Microneedle?Based Local Delivery of CCL22 and IL?2 Enriches T _reg Homing to the Skin Allograft and Enables Temporal Monitoring of Immunotherapy Efficacy

Skin allografts only serve as temporary dressing for patients suffering major burns due to their high immunogenicity and rejection by the immune system, requiring systemic immunosuppressive therapies that lead deleterious side effects. Microneedle arrays composed of hyaluronic acid (HA) placed on skin can locally deliver immunomodulators simultaneously sample cells in interstitial fluid monitor response therapy. The be retrieved from microneedles downstream analysis degrading HA using a reducing agent. Using an allogeneic transplantation model, it is shown microneedle-mediated local delivery chemokine CCL22 (to attract Tregs) cytokine IL-2 promote expansion) increases suppression allograft. Moreover, cell population allograft correlates with seen microneedles. sampling functions microneedle help regulate system locally, without inducing suppression, facilitate monitoring therapy following transplantation.