Fluorescent Turn-On Probes for Visualizing GPx4 Levels in Live Cells and Predicting Drug Sensitivity.

Glutathione peroxidase 4 (GPx4) is the membrane peroxidase in mammals that is essential for protecting cells against oxidative damage and critical for ferroptosis. However, no live cell probe is currently available to specifically label GPx4. Herein, we report both inhibitory and noninhibitory fluorescent turn-on probes for specific labeling of GPx4 in live cells. With these probes, the GPx4 expression levels and degradation kinetics in live cells could be visualized, and their real-time responses to the cellular selenium availability were revealed. These probes could also potentially serve as staining reagents to predict the sensitivity of GPx4-related ferroptosis drugs. In view of these features, these GPx4-selective probes will offer opportunities for a deeper understanding of GPx4 function in natural habitats and hold great promise for biomedical applications.

Digital Numbers Constructed by Fine Patterned Polydopamine on DNA Templates.

Using DNA nanostructures as templates to synthesize shape-controlled polydopamine (PDA) is a promising strategy to realize the fabrication of exquisite PDA nanomaterials. However, previous studies using small DNA tiles as templates could only afford very simple structures such as lines and crosses due to the limited space on the template and the relatively low resolution of the PDA nanopatterns. Therefore, the best resolution of the PDA nanostructures that can be achieved by this technique is carefully investigated. And by connecting several DNA tiles together, larger DNA templates are built up and achieve the synthesis of complicated digital nanopatterned PDA structures.

In situ synthesis of fluorescent polydopamine on biogenic MnO2 nanoparticles as stimuli responsive multifunctional theranostics.

Multifunctional nanocomposites have drawn great attention in clinical applications because of their ability to integrate diagnostic and therapeutic functions. Manganese dioxide (MnO2), owing to its biocompatibility and magnetic resonance imaging (MRI) properties, has been widely applied in biomedical research. Our previous work on biogenic MnO2 nanoparticles (Bio-MnO2 NPs) revealed that intrinsic photothermal properties and stimuli-responsive MRI imaging are particularly promising for the development of theranostic systems. However, further improvement in the photothermal therapy (PTT) performance of Bio-MnO2 NPs is still required. Herein, we have improved the PTT efficiency of Bio-MnO2 NPs by in situ synthesis of fluorescent polydopamine (PDA) while generating additional stimuli responsive fluorescence properties in this system, thus further broadening the scope of their theranostic functions. These synthesis conditions are mild and green. The fluorescence of PDA was quenched by capping Bio-MnO2 NPs and could be recovered upon degradation of Bio-MnO2 NPs inside tumour cells. Additionally, Mn2+ released from the nanoparticles can support T1-weighted MR imaging. Compared to the Bio-MnO2 NPs alone, the integration of Bio-MnO2 NPs and PDA significantly enhances the photothermal performance in vitro and in vivo. With their high biocompatibility, these multifunctional composite nanodevices hold great potential for fluorescence imaging and MRI-guided photothermal therapy.

Functional DNA-Polymer Conjugates.

DNA nanotechnology has seen large developments over the last 30 years through the combination of solid phase synthesis and the discovery of DNA nanostructures. Solid phase synthesis has facilitated the availability of short DNA sequences and the expansion of the DNA toolbox to increase the chemical functionalities afforded on DNA, which in turn enabled the conception and synthesis of sophisticated and complex 2D and 3D nanostructures. In parallel, polymer science has developed several polymerization approaches to build di- and triblock copolymers bearing hydrophilic, hydrophobic, and amphiphilic properties. By bringing together these two emerging technologies, complementary properties of both materials have been explored; for example, the synthesis of amphiphilic DNA-polymer conjugates has enabled the production of several nanostructures, such as spherical and rod-like micelles. Through both the DNA and polymer parts, stimuli-responsiveness can be instilled. Nanostructures have consequently been developed with responsive structural changes to physical properties, such as pH and temperature, as well as short DNA through competitive complementary binding. These responsive changes have enabled the application of DNA-polymer conjugates in biomedical applications including drug delivery. This review discusses the progress of DNA-polymer conjugates, exploring the synthetic routes and state-of-the-art applications afforded through the combination of nucleic acids and synthetic polymers.

Fine Customization of Calcium Phosphate Nanostructures with Site-Specific Modification by DNA Templated Mineralization.

Calcium phosphate (Ca-P) is the most abundant biomineral in hard tissues with diverse microstructures, which in nature ensure a broad range of functionalities with virtually similar and simple chemical compositions. Artificial fabrication of rationally designed Ca-P materials with arbitrary microstructures is a long-standing challenge for inorganic chemists. Although DNA nanotechnology has been elegantly used to modulate the nanofabrication of inorganic materials because of its programmability, encoding customized Ca-P mineralization with high structural precision remains unachievable because of fast affinity-driven crystal growth. Herein, this long-standing ambition has been skillfully fulfilled by taking advantage of crystallization via a particle attachment (CPA) process. The derived hybrid materials not only well inherited the structural details encoded by the DNA template but also exhibited significantly enhanced mechanical strength, even after heating. Moreover, this method preserved preinstalled synthetic functionalities on the DNA surface, allowing for downstream site-specific modification.