pH-Triggered Controlled Drug Release from Mesoporous Silica Nanoparticles via Intracelluar Dissolution of ZnO Nanolids

Abstract

Acid-decomposable, luminescent ZnO quantum dots (QDs) have been employed to seal the nanopores of mesoporous silica nanoparticles (MSNs) in order to inhibit premature drug (doxorubicin) release. After internalization into HeLa cells, the ZnO QD lids are rapidly dissolved in the acidic intracellular compartments, and as a result, the loaded drug is released into the cytosol from the MSNs. The ZnO QDs behave as a dual-purpose entity that not only acts as a lid but also has a synergistic antitumor effect on cancer cells. We anticipate that these nanoparticles may prove to be a significant step toward the development of a pH-sensitive drug delivery system that minimizes drug toxicity.

ZnO quantum dots modified bioactive glass nanoparticles with pH-sensitive release of Zn ions, fluorescence, antibacterial and osteogenic properties

“…This phenomenon can be explained by the significant pH sensitivity of ZnO QDs, which are stable at pH 7.4 but rapidly dissolve at pH o 5.5. 27 Additionally, the sustained release of Zn ions in PBS suggests the robust bonding between ZnO QDs and BGN after calcination. As a comparison, the release of Ca ions also occurred in a pH-sensitive manner (Fig.…”

“…25 ZnO QDs are also effective antibacterial agents, due to their either killing or growth suppression effects on bacteria. 26 Furthermore, owing to their unique degradation behavior (rapid degradation under acidic conditions but slow degradation under neutral or basic conditions), ZnO QDs could be used as nanolids to cap nanopores on drug carriers 27,28 to allow loaded drugs to be released at low pH (a low pH is associated with inflammation, bacterial infection or cancer).…”

Coordination Polymer Coated Mesoporous Silica Nanoparticles for pH‐Responsive Drug Release

“…[ 6b , 7a , 11 ] Zhu et al reported that ZnO quantum dot lids on MSNs can be effi ciently dissolved in the acidic intracellular compartments of cancer cells, resulting in the release of the drugs from the pores of the MSNs into the cytosol. [ 13 ] Shi et al reported a pH-responsive controlled drug release system by using poly(allylamine hydrochloride)/sodium polystyrene sulfonate multilayers as a coating to cap the mesopore openings of drug-loaded hollow mesoporous silica spheres. [ 4b ] Coordination polymer nanoparticles (CPNs) have demonstrated their feasibility for use in a variety of biological applications such as bioimaging and drug delivery.…”

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

“…Muhammad et al 75 reported a pH-responsive DDS based on acid-decomposable, luminescent ZnO quantum dots (QDs)-capped MSN to inhibit premature drug release (Figure 4). Following cellular uptake by HeLa cells, the ZnO QDs were fast dissolved in the acidic intracellular condition that resulted in a burst drug release into the cytosol.…”