Combination of [12]aneN₃ and Triphenylamine-Benzylideneimidazolone as Nonviral Gene Vectors with Two-Photon and AIE Properties

Abstract

Three nonviral gene vectors, <b>TPA-BI-A</b>/<b>B</b>/<b>C</b>, have been designed and synthesized by the combination of one or two hydrophilic [12]aneN₃ moieties and two-photon fluorescent triphenylamine-benzylideneimidazolone (TPA-BI) units through different ester linkage. Spectroscopic characterization demonstrated that <b>TPA-BI-A</b>/<b>B</b>/<b>C</b> had strong aggregation-induced emissions (AIE), large Stokes shifts (230, 284, and 263 nm), and large two-photon absorption cross sections (δ_2PA) (67, 592, and 80 GM). Gel electrophoresis indicated that the three compounds completely condensed DNA at 15 μM in the presence of DOPE, and showed the lipase- and pH-triggered reversible release of DNA and the fluorescent recognition of the different lengths of ssDNA and dsDNA. The optimal <b>TPA-BI-C</b>/DOPE-mediated luciferase and GFP activity was 146% and 290% higher than those of Lipo2000. The transfection process of DNA could be traced clearly through one- and two-photon fluorescence spectra, and displayed in a 3D-video. <b>TPA-BI-C</b>/DOPE successfully transfected the GFP gene into zebrafish, which was superior to Lipo2000 (192%). In conclusion, <b>TPA-BI-C</b>/DOPE is the first nonviral gene vector with the abilities of pH/lipase enzyme responsiveness, one/two-photon fluorescent tracking of intracellular delivery of DNA, and successful transfection in vivo and in vitro, even better than Lipo2000.