Hyaluronic Acid-Based, Double Network Hydrogels With Tunable Viscoelasticity for Neural Cell Culture

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Neuroscience

Background:

• Mammalian brain tissue is highly viscoelastic, influencing cell phenotypes.
• Conventional hydrogels lack independent control over elasticity and viscosity, hindering mechanical studies.
• Decoupling mechanical properties is essential for understanding cell behavior in 3D cultures.

Purpose of the Study:

• To develop a hyaluronic acid-based double network hydrogel platform enabling independent tuning of elasticity and viscosity.
• To create a biomaterial that mimics the mechanical properties of native brain tissue.
• To investigate the effects of independently tuned viscoelasticity and elasticity on glioblastoma and neural stem cell behavior.

Main Methods:

• Fabrication of a double network hydrogel using covalently photocrosslinked (thiolene) and dynamically crosslinked (hydrazone) hyaluronic acid.
• Independent tuning of storage modulus (G') and loss modulus (G″) by varying network compositions.
• Assessment of viscoelastic properties using stress-relaxation time and dissipation factor (tan(δ)).
• Culturing patient-derived glioblastoma (GBM) tumor cells and mouse neural stem cells (mNSCs) in hydrogels with varying mechanical properties.

Main Results:

• The double network hydrogel achieved independent control over elasticity and viscosity, maintaining G' within brain tissue ranges.
• Viscoelasticity was increased fourfold compared to single network hydrogels without altering elasticity.
• Increased viscoelasticity enhanced GBM cell proliferation in one line, while elasticity influenced mNSC proliferation.
• Both cell types exhibited increased spreading in stiffer double network hydrogels compared to single network gels.

Conclusions:

• The developed double network hydrogel platform allows orthogonal tuning of elasticity and viscosity.
• This biomaterial provides a better model for studying the mechanics of central nervous system (CNS) tissue.
• Independent control over hydrogel mechanics reveals distinct cellular responses to elasticity and viscoelasticity in neural cells and tumors.