Reversible Nanogate System for Mesoporous Silica Nanoparticles Based on Diels–Alder Adducts

Abstract

The implementation of nanoparticles as nanomedicines requires sophisticated surface modifications to reduce the immune response and enhance recognition abilities. Mesoporous silica nanoparticles present extraordinary host-guest abilities and facile surface functionalization. These two factors make them ideal candidates for the development of novel drug-delivery systems, at the expense of increasing structural complexity. With this idea in mind, a system composed of triggerable and tunable silica nanoparticles was developed for application as drug-delivery nanocarriers. Diels-Alder cycloaddition adducts were chosen as thermal-responsive units that permitted the binding of gold nanocaps able to block the pores and allow the incorporation of targeting fragments. The capping efficiency was tested under different thermal conditions to give outstanding efficiencies within the physiological range and mild temperatures, as well as enhanced release under pulsing heating cycles, which showed the best release profiles.

Click Chemistry in Polymersome Technology

“…Surface modification can be conducted through various methods and reactions, namely, the inverse electron-demand Diels–Alder [ 61 , 62 , 63 ], thiol-ene chemistry [ 64 , 65 , 66 ], click chemistry [ 67 , 68 , 69 ], or Diels–Alder reactions [ 70 , 71 , 72 ]. However, this broad spectrum of reactions is not always possible, given their limitations in material functionalisation.…”

Advances in mesoporous silica nanoparticles for targeted stimuli-responsive drug delivery: an update

“…Another important vitamin employed as targeting label is biotin (vitamin B7 or H), whose relevance is also based on its simplicity and ease functionalization. Like FA, biotin has been employed to target MSNs-based nanosystems containing polymeric coatings [88], AuNPs caps [89], lipid bilayers [90] or surface-loaded prodrugs [91]. Another interesting vitamin for developing targeted examples is cyanocobalamine (vitamin B12), which has been elegantly coordinated to cisplatin-functionalized MSNs by Leeladee and coworkers [92] to obtain a MSN-based system with great potential for drug co-delivery.…”

Functional Mesoporous Silica Nanocomposites: Biomedical Applications and Biosafety

“…In addition to the strategy that employs Au embedded in a MS matrix, it is possible to carry out the opposite strategy, where Au particles are on the surface of regular MSNs. In addition to the expected greater sensitivity to stimulation with NIR, this strategy may simplify the gating process, as the AuNPs can act as nanogates [131]. This coating strategy was followed by Li et al to develop themoresponsive nanodevices with multimodal imaging possibilities using GNSts [132]; demonstrating their adequacy for multimodally, ultrasonically, tomographically, photoacoustically and photothermally induced imaging.…”