Anisotropic and Amphiphilic Mesoporous Core–Shell Silica Microparticles Provide Chemically Selective Environments for Simultaneous Delivery of Curcumin and Quercetin

Abstract

Porous silica materials are often used for drug delivery. However, systems for simultaneous delivery of multiple drugs are scarce. Here we show that anisotropic and amphiphilic dumbbell core–shell silica microparticles with chemically selective environments can entrap and release two drugs simultaneously. The dumbbells consist of a large dense lobe and a smaller hollow hemisphere. Electron microscopy images show that the shells of both parts have mesoporous channels. In a simple etching process, the properly adjusted stirring speed and the application of ammonium fluoride as etching agent determine the shape and the surface anisotropy of the particles. The surface of the dense lobe and the small hemisphere differ in their zeta potentials consistent with differences in dye and drug entrapment. Confocal Raman microscopy and spectroscopy show that the two polyphenols curcumin (Cur) and quercetin (QT) accumulate in different compartments of the particles. The overall drug entrapment efficiency of Cur plus QT is high for the amphiphilic particles but differs widely between Cur and QT compared to controls of core–shell silica microspheres and uniformly charged dumbbell microparticles. Furthermore, Cur and QT loaded microparticles show different cancer cell inhibitory activities. The highest activity is detected for the dual drug loaded amphiphilic microparticles in comparison to the controls. In the long term, amphiphilic particles may open up new strategies for drug delivery.

Three-Dimensional (3D) Surface-Enhanced Raman Spectroscopy (SERS) Substrates: Fabrication and SERS Applications

“…Silica microspheres (SMPs) are excellent candidates for this purpose and have attracted great attention for their usage in drug delivery, 11 electrochemical sensors, 12,13 and catalysis. 14 The versatile synthesis of SMPs gives the flexibility to tailor their properties like size, shape, and porosity.…”

“…Silica microspheres (SMPs) are excellent candidates for this purpose and have attracted great attention for their usage in drug delivery, electrochemical sensors, , and catalysis . The versatile synthesis of SMPs gives the flexibility to tailor their properties like size, shape, and porosity. ,, The tuning of the porosity allows to control pore size and pore volume, and their surface can be chemically modified by different functional groups. , This physical and chemical flexibility allows to optimize the properties to immobilize metal NPs on their surface .…”

Sol–Gel-Controlled Size and Morphology of Mesoporous Silica Microspheres Using Hard Templates

“…Porous silica particles are relevant in catalysis, in biosensors, , as drug carriers, − and as column material in purification and separation via chromatography. − To fit the requirements of a particular application, the control of particle size, size distribution, morphology, specific surface area, and pore parameters of these silica particles is of great importance. For instance, in drug delivery, silica particles as drug carriers require a size of <5 μm to be able to penetrate through the skin and release the drug in the tissue.…”

“…Porous silica particles are relevant in catalysis, 1 in biosensors, 2 , 3 as drug carriers, 4 − 6 and as column material in purification and separation via chromatography. 7 − 9 To fit the requirements of a particular application, the control of particle size, size distribution, morphology, specific surface area, and pore parameters of these silica particles is of great importance.…”

In situ carbonization metamorphoses porous silica particles into biodegradable therapeutic carriers of lesser consequence on TGF-β1 mediated fibrosis

“…1C). 22,23 As shown by the Si-Ps, the well-arranged MCM-41 type of hexagonal mesopores might be present as indicated by the distinctive H1 loop, whereas Si-NPs don't show any hysteresis or loop due to their nonporous nature. The BJH method shows that a higher average pore size (Table 1) that varied from 0.2 to 3 nm exists, while the specific surface area of Si-Ps was around 228 m 2 g −1 .…”