Gold nanoparticles developed in sol–gel derived apatite—bioactive glass composites

Abstract

The study is focussed on synthesis and characterisation of a new sol-gel derived composite system consisting of nanocrystalline apatite, bioactive glass and gold nanoparticles, which are of interest both for regenerative medicine and for specific medical applications of the releasable gold nanoparticles. Samples dried at 110°C and then heat treated for 30 min at 300 and 500°C were investigated by thermal analysis (DTA/TG), X-ray diffraction (XRD), UV-VIS-NIR, Fourier Transform Infrared (FTIR) spectroscopy, X-ray Photoelectron(XPS) spectroscopy, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Gold nanoparticles and nanocrystalline apatite are developed already after heat treatment at 300°C. XPS analysis clearly revealed the presence of both metallic and ionic gold species. The development of gold nanoparticles was evidenced by UV-VIS-NIR and TEM analysis, and their size increased from few nanometers to 25 nm by increasing the treatment temperature from 300 to 500°C. The bioactivity of the samples immersed in simulated body fluid was demonstrated by XRD and SEM results.

In Situ Generated Gold Nanoparticle Hybrid Polymersomes for Water‐Soluble Chemotherapeutics: Inhibited Leakage and pH‐Responsive Intracellular Release

“…Adding auric cations into PNP polymersome solution, these auric cations could be instantly transferred to AuNPs through a reduction reaction with suitable reductants. Then, the newborn AuNPs would be immediately conjugated with tertiary amino groups of DEAB in PNPs as ligands . On the other hand, PNP polymersomes have excellent capability to load water‐soluble anticancer drug, DOX·HCl, which in turn makes inhibiting drug permeability of polymersome more meaningful and more important.…”

Gold-containing bioactive glasses: a solid-state synthesis to produce alternative biomaterials for bone implantations

“…species and Au 0 in the form of isolated atoms give rise to bands in the approximately 300-330 nm and in the approximately 350-430 nm spectral ranges, respectively [18]. The UV -visible spectrum of the HAu sample is also characterized by the presence of a weak band at approximately 310 nm, ascribable to Au nþ oxidized in agreement with our previous paper [2], in which Au-containing glasses, before the thermal treatment, were characterized by the presence of both Au 3þ and Au þ species.…”

“…Bioactive glasses containing AuNPs have been developed and they could be used both for bone tissue reconstruction owing to their ability to form an apatite layer [18] and for cancer treatment owing to their use in photothermal therapy or their functionalization with therapeutic and targeted peptides [19]: indeed gold can bind strongly to thiols and amines through a simple mixing process [20,21].…”

Synthesis and characterisation of Gossypium hirsutum seeds extract nanoencapsulated in silica microparticles

“…6). For all samples, the broad peak around 3450 cm -1 is characteristic to -OH vibration [45,46]. The most intense absorption band near 1080 cm -1 is assigned to O-Si-O asymmetric stretching vibrations in which adjacent O atoms move in phase with each other [47][48][49].…”

“…The band at about 1630 cm -1 is assigned to the deformation mode of water molecules, which are probably trapped inside the silica matrix. The bands located at about 450 and 800 cm -1 can be attributed to the Si-O-Si bending and Si-O-Si stretching vibrations, respectively [45,46,50,51]. The absorption band close to 950 cm -1 corresponds to stretching vibrations of silanol groups-Si-OH [48].…”