Evaluation of Gold, Silver and Silver–Gold (Bimetallic) Nanoparticles as Radiosensitizers for Radiation Therapy in Cancer Treatment

Abstract

One of the most recognized and widely used treatment modality in cancer is radiation therapy which depends on the radiosensitivity of tumour tissue. Over the past few years there has been lot of interest in the use of formulations to enhance radiotherapeutic effects, especially using metallic (mainly gold) based nanoparticles. Our goal here is to fabricate nanoparticles (NPs) that can be delivered to tumor tissue to increase its radiosensitivity. This would increase efficiency of radiation absorption by the tumor tissue and reduce radiation doses delivered during radiotherapy. This could potentially decrease radiation exposure related side effects to patients. We have achieved this by synthesizing nanoparticles of high Z elements such as gold, silver and a more efficient bimetallic silver-gold size ranging from 3nm to 72nm using chemical reduction and hydrothermal method. The synthesized metallic nanoparticles were characterised using Ultraviolet (UV)-Visible Spectroscopy, Fluorescence spectroscopy and Dynamic Light Scattering. The metallic nanoparticles showed radiosensitizing activity in colloidal form by absorbing radiations when irradiated by 60 Co source which emits two gamma rays of energy 1173keV and 1332keV. Based on our results, we are of the opinion that such radio-sensitizing agent if injected into the tumour tissue would increase radiation absorption and enhance treatment effect with lower therapeutic radiation dosage.

Synthesis of Colloidal Silver Nanoparticles in Various Liquid Media Using Pulse Laser Ablation Method and Its Antibacterial Properties

“…For producing these colloidal AgNPs, the Nd:YAG laser beam with a pulse repetition rate of 10 Hz was bombarded and focused on a high-purity Ag metal plate for 11 h. It can be seen in the figure that the formation of colloidal AgNPs in the three liquid mediums is identified by the color changing of the liquid medium that was previously colorless or clear to golden yellow. The golden yellow color of colloidal silver nanoparticles indicates the formation of silver nanoparticles as reported elsewhere [18].…”

“…The distinctive color of AgNPs is the result of the localized surface plasmon resonance (LSPR) phenomenon where silver material absorbs. The LSPR of AgNPs ranges from 380 to 425 nm, which means that they absorb blue or red light, so it will reflect the yellow color [18,[20][21][22]. For further information, it will be discussed in the characterization section.…”

One Pot Synthesis of PEGylated Bimetallic Gold–Silver Nanoparticles for Imaging and Radiosensitization of Oral Cancers

“…Figure 2B is a digital photograph of colloidal BNPs which is brownish-orange in colour. 35 In supporting information, Figure S1, we have shown repeatability of synthesis of BNPs at three different time points using UV-visible spectra. The PEG is a stabilizing Size and Zeta Potential of BNPs with Dynamic Light Scattering Method The stability of the dispersed nanoparticles depends on their pH and the surface charge.…”

“…29,30 In recent years, gold-silver nanoalloy or Au-Ag bimetallic nanoparticles gained special attention because of their unique properties such as anticancer agent, radiosensitizers and contrast agent for imaging in comparison with individual monometallic systems. [31][32][33][34][35] To explore the advantageous and synergistic property of an alloy, this is first of such studies, we report here one pot synthesis of colloidal PEGylated bimetallic Au-Ag nanoparticles using PEG 600 by polyol method reducing HAuCl 4 and AgNO 3 simultaneously. These nanoparticles were characterized thoroughly to establish the structure and nano architect and showed anticancer activity, nuclear damage, and potential radiosensitizer against oral cancer cell line.…”

A GdW10@PDA-CAT Sensitizer with High-Z Effect and Self-Supplied Oxygen for Hypoxic-Tumor Radiotherapy

“…Commonly, radiosensitizers are classified into five categories: (1) the inhibition of intracellular mercaptan or other endogenous radiation protective substances; (2) radiosensitizer radiolysis to form cytotoxic substances; (3) biomolecular repair inhibitors; (4) thymine analogues that can be incorporated into DNA; (5) oxygen simulants with electrophilic activity [ 10 ]. Many studies have found that nanoparticles synthesized by the atomic number (high-Z) elements have effective lethal effects on tumors [ 11 , 12 , 13 , 14 , 15 ]. When x-rays or γ-rays are applied to metal nanoparticles, a range of effects can occur.…”