Shape-Tunable Hollow Silica Nanomaterials Based on a Soft-Templating Method and Their Application as a Drug Carrier

Abstract

A one-step soft-templating method for synthesizing shape-tunable hollow silica nanomaterials was developed in a reliable and highly reproducible way. For the first time, both nonspherical and spherical shapes with hollow interiors, including nanowire, nanospheres, and nanotadpole, were successfully obtained by simply changing the solvent. Poly(vinylpyrrolidone) (PVP)-water droplets were used as soft templates for the formation of hollow structures, while three different solvents, including 1-propanol, 1-pentanol, and ethanol, led to the designed shapes. It was found that the solvent, the formation of PVP-water droplets, the amount of ammonia, and the reaction time had great effects on the morphology of synthesized hollow nanomaterials. The effect of various factors on the morphology was systematically studied to propose a growth mechanism. The obtained hollow silica nanomaterials showed excellent reproducibility and great potential for a large-scale synthesis. Finally, the application of the developed hollow silica nanomaterials was demonstrated using the hollow spherical silica nanoparticles. Its drug-carrying ability was studied. The results could be extended for doping various target molecules into the hollow structures for a broad range of applications.

Self-Assembly Hierarchical Silica Nanotubes with Vertically Aligned Silica Nanorods and Embedded Platinum Nanoparticles

“…Well-organized silica nanotubes could be prepared on the basis of the regularly gathered multicore Pt@SiO 2 spheres (Figure 4c). Therefore, with the increasing of the ratio of NH 4 OH to TEOS, the silica production exhibits an improved regularity, indicating that NH 4 OH has an inducing effect on the formation of the nanotube structure. If the molar ratio further increased to 4.2, few sparse silica nanorods started to grow on the silica nanotube surface.…”

“…Hollow silica nanomaterials (HSNs) integrate the advantages of silica materials with hollow colloids, which gives them several unique features, such as easy etching, good thermal stability, facile surface functionalization accessibility, and controllable particle configuration. − These innovative materials, therefore, present great utilitarian value for drug delivery, catalysis, adsorption, energy storage, and conversion. − Among them, silica nanotubes (SNTs) are of special interest because of their hydrophilic nature, controlled surface properties, and easy colloidal suspension formation. − Over the past ten years, there has been explosive growth in the synthesis, characterization, and application of SNTs. Various synthesis strategies for SNTs have been reported.…”

Shape-controlled synthesis and lithium storage properties of SnO2 nonspherical hollow structures

“…Aer the silica is etched by HF solution, the SnO 2 hollow structures with different shapes, uniform sizes and shells are obtained. Compared with the reported procedures for hollow particles with different shapes, 23,[34][35][36][37] the present approach has three main characteristics: (1) three different shapes of SnO 2 nonspherical hollow structures can be easily tailored by simply adjusting the shapes of silica colloidal templates; (2) no protective surfactant is used, so the asprepared SnO 2 hollow structures should have relatively clean surfaces, which are important in some application areas needing strict surface chemistry requirements, such as catalysis, electrochemistry, sensing, etc. ; 23,30,38 (3) the as-obtained SnO 2 hollow structures with different shapes have uniform sizes and shapes.…”

Hollow Silica Particles: Recent Progress and Future Perspectives

“…Amorphous silica easily degrades in water over time [89] and silica particles are easily removed from body through the kidneys [88]. HSPs have been demonstrated as carriers for the delivery of drugs such as doxorubicin hydrochloride, cytochrome C, polymyxin B, camptothecin, and cytosine-phosphodiester-guanine oligodeoxynucleotide [90][91][92][93][94][95]. Besides their use in conventional drugs, HSPs have also been shown to be useful as carriers for unconventional vaccines, such as virus-like particles (VLPs).…”