Indocyanine green loaded poly(lactic acid) nanoparticles mediated phototherapy of cancer

Phototherapy is a promising approach for cancer treatment which can be utilized alone or in combination with other treatment modalities. Among the available photosensitizers for phototherapy, indocyanine green (ICG) merits special attention, owing to its near infrared absorption characteristics and low dark toxicity. However, a strong tendency for protein-binding and aggregate-forming limits its use as a phototherapeutic agent. Such a drawback can be eliminated with the utilization of nanosized drug delivery systems to encapsulate and protect ICG molecules. Numerous drug delivery systems incorporating ICG for phototherapeutic or imaging purposes are reported in the literature. However; these systems mostly contain other therapeutic agents as well, making it difficult to assess the effects of ICG alone. Hence, this study was aimed to explore the impact of only-ICG encapsulating polymeric nanoparticles as a phototherapeutic agent. Poly(lactic acid) nanoparticles produced via a single-step nanoprecipitation method for encapsulation and delivery of ICG molecules were used to this end and their phototherapeutic effects on prostate cancer cells were examined. This study demonstrated that ICG-encapsulating poly(lactic acid) nanoparticles could be utilized as a phototherapeutic agent in order to inhibit cellular viability on prostate cancer cells and that the decrease in cell viability was primarily due to photothermal effect.