Sub‐Micrometer Au@PDA‐¹²⁵I Particles as Theranostic Embolism Beads for Radiosensitization and SPECT/CT Monitoring

Abstract

Au nanoparticles (3.8 ± 0.6 nm) are assembled to sub‐micrometer Au particles (186.3 ± 20.4 nm) and covered with adhesive polydopamine (PDA) as embolism beads (198.8 ± 23.2 nm). Radioactive iodine‐125 is labeled to Au@PDA to introduce the function of intra‐irradiation. For the therapeutic effects of Au@PDA‐125I, Au particles sensitize the radiation to MHCC97H hepatoma cells and tumor‐bearing mice. At the cellular level, after being treated with a relatively low‐dose (5 Gy) γ‐ray, Au‐sensitized radiotherapy (RT) leads to an immediate increase of intracellular reactive oxygen species, accompanying with an increase of cell apoptosis. Due to the intra‐irradiation, self‐healing of RT‐leaded DNA double‐strand breakage is suppressed, inducing a further increase of cell apoptosis after RT treatment. Likewise, 3 cycles of sensitized RT leads to a valid control of tumor volume growth, but Au@PDA‐125I has no harm or radioactive residual on or in the radiosensitive organs, including the thyroid, heart, lungs, liver, and spleen. Additionally, photons emitted from 125I and high X‐ray absorption of the Au element makes the beads suitable for single photon emission computed tomography/computed tomography (SPECT/CT) imaging. Therefore, as theranostic embolism beads, Au@PDA‐125I can both enhance the therapeutic effects of external RT, and provide a real‐time SPECT/CT monitoring of therapeutic time window.

Auger Electrons Constructed Active Sites on Nanocatalysts for Catalytic Internal Radiotherapy

“…Finally, 125 I was labeled to TiO 2 ‐tyr via a classical Iodogen‐catalyzed method to obtain the final product of 125 I‐TiO 2 . [ 26 ] The initial radiochemical purity of 125 I‐TiO 2 was 93.43% and remained above 88% during a 24‐h incubation with 0.1% fetal bovine serum in phosphate buffer solution, signifying a successful and stable radiolabeling (Figure 1f and Figure S3, Supporting Information).…”

Co‐Delivery of 131I and Prima‐1 by Self‐Assembled CD44‐Targeted Nanoparticles for Anaplastic Thyroid Carcinoma Theranostics

“…[ 19 ] In addition, 125 I is a more appropriate nuclide for SPECT/CT imaging than 131 I due to the low‐energy gamma ray and long half‐life time (60 days). [ 20 ] Therefore, 125 I was selected for radionuclide imaging in this research. To evaluate in vivo behavior of radioisotope–labeled PEI–HA–Tyrs nanoparticles, nude mice loaded with 8305C tumors were randomly divided into two groups and were intravenously injected with Prima‐1@PEI–HA–Tyrs– 125 I (200 µCi/200 µL of 125 I) and free 125 I, respectively.…”

Palladium-based nanomaterials for cancer imaging and therapy

“…Single photon emission computed tomography (SPECT), as a quantitative nuclear imaging method, can provide 3-dimensional spatial images of the in vivo distribution of injected radioisotopes, and plays an important role in preclinical and clinical research 34 - 36 . The commonly used radioisotopes for SPECT include 99m Tc 37 , 131 I 38 , 125 I 39 , 111 In 40 , 177 Lu 41 , and 67 Ga 42 . Compared with traditional optical imaging technologies, SPECT exhibits great potential in clinical applications with unlimited penetration depth.…”