Using Electrospun Scaffolds to Promote Macrophage Phenotypic Modulation and Support Wound Healing

Abstract The development of pressure ulcers in spinal cord injury patients is extremely common, often requiring extensive surgical procedures. Macrophages (MACs) play a crucial role in the innate immune system, contributing to wound healing and overall regeneration. MACs have been found to possess the potential to be activated by external factors from their M0 inactive state to an M1 proinflammatory or M2 regenerative state. This study conducted a comprehensive evaluation of MAC phenotype in response to electrospun scaffolds of varying material fiber/pore diameter, fiber stiffness, and +/− inclusion of platelet-rich plasma (PRP). Generally, itwas found that the addition of PRP resulted in decreased pore size, where 5 silk fibroin (SF) had the stiffest fibers. Furthermore, PRP scaffolds demonstrated an increased production of VEGF and chemotaxis. The polycaprolactone (PCL) and SF scaffolds had the largest cell infiltration and proliferation. Overall, it was found that 5% SF had both ideal fiber and pore structure, allowing for cell infiltration further enhanced by the presence of PRP. Additionally, this scaffold led to a reasonable production of VEGF while still allowing fibroblast proliferation to occur. These results suggest that such a scaffold could provide an off-the-shelf product capable of modifying the local MAC response.