Long-term spatially defined coculture within three-dimensional photopatterned hydrogels

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Mimicking in vivo tissue architecture is crucial for stem cell research and clinical therapies.
• Current methods for 3D cell culture often lack spatial control and require specialized equipment.

Purpose of the Study:

• To develop a novel, cost-effective fabrication system for photopatterning and assembling cell-laden hydrogels in 3D.
• To achieve high spatial fidelity and thickness in hydrogel constructs for mimicking native tissue.

Main Methods:

• Utilized oligo(polyethylene glycol)-fumarate:poly(ethylene glycol)-diacrylate hydrogels cross-linked with Irgacure-2959 photoinitiator and 365-nm light.
• Employed a controlled, inert nitrogen environment to enhance gel thickness and spatial control.
• Applied the technique for spatially controlled patterning of primary fibroblasts and marrow stromal cells in laminated hydrogel constructs.

Main Results:

• Achieved hydrogel gels ranging from 0.9 to 3 mm in width with high spatial fidelity.
• The nitrogen environment increased gel thickness by up to 240%, yielding gels over 1 mm thick.
• Encapsulated cells maintained viability for over 14 days in the 1.5-mm-thick laminated hydrogel construct.

Conclusions:

• The novel fabrication system enables precise 3D spatial control of cell coculture in hydrogels.
• This technique facilitates a better understanding of stem cell paracrine effects and functions.
• The system holds potential as an in vitro model for diverse regenerative medicine applications.