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Deterministic encapsulation of single cells in thin tunable microgels for niche modelling and therapeutic delivery


Existing techniques to encapsulate cells into microscale hydrogels generally yield high polymer-to-cell ratios and lack control over the hydrogel’s mechanical properties1. Here, we report a microfluidic-based method for encapsulating single cells in an approximately six-micrometre layer of alginate that increases the proportion of cell-containing microgels by a factor of ten, with encapsulation efficiencies over 90%. We show that in vitro cell viability was maintained over a three-day period, that the microgels are mechanically tractable, and that, for microscale cell assemblages of encapsulated marrow stromal cells cultured in microwells, osteogenic differentiation of encapsulated cells depends on gel stiffness and cell density. We also show that intravenous injection of singly encapsulated marrow stromal cells into mice delays clearance kinetics and sustains donor-derived soluble factors in vivo. The encapsulation of single cells in tunable hydrogels should find use in a variety of tissue engineering and regenerative medicine applications.

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Figure 1: Encapsulation of single cells in thin layers of alginate gel.
Figure 2: Characterization of cell-encapsulating microgels.
Figure 3: Modulating polymer composition and mechanical properties of microgels to impact cell behaviour in vitro.
Figure 4: Culture and differentiation of mMSC-encapsulating microgels in microwells.
Figure 5: Microgel encapsulation prolongs the in vivo residence time of donor cells and systemic levels of secreted soluble factors after i.v. injection.


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This work was supported by the National Institutes of Health (NIH) Grants RO1EB014703 (D.J.M. and D.A.W.) and K99HL125884 (J.-W.S.), and the National Science Foundation (NSF) Graduate Research Fellowship Program (A.S.M.). S.U. was supported by the Deutsche Forschungsgemeinschaft (DFG).

Author information




A.S.M., J.-W.S. and D.J.M. conceived and designed the experiments. S.U., H.W. and D.A.W. contributed to microfluidic design and fabrication. A.S.M. and J.-W.S. performed the experiments. A.S.M., J.-W.S. and D.J.M. analysed the data. A.S.M., J.-W.S. and D.J.M. wrote the manuscript. All authors discussed the results and commented on the manuscript. A.S.M. and J.-W.S. contributed equally to this work. The principal investigator is D.J.M.

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Correspondence to David J. Mooney.

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The authors declare no competing financial interests.

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Mao, A., Shin, JW., Utech, S. et al. Deterministic encapsulation of single cells in thin tunable microgels for niche modelling and therapeutic delivery. Nature Mater 16, 236–243 (2017).

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