Activated Gold Particles Help Ablate Prostate Tumors

Gold-silica nanoshell (GSN) particles that absorb near-infrared light (NIR) can induce photothermal ablation of prostate cancer, claims a new study.

Researchers at Nanospectra Biosciences (Nanospectra; Houston, TX, USA), the Icahn School of Medicine at Mount Sinai (New York, NY, USA), Rice University (Rice, Houston, TX, USA), and other institutions conducted a clinical trial to examine the use of ultrafocal photothermal ablation for cancerous tumors. For the study, they used the Nanospectra AuroLase Therapy system, a focal ablation modality that relies on laser excitation of GSN to selectively target and treat focal lesions.

The GSN particles were designed to absorb NIR at wavelengths of high tissue transparency, providing highly localized treatment of prostate cancer with substantially reduced risks of deleterious treatment-related side effects. The study included 16 men (58-79 years of age) diagnosed with low or intermediate risk localized prostate cancer. All were given intravenous (IV) GSN nanoparticles, underwent treatment, and had a multiparametric MRI of the prostate at 48-72 hours. Targeted fusion biopsies were taken at 3 and 12 months, and finally a 12 core systematic biopsy was done one year after therapy.

The results revealed that GSN-mediated focal laser ablation was successful in 87.5% of lesions treated at one year of follow-up. The treatment protocol was found to be safe and feasible, and did not affect the genitourinary system of the patients. In addition, the patients’ quality of life (QOL) was preserved by reducing unwanted side effects, including erectile dysfunction and/or urine leakage, and there were no serious complications. The study was published on August 26, 2019, in Proceedings of National Academy of Science (PNAS).

Intravenously delivered GSNs preferentially accumulate within solid tumor tissue due to vessel wall fenestrations associated with aberrant tumor neovasculature and inherently defective lymphatic drainage within these lesions. On illumination with a NIR laser at subablative power, healthy tissue with lower concentrations of GSN suffers mild and reversible hyperthermia, while the higher concentrations of GSN within the cancerous lesion generate sufficient photothermal energy to produce coagulative necrosis.

Related Links:
Nanospectra Biosciences
Icahn School of Medicine at Mount Sinai
Rice University