Functionalized gelatin/strontium hydrogel bearing endothelial progenitor cells for accelerating angiogenesis in wound...

While polymer hydrogels are frequently utilized as wound dressings, they lack the sufficient bioactivity necessary to promote re-epithelialization and angiogenesis. In this work, a therapeutic angiogenesis complex is developed using a mixture of dopamine-modified polyhedral oligomeric silsesquioxane (Dopa-POSS), strontium ions (Sr²⁺ ions) photocrosslinked gelatin methacryloyl (GelMA) hydrogel and endothelial progenitor cells (EPCs) for full-thickness burn wound healing. Dopa-POSS is used to reinforce the hydrogel, and Sr²⁺ ions stabilizer is densely incorporated inside the network of GelMA hydrogels by ultraviolet cross-linking, thus effectively enhancing the hydrogel mechanical strength. The multifunctional GelMA hydrogels comprised gelatin's arginine-glycine-aspartate (RGD) patterns and active Sr²⁺ ions that promote EPC biological activity and proliferation. Notably, the Sr²⁺ ions in the functional hydrogels substantially enhanced EPC proliferation in a three-dimensional environment, migration, and angiogenesis-related protein expression. After 14 days, the Gel/Sr²⁺@POSS/EPCs composite hydrogel substantially accelerates and enhances the new blood vessel development process, collagen deposition, and re-epithelialization with the almost closed wounds and newly created tissue. Thus, UV-crosslinked Gel/Sr²⁺@POSS hydrogels functionalized with EPCs can be a potentially beneficial therapeutic system for full-thickness burn wound healing.