Injectable and Spatially Patterned Microporous Annealed Particle (MAP) Hydrogels for Tissue Repair Applications.

Spatially patterned hydrogels are becoming increasingly popular in the field of regenerative medicine and tissue repair because of their ability to guide cell infiltration and migration. However， postfabrication technologies are usually required to spatially pattern a hydrogel， making these hydrogels difficult to translate into the clinic. Here， an injectable spatially patterned hydrogel is reported using hyaluronic acid (HA)-based particle hydrogels. These particle hydrogels are sequentially loaded into a syringe to form a pattern and， once injected， they maintain the pattern. The applicability of this hydrogel in a wound healing skin model， a subcutaneous implant model， as well as a stroke brain model is examined and distinct patterning in all models tested is shown. This injectable and spatially patterned hydrogel can be used to create physical or biochemical gradients. Further， this design can better match the scaffold properties within the physical location of the tissue (e.g.， wound border vs wound center). This allows for better design features within the material that promote repair and regeneration.