A Facile Multi-interface Transformation Approach to Monodisperse Multiple-Shelled Periodic Mesoporous Organosilica Hollow Spheres

Abstract

The synthesis of well-defined and complex hollow structures via a simple method is still a major challenge. In this work, a facile and controllable "multi-interface transformation" approach for preparation of monodisperse multi-shelled periodic mesoporous organosilica (PMO) hollow spheres has been established by a one-step hydrothermal treatment of successively grown organosilica particles. The multi-shelled PMO hollow spheres have inorganic-organic hybrid frameworks, controllable number (1-4) of shells, high surface area (∼805 m(2)/g), accessible ordered mesochannels (∼3.2 nm), large pore volume (1.0 cm(3)/g), and uniform and tunable diameter (300-550 nm), chamber size (4-54 nm), and shell thickness (10-30 nm). In addition, various organic groups (alkyl, aromatic, and heteroelement fragments) are successfully incorporated into the multi-shelled PMO hollow spheres by successively adding different bridged organosilica precursors. Notably, the distribution of different kinds of organic groups in the multi-shelled PMO hollow spheres can be precisely controlled, showing great potential for future applications. We propose that the formation of the multi-shelled PMO hollow structures is ascribed to the creation of multiple highly cross-linked organosilica interfaces, providing a new and interesting fundamental principle for PMO materials. Due to their unique structure and frameworks, triple-shelled ethane-bridged PMO hollow spheres were successfully loaded with an anti-cancer drug doxorubicin and perfluoropentane gas, which present excellent effects in the killing of cancer cells and ultrasound imaging. It is expected that the multi-interface transformation strategy provides a simple, controllable, versatile, and template-free method for preparation of various multifunctional PMOs for different applications.

Facile Synthesis of Yolk-Shell-Structured Triple-Hybridized Periodic Mesoporous Organosilica Nanoparticles for Biomedicine

“…[35,36] Moreover, by utilizing the interactions of organic groups with guest molecules, the PMOs present stimuli-responsive drug release profiles without using capping agents to block the mesopores. [37,38] Different morphologies of PMOs, such as spheres, [24,36] rods, [39] films, [27,40] and hollow or yolk-shell particles, [35,41,42] have been successfully prepared. Among them, yolk-shellstructured PMOs have attracted much greater attention in drug delivery due to their interior core, void space, permeable outer shell, low density, and excellent loading capacity.…”

Periodic Mesoporous Organosilica Coated Prussian Blue for MR/PA Dual‐Modal Imaging‐Guided Photothermal‐Chemotherapy of Triple Negative Breast Cancer

“…However, pure PB nanoparticles cannot deliver drug for cancer chemotherapy because of their small micropores and limited loading capacity. Periodic mesoporous organosilicas (PMOs) synthesized via surfactant‐directed sol–gel process has been used for drug delivery because of their uniform and large mesopore size, high surface area, organic groups incorporated frameworks, and excellent biodegradation and biocompatibility 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43. Based on the unique features, we presumed that an imaging‐guided combination therapy strategy can be developed by intergating the advantages of PMO and PB.…”

Chemistry of Mesoporous Organosilica in Nanotechnology: Molecularly Organic–Inorganic Hybridization into Frameworks

“…[ 124,[143][144][145][146] For instance, HMONs with multi-shells were recently synthesized by a facile and controllable "multiinterface transformation" methodology. [ 147 ] Organosilica shells were successively grown onto the surface of as-synthesized solid organosilica/CTAB composite particles ( Figure 7 ). After one-pot post-hydrothermal treamtent, the interface was perfectly retained while the inner part was selectively etched away, leaving multi-shelled HMONs.…”

“…For example, 1,4-bis(triethoxysily)propane tetrasulfi de (TESPTS) ( R 1 = thioether) and 1,2-bis(triethoxysilyl)ethane (BTSE) ( R 2 = ethane) were employed as the organosilica precursors to introduce thioether ( R 1 ) and ethane ( R 2 ) groups within the separate shells of the multi-shelled HMONs. [ 147 ] For other multi-shelled MONs, organosiliceous multimellar vesicles (MLVs) were synthesized via a soft-templating approach where the block copolymer Pluronic P85 was employed as the SDA and 1,2-bis(triethoxysilyl)ethane (BTEE) ( R = ethane) was used as the organosilica precursor. [ 148 ] The synthesized MLVs featured a well-defi ned mesoporous structure with high surface area (695 m 2 g −1 ) and pore volume (2.10 cm 3 g −1 ).…”