Controlled Release of Guest Molecules from Mesoporous Silica Particles Based on a pH‐Responsive Polypseudorotaxane Motif

Abstract

Stringing them along: The pores of a mesoporous silica particle were filled with guest molecules and then blocked by threading cyclodextrin molecules (CDs) onto the surface‐grafted polyethylenimine (PEI) chains at pH 11. At pH 5.5, the guest molecules can be released from the pores of the particle by reversible dethreading of the CDs from the PEI chains.

Mesoporous silica nanoparticles for stimuli-responsive controlled drug delivery: advances, challenges, and outlook

“…[59][60][61][62][63] Herein, the aromatic amines/ammonium stalks were immobilized on the MSN surface, and mobile cyclic molecular gates were introduced to encircle the stalks via non-covalent interactions for controlling the transport of the model drugs loaded in the nanopores. 64 Under certain conditions (especially acidic conditions), the weak binding constant between cyclic caps and stalks resulted in largeamplitude sliding motions of the caps and burst drug release.…”

“…Upon the drug-loaded MSN was internalized by THP-1 and KB-31 cells, the acidic pH in lysosome triggered the decomposition of the nanovalves and resulted in an observable drug release. Park et al 63 also reported a cyclodextrin (CD) rotaxane-based pH-responsive DDS, in which the guest molecules were entrapped in the pores of MSN and then polyetherimide (PEI)/CD poly pseudorotaxane was grafted onto the surface to block the nanopores. PEI was used as the guest polymer for CD hosts.…”

Nanoassemblies driven by cyclodextrin-based inclusion complexation

“…58 As shown in Fig. 15, the pores of silica particles were filled with guest molecules and then blocked by threading of CDs onto the surface-grafted PEI chains at pH 11.…”

In vitro controlled release of cisplatin from gold-carbon nanobottles via cleavable linkages

“…In the realm of drug delivery, a sophisticated nanodelivery system, which is capable of storing and protecting drug molecules, controlling and regulating release of cargo molecules only at target site, is unequivocally desired. In this regard, release of the drugs or active agents from nanocontainers had been successfully demonstrated to be regulated in response to changes in redox potential, 17 pH, 18,19 temperature, 20 light, 21 and the presence of enzymes found in certain diseases. 22 The rate of release of the cargo molecules relies on the shape and geometrical properties of nanocontainers.…”

“…These conditions were previously reported to shorten our tubes' length from a few microns to a range of approximately 200-900 nm 38 ( Figure S3). All the samples had the same external diameter (38 nm in average, n=144, σ=13.6) and aspect ratio in the range of [19][20][21]39 which therefore had the same influence in terms of release profiles. …”