An effective strategy for preparing macroporous and self-healing bioactive hydrogels for cell delivery and wound healing

Macroporous hydrogels have been attracting increasingly attention in cell delivery and tissue regeneration. Assembling microgels is an effective method for preparing macroporous hydrogels. However, current methods are limited to specific requirements to devices and hydrogel inherent properties. In addition, most of macroporous hydrogels lack self-healing abilities due to the permanent covalent crosslink of microgels. In this study, we proposed an effective strategy for preparing a bioactive macroporous self-healable hydrogel by producing microgels through squeezing methacrylated hyaluronic acid (MeHA) and 3-aminophenylboronic acid modified sodium alginate (SABA) nanoporous hydrogels through steel meshes and assembling the MeHA-SABA microgels under alkaline condition created by bioglass (BG) ionic products. Results demonstrated that the obtained macroporous hydrogels have significant larger pore size than nanoporous hydrogels, which facilitated cell infiltration, viability and proliferation. Meanwhile, the macroporous hydrogels had good self-healing abilities with the formation of dynamic B-O bonds. Furthermore, with the bioactivity of BG, the hydrogels could induce cell migration and ingrowth of cells and blood vessels. Thus, bioactivity and macroporous structure of the hydrogels can work synergistically to stimulate tissue regeneration. Taken together, this strategy is effective, simple and can be widely applied in fabricating binary components self-healable macroporous hydrogels as long as the two components are crosslinkable, indicating a great application potential in fabricating macroporous hydrogels for cell delivery and tissue regeneration.