Gold Tablets: Gold Nanoparticles Encapsulated into Dextran Tablets and Their pH-Responsive Behavior as an Easy-to-Use Platform for Multipurpose Applications

Abstract

Many applications using gold nanoparticles (AuNPs) require (i) their functionalization with a biopolymer to increase their stability and (ii) their transformation into an easy-to-handle material, which provide them with specific properties. In this research, a portable tablet platform is presented based on dextran-encapsulated gold nanoparticles (AuNPs-dTab) by a ligand exchange reaction between citrate-capped gold nanoparticles (AuNPs-Cit) and dextran. These newly fabricated tablets were characterized utilizing ultraviolet–visible spectroscopy (UV–vis), Fourier transform infrared spectroscopy–attenuated total reflectance (FTIR–ATR), transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray diffraction spectroscopy (XRD), differential scanning calorimetry (DSC), and atomic force microscopy (AFM) techniques. The results showed that dextran-capped gold nanoparticles in a tablet platform (AuNPs-dTab) were well-dispersed and highly stable for at least a year at room temperature. In addition to particle and surface characterization of AuNPs-dTab, the tablet morphology in terms of thickness, diameter, density, and opacity was also measured using 6 and 10% dextran with 2, 4 and 8 nM AuNPs-Cit. We further investigated the pH-responsive behavior of AuNPs-dTab in the presence and absence of sodium chloride. Results showed that neutral and alkaline environments were suitable to render AuNPs dispersed in a tablet, while an acidic condition controls the aggregation rate of AuNPs as confirmed by concentration-dependent aggregation phenomena. Besides the easy fabrication, these tablets were portable and low-cost (approx. 1.22 CAD per 100 tablets of a 100 μL solution of dextran-capped gold nanoparticles (AuNPs-dSol)). The biocompatible nature of dextran along with the acidic medium trigger nature of AuNPs makes our proposed tablet a potential candidate for cancer therapy due to the acidic surrounding of tumor tissues as compared to normal cells. Also, our proposed tablet approach paves the way for the fabrication of portable and easy-to-use optical sensors based on the AuNPs embedded in a natural polymeric architecture that would serve as a colorimetric recognition indicator for detecting analytes of interest.

Tabletized Nanomedicine: From the Current Scenario to Developing Future Medicine

“…AuNPs within dextran matrices. 76 This design ensures resilience to alkaline conditions while exhibiting heightened responsiveness in acidic environments due to nanogold aggregation within the lower pH range. Along the same lines, AuNPs encapsulated with a pullulan matrix tablet have been generated.…”

“…The peroxidase catalytic activity of these AuNPspullulan tables is showcased through the oxidation of the substrate. 76 These AuNPs-based tablets provide sensor activity in measuring the levels of glucose and hydrogen peroxide.…”

Ce6/PTX2-NP/G@NHs Confer Radiosensitivity in Non-Small Cell Lung Cancer via Promotion of Apoptotic Body-Mediated Neighboring Effects

“…Au NPs can provoke reactive oxygen species (ROS) production in A549 cells and oxidative stress-mediated apoptosis to exert anticancer activity in lung cancer . However, many applications using Au NPs require a combination with different ligands to increase their stability and provide them with specific properties . Recent research has found dextran as a stabilizing and reducing agent for the synthesis of Au NPs .…”

“…12 However, many applications using Au NPs require a combination with different ligands to increase their stability and provide them with specific properties. 13 Recent research has found dextran as a stabilizing and reducing agent for the synthesis of Au NPs. 14 Dextran is defined as a polysaccharide consisting of glucose units.…”

User-friendly and ultra-stable all-inclusive gold tablets for cysteamine detection

“…17 In recent studies, the incorporation of reagent encapsulation techniques has been preferred to ensure swift detection in a liquid phase by discharging enclosed reagents during the testing process. 18–21 This combined method not only yields a sensitive detection system but also merges the beneficial aspects of point-of-care analytical devices. Therefore, scientists and researchers are keen to investigate novel platforms for point-of-care devices.…”