Perfusable and toughening cardiac patch with hierarchically branched microchannels for myocardial infarction revascularization†

A cardiac patch is a promising therapeutic graft for repairing infarcted myocardium and preventing irreversible ventricular remodeling. However, most existing patches lack perfusable microchannels and exhibit poor fatigue resistance, making it difficult to restore blood supply to the myocardial infarction (MI) region, thereby limiting their effectiveness in halting the disease progression. To overcome these challenges, we developed a cardiac patch featuring a hierarchical branched microchannel network using an arrayed radial freeze-casting technique. This innovative patch incorporates a dual-scale microchannel network, comprising interconnected primary microchannels (500 μm) and branched microchannels (<50 μm), which promotes cell perfusion and tissue integration by guiding cell growth and supporting microvascular reconstruction. Additionally, the patch is mechanically toughened through a salting-out process to maintain microchannel patency and provide critical structural support to the infarcted region. The arrayed radial freeze-casting enables the precise formation of capillary-sized microchannels, which promote revascularization, improving cardiac function. This perfusable and mechanically toughened patch, featuring a hierarchically branched microchannel network, serves a dual role by enabling microvascular reconstruction and providing essential mechanical support. Its innovative design offers a versatile and scalable protocol for developing microvascularized solutions, applicable to a wide range of tissue-engineered grafts.