Supplementary file 1_Sustained microparticle-mediated intracellular immunomodulation enhances tolerogenic dendritic cell stability and antigen-specific Treg induction.docx

BMDCs loaded with PPI MPs exhibited prolonged viability, increased PD-L1 and IL-10 expression, and resistance to inflammatory reprogramming following lipopolysaccharide challenge compared to dexamethasone-loaded microparticles or soluble drug controls. Administration of PPI MPs during BMDC differentiation further enhanced tolerogenic programming, producing marked increases in PD-L1 and IL-10 while suppressing TNFα secretion.

Following adoptive transfer in vivo, PPI MP-treated DCs demonstrated prolonged persistence and accumulation in draining lymph nodes for up to 7 days. Finally, PPI MP-treated DCs induced robust antigen-specific Foxp3+ regulatory T cell responses in OVA-sensitized mice and suppressed antigen recall responses ex vivo. Together, these findings demonstrate that sustained intracellular combinatorial immunomodulation can generate a durable and functionally stable tolDC phenotype with enhanced antigen-specific tolerogenic activity, supporting this platform as a potential strategy for autoimmune therapies.</p>