Cell Contractile Force-Mediated Morphodynamical Tissue Engineering via 4D Printed Degradable Hydrogel Scaffolds

Area of Science:

• Biomaterials Science
• Developmental Biology
• Tissue Engineering

Background:

• Tissue morphogenesis is crucial for development, with four-dimensional (4D) cell scaffolds showing potential for modeling.
• Current 4D systems often neglect intrinsic cell-generated forces, like cell contractile forces (CCFs), which are key drivers of morphogenesis.
• A significant challenge lies in reconciling the weak nature of CCFs with the robust mechanical support of tissue scaffolds for effective shape transformation.

Purpose of the Study:

• To introduce an easily printable, freestanding, cell-laden hydrogel platform designed to leverage CCFs for 4D shape morphing.
• To develop a system that overcomes the limitations of existing 4D scaffolds by utilizing intrinsic cellular forces.
• To enable the creation of scaffold-free tissue constructs with programmed shape transformations and dynamic shape evolution.

Main Methods:

• Development of a printable, freestanding, cell-laden hydrogel platform.
• Utilizing rapid hydrogel degradation to enhance cell-cell interactions and local cell density, thereby amplifying CCFs.
• Modulating initial printed geometries to control global shape transformations and generate complex tissue constructs.
• Integrating tissue differentiation with dynamic shape evolution for 4D tissue engineering.

Main Results:

• The hydrogel platform provides initial mechanical support and subsequently degrades, amplifying CCFs to induce tissue morphogenesis.
• Scaffold-free constructs with programmed shape transformations were successfully generated.
• Complex and large tissue constructs were formed through controlled global shape transformations by altering initial printed geometries.
• The platform demonstrated the ability to facilitate tissue differentiation alongside dynamic shape evolution.

Conclusions:

• The CCF-4D system effectively harnesses intrinsic cell contractile forces for biomimetic tissue morphogenesis.
• This platform enables the creation of dynamic tissue models that closely replicate native developmental processes.
• It offers a significant advancement in 4D tissue engineering, opening new possibilities for studying and engineering complex tissues.