Dual-Stiffness Hydrogel-Based Glioblastoma In Vitro Model to Observe Cell Behavior at Interfaces.

Area of Science:

• Biomedical Engineering
• Cancer Research
• Materials Science

Background:

• Three-dimensional in vitro models are crucial for studying cellular behavior, particularly cell interactions with matrix interfaces.
• Glioblastoma (GBM) is an aggressive brain cancer known to spread along stiffness interfaces in the brain.
• Existing models often lack the complexity to fully replicate the in vivo microenvironment and GBM's invasive nature.

Purpose of the Study:

• To develop and validate a dual-stiffness hydrogel-encapsulated glioblastoma (GBM) spheroid model.
• To investigate GBM cell spreading and migration along a stiffness interface in vitro.
• To assess GBM cell viability and infiltration within different stiffness hydrogels.

Main Methods:

• Development of a dual-stiffness hydrogel system using polyethylene glycol (PEG) with varying concentrations (5% w/v soft, 10% w/v stiff).
• Encapsulation of GBM spheroids within the hydrogel interface by adjusting precursor solution pH to control gelation time.
• Assessment of GBM spheroid infiltration, viability, and migration across the stiffness interface over 7 days.

Main Results:

• GBM spheroids maintained high viability in both soft and stiff hydrogels.
• A higher infiltration index was observed in the soft hydrogel compared to the stiff hydrogel.
• Migration across the stiffness interface was unidirectional, occurring only from the soft to the stiff hydrogel.

Conclusions:

• The developed dual-stiffness hydrogel model effectively replicates GBM's tendency to follow stiffness gradients.
• This model provides a simple, robust, and imageable platform for studying GBM invasion in vitro.
• The model's compatibility with multiwell plates facilitates high-throughput analysis of glioblastoma behavior.