Table 3 Recently studied radionuclide delivery systems based on inorganic NPs
Radionuclide | Delivery system | Labeling | Application | Comments | Refs. |
|---|---|---|---|---|---|
225Ac | Gold coated lanthanide phosphate NPs | ‘Hot’ + ‘cold’ precursor | Radiotherapy | McLaughlin et al. developed multilayered NPs that can deliver multiple a radiations and contain the decay daughters of 225Ac while targeting biologically relevant receptors in a female BALB/c mouse model | [200] |
198Au | Au NPs | ‘Hot’ + ‘cold’ precursor | Radiotherapy | Katti et al. developed a novel approach to treat prostate cancer with 198Au NPs, which were modified with glucoside molecules mangiferin. In vivo experiments on severe combined immunodeficient (SCID) mice revealed over 85% reduction of bearing prostate tumor volume as compared to the control groups | [201] |
166Ho | Garnet magnetic NPs | Neutron activation | Radiotherapy | Munaweera et al. developed magnetic NPs, which were modified with 165Ho/cytostatic drug and navigated into tumor area using external magnet. In vitro and in vivo results suggested that the external magnetic field navigation was achieved, since higher amounts of 165Ho were observed in tumor than in liver, which led to the inhibition of tumor growth | [206] |
89Zr | Ultrasmall silica NPs | Chelation (DFO) | PET and optic imaging | Chen et al. described synthesis of a PEGylated ultrasmall silica particles labeled with Cy5 dye. Reported NPs were modified with chelators and anti-HER2 scFv fragments. This allowed to achieve more efficient tumor-targeting with bulk renal clearance, which surpasses already existing characteristics of scFv molecules and scFv-conjugated NPs larger than 10Â nm. The experiments in vivo revealed a favorable pharmacokinetics and clearance with decreased hepatic and reticuloendothelial system uptake | [212] |
99mTc | Mesoporous silica NPs | Reduction of Tc(VII) in TcO4− using SnCl2 | SPECT | Pascual et al. improved targeting properties of developed Si-based systems by functionalization of NPs with Mucin 1 aptamer that is specific to breast cancer. Pronounced targeted delivery of 99mTc into tumor of tumor-bearing Balb/c mice was shown and monitored with SPECT and bioluminescence options | [214] |
89Zr | Mesoporous silica NPs | Chelation with the deprotonated silanol groups | Photodynamic therapy | Kamkaew et al. reported mesoporous silica NPs loaded with 89Zr and photosensitizer Chlorin e6, which can be activated by Cherenkov radiation from 89Zr. Therefore, the developed radionuclide delivery systems overcame the limitations of conventional photodynamic therapy, which requires light source to activate photosensitizer | [216] |
225Ac | CNT | Chelation (DOTA) | Radiotherapy | Ruggiero et al. developed CNT-based carriers to deliver 225Ac into the tumor angiogenic vessels, which express the monomeric vascular endothelial-cadherin. The developed carrier system was able to achieve 100-fold amplified cargo delivery (relative to the gold standard for targeted therapy—IgG) | [223] |
131I | Reduced graphene oxide | Standard chloramine-T oxidation method | Photothermal and radiotherapy | Chen et al. developed radio-labeled graphene-derivative, which offers the ability of in vivo tumor imaging, and is able to deliver both photothermal and radiotherapy at the same time in order to achieve synergistic therapeutic effect using a single nanoscale theranostic agent | [226] |