Gold nanoparticle clusters for the investigation of therapeutic efficiency against prostate cancer under near-infrared irradiation

Abstract

Gold particles have been widely used in the treatment of prostate cancer due to their unique optical properties, such as their light-heat conversion in response to near-infrared radiation. Due to well-defined synthesis mechanisms and simple manufacturing methods, gold particles have been fabricated in various sizes and shapes. However, the low photothermal transduction efficiency in their present form is a major obstacle to practical and therapeutic uses of these particles. In the current work, we present a silica-coated gold nanoparticle cluster to address the therapeutic limit of single gold nanoparticles (AuNPs) and use its photothermal effect for treatment against PC-3, a typical prostate cancer. Due to its specific nanostructure, this gold nanocluster showed three times higher photothermal transduction efficiency than free single AuNPs. Moreover, while free single particles easily clump and lose optical properties, this silica-coated cluster form remained stable for a longer time in a given medium. In photothermal tests under near-infrared radiation, the excellent therapeutic efficacy of gold nanoclusters, referred to as AuNC@SiO 2 , was observed in a preclinical sample. Only the samples with both injected nanoclusters followed by photothermal treatment showed completely degraded tumors after 15 days. Due to the unique intrinsic biocompatibility and higher therapeutic effect of these silica-coated gold nanoclusters, they may contribute to enhancement of therapeutic efficacy against prostate cancer.

On the Equivalence of the Biological Effect Induced by Irradiation of Clusters of Heavy Atom Nanoparticles and Homogeneous Heavy Atom-Water Mixtures

“…Previous experiments support the evidence that the nanoparticles tend to cluster inside the cell [9][10][11], suggesting this study represents a more realistic scenario than those interpreting GNPs with a uniform random distribution inside the cell. Furthermore, the approach used to model the aggregation of nanoparticles using a spherical geometry is supported by previous work in the literature [34] where the sizes of the clusters were measured by their diameters using TEM scan.…”

Nanocarriers Used in Drug Delivery to Enhance Immune System in Cancer Therapy

“…Multi-drug resistance (MDR) in cancer can lead to the failure of chemotherapy and radiotherapy and has become one of the main obstacles to the success of cancer treatment [ 65 ]. Resistance to multiple drugs is the ability of tumor cells to exhibit simultaneous resistance to various structural and functional chemotherapeutic agents or radiation [ 66 ].…”

Quo Vadis Advanced Prostate Cancer Therapy? Novel Treatment Perspectives and Possible Future Directions

“…To avoid this undesirable phenomenon, the particles should be further functionalized on their surface, e.g., by using silicon dioxide. This approach was utilized by Kim et al [61], who prepared silica-coated gold-nanoparticle clusters (AuNC@SiO 2 ) for PTT. The AuNC@SiO 2 exhibited enhanced stability in solution as well as higher efficacy of photothermal transduction than unmodified GNPs tending to agglomerate.…”

“…Moreover, in vivo experiments evidenced a substantial reduction in tumor size after the application of AuNC@SiO 2 and laser photoactivation. Notably, 15 days after the treatment, the tumors were eliminated [61]. Another valuable tool for targeted PTT of prostate cancer is so-called mesenchymal stem cell-derived gold star nanoparticles produced directly in the cells and secreted in a form of microvesicles based upon a light irradiation stimulus.…”