Purchase this article with an account.
Sarah Hull, Gabriella Fernandes-Cunha, Hyun Jong Lee, Sarah Heilshorn, David Myung; Effects of engineered cellular microenvironments on the secretome of human mesenchymal stem cells. Invest. Ophthalmol. Vis. Sci. 2018;59(9):2293.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
The human mesenchymal stem cell (hMSC) secretome, a collection of bioactive secreted factors, has therapeutic potential in corneal wound healing. However, the conditions for reliably controlling the molecular profile to maximize its regenerative effects remains unknown. This study tests the hypothesis that the secretome’s molecular profile can be modulated by changing the hMSC’s 3D microenvironment. We compare the effects of using bioorthogonal chemistry and traditional chemical crosslinking to synthesize collagen-based hydrogels for 3D cell culture by monitoring the hMSCs secretion profiles following encapsulation.
Bioorthogonal collagen gels were formed using strain-promoted azide-alkyne cycloaddition (SPAAC), a biocompatible form of copper-free click chemistry. Briefly, type I collagen was functionalized with either azide or cyclooctyne groups using NHS ester chemistry, and then these two components were combined to produce a gel. Non-bioorthogonal gels were made using multi-arm succinimidyl chemistry to crosslink type I collagen. In each case, concentration and degree of functionalization were tuned to modulate the mechanical properties of the gels, and rheological measurements were performed to measure gel stiffness. Bone marrow-derived hMSCs were then encapsulated within either (1) bioorthogonally crosslinked collagen gels, (2) non-bioorthogonally crosslinked collagen gels, or (3) uncrosslinked collagen gels. Conditioned media was collected on days 2, 4, and 8 of culture from these gels for proteomic analysis using a Luminex Multiplex immunoassay.
Culturing hMSCs in bioorthogonal vs non-bioorthogonal environments yielded significantly different secretion profiles as determined by immunoassay. In a 3D bioorthogonal environment, factors favorable for corneal wound healing, including EGF, NGF, IL6 and VCAM-1, were upregulated as compared to both uncrosslinked collagen and non-bioorthogonally crosslinked collagen gels. In addition, MSCs exhibited greater spreading morphology when encapsulated within bioorthogonally crosslinked gels. In all cases, encapsulated hMSCs remained viable for the 8 days prior to secretome collection.
Our results confirm our hypothesis that changing the cells’ microenvironment alters their secretion profile and demonstrate the feasibility of controlling the hMSC secretome for potential therapeutic benefit on corneal wound healing.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.
This PDF is available to Subscribers Only