Shaping soft hydrogels into 3D, multiscale, perfusable models using multimodal printing

Area of Science:

• Biomaterials Engineering
• Biofabrication
• Microfluidics

Background:

• Fabricating complex 3D hydrogel structures with multiscale features is challenging.
• Existing methods like digital light projection (DLP) and two-photon ablation (TPA) have limitations.
• Soft hydrogel bioinks present unique processing difficulties for complex designs.

Purpose of the Study:

• To develop a hybrid 3D printing platform combining macroscale DLP and microscale TPA.
• To overcome limitations in fabricating multiscale, multi-material, and topologically complex soft hydrogel constructs.
• To create advanced bio-printed structures with integrated perfusable microarchitectures.

Main Methods:

• Combined additive DLP (macroscale) and subtractive TPA (microscale) 3D printing.
• Utilized multi-material exchange capability for diverse bioink formulations.
• Identified and optimized hydrogel bioinks compatible with both DLP and TPA processing modes.
• Resolved technical challenges in multimodal fabrication, including alignment, soft-hard material integration, and swelling control.

Main Results:

• Successfully fabricated centimeter-scale hydrogel constructs with embedded microscale perfusable topologies.
• Demonstrated the creation of complex structures not achievable with isolated DLP or TPA.
• Fabricated microfluidic chips with independently perfusable channels and dual-fluidic circuits mimicking biological interfaces.
• Created endothelialized microfluidic channels within complex 3D constructs.

Conclusions:

• The hybrid DLP-TPA platform offers unprecedented capabilities for fabricating multiscale, perfusable bio-structures.
• This technology enables the creation of in vivo-like complexities for advanced biological models.
• Potential applications include the development of next-generation organ-on-chips and tissue engineering scaffolds.