Critical Considerations in the Biomedical Use of Mesoporous Silica Nanoparticles

Abstract

Since the first report of mesoporous silica nanoparticles in 2001, many efforts have been made to develop them for biomedical applications. With the emergence of new designs and increasingly complex synthetic schemes, mesoporous silica nanoparticles have never been more promising. For this promise to be fulfilled, however, practical considerations for biomedical use must be carefully addressed. Many current mesoporous silica reports, even those reporting in vivo work, neglect the observation of nanoparticle size, pore structure, aggregation state, and biodegradability under biological conditions before administration. These critical considerations, beginning at synthetic stages, must be taken into account to make effective and safe mesoporous silica nanoparticles for biomedical use and timely application in clinical trials. Herein, we present a comprehensive review of mesoporous silica nanoparticle synthetic strategies, pointing out nanoparticle behavior under biological conditions and how it may affect in vitro and in vivo results.

Mesoporous silica nanoparticles functionalized with fluorescent and MRI reporters for the visualization of murine tumors overexpressing αvβ3receptors

“…14 Currently, few MSNs-based agents have been proposed, whose main limitation appears associated to their overall large size and to their tendency to aggregate when dispersed in a physiological medium. 15 Although a recent report has shown that the size of MSNs can be reduced to be smaller than 50 nm, nevertheless, the obtained nanoparticles resulted to aggregate. [15][16] Therefore, a reliable large scale preparation of MSNs endowed with a small hydrodynamic diameter, functional groups and excellent dispersity in physiological aqueous conditions still remains challenging.…”

“…15 Although a recent report has shown that the size of MSNs can be reduced to be smaller than 50 nm, nevertheless, the obtained nanoparticles resulted to aggregate. [15][16] Therefore, a reliable large scale preparation of MSNs endowed with a small hydrodynamic diameter, functional groups and excellent dispersity in physiological aqueous conditions still remains challenging.…”

Morphology control of microporous silica particles obtained by gradual injection of reactants

“…Micro-and mesoporous silica particles are widely used as catalysts and carriers for drug delivery systems (DDS), because of those unique porous characteristics [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Among them, those ca.…”

“…Among them, those ca. 100 nm in diameter are expected to be useful for applications in DDS and transparent media such as low-refractive index materials, thermal insulation films, and low dielectric materials [6][7][8][9][10][11][12][13][14]. However, it has been difficult to synthesize monodisperse porous silica particles of 100 nm in diameter on an industrial scale, because the synthesis should take place in highly diluted solutions [10,[15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30].…”

Continuous Detection of pH‐responsive Drug Delivery System in Cells in situ by Confocal Laser Scanning Microscopy

“…Drug release can be moderated by a variety of capping mechanisms over the pore openings, work in controlled release focuses on both preventing premature release and regulating release once the "caps" are off. [9] Until now, different stimuli-responsive mechanisms have been employed in antitumor controlled release system. When external stimuli, such as temperature, [10][11][12] pH, [13][14][15][16] light irradiation, [17,18] redox reagents [19][20][21] and enzymes [22][23][24] are applied, the release of guest molecules can be achieved as a response.…”