Photodynamic Therapy Using Indocyanine Green Loaded on Super Carbonate Apatite as Minimally Invasive Cancer Treatment

Abstract

Minimally invasive treatment is getting more and more important in an aging society. The purpose of this study was to explore the possibility of ICG loaded on super carbonate apatite (sCA) nanoparticles as a novel photodynamic therapy (PDT) against cancers. Using colon cancer cells, ICG uptake and anti-tumor effects were examined between the treatments of ICG and sCA-ICG. Reactive oxygen species (ROS) production and temperature rise were also evaluated to explore the underlying mechanism. Atomic force microscopy revealed that the size of sCA-ICG ranged from 10 to 20 nm. In aqueous solution with 0.5% albumin, the temperature increase after laser irradiation was 27.1°C and 23.1°C in sCA-ICG and ICG, respectively (control DW: 5.7°C). A significant increase in ROS generation was noted in cell cultures treated with sCA-ICG plus irradiation compared with those treated with ICG plus irradiation ( < 0.01). Uptake of ICG in the tumor cells significantly increased in sCA-ICG compared with ICG and The fluorescence signals of ICG in the tumor, liver, and kidney faded away in both treatments by 24 hours. Finally, the HT29 tumors treated with sCA-ICG followed by irradiation exhibited drastic tumor growth retardation ( < 0.01), whereas irradiation of tumors after injection of ICG did not inhibit tumor growth. This study shows that sCA is a useful vehicle for ICG-based PDT. Quick withdrawal of ICG from normal organs is unique to sCA-ICG and contrasts with the other nanoparticles remaining in normal organs for a long time. .

A Hybrid Organo‐Nanotheranostic Platform of Superlative Biocompatibility for Near‐Infrared‐Triggered Fluorescence Imaging and Synergistically Enhanced Ablation of Tumors

“…To enable adequate tracking of the photothermal agents in tumor cells, cell nuclei were stained with Hoechst 33 256 which is imbued with a blue fluorescence. Consequently, the red and green fluorescence of ICG@GC-PP and GC-PP-FI NPs, respectively, could be clearly visualized in the cell membranes and nuclei of KYSE-30 ( Figure 5) and 4T1 ( Figure S11 [46] and HeLa, [47] free ICG also accumulated mostly in cell membranes and showed weak fluorescence signal. In 4T1 cell membranes however, free ICG provides a considerably bright fluorescence compared with those of ICG@GC-PP NPs.…”

The Supercarbonate Apatite-MicroRNA Complex Inhibits Dextran Sodium Sulfate-Induced Colitis

“…Our previous study showed that repeated administration or 5-fold greater amounts of sCA alone did not cause toxicity in mice. 26 Moreover, our recent studies showed that ICG 45 or miRNA 31 loaded on sCA efficiently accumulated in tumors and that it did not cause any abnormalities in blood chemistry tests or histology of normal organs of mice. However, considerable uptake of miRNA or ICG loaded on sCA in the liver ( Figure S8 ;Tamai et al.…”

“…In our recent study, we reported that indocyanine green (ICG) loaded on sCA was distributed largely in the liver and kidney in addition to tumors. 45 When we examined the distribution of the artificial miRNA by RT-PCR after injection of the sCA-miRNA complex into the tail vein, we found that the artificial miRNA was mainly distributed in the liver, followed by the spleen to some extent ( Figure S8 ). Compared with these organs, sCA-miRNA uptake in the colon and intestine was only minimal.…”

“…However, considerable uptake of miRNA or ICG loaded on sCA in the liver ( Figure S8 ;Tamai et al. 45 ) may cause clinical problems, as is the case with many vial and non-viral vehicles. To overcome this issue, development of an improved vehicle for clinical use is currently underway in our laboratory.…”

Uptake and release of photosensitizers in a hydrogel for applications in photodynamic therapy: the impact of structural parameters on intrapolymer transport dynamics

“…The substances were chosen because all are well known to be excellent photosensitizers. 1,10,11,13,17,44 Furthermore, they were selected because of their differences in charge, size and absorption wavelength. Two porphyrins (TMPyP and TPPS 4 ) a phenothiazine (methylene blue) and a xanthene (eosin y) have been selected.…”