Targeted delivery of tacrolimus to T cells by pH‐responsive aptamer‐chitosan‐ poly(lactic‐co‐glycolic acid) nanocomplex.

Tacrolimus (TAC) acts as an inhibitor of calcineurin, which inhibits the production of interleukin‐2. In this study, we aimed to design a targeted delivery platform with poly (lactide‐co‐glycolide; PLGA) nanoparticles modified with chitosan (CS) and CD8AP17s aptamer (Apt). MOLT‐4 cells as CD8 positive and JURKAT cells as CD negative were adopted to investigate the efficacy of the proposed delivery system in vitro. The particle size and Ζ potential of the TAC‐PLGA‐CS‐Apt nanocomplex were 345 nm and 13.7 mV, respectively. Release study showed an efficient TAC release from complex in citrate buffer (pH 5.5). The 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay showed that TAC‐PLGA‐CS‐Apt nanocomplex was highly selective toward MOLT‐4 cells. Complex increased the cellular uptake of TAC in MOLT‐4 cells (target) while reducing its cytotoxicity in JURKAT cells (nontarget). Our study showed that complex nanoconjugate could efficiently deliver TAC into MOLT‐4 cells as a model of cytotoxic T cell and it could be considered as a potential candidate for TAC delivery. [ABSTRACT FROM AUTHOR]