Cyanine–Gemcitabine Conjugates as Targeted Theranostic Agents for Glioblastoma Tumor Cells

A small subset of
heptamethine dyes (cyanine-7 or Cy7) share an
intriguing characteristic: preferential tumor accumulation and retention.
These dyes absorb in the near-infrared (NIR) region (above 750 nm)
and perform active targeting to deliver therapeutic and toxic cargoes
to various tumor models in vivo. In this work, four heptamethines 1 were synthesized, which have a gemcitabine fragment attached
to the meso-position of the Cy7 core. Theranostic
agent 1a was discovered that localized in glioblastoma
tumor cells, has absorption maxima in NIR region, and showed similar
therapeutic effect to gemcitabine but at one-third the molar dose.