Modular photoorigami-based 4D manufacturing of vascular junction elements

Area of Science:

• Biomaterials Science
• Additive Manufacturing
• Tissue Engineering

Background:

• Conventional three-dimensional (3D) printing faces limitations in fabricating complex hollow structures.
• Existing four-dimensional (4D) printing techniques are restricted in the shapes achievable from a single object.
• Fabricating intricate vascular structures like T-junctions requires advanced manufacturing methods.

Purpose of the Study:

• To develop an advanced 4D printing approach for creating vascular T-junctions.
• To overcome limitations of single shape-changing objects in 4D printing.
• To demonstrate the feasibility of fabricating functional vascular junctions using stimuli-responsive materials.

Main Methods:

• Utilized a 4D printing technique based on the coordinated sequential folding of multiple shape-changing elements.
• Split T-junctions into two components, each 4D printed with distinct shape memory polyurethanes and nanohybrids.
• Incorporated photo-responsive copper sulfide-polyvinyl pyrrolidone nanoparticles and varied hard segment content for tailored shape memory behaviors.

Main Results:

• Successfully demonstrated the formation of T-junctions by programming differential shape memory responses in each component.
• Cell culture studies with human umbilical vein endothelial cells showed high cell viability (approx. 90% at day 7).
• Confirmed T-junction formation under near-infrared light after endothelial cell seeding, with cells adhering and proliferating over time.

Conclusions:

• The proposed coordinated sequential folding 4D printing approach enables the fabrication of complex vascular T-junctions.
• The developed materials and method support endothelial cell adhesion and proliferation, indicating potential for vascular tissue engineering.
• This advanced 4D fabrication technique offers a promising alternative for future vascular junction construction.