Irradiation Effects on Polymer-Grafted Gold Nanoparticles for Cancer Therapy.

Area of Science:

• Nanotechnology
• Materials Science
• Radiochemistry

Background:

• Gold nanoparticles (AuNPs) are investigated as radiosensitizers in cancer therapy.
• Understanding radiation interactions with AuNP-polymer systems is crucial for optimizing their use.

Purpose of the Study:

• To synthesize and characterize polymer-grafted AuNPs.
• To investigate the effects of gamma irradiation on these hybrid nanoparticles.
• To explore potential dual-action radiosensitizers and chemotherapeutic agents.

Main Methods:

• Synthesis of thiol-functionalized polymers via atom transfer radical polymerization.
• One-step synthesis of stable hybrid metal-polymer nanoparticles.
• Gamma irradiation of nanoparticles in solution.
• Characterization using size exclusion chromatography, small-angle X-ray scattering, and small-angle neutron scattering.

Main Results:

• Radiation-induced polymer scissions were quantified and localized, with near-surface scissions being prominent.
• The ratio of external to near-surface scissions varied with polymer ligand type.
• No significant dose enhancement at medium or long distances was observed.
• Cytotoxicity assays showed non-irradiated and irradiated nanoparticles had equivalent toxicity.

Conclusions:

• Polymer-grafted AuNPs exhibit specific radiation interaction mechanisms, primarily near-surface polymer scission.
• The polymer corona's nature influences radiation impact localization.
• The non-toxicity of released polymer fragments supports their safety profile.
• Grafting bioactive molecules like doxorubicin offers potential for combined radiosensitization and chemotherapy.