Conductive Microfibers Improve Stem Cell-Derived Cardiac Spheroid Maturation

Area of Science:

• Biomaterials Science
• Cardiovascular Research
• Tissue Engineering

Background:

• Two-dimensional (2D) cardiomyocyte differentiation yields cells with limited maturity, hindering predictive capacity.
• Three-dimensional (3D) cardiac spheroids offer improved maturity but still lack full contractile and electrical maturation.
• Engineered cardiac tissues are desirable for advanced disease modeling.

Purpose of the Study:

• To investigate if conductive polymer microfibers can accelerate the maturation of cardiac spheroids.
• To determine the optimal properties (length, concentration) of microfibers for enhancing spheroid function.
• To assess the impact of microfibers on cardiac protein expression, calcium handling, and drug response.

Main Methods:

• Incorporation of conductive polymer microfibers into cardiac spheroids.
• Comparison of functional and transcriptional maturity between spheroids with conductive and nonconductive fibers.
• Analysis of spheroid structure, contractility parameters, protein expression, and drug response.
• Optimization of microfiber length (e.g., 5 μm) and mass (e.g., 20 μg/spheroid).

Main Results:

• Conductive microfibers improved cardiac spheroid contractility over time compared to nonconductive controls.
• Optimal microfiber properties (short length, moderate mass) led to enhanced contractile work.
• Spheroids with conductive microfibers showed increased expression of contractility and calcium handling proteins.
• Improved calcium handling abilities and drug responses were observed in engineered cardiac spheroids.

Conclusions:

• Conductive polymer microfibers effectively accelerate the functional maturation of cardiac spheroids.
• Optimized microfiber incorporation enhances cardiac spheroid performance for disease modeling.
• These findings support the use of conductive microfibers in 3D cardiac tissue models for improved predictive power.