Multifunctional UCNPs@PDA-ICG nanocomposites for upconversion imaging and combined photothermal/photodynamic therapy with enhanced antitumor efficacy

Abstract

Integrated theranostic nanosystems that combine therapeutic methods with suitable medical imaging modality are highly needed in the improvement of cancer theranostic approaches. Herein, polydopamine (PDA)-shelled NaYF4: Yb,Er@NaYF4: Yb nanoparticles (UCNPs) capable of loading indocyanine green (ICG) molecules via electrostatic adsorption, hydrophobic interaction and π-π stacking were successfully designed and synthesized (UCNPs@PDA-ICG, labeled as UPI) for upconversion imaging and combined photothermal/photodynamic therapy (PTT/PDT) with enhanced antitumor efficacy. We have found that ICG in this novel anticancer nanoplatform can be triggered impressively by 808 nm to produce both photothermal effect and cytotoxic reactive oxygen species (ROS), thus achieving a good PTT/PDT synergistic effect. Notably, compared with free ICG molecules, UPI nanocomposites show much higher photostability and thermal stability. Both in vitro and in vivo experiments show that the as-obtained UPI can ablate the cancer cells effectively with 808 nm irradiation, revealing their great potential as NIR-mediated dual-modal therapeutic platform. Meanwhile, the core of UCNPs can be used for UCL imaging. All these results demonstrate great potentiality of UPI as a new kind of novel theranostic agents for the treatment of tumors. Figure 6. (a) Representative photographs of temperature change behavior of UPI aqueous solution under different 808 nm irradiation times. (b) Infrared thermal images of tumor-bearing mice injected with saline or UPI solutions exposed to the 808 nm laser recorded at different time intervals, respectively.Figure 7.(a) Representative photographs of mice after different intratumoral treatments: Control group, 808 nm laser irradition only and UPI exposed to 808 nm light, respectively. The body weights (b) and the relative tumor volumes (c) of mice after the treatment with PBS as control, Only NIR, Pure ICG, UPI, ICG+NIR and UPI+NIR, respectively. Mean tumor weights (d) and photographs (e) of excised tumors with different treatments at the last day of experiments. (f) Haematoxylin and eosin (H&E) staining of tumor slices for control, UPI and UPI+NIR groups, respectively.

808‐nm‐Light‐Excited Lanthanide‐Doped Nanoparticles: Rational Design, Luminescence Control and Theranostic Applications

“…The results show that the photobleaching effect could be completely suppressed, which may be attributed to the isolation of dye‐sensitized LnNPs from environmental oxygen molecules. Another challenge is PL quenching of organic dyes, which can result in nonradiative ET from the excited luminophore to the dye . To overcome this problem, several prerequisites must be satisfied, including: i) a strong overlap between the emission spectrum of dyes and the absorption spectrum of LnNPs; ii) a minimum absorption of dyes for the excited photons of LnNPs; iii) an appropriate distance between dyes and LnNPs; iv) decreased mutual interactions between organic dyes; and v) a minimum concentration of unbound (excess) organic dyes.…”

Advanced Functional Nanomaterials for Theranostics

“…Liu et al built a multifunctional UCNPs with PDA-ICG for theranostic applications (termed as UPI). [243] With the particles, HeLa cells became fluorescent upon 980 nm laser exposure, and strong upconversion luminescence was detected after intratumoral injection of UPI. Further, the UPI successfully combined PDT and PTT together for better cancer therapeutic efficiency.…”

Combination of Fluorescence-Guided Surgery With Photodynamic Therapy for the Treatment of Cancer

“… 28 To improve performance in clinical applications, ICG has been encapsulated into a variety of nanoparticles and equipped with targeting moieties or incorporated into multifunctional platforms. 29 , 30 In the realm of molecular imaging, these strategies significantly promote the tissue signal of interest and simultaneously decrease the background signal. Clinically, the vast majority of surgical techniques performed with ICG are based on the free form.…”