TGFB1 and Autoimmunity: Having confirmed that PLGA-Ni delivery resulted in substantial accumulation inside DC, with the expectation that these DC would be converted into tolerogenic cells using RA and TGFβ1-formulated microparticles, we then sought to determine if a PLGA-Ni formulation of RA and TGFβ1 additionally-engineered with adsorbed insulin peptide B9-23 (Ins-RT-NP) could alter the progression of the underlying autoimmunity in NOD female mice toward overt diabetic hyperglycemia.