Indocyanine green-based nanodrugs: A portfolio strategy for precision medicine

As the sole cyanine dye approved by the Food and Drug Administration (FDA), indocyanine green (ICG) has been widely applied in solid tumor and metastases surgical navigation as well as malignant tissue destruction. The great performance of ICG benefits from excellent fluorescent properties in the near infrared region (NIR) and reactive oxygen species (ROS) or hyperthermia effects under irradiation. Nevertheless, some intrinsic limitations, such as unstable optical properties, concentration-dependent aggregation, proneness to photo-bleaching, and poor aqueous stability in vivo, severely restrict its further applications. To overcome these challenges, ICG-based nanodrugs (nano-ICG), as one kind of portfolio strategy, could bridge the efficient cargo-carriers and ICG molecules to artificially improve their existing performance. In this mini-review, we will focus on the developed engineering strategies for nano-ICG formulation synthesis and their desired performance in tumor tracing and eradication. A critical analysis of assembly mechanisms, excellent performance, and further improvement tactics will be examined. [Display omitted] •ICG-based nanodrugs (nano-ICG) can bridge carriers and ICG molecules to artificially improve their inherent capacity.•Two main strategies are summarized for improving the properties of free ICG in this review.•The potential pitfalls and opportunities of these two nano-ICG synthetic tactics are described in more detail.