Auger electron-emitting EGFR-targeted and non-targeted [197Hg]Hg-gold nanoparticles for treatment of glioblastoma multiforme (GBM)
Abstract Background We describe here radiation nanomedicines for glioblastoma multiforme (GBM) composed of gold nanoparticles (AuNPs) that integrate the Auger electron-emitter, 197Hg. [197Hg]Hg-AuNPs were conjugated to anti-epidermal growth factor receptor (EGFR) panitumumab or were non-targeted. Ou...
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| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
SpringerOpen
2025-07-01
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| Series: | EJNMMI Radiopharmacy and Chemistry |
| Subjects: | |
| Online Access: | https://doi.org/10.1186/s41181-025-00367-2 |
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| Summary: | Abstract Background We describe here radiation nanomedicines for glioblastoma multiforme (GBM) composed of gold nanoparticles (AuNPs) that integrate the Auger electron-emitter, 197Hg. [197Hg]Hg-AuNPs were conjugated to anti-epidermal growth factor receptor (EGFR) panitumumab or were non-targeted. Our aim was to compare the cytotoxicity and DNA-damaging properties in vitro of panitumumab-[197Hg]Hg-AuNPs and non-targeted [197Hg]Hg-AuNPs on U251-Luc human GBM cells and estimate their cellular dosimetry. We further aimed to compare the biodistribution in vivo of panitumumab-[197Hg]Hg-AuNPs and [197Hg]Hg-AuNPs after convection-enhanced delivery (CED) in NRG mice with U251-Luc tumours in the brain and estimate the absorbed doses in the tumour and surrounding margins of healthy brain. Results [197Hg]Hg-AuNPs (26.8 ± 6.4 nm) were produced with a radiochemical yield of 98 ± 1% by incorporating 197Hg into the Turkevich synthesis method, forming a mercury-gold amalgam. Panitumumab-[197Hg]Hg-AuNPs exhibited high affinity (KD = 1.8 × 10–9 mol/L) binding to EGFR-positive U251-Luc cells. The binding of panitumumab-[197Hg]Hg-AuNPs to U251-Luc cells was 15-fold higher than [197Hg]Hg-AuNPs, and internalization and nuclear uptake were 12-fold and 18-fold greater, respectively. Panitumumab-[197Hg]Hg-AuNPs caused 84-fold more DNA double-strand breaks (DSBs) in U251-Luc cells than [197Hg]Hg-AuNPs. Panitumumab-[197Hg]Hg-AuNPs were ninefold more effective at reducing the clonogenic survival of U251-Luc cells than [197Hg]Hg-AuNPs. Panitumumab-[197Hg]Hg-AuNPs were twofold more cytotoxic than non-radioactive panitumumab-AuNPs (P = 0.04) and fivefold more cytotoxic than panitumumab (P = 0.01). The absorbed doses in the nucleus of U251-Luc cells treated in vitro with panitumumab-[197Hg]Hg-AuNPs or [197Hg]Hg-AuNPs were 8.8 ± 2.9 Gy and 0.6 ± 0.1 Gy, respectively. SPECT/CT imaging showed that panitumumab-[197Hg]Hg-AuNPs and [197Hg]Hg-AuNPs were strongly retained at the infusion site in the brain after CED up to 7 d in NRG mice with orthotopic U251-Luc tumours. Uptake of panitumumab-[197Hg]Hg-AuNPs in the tumour-bearing right hemisphere [484.5% injected dose/g (%ID/g)] was 172-fold and 579-fold greater than in the healthy left hemisphere and cerebellum, respectively. The uptake of [197Hg]Hg-AuNPs (423.9% ID/g) in the tumour-bearing right hemisphere was 85-fold and 64-fold higher than the left hemisphere and cerebellum, respectively. Most normal tissue uptake was < 1% ID/g, except for kidneys (9–20% ID/g), spleen (3.5–6.6% ID/g) and liver (0.6–3.3% ID/g). Dosimetry showed that 58% of the tumour received > 190 Gy for CED of 1.0 MBq of panitumumab-[197Hg]Hg-AuNPs vs. 0.6% of the tumour for non-targeted [197Hg]Hg-AuNPs, but both agents deposited > 50 Gy in 95% of the tumour. Doses decreased dramatically to 1.7 and 3.3 Gy at 1–3 mm from the tumour edge for panitumumab-[197Hg]Hg-AuNPs and [197Hg]Hg-AuNPs, respectively. Conclusion Radiation nanomedicines incorporating the AE-emitter, 197Hg administered by CED are a promising approach to treatment of GBM. Panitumumab-[197Hg]Hg-AuNPs are particularly attractive due to their EGFR-mediated binding, internalization and nuclear importation in GBM cells, which amplifies their in vitro cytotoxicity. |
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| ISSN: | 2365-421X |