Reversible Intracellular Gelation of MCF10A Cells Enables Programmable Control Over 3D Spheroid Growth

• Published in: Advanced healthcare materials Vol. 13; no. 7; p. e2302528
• Main Authors: McNally, Delaney L, Macdougall, Laura J, Kirkpatrick, Bruce E, Maduka, Chima V, Hoffman, Timothy E, Fairbanks, Benjamin D, Bowman, Christopher N, Spencer, Sabrina L, Anseth, Kristi S
• Format: Journal Article
• Language: English
• Published: Germany 01.03.2024
• Subjects: intracellular crosslinking; biostasis; metabolism; spheroids; hydrogel
• ISSN: 2192-2659
• DOI: 10.1002/adhm.202302528

In nature, some organisms survive extreme environments by inducing a biostatic state wherein cellular contents are effectively vitrified. Recently, a synthetic biostatic state in mammalian cells is achieved via intracellular network formation using bio-orthogonal strain-promoted azide-alkyne cycloaddition (SPAAC) reactions between functionalized poly(ethylene glycol) (PEG) macromers. In this work, the effects of intracellular network formation on a 3D epithelial MCF10A spheroid model are explored. Macromer-transfected cells are encapsulated in Matrigel, and spheroid area is reduced by ≈50% compared to controls. The intracellular hydrogel network increases the quiescent cell population, as indicated by increased p21 expression. Additionally, bioenergetics (ATP/ADP ratio) and functional metabolic rates are reduced. To enable reversibility of the biostasis effect, a photosensitive nitrobenzyl-containing macromer is incorporated into the PEG network, allowing for light-induced degradation. Following light exposure, cell state, and proliferation return to control levels, while SPAAC-treated spheroids without light exposure (i.e., containing intact intracellular networks) remain smaller and less proliferative through this same period. These results demonstrate that photodegradable intracellular hydrogels can induce a reversible slow-growing state in 3D spheroid culture.