Muscle on a chip: In vitro contractility assays for smooth and striated muscle

article i nfo Introduction: To evaluate the viability of a muscle tissue, it is essential to measure the tissue's contractile performance as well as to control its structure. Accurate contractility data can aid in development of more ef- fective and safer drugs. This can be accomplished with a robust in vitro contractility assay applicable to var- ious types of muscle tissue. Methods: The devices developed in this work were based on the muscular thin film (MTF) technology, in which an elastic film is manufactured with a 2D engineered muscle tissue on one side. The tissue template is made by patterning extracellular matrix with microcontact printing. When muscle cells are seeded on the film, they self-organize with respect to the geometric cues in the matrix to form a tissue. Results: Several assays based on the "MTF on a chip" technology are demonstrated. One such assay incorporates the contractility assay with striated muscle into a fluidic channel. Another assay platform in- corporates the MTFs in a multi-well plate, which is compatible with automated data collection and analysis. Fi- nally, we demonstrate the possibility of analyzing contractility of both striated and smooth muscle simultaneously on the same chip. Discussion: In this work, we assembled an ensemble of contractility assays for striated and smooth muscle based on muscular thin films. Our results suggest an improvement over current methods and an alternative to isolated tissue preparations. Our technology is amenable to both primary har- vests cells and cell lines, as well as both human and animal tissues.