Wenqian Wang

Highly efficient remote controlled release system based on light-driven DNA nanomachine functionalized mesoporous silica

An intelligent photoswitchable single-molecule nanomachine with DNA hairpin-loop structure was designed by the incorporation of azobenzene groups in DNA sequences, which was studied by fluorescence resonance energy transfer (FRET) and attached onto the surface of mesoporous silica. Based on the photo-induced conformational transformation of DNA, highly efficient controlled release was realized.

Recent Advance on Mesoporous Silica Nanoparticles-Based Controlled Release System: Intelligent Switches Open up New Horizon

Mesoporous silica nanoparticle (MSN)-based intelligent transport systems have attracted many researchers’ attention due to the characteristics of uniform pore and particle size distribution, good biocompatibility, high surface area, and versatile functionalization, which have led to their widespread application in diverse areas. In the past two decades, many kinds of smart controlled release systems were prepared with the development of brilliant nano-switches. This article reviews and discusses the advantages of MSN-based controlled release systems. Meanwhile, the switching mechanisms based on different types of stimulus response are systematically analyzed and summarized. Additionally, the application fields of these devices are further discussed. Obviously, the recent evolution of smart nano-switches promoted the upgrading of the controlled release system from the simple “separated” switch to the reversible, multifunctional, complicated logical switches and selective switches. Especially the free-blockage switches, which are based on hydrophobic/hydrophilic conversion, have been proposed and designed in the last two years. The prospects and directions of this research field are also briefly addressed, which could be better used to promote the further development of this field to meet the needs of mankind.

A Selective Release System Based on Dual‐Drug‐Loaded Mesoporous Silica for Nanoparticle‐Assisted Combination Therapy

A selective release system was demonstrated with a dual-cargo loaded MSNs. When stimulated by different signals (UV or H(+)), this system could selectively release different kinds of cargoes individually. Furthermore, this system has been used to provide a combination of chemotherapy and biotherapy for cancer treatment. This controlled release system could be an important step in the development of more effective and sophisticated nanomedicine and nanodevices, due to the possibility of selective release of a complex multi-drug.

A free-blockage controlled release system based on the hydrophobic/hydrophilic conversion of mesoporous silica nanopores.

A pH-responsive free-blockage release system was achieved through controlling the hydrophobic/hydrophilic conversion of mesoporous silica nanopores. This system further presented pulsatile release with changing pH values between 4.0 and 7.0 for several cycles. This free-blockage release system could also release antitumor agents to induce cell death after infecting tumor cells and could have the ability of continuous infection to tumor cells with high drug-delivery efficiency and few side effects.

Dual-cargo selectively controlled release based on a pH-responsive mesoporous silica system.

A pH-controlled delivery system based on mesoporous silica nanoparticles (MSNs) was constructed for dual-cargo selective release. To achieve a better controlled-release effect, a modified sol-gel method was employed to obtain MSNs with tunable particle and pore sizes. The systems selectively released different kinds of cargo when stimulated by different pH values. At the lower pH value (pH 2.0) only one kind of cargo was released from the MSNs, whereas at a higher pH value (pH 7.0) only the other kind of cargo was released from the MSNs. The multi-cargo delivery system has brought the concept of selective release to new advances in the field of functional nanodevices and allows more accurate and controllable delivery of specific cargoes, which is expected to have promising applications in nanomedicine.

A Versatile Multiple Target Detection System Based on DNA Nano-assembled Linear FRET Arrays

DNA molecules have been utilized both as powerful synthetic building blocks to create nanoscale architectures and as inconstant programmable templates for assembly of biosensors. In this paper, a versatile, scalable and multiplex detection system is reported based on an extending fluorescent resonance energy transfer (FRET) cascades on a linear DNA assemblies. Seven combinations of three kinds of targets are successfully detected through the changes of fluorescence spectra because of the three-steps FRET or non-FRET continuity mechanisms. This nano-assembled FRET-based nanowire is extremely significant for the development of rapid, simple and sensitive detection system. The method used here could be extended to a general platform for multiplex detection through more-step FRET process.

pH-Responsive nano sensing valve with self-monitoring state property based on hydrophobicity switching

Nano valves have been used in functional porous materials to control molecular transport by changing their properties in response to external stimuli. But most of them are limited by the blocking units and cannot show their state by themselves. Herein, pH switchable nano valves were constructed using mesoporous inverse opal photonic crystal, which realized free-blockage nano valves and achieved the monitoring of the state of the valve by the naked eye without an external indicator. The nano valves were modified by phenylamine groups, which has a convertible hydrophobic/hydrophilic property between deprotonation and protonation. The valves were hydrophobic enough to prevent solution passing through at pH 7.0, and meanwhile a green color was presented. With the decrease of the pH value of the solution, the valves became open and presented a yellow to red color because of the protonation of phenylamine groups followed by the invasion of solution. Thus, in this study not only a free-blockage valve but also nano sensing valve was constructed. We believe that our studies provide new insights into photonic crystal sensors and nano sensing valve.

Voltage-Responsive Controlled Release Film with Cargo Release Self-Monitoring Property Based on Hydrophobicity Switching

Herein, voltage-responsive controlled release film was constructed by grafting ferrocene on the mesoporous inverse opal photonic crystal (mIOPC). The film achieved free-blockage controlled release and realized the monitoring of cargo release without external indicator. Free-blockage was attributed to the voltage switchable nanovalves which undergo hydrophobic-to-hydrophilic transition when applying voltage. Monitoring of cargo release was attributed to the optical property of mIOPC, the bandgap of mIOPC had a red shift when the solution invaded in. The film was hydrophobic enough to stop solution intrusion. Once the voltage was applied, the film became hydrophilic, leading to invasion of the solution. As a result, the cargos were released and the bandgap of mIOPC was red-shifted. Therefore, in this paper both a free-blockage controlled release film and a release sensing system was prepared. The study provides new insights into highly effective controlled release and release sensing without indicator.

Enrichment and Viability Inhibition of Circulating Tumor Cells on a Dual Acid‐responsive Composite Nanofiber Film

The formation and metastatic colonization of circulating tumor cells (CTCs) are responsible for the vast majority of cancer‐related deaths. Over the last decade, drug‐delivery systems (DDSs) have rapidly developed with the emergence of nanotechnology; however, most reported tumor‐targeting DDSs are able to deliver drugs only to solid tumor cells and not CTCs. Herein, a novel DDS comprising a composite nanofiber film was constructed to inhibit the viability of CTCs. In this system, gold nanoparticles (Au NPs) were functionalized with doxorubicin (DOX) through an acid‐responsive cleavable linker to obtain Au‐DOX NPs. Then, the Au‐DOX NPs were mixed in a solution of an acid‐responsive polymer {i.e., poly[2‐(dimethylamino)ethyl methacrylate]} to synthesize the nanofiber film through electrospinning technology. After that, the nanofiber film was modified with a specific antibody (i.e., anti‐EpCAM) to enrich the concentration of CTCs on the film. Finally, the Au‐DOX NPs were released from the nanofiber film, and they consequently inhibited the viability of CTCs by delivering DOX to the enriched CTCs. This composite nanofiber film was able to decrease the viability of CTCs significantly in the suspended and fluid states, and it is expected to limit the migration and proliferation of tumor cells.