We present the development of three-dimensional cardiac tissues within a microfluidic device with the ability to quantify real-time contractile force measurements in situ. Using a three-dimensional (3D) patterning technology that allows for the precise spatial distribution of cells within the device, we created an array of 3D cardiac microtissues from neonatal mouse cardiomyocytes. We integrated the 3D micropatterning technology with microfluidics to achieve perfused cell-laden structures. The cells were encapsulated within a degradable gelatin methacrylate structure, which was sandwiched between polyacrylamide hydrogels. The polyacrylamide hydrogels were used as "force sensors" to acquire the real-time contractile forces generated by the cardiac cells. We further validated the engineered cardiac microfluidic system's cardiac-specific response to drugs by exposing it to epinephrine, an adrenergic neurotransmitter known to increase the magnitude and frequency of cardiac contractions. Such cost-effective and easy-to-adapt systems with real-time functional readout could be attractive technological platforms for drug discovery and development

We present the development of three-dimensional (3D) cardiac microtissues within a microfluidic device with the ability to quantify real-time contractile stress measurements in situ. Using a 3D patterning technology that allows for the precise spatial distribution of cells within the device, we created an array of 3D cardiac microtissues from neonatal mouse cardiomyocytes. We integrated the 3D micropatterning technology with microfluidics to achieve perfused cell-laden structures. The cells were encapsulated within a degradable gelatin methacrylate hydrogel, which was sandwiched between two polyacrylamide hydrogels. The polyacrylamide hydrogels were used as stress sensors to acquire the contractile stresses generated by the beating cardiac cells. The cardiac-specific response of the engineered 3D system was examined by exposing it to epinephrine, an adrenergic neurotransmitter known to increase the magnitude and frequency of cardiac contractions. In response to exogenous epinephrine the engineered cardiac tissues exhibited an increased beating frequency and stress magnitude. Such cost-effective and easy-to-adapt 3D cardiac systems with real-time functional readout could be an attractive technological platform for drug discovery and development.