Polyglycerol-Based Hydrogel as Versatile Support Matrix for 3D Multicellular Tumor Spheroid Formation

Area of Science:

• Biomaterials Science
• Cancer Biology
• Cellular Mechanobiology

Background:

• Three-dimensional (3D) cell culture models are crucial for mimicking in vivo physiological conditions, advancing beyond traditional 2D cultures.
• Cellular mechanosensing, the process by which cells respond to mechanical cues like stiffness, significantly influences cancer cell behavior and malignancy.
• Developing biomimetic scaffolds that can modulate mechanical properties is essential for understanding cancer cell responses to microenvironmental stimuli.

Purpose of the Study:

• To engineer a non-degradable, tunable hydrogel scaffold for the 3D culture of various cancer cell lines.
• To investigate the formation and characteristics of multicellular tumor spheroids (MCTSs) within this 3D hydrogel environment.
• To assess the stability and suitability of the hydrogel for long-term cancer cell growth and spheroid development.

Main Methods:

• Utilized a thiol-Michael click reaction to synthesize a non-degradable hydrogel from alpha acrylate-functionalized dendritic polyglycerol (dPG) and thiol-functionalized 4-arm polyethylene glycol (PEG).
• Tailored the hydrogel's rheological viscoelasticity to achieve a stiffness of approximately 1 kPa, optimal for cell growth.
• Encapsulated diverse cancer cell lines (MCF-7, HT-29, HeLa, A549, BT-474, SK-BR-3) within the 3D hydrogel network for in situ culture and spheroid formation.

Main Results:

• Successfully formed stable, multicellular tumor spheroids (MCTSs) for all tested cancer cell lines within the 3D hydrogel.
• Characterized the grown tumoroids using fluorescence and confocal microscopy, observing an average size of approximately 150 µm after 25 days.
• Demonstrated the non-degradable nature and long-term stability of the hydrogel, with no significant swelling changes observed after 2 months under physiological conditions.

Conclusions:

• The developed dPG-PEG hydrogel platform is versatile and effective for the 3D culture of multiple cancer cell lines, facilitating the formation of stable MCTSs.
• The tunable mechanical properties and non-degradable nature of the hydrogel make it a promising tool for investigating cancer cell behavior and responses to mechanical stimuli in a physiologically relevant context.
• This 3D cell culture system offers a valuable model for advancing cancer research, drug screening, and understanding tumor microenvironment dynamics.