Recent Developments, Applications, and Future Prospects of Advanced Hearts-on-a-Chip.

Heart-on-a-chip (HoC) platforms represent a cutting-edge convergence of microfluidics and cellular biology, designed to imitate the complex physiological, electrical, and mechanical environments of a human heart. HoC devices are used to culture and observe cardiac cells in a highly customizable environment while allowing for real-time observations. However, current HoC systems face critical translational bottlenecks. Most notably, laboratory-grown cardiomyocytes consistently exhibit structural and functional immaturity and a lack of cellular complexity. This review evaluates recent engineering and biological strategies engineered to address these limitations. We dissect advancements in multicellular co-culture, biomimetic electrical/mechanical stimulation regimes, and microvascular fabrication techniques aimed at driving functional cell maturation. Finally, we highlight current cardiac model applications, existing challenges, and future perspectives.