A high mobility group B-1 box A peptide combined with an artery wall binding peptide targets delivery of nucleic acids to smooth muscle cells.

The TAT-high mobility group box-1 A box peptide (TAT-HMGB1A) has been reported previously to be able to deliver DNA into cells without cytotoxicity. In this study, an artery wall smooth muscle cell-targeting carrier was developed using TAT-HMGB1A combined with an artery wall binding peptide (ABP). For the production of ABP linked TAT-HMGB1A (TAT-HMGB1A-ABP), pET15b-TAT-HMGB1A-ABP was constructed by inserting the ABP cDNA into pET15b-TAT-HMGB1A. TAT-HMGB1A-ABP was expressed in E. coli and purified by Nickel chelate chromatography. Gel retardation assays showed that TAT-HMGB1A-ABP formed a complex with the plasmid at or above a 5:1 weight ratio (peptide:plasmid). At a 20:1 weight ratio, the zeta-potential was approximately 25 mV and the particle size was approximately 120 nm. TAT-HMGB1A-ABP had the highest transfection efficiency in A7R5 smooth muscle cells at a weight ratio of 20:1. TAT-HMGB1A-ABP exhibited higher transfection efficiency in A7R5 cells than PLL or TAT-HMGB1A, while TAT-HMGB1A-ABP had lower transfection efficiencies in Hep3B hepatoma, 293 kidney, NIH3T3 fibroblast, and Raw264.7 macrophage cells compared with PLL. Together, these results suggest that the ABP moiety of the peptide increased transfection efficiency specifically in smooth muscle cells. In a competition assay, the transfection efficiency of TAT-HMGB1A-ABP in A7R5 cells was reduced by the addition of free ABP. MTT assays showed that TAT-HMGB1A-ABP did not produce any cytotoxicity in A7R5 cells. Therefore, TAT-HMGB1A-ABP may be useful for a targeting gene delivery to smooth muscle cells.