Stiffening of human mesenchymal stem cell spheroid microenvironments induced by incorporation of gelatin microparticles.
Culturing multipotent adult mesenchymal stem cells as 3D aggregates augments their differentiation potential and paracrine activity. One caveat of stem cell spheroids, though, can be the limited diffusional transport barriers posed by the inherent 3D structure of the multicellular aggregates. In order to circumvent such limitations, polymeric microparticles have been incorporated into stem cell aggregates as a means to locally control the biochemical and physical properties of the 3D microenvironment. However, the introduction of biomaterials to the 3D stem cell microenvironment could alter the mechanical forces sensed by cells within aggregates, which in turn could impact various cell behaviors and overall spheroid mechanics. Therefore, the objective of this study was to determine the acute effects of biomaterial incorporation within mesenchymal stem cell spheroids on aggregate structure and mechanical properties. The results of this study demonstrate that although gelatin microparticle incorporation results in similar multi-cellular organization within human mesenchymal stem cell spheroids, the introduction of gelatin materials significantly impacts spheroid mechanical properties. The marked differences in spheroid mechanics induced by microparticle incorporation may hold major implications for in vitro directed differentiation strategies and offer a novel route to engineer the mechanical properties of tissue constructs ex vivo.
The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, 313 Ferst Drive, Atlanta, GA 30332, USA. priya.r.baraniak@gatech.edu
Priya R
PR
Baraniak
Marissa T
MT
Cooke
Rabbia
R
Saeed
Melissa A
MA
Kinney
Krista M
KM
Fridley
Todd C
TC
McDevitt
D000818:Animals; D001696:Biomechanical Phenomena; D002454:Cell Differentiation / Q000187:drug effects; D060833:Cellular Microenvironment / Q000187:drug effects*; D005780:Gelatin / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D055595:Mechanical Phenomena; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects*; D008863:Microspheres; D044968:Regenerative Medicine; D018874:Spheroids, Cellular / Q000166:cytology* / Q000187:drug effects; D023822:Tissue Engineering
D005780:Gelatin