Polyacrylamide-Based Hydrogel with Biocompatibility and Tunable Stiffness for Three-Dimensional Cell Culture

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Cell Biology

Background:

• Three-dimensional (3D) cell culture offers greater physiological relevance than 2D models.
• Existing 3D platforms like Matrigel struggle to decouple biological functions from mechanical properties.
• Polyacrylamide (PAAm) is suitable for 2D culture but its precursor, acrylamide (AAm), is cytotoxic, hindering 3D applications.

Purpose of the Study:

• To synthesize non-toxic PAAm hydrogels for 3D cell culture.
• To create a platform allowing independent tuning of biological and mechanical properties.
• To evaluate the biocompatibility and utility of PAAm hydrogels in supporting cell and organoid 3D culture.

Main Methods:

• RAFT copolymerization of AAm with a functional monomer, followed by post-polymerization modification to introduce thiol or norbornene groups.
• Fabrication of PAAm hydrogels via photoinduced thiol-norbornene coupling.
• 3D culture of human umbilical vein endothelial cells (HUVECs) and intestinal organoids.

Main Results:

• Synthesized non-toxic, linear PAAm with tunable chain lengths and functional groups (multithiol or multinorbornene).
• Fabricated biocompatible, structurally homogeneous PAAm hydrogels with tunable and reproducible mechanical properties.
• Demonstrated successful 3D culture of HUVECs, with higher adhesive ligand density improving viability.
• Showed favorable results for intestinal organoid culture in combination with Matrigel, indicating lower mechanical strength is beneficial.

Conclusions:

• Developed a novel, non-toxic PAAm hydrogel system for 3D cell culture.
• This platform enables the decoupling of biological functions and mechanical properties in 3D environments.
• The PAAm hydrogels show significant potential for advanced 3D cell culture applications, including organoid development.