Morphology Evolution and Spatially Selective Functionalization of Hierarchically Porous Silica Nanospheres for Improved Multidrug Delivery

Abstract

Hierarchically porous materials are believed one of the most promising matrix materials due to their unique multimodal pore structures and great application potentials in catalysis, separation, and biomedicine. In this article, a series of hierarchically porous silica nanospheres with adjustable morphologies and pore structures/sizes has been successfully developed by controlling the electrostatic interaction-induced interfacial self-assembly behaviors between anionic block copolymer polystyrene-b-poly­(acrylic acid) (PS-b-PAA), cationic surfactant cetyltrimethylammonium bromide, and tetraethyl orthosilicate. Especially, “embedded” structured dual-mesoporous silica nanospheres (E-DMSNs) containing connected large mesopores (>10 nm) and abundant small mesopores (2–3 nm) in the large-pore framework have been prepared for the first time. Moreover, by employing PS-b-PAA with shorter PAA block lengths as template, the morphology conversion of porous silica nanospheres from core–shell structured dual-mesoporous silica nanospheres to well-defined hollow mesoporous silica nanospheres has been achieved. To endow the capability of E-DMSNs as multidrug delivery vehicles, a spatially selective functionalization strategy has been adopted to obtain dual-functionalized E-DMSNs (E-DMSNs-NH2/OH) with amino-functionalized large mesopores and hydroxyl-modified small mesopores. Thermogravimetric-differential scanning calorimetry analysis shows that the loading amount of curcumin (Cur) and doxorubicin hydrochloride (DOX) were about 3.4% and 10.0% in weight, respectively. In addition, the cytotoxicity assay and cellular uptake of DOX@Cur@E-DMSNs-NH2/OH on SMMC-7721 cells (human hepatoma cells) have been investigated. Thus, such a simple methodology to synthesize hierarchically porous silica with adjustable morphologies, pore sizes, and pore modifications provides a new pathway for the rational design of antitumor multidrug nanocarriers in further cancer treatment.

High Surface Area Mesoporous Silica Nanoparticles with Tunable Size in the Sub-Micrometer Regime: Insights on the Size and Porosity Control Mechanisms

“…It has been also found that the nature of silica precursors, solvents or co-solvents, catalysts, and, finally, pH of the reaction medium also affect the MSN structure. Spherical worm-like MSNs with mesopores or hierarchical porous structures, including hollow [ 16 , 17 , 18 ], yolk-shell, stellate nanoparticles (NPs) [ 19 ] have been synthesized by suitably tuning SDA, precursors nature, concentration, reaction condition such as duration and temperature of hydrolysis and condensation or application of post-synthetic treatments.…”

Hollow Porous MnFe2O4 Sphere Grown on Elm‐Money‐Derived Biochar towards Energy‐Saving Full Water Electrolysis

“…The hollow porouss phere is as pecial functional material, due to its unique structure, whichh as become ap romising and attractive material for chemical catalysis, nanoreactors, drug delivery vehicles, and energy conversion and storage. [40][41][42][43][44][45][46] Nano-sized hollow porouss pheres can adjust the volume change in the catalytic process to increaset he structural stability.T herefore, hollow porousM nFe 2 O 4 spheres were prepared in presentw ork to obtain excellent HER and OER performance, and it was further optimized by growingo nt he surfaceo fb iochar.T he elm moneyh as meritorious physical and chemical properties because of its unique structure and natural carbon skeleton, which could afford many natural pores and facilitate the rapid transfer of electrolytes, and is beneficialt of aster release of air bubbles. [47][48][49] In this paper, MnFe 2 O 4 hollow porous sphere ande lm-money-derived biocharc omposites (MnFe 2 O 4 / BC) are obtained as dual-functional electrocatalysts for overall water decomposition.…”

“…The hollow porous sphere is a special functional material, due to its unique structure, which has become a promising and attractive material for chemical catalysis, nanoreactors, drug delivery vehicles, and energy conversion and storage [40–46] . Nano‐sized hollow porous spheres can adjust the volume change in the catalytic process to increase the structural stability.…”

Cooperative organizations of small molecular surfactants and amphiphilic block copolymers: Roles of surfactants in the formation of binary co‐assemblies

“…[95] Our group has developed a series of dualmodal mesoporous silica nanoparticles based on the this co-templating system (Figure 10A). [95][96][97][98] During the cotemplating process, the bridging effect of CTAB is important since single PS-b-PAA lacks sufficient interaction with the backbone species, the hydrolyzed silane. In slightly basic aqueous solution, the hydrophilic PAA blocks could couple with CTAB micelles via electrostatic Coulomb force to form F I G U R E 1 0 (A) Formation of the dual mesoporous materials templated by PS-b-PAA/CTAB composite micelle aggregates.…”