Following in Situ the Degradation of Mesoporous Silica in Biorelevant Conditions: At Last, a Good Comprehension of the Structure Influence

Publication year: 2020
Authors: Bindini E. 1,2, Chehadi Z. 1, Faustini M. 1, Albouy P. 3, Grosso D. 4, Cattoni A. 2, Chanéac C. 1, Azzaroni O. 5, Sanchez C. 1, Boissiè C. 1

1 - Laboratoire Chimie de la Matière Condensée de Paris, UMR 7574, Sorbonne Université, 4 Place Jussieu, 75252 Paris, France

2 - Centre de Nanosciences et de Nanotechnologies (C2N), CNRS, 10 Boulevard Thomas Gobert, 91120 Palaiseau, France

3 - Laboratoire de Physique des Solides, UMR 8502, Université Paris Sud, 1 rue Nicolas Appert Bâtiment, 510 Orsay, France
4 - Institut Matériaux Microélectronique Nanoscience de Provence Case,142 Avenue Escadrille Normandie Niemen, 13397 Marseille, France
5 - Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas, Diagonal 113 y 64 S/N, LaPlata, Argentina
Published in: ACS Applied Materials and Interfaces, 2020, Vol.12, p.13598–13612
doi: doi/10.1021/acsami.9b19956

Mesoporous silica nanoparticles (MSNs) have seen a fast development as drug delivery carriers thanks to their tunable porosity and high loading capacity. The employ of MSNs in biomedical applications requires a good understanding of their degradation behavior both to control drug release and to assess possible toxicity issues on human health. In this work, we study mesoporous silica degradation in biologically relevant conditions through in situ ellipsometry on model mesoporous nanoparticle or continuous thin films, in buffer solution and in media containing proteins. In order to shed light on the structure/dissolution relationship, we performed dissolution experiments far from soluble silicate species saturation. Via a complete decorrelation of dissolution and diffusion contributions, we proved unambiguously that surface area of silica vectors is the main parameter influencing dissolution kinetics, while thermal treatment and open mesoporous network architecture have a minor impact. As a logical consequence of our dissolution model, we proved that the dissolution lag-time can be promoted by selective blocking of the mesopores that limits the access to the mesoporous internal surface. This study was broadened by studying the impact of the organosilanes in the silica structure, of the presence of residual structuring agents, and of the chemical composition of the dissolution medium. The presence of albumin at blood concentration was found affecting drastically the dissolution kinetics of the mesoporous structure, acting as a diffusion barrier. Globally, we could identify the main factors affecting mesoporous silica materials degradation and proved that we can tune their structure and composition for adjusting dissolution kinetics in order to achieve efficient drug delivery.

MP-SPR keywords: degradation behavior of material, desorption, Drug delivery, layer characterization, silica