Near-Infrared Fluorescent Sorbitol Probe for Targeted Photothermal Cancer Therapy.

Lee Lee,Yang Yang,Hyun Hyun,Jo Jo,Koh Koh,Jung Jung

doi:10.3390/cancers11091286

Abstract

Photothermal therapy (PTT) using a near-infrared (NIR) heptamethine cyanine fluorophore has emerged as an alternative strategy for targeted cancer therapy. NIR fluorophores showing a high molar extinction coefficient and low fluorescence quantum yield have considerable potential applications in photothermal cancer therapy. In this study, a bifunctional sorbitol–ZW800 conjugate was used as an advanced concept of photothermal therapeutic agents for in vivo cancer imaging and therapy owing to the high tumor targetability of the sorbitol moiety and excellent photothermal property of NIR heptamethine cyanine fluorophore. The sorbitol–ZW800 showed an excellent photothermal effect increased by 58.7 °C after NIR laser irradiation (1.1 W/cm2) for 5 min. The HT-29 tumors targeted by sorbitol–ZW800 showed a significant decrease in tumor volumes for 7 days after photothermal treatment. Therefore, combining the bifunctional sorbitol–ZW800 conjugate and NIR laser irradiation is an alternative way for targeted cancer therapy, and this approach holds great promise as a safe and highly efficient NIR photothermal agent for future clinical applications.

Highlights

Photothermal therapy (PTT), based on the principle of light-to-heat conversion, has great potential for effective cancer treatment because of its high tumor ablation efficiency and minimal side effects on normal tissue [1,2,3,4,5]
The sorbitol–ZW800 conjugate was separated by a preparative HPLC system with high yield (91%) and purity (94%)
Since the sorbitol–ZW800 conjugate was highly soluble in aqueous solution, the molar extinction coefficient and quantum yield (ε = 246,000 M−1 cm−1, Φ = 13.5% in phosphate-buffered saline (PBS)) are relatively higher than indocyanine green (ICG) (ε = 121,000 M−1 cm−1, Φ = 9.3% in serum) [19]

Summary

Introduction

Photothermal therapy (PTT), based on the principle of light-to-heat conversion, has great potential for effective cancer treatment because of its high tumor ablation efficiency and minimal side effects on normal tissue [1,2,3,4,5]. PTT is a noninvasive therapeutic intervention for specific target tissues when combined with light excitation and laser-induced heating materials. Illumination in the wavelength range 650–950 nm is necessary for the use of various photothermal agents for deep tissue penetration and no damage to normal tissue [6,7,8,9,10]. PTT agents with high absorption in the NIR window efficiently convert light energy into heat energy to induce hyperthermia (>48 ◦ C) and promote tumor necrosis and apoptosis [11,12,13].

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Results

Conclusion