation: Department of Biomedical Engineering, University of California Davis, Davis, California, USA.|Department of Orthopaedic Surgery, School of Medicine, University of California Davis, Sacramento, California, USA.
authors.forename: J Kent
authors.identifier: 0000-0002-1673-3335
authors.initials: JK
authors.lastname: Leach
mesh_terms: D000893:Anti-Inflammatory Agents / Q000378:metabolism*; D016764:Cell Polarity / Q000187:drug effects; D048429:Cell Size / Q000187:drug effects; D060833:Cellular Microenvironment / Q000187:drug effects; D003114:Colony-Forming Units Assay; D017077:Culture Media, Conditioned / Q000494:pharmacology; D006801:Humans; D008262:Macrophage Activation / Q000187:drug effects; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000187:drug effects; D010641:Phenotype; D015203:Reproducibility of Results; D012107:Research Design; D015398:Signal Transduction / Q000187:drug effects; D017768:Skin, Artificial; D018874:Spheroids, Cellular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D014945:Wound Healing / Q000187:drug effects
chemical_list: D000893:Anti-Inflammatory Agents; D017077:Culture Media, Conditioned; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha
keywords: Design of experiments; Inflammation; Mesenchymal stem cell; Proangiogenic; Prostaglandin E2