Controlling 3D Contractility via Engineered Fibrous Hydrogel Composites

Area of Science:

• Biomaterials Science
• Cell Biology
• Tissue Engineering

Background:

• Cell-extracellular matrix (ECM) mechanobiological crosstalk is crucial for tissue morphogenesis and wound healing.
• In vitro models using natural hydrogels lack independent control over material properties and contraction.
• Existing models struggle to precisely mimic the complex cell-ECM interplay.

Purpose of the Study:

• To introduce a fully-defined hydrogel composite that mimics ECM structure and mechanics.
• To enable tunable control over cell-mediated contraction in vitro.
• To investigate the impact of contraction on microtissue formation and cell behavior.

Main Methods:

• Fabrication of a synthetic hydrogel composite with fragmented synthetic fibers mimicking collagen.
• Modulation of fiber density/length and hydrogel density/crosslinking to tune material properties.
• Culture of cells within the composite to assess cell-mediated contraction and tissue formation.

Main Results:

• The defined hydrogel composite supports cell-mediated traction-based contraction, similar to natural collagen gels.
• Tuning composite properties (fiber and hydrogel characteristics) allows for controlled contraction.
• Contraction-permissive constructs promoted microtissue cell alignment and fiber fragment densification.
• Contraction-resistant composites (higher crosslinking) did not induce these cellular responses.

Conclusions:

• The developed hydrogel composite offers a powerful, tunable platform for studying cell-ECM mechanobiology.
• This material advances the ability to interrogate cell-matrix interactions in controlled microenvironments.
• Independent control over material properties facilitates deeper understanding of tissue morphogenesis mechanisms.