Core-Shell Pluronic-Organosilica Nanoparticles with Controlled Polarity and Oxygen Permeability.

Cristina De La Encarnacion Bermudez,Damiano Genovese,Luca Petrizza,Enrico Rampazzo,Elahe Haddadi,Luca Prodi

doi:10.1021/acs.langmuir.0c03531

Cristina De La Encarnacion Bermudez, Damiano Genovese + Show 4 more

Open Access

https://doi.org/10.1021/acs.langmuir.0c03531

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Abstract

Nanostructured systems constitute versatile carriers with multiple functions engineered in a nanometric space. Yet, such multimodality often requires adapting the chemistry of the nanostructure to the properties of the hosted functional molecules. Here, we show the preparation of core–shell Pluronic-organosilica “PluOS” nanoparticles with the use of a library of organosilane precursors. The precursors are obtained via a fast and quantitative click reaction, starting from cost-effective reagents such as diamines and an isocyanate silane derivative, and they condensate in building blocks characterized by a balance between hydrophobic and H-bond-rich domains. As nanoscopic probes for local polarity, oxygen permeability, and solvating properties, we use, respectively, solvatochromic, phosphorescent, and excimer-forming dyes covalently linked to the organosilica matrix during synthesis. The results obtained here clearly show that the use of these organosilane precursors allows for finely tuning polarity, oxygen permeability, and solvating properties of the resulting organosilica core, expanding the toolbox for precise engineering of the particle properties.

Highlights

Functional nanoarchitectures, defined as materials engineered at the nanoscale to perform specific functions,[1] have revealed in the last decades an enormous potential for transversal application in science and technology,[2,3] owing to their versatility and to their small scale, which allows us to and creatively interface them with biological structures.[4−6] In the field of drug delivery, the production of carriers with high load, fast dissolution rate, and specific targeting ability has been of capital importance to maximize the action of many pharmaceuticals
The well-known preparation of core−shell Pluronic-silica “PluS” nanoparticles[20,21] has recently demonstrated to yield small, monodisperse, and colloidally and photophysically stable nanoparticles, in vivo. This type of silica nanoparticles grows templated by micelles of Pluronic F127 a triblock copolymer composed of poly(ethylene glycol) (PEG) and poly(propylene glycol) (PPO) in acidic water at 30 °C, and exhibits a silica core diameter of ca. 10 nm and a hydrodynamic diameter of ca. 25 nm, which corresponds to the PEG blocks of Pluronic surfactant, which remain as brushes on the silica surface
Starting from this method, we investigated the possibility to mix TEOS and an organosilane precursor to produce colloidally stable, long shelf-life, small core−shell organosilica-PEG nanoparticles (Pluronic-organosilica nanoparticles, here abbreviated as PluOS NPs, Figure 1)

Summary

Introduction

Functional nanoarchitectures, defined as materials engineered at the nanoscale to perform specific functions,[1] have revealed in the last decades an enormous potential for transversal application in science and technology,[2,3] owing to their versatility and to their small scale, which allows us to and creatively interface them with biological structures.[4−6] In the field of drug delivery, the production of carriers with high load, fast dissolution rate, and specific targeting ability has been of capital importance to maximize the action of many pharmaceuticals. The possibility to tune the chemistry of the nanocarrier is of utmost importance, and organosilanes[22−24] have the potential to modify the network of silica nanostructures for this purpose.[15−17] Besides controlling the hosting ability of nanocarriers, a pre-requirement for the design of successful nanostructures for nanomedicine is their colloidal stability,[18] in biological fluids in the presence of large protein concentration.[12,19] The well-known preparation of core−shell Pluronic-silica “PluS” nanoparticles[20,21] has recently demonstrated to yield small, monodisperse, and colloidally and photophysically stable nanoparticles, in vivo This type of silica nanoparticles grows templated by micelles of Pluronic F127 a triblock copolymer composed of poly(ethylene glycol) (PEG) and poly(propylene glycol) (PPO) in acidic water at 30 °C, and exhibits a silica core diameter of ca. Their very small size and the shielding PEG surface are responsible for long circulation time, low accumulation rate, and enhanced targeting ability.[13,21]

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