Injectable, Pore‐Forming, Perfusable Double‐Network Hydrogels Resilient to Extreme Biomechanical Stimulations

Biological tissues hinge on blood perfusion and mechanical toughness to function. Injectable hydrogels that possess both high permeability and toughness have profound impacts on regenerative medicine but remain a long‐standing challenge. To address this issue, injectable, pore‐forming double‐network hydrogels are fabricated by orchestrating stepwise gelation and phase separation processes. The interconnected pores of the resulting hydrogels enable direct medium perfusion through organ‐sized matrices. The hydrogels are amenable to cell encapsulation and delivery while promoting cell proliferation and spreading. They are also pore insensitive, tough, and fatigue resistant. When tested in biomimetic perfusion bioreactors, the hydrogels maintain physical integrity under prolonged, high‐frequency biomechanical stimulations (>6000 000 cycles at 120 Hz). The excellent biomechanical performance suggests the great potential of the new injectable hydrogel technology for repairing mechanically dynamic tissues, such as vocal folds, and other applications, such as tissue engineering, biofabrication, organs‐on‐chips, drug delivery, and disease modeling. A design and methodology to form injectable, in situ pore‐forming, tough, and cytocompatible hydrogels are reported. Such hydrogels combine superior permeability and toughness, enabling direct medium perfusion through organ‐sized matrices. They are immune against extreme biomechanical loads and auspicious to cells. This work advances the injectable hydrogel technology and opens new opportunities in tissue engineering, drug/cell delivery, biofabrication, microfluidics, and organs‐on‐chips.