z-Wire: A Microscaffold That Supports Guided Tissue Assembly and Intramyocardium Delivery for Cardiac Repair.

Tissue engineering holds promise to replace damaged tissues for repair of vital organs in the human body. In cardiac repairs specifically, approaches are developed for intramyocardial delivery of cells and the epicardial delivery of tissue-engineered cardiac patches, providing benefit of cell localization and tissue structure, respectively. However, to improve cell retention and integration, there is a need for the intramyocardial delivery of functional tissues while preserving anisotropic muscle alignment. Here, a biodegradable z-wire scaffold that supports the scalable gel-free production of an array of functional cardiac tissues in a 384-well plate format is developed. The z-wire scaffold design supports cellular alignment, provides tunable mechanical support, and allows for tissue contraction. When the scaffold is imparted with magnetic properties, individual tissues can be assembled with macroscopic alignment under magnetic guidance. When used in combination with a customized surgical delivery tool, z-wire tissues can be injected directly into the myocardial wall, with controlled tissue orientation according to the injection path. This modular tissue engineering approach, in combination with the use of smart scaffolds, can expand opportunity in functional tissue delivery.