Interfacial engineering for silica nanocapsules

Abstract

Silica nanocapsules have attracted significant interest due to their core-shell hierarchical structure. The core domain allows the encapsulation of various functional components such as drugs, fluorescent and magnetic nanoparticles for applications in drug delivery, imaging and sensing, and the silica shell with its unique properties including biocompatibility, chemical and physical stability, and surface-chemistry tailorability provides a protection layer for the encapsulated cargo. Therefore, significant effort has been directed to synthesize silica nanocapsules with engineered properties, including size, composition and surface functionality, for various applications. This review provides a comprehensive overview of emerging methods for the manufacture of silica nanocapsules, with a special emphasis on different interfacial engineering strategies. The review starts with an introduction of various manufacturing approaches of silica nanocapsules highlighting surface engineering of the core template nanomaterials (solid nanoparticles, liquid droplets, and gas bubbles) using chemicals or biomolecules which are able to direct nucleation and growth of silica at the boundary of two-phase interfaces (solid-liquid, liquid-liquid, and gas-liquid). Next, surface functionalization of silica nanocapsules is presented. Furthermore, strategies and challenges of encapsulating active molecules (pre-loading and post-loading approaches) in these capsular systems are critically discussed. Finally, applications of silica nanocapsules in controlled release, imaging, and theranostics are reviewed.

Controlling protein interactions in blood for effective liver immunosuppressive therapy by silica nanocapsules

“…62 A silica shell was therefore formed around nanodroplets containing DXM and Fe 3 O 4 NPs. 63 Simultaneously, fluorescently modified silica precursors were copolymerized in the silica network. Therefore, drug encapsulation and fluorescent and magnetic labeling of NCs were carried out in one step.…”

A Review of the Structure, Preparation, and Application of NLCs, PNPs, and PLNs

“…The dispersed phase properties of the emulsion and composition of the microemulsion formulation are indices for determining nanocapsule content. Generally, two methods are available for the formation of the liquid core and polymer shell: polymerization occurs between the dispersed phase and the continuous phase [18,19,20,21,22,23,24,25,26], or the precipitation of the surface [27,28,29,30] is formed by emulsion droplets.…”

Versatile Preparation of Silica Nanocapsules for Biomedical Applications

“…[ 5–15 ] Compared with mesoporous silica nanoparticles with a solid core, core–shell silica nanocapsules (SiO 2 NCs) have the advantages that their interior cavity offers a large loading capacity for guest molecules and the shell can be designed to display a tunable permeability for specific cargo release. [ 16 ] In spite of recent progress in nanocapsules design, a versatile approach for the preparation of functional SiO 2 NCs for biomedical applications with control at morphological and molecular levels, e.g., the core–shell structure, tunable size, interior contents, and the shell composition, permeability, and surface functionalization, is still needed.…”

“…This strategy often results in low loading efficiency and initial burst release especially for water‐soluble molecules. [ 16,20,21 ] Alternatively the payloads can be predissolved or adsorbed in the template material. Nonetheless, this approach takes several steps and the loading efficiency of guest molecules relies highly on their adsorption to the template nanoparticles.…”

“…Nonetheless, this approach takes several steps and the loading efficiency of guest molecules relies highly on their adsorption to the template nanoparticles. [ 16 ]…”