Synthesis of Controlled-Size Silica Nanoparticles from Sodium Metasilicate and the Effect of the Addition of PEG in the Size Distribution.

Christian Chapa-González,Perla García-Casillas,Ana Piñón-Urbina

doi:10.3390/ma11040510

Christian Chapa-González, Perla García-Casillas + Show 1 more

Open Access

https://doi.org/10.3390/ma11040510

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Abstract

Silica nanoparticles are widely studied in emerging areas of nanomedicine because they are biocompatible, and their surface can be modified to provide functionalization. The size is intrinsically related to the performance of the silica nanoparticles; therefore, it is important to have control over the size. However, the silica nanoparticles obtained from sodium metasilicate are less studied than those obtained from tetraethyl orthosilicate. Moreover, the methods of surface modification involve several steps after the synthesis. In this work, the effect of different concentrations of sodium metasilicate on the size of silica nanoparticles was studied. In the same way, we studied the synthesis of organically modified silica nanoparticles in a one-step method, using poly(ethylene glycol). The nanoparticles were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. It was found that the size distribution of the silica nanoparticles could be modified by changing the initial concentration of sodium metasilicate. The one-step surface-modification method caused a significant decrease in size distribution.

Highlights

Silica nanoparticles (Si-NPs) have a promising role in emerging nanomedicine because of their low cytotoxicity, ultra-fine size range, and they can be modified with molecules of biomedical interest
The size of the ORMOSIL-NPs is lower compared to the Si-NPs in all the samples, it was clearly evidenced by SEM (Figure 1)
The size distribution of the nanoparticles in the Si-NPs were higher than ORMOSIL-NPs in all the samples obtained from the solution with the same concentration of the precursor

Summary

Introduction

Silica nanoparticles (Si-NPs) have a promising role in emerging nanomedicine because of their low cytotoxicity, ultra-fine size range (below 100 nm), and they can be modified with molecules of biomedical interest. Organic modified silica nanoparticles (ORMOSIL-NPs) are a type of silica-based nanoparticles [3], which by combining organic molecules and functional groups in their structure they acquire additional functions, so they widely extend their in vitro applications to bioimaging [4,5,6], biosensors [7,8], and in vivo applications, such as cancer therapy [9,10,11,12] and drug administration [13,14,15]. The size of ORMOSIL-NPs can affect both the amount of immobilized drug, as well as the release kinetics

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