Synthesis and surface functionalization of silica nanoparticles for nanomedicine

Abstract

There are a wide variety of silica nanoformulations being investigated for biomedical applications. Silica nanoparticles can be produced using a wide variety of synthetic techniques with precise control over their physical and chemical characteristics. Inorganic nanoformulations are often criticized or neglected for their poor tolerance; however, extensive studies into silica nanoparticle biodistributions and toxicology have shown that silica nanoparticles may be well tolerated, and in some case are excreted or are biodegradable. Robust synthetic techniques have allowed silica nanoparticles to be developed for applications such as biomedical imaging contrast agents, ablative therapy sensitizers, and drug delivery vehicles. This review explores the synthetic techniques used to create and modify an assortment of silica nanoformulations, as well as several of the diagnostic and therapeutic applications.

Enhancing T 1 magnetic resonance imaging contrast with internalized gadolinium(III) in a multilayer nanoparticle

“…S4 shows the effect of the accumulation of water molecules in the silica inner layer). It has additionally been proposed that systems with an excessive payload of Gd(III) may lead to a disproportionate weight of T 2 effects, which would have a negative effect on T 1 -weighted images (8,25,27,28). We did observe an increase in T 2 relaxivity by increasing the number of Gd(III) per nanoparticle.…”

“…A simple addition of APTES-SCN-DOTA (Fig. S1B) solution in ethanol during the silica growth process results in a different network structure with more defect sites compared with the TEOS network alone, which is more resistant to the etching process of Gd(NO 3 ) 3 (25)(26)(27). The difference in the particle's surface functionality and porosity can be examined by TEM ( Fig.…”

Biodegradable Polymers Grafted onto Multifunctional Mesoporous Silica Nanoparticles for Gene Delivery

“…Furthermore, it has been demonstrated that the mesopores of these nanoparticles can be closed by APTES + PCL, GPTMS + CS, and their surfaces with the same organic matrices capping. As reported by Liberman et al [30], the presence of organic moieties in the surface increased the shapes and sizes of nanoparticles. It is worth mentioning that the MCM-41 is within the size expected to be used in biological applications.…”

The role of surface functionalization of silica nanoparticles for bioimaging

“…[86][87][88] Hence, surface modi¯-cation methods have been used aiming to improve the colloidal stability of SNP in biological systems and increase circulation times, as well as to reduce overall toxicity and aggregation. 89 Bare colloidal SNP have the surfaces negatively charged at physiological pH due to the ionization of the hydroxyl groups (−OH).…”