The absence of regulatory T cells (Treg) may underlie disorders including but not limited to autoimmunity, dermatitis, periodontitis and even transplant rejection. Enhancing local numbers of Treg through in situ Treg expansion or induction is contemplated herein as a treatment option for these disorders. Current methods for in vivo Treg expansion are not Treg specific and are associated with many adverse side-effects. The data presented herein provides in vitro testing of a Treg-inducing microparticle providing a predictable controlled release for combinations of cytokines and drugs (e.g., IL-2, TGF-β, and/or rapamycin) resulting in targeted Treg migration. These controlled release microparticles are also capable of inducing FoxP3+ Treg in human cells in vitro suggesting that these compositions be developed into an in vivo Treg induction and expansion therapy.