Digital microfabrication of user-defined 3D microstructures in cell-laden hydrogels

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Biofabrication

Background:

• Complex 3D cell arrangements are crucial in biological systems like blood vessels.
• Existing tissue engineering methods struggle to replicate intricate 3D microenvironments for studying cell-topography interactions.
• A need exists for advanced fabrication techniques to control cell distribution within complex 3D structures.

Purpose of the Study:

• To develop a dynamic projection printing process for rapid fabrication of complex 3D micro-architectures.
• To investigate cell viability, morphology, and behavior within these engineered 3D scaffolds.
• To establish a versatile platform for evaluating cell responses to defined 3D micro-geometries.

Main Methods:

• Dynamic projection printing was employed to fabricate gelatin-methacrylate (GelMA) scaffolds with user-defined micro-geometries (spiral, pyramid, flower, dome).
• Scaffolds were fabricated with and without encapsulated cells (human mesenchymal stem cells implied).
• Cell viability, proliferation, morphology, and response to geometric cues were assessed using microscopy and time-lapse imaging.

Main Results:

• The dynamic projection printing process successfully created complex 3D GelMA structures with high fidelity.
• Encapsulated cells exhibited good viability and survival within various geometries, both on surfaces and internally.
• Cells demonstrated distinct responses to individual and collective geometric cues, influencing proliferation and morphology.
• Time-lapse observations revealed dynamic cell-micro-geometry mechanical interactions.

Conclusions:

• Cell encapsulation within complex 3D patterned scaffolds offers superior long-term control over cell behavior compared to conventional seeding.
• This biofabrication technique provides a flexible platform for studying cell-matrix interactions in controlled 3D environments.
• The method is scalable for high-throughput screening, advancing tissue engineering and regenerative medicine.