Tailoring Hydrogel Composition and Stiffness to Control Smooth Muscle Cell Differentiation in Bioprinted Constructs

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Cell Biology

Background:

• Reliable in vitro models are crucial for studying smooth muscle cell (SMC) phenotypic modulation in various conditions.
• Current limitations necessitate the development of advanced cellular models for comprehensive research.

Purpose of the Study:

• To optimize gelatin methacrylate (GelMA)/alginate hydrogels for bioprinting three-dimensional (3D) SMC constructs.
• To investigate the impact of varying GelMA and alginate concentrations on hydrogel properties and cell behavior.

Main Methods:

• Four GelMA/alginate hydrogel compositions (G1-G4) were prepared with varying concentrations.
• Human bladder SMCs were encapsulated within hydrogels and bioprinted into 3D circular structures.
• Printability, cell viability, proliferation, and differentiation were assessed over an 8-day period.

Main Results:

• The hydrogel with the highest GelMA and alginate concentrations (G4) demonstrated superior viscosity and 3D construct stability.
• Cells within the G4 hydrogel exhibited high viability (>80%), spindle-shaped morphology, and significantly increased proliferation.
• G4 hydrogels effectively promoted the induction of a contractile SMC phenotype, indicated by marker protein expression and morphology.

Conclusions:

• Hydrogel composition is a key factor in controlling SMC phenotype.
• Optimized GelMA/alginate hydrogels facilitate the bioprinting of 3D SMC models for studying phenotypic adaptation.
• These 3D constructs hold promise for investigating therapies for conditions like urethral strictures.