A Voltage‐Responsive Free‐Blockage Controlled‐Release System Based on Hydrophobicity Switching

Abstract

Controlled-release systems based on mesoporous silica nanomaterials (MSNs) have drawn great attention owing to their potential biomedical applications. Various switches have been designed to control the release of cargoes through the construction of physical blocking units on the surface of MSNs. However, such physical blockages are limited by poor sealing ability and low biocompatibility, and most of them lack closure ability. Herein, a voltage-responsive controlled-release system was constructed by functionalizing the nanopore of MSNs with ferrocene. The system realized free-blockage controlled release and achieved pulsatile release. The nanopores of the ferrocene-functionalized MSNs were hydrophobic enough to prevent invasion of the solution. Once a suitable voltage was applied, the nanopores became hydrophilic, which was followed by invasion of the solution and the release of the cargos. Moreover, pulsatile release was realized, which avoided unexpected release after the stimulus disappeared. Thus, we believe that our studies provide new insight into highly effective blockage for MSNs. Furthermore, the voltage-responsive release system is expected to find use in electrical stimulation combination therapy and bioelectricity-responsive release.

Dual Stimuli‐Responsive Controlled Release Nanocarrier for Multidrug Resistance Cancer Therapy

“…To date, many mechanisms have been proposed to regulate the time, rate and location of the drugs . Recently, we developed a free‐blockage controlled release system by integrating water channel with mesoporous nanocarriers, which realized controlled releasing chemotherapeutic agents in tumor cells . However, multidrug resistance (MDR) of cancer cells is still a major issue affecting the therapeutic efficacy of nanocarriers.…”

Electro-responsive films containing voltage responsive gated mesoporous silica nanoparticles grafted onto PEDOT-based conducting polymer

“…In contrast, there are only few examples in which cargo delivery from mesoporous silica nanoparticles (MSNs) is induced by the application of a voltage. In this area, reported examples involve the use of MSNs functionalized with ferrocene derivatives and capped by an inclusion complex formed between a grafted ferrocene derivative and β-cyclodextrin (β-CD) [24][25][26][27]. However, the use of these ferrocene-based system in biological applications is somehow limited due to the relatively high potential needed (ca.…”

Controlling Release Kinetics of Payloads from Polymer Conjugates by Hydrophobicity

“…This feature has been used to control the release of 1‐butanol from ferrocene‐containing polymers by changing their hydrophobic/hydrophilic ratio . Pores of mesoporous silica nanomaterials were modified by grafting ferrocene silane to control payloads release by switching hydrophobicity upon application of an electrical field . Upon oxidation of ferrocene units, hydrophilicity of the pores increased, and water could diffuse into the pores to induce a release of trapped cargos.…”