Collagen is the most abundant protein in the extracellular matrix of mammals and has a great effect on various cell behaviors including adhesion, differentiation, and migration. However, it is difficult to utilize collagen gel as a physical scaffold in vitro because of its severe contraction. Decrease in the overall hydrogel volume induces changes in cell distribution, and mass transfer within the gel. Uncontrolled mechanical and physiological factors in the fibrous matrix result in uncontrolled cell behaviors in the surrounding cells. In this study, two strategies were used to minimize the contraction of collagen gel. A disk-shaped frame made of polydopamine-coated polydimethylsiloxane (PDMS) prevented horizontal contraction at the edge of the hydrogel. The sequentially cross-linked collagen gel with alginate outer shell (CA-shell) structure inhibited the vertical gel contraction. The combined method synergistically prevented the hydrogel from shrinkage in long-term 3D cell culture. We observed the shift in balance of differentiation from adipogenesis to osteogenesis in mesenchymal stem cells under the environment where gel contraction was prevented, and confirmed that this phenomenon is closely associated with the mechanotransduction based on Yes-associated protein (YAP) localization. Development of this contraction inhibition platform made it possible to investigate the influence of regulation of cellular microenvironments. The physical properties of the hydrogel fabricated in this study were similar to that of pure collagen gel but completely changed the cell behavior within the gel by inhibition of gel contraction. The platform can be used to broaden our understanding of the fundamental mechanism underlying cell-matrix interactions and reproduce extracellular matrix in vivo.
Bibliographical noteFunding Information:
This work was supported by National Research Foundation of Korea (NRF) funded by the Korean government (MSIT) [grants numbers 2017M3A9C6031786 and 2019R1F1A1048994 ]; National Research Foundation of Korea (NRF) through the National Research Foundation of Korea (NRF) funded by the Ministry of Education [grant number 2021R1A6A3A13039194 ]; and J.A Kim was also supported by Korea Basic Science Institute [grant number D210600 ].
© 2022 Elsevier B.V.
- Collagen contraction
- Yes-associated protein (YAP)