Engineering a microfibrous composite hydrogel with cell actuation‐mediated contractile properties

Abstract

AbstractNatural extracellular matrix is a complex system of nano‐ and micrometer sized fibers creating a porous structure that can be recruited, rearranged and contracted by cells. Modeling appropriate analogues of this dynamic system poses a challenge to the field of tissue engineering. Here, we introduce a shape‐changing modifiable composite hydrogel consisting of cellulose microfibers and degradable fibrin with encapsulated NIH3T3 fibroblasts as a shape‐changing actuator. We demonstrate that the extent of hydrogel contraction is adjustable over a range from 12 to 95% by altering cellulose microfiber concentration and length, along with customizing contraction speed by changing cellular seeding density. Cell viability and proliferation capacity were preserved at seeding densities of up to 16 million/ml even after complete fibrin degradation, likely due to the microporous structural support of the stacked cellulose fibers. The hierarchical, living fibrous construct presented here may provide numerous benefits over existing models and enable various new applications in tissue engineering and in vitro disease modeling.