Design and Synthesis of Multifunctional Drug Carriers Based on Luminescent Rattle‐Type Mesoporous Silica Microspheres with a Thermosensitive Hydrogel as a Controlled Switch

Abstract

A novel approach for the fabrication of multifunctional microspheres integrating several advantages of mesoporous, luminescence, and temperature responses into one single entity is reported. First, the hollow mesoporous silica capsules are fabricated via a sacrificial template route. Then, Gd2O3:Eu3+ luminescent nanoparticles are incorporated into the internal cavities to form rattle‐type mesoporous silica nanocapsules by an incipient‐wetness impregnation method. Finally, the rattle‐type capsules serve as a nanoreactor for successfully filling temperature‐responsive hydrogel via photoinduced polymerization to form the multifunctional composite microspheres. The organic–inorganic hybrid microspheres show a red emission under UV irradiation due to the luminescent Gd2O3:Eu3+ core. The in vitro cytotoxicity tests show that the samples have good biocompatibility, which indicates that the nanocomposite could be a promising candidate for drug delivery. In addition, flow cytometry and confocal laser scanning microscopy (CLSM) confirm that the sample can be effectively taken up by SKOV3 cells. For in vitro magnetic resonance imaging (MRI), the sample shows the promising spin‐lattice relaxation time (T1) weighted effect and could potentially apply as a T1‐positive contrast agent. This composite drug delivery system (DDS) provides a positive temperature controlled “on‐off”drug release pattern and the drug, indomethacin (IMC), is released fast at 45 °C (on phase) and completely shut off at 20 °C (off phase). Meanwhile Gd2O3:Eu3+ plays an important role as the luminescent tag for tracking the drug loading and release process by the reversible luminescence quenching and recovery phenomenon. These results indicate that the obtained multifunctional composite has the potential to be used as a smart DDS for biomedical applications.

pH- and redox-triggered synergistic controlled release of a ZnO-gated hollow mesoporous silica drug delivery system

“…studies indicate that hollow spheres with walls composed of ordered mesoporous shells also exhibit this type of hysteresis behavior due to the delay of nitrogen evaporation from the hollow cores blocked by the surrounding mesopores in the shells during the nitrogen desorption process. 13,28,29 These results further support that the HMSS materials possess hierarchical mesoporous structures composed of hollow cavities with mesoporous shells. HMSS12 had the largest surface area of 1029 m 2 g À1 and a pore size of 2.6 nm (Table S1 †), thus HMSS12 was chosen for the subsequent experiments.…”

Nanoreactor Based on Macroporous Single Crystals of Metal-Organic Framework

“…As we demonstrate before, the yolk–shell Au@ZIF‐8 preserves the crystalline, microporous structure of ZIF‐8 single crystals, which distinguishes our super nanoreactors from other ones with amorphous shells (e.g., porous silica, carbon, metal oxide, dendrimers, polymer, or virus capsid) or polycrystalline ZIF‐8 crystals . The crystalline, microporous ZIF‐8 shell should provide fine control over selective mass transfer of reactants through the MOF shell, and only those reactants with molecular size smaller than or comparable to the pore aperture of ZIF‐8 are allowed to diffuse into the void.…”

Irradiation-free photodynamic therapy in vivo induced by enhanced deep red afterglow within NIR-I bio-window

“…4d. For the ZGGO:Cr,Bi@mSiO 2 nanoplatforms, new absorption bands appear in relation with Si-O-Si (1080 cm −1 , 803 cm −1 ) and Si-OH (951 cm −1 ) appear compared to the ZGGO:Cr,Bi bare core, supporting the formation of the core/shell structure [59]. The phosphorescence spectrum of ZGGO:Cr,Bi@mSiO 2 nanoplatforms is partly overlapped with absorption of ZnPc molecule, as shown in Fig.…”