Mitochondria targeting and near-infrared fluorescence imaging of a novel heptamethine cyanine anticancer agent.

The future of personalized cancer treatments relies on the development of functional agents that have tumor-targeted anticancer activities and can be detected in tumors using imaging. However, application of these functional agents in the clinic has been limited due to inefficient drug delivery, low specificity for tumor imaging, development of drug resistance, low signal-to-noise ratio and safety concerns regarding potential toxicity. Currently, the most common strategy to develop these functional agents is to conjugate therapeutic agents with the appropriate fluorescent probe. The present study synthesized a novel mitochondria-targeted heptamethine cyanine (Cy) derivative Cy‑triphenylphosphonium. The newly developed compound exhibited stronger near infrared (NIR) fluorescence and reacted with bovine serum albumin. In addition, it preferentially accumulated in the mitochondria of cancer cells, as observed using confocal microscopy, and efficiently reduced cancer cell viability (IC50=3.04 µM). This novel multifunctional heptamethine Cy derivative, with cancer mitochondria targeting and NIR fluorescence imaging, may be promising as an alternative anticancer agent.