Faming Wang

Nanozyme Decorated Metal–Organic Frameworks for Enhanced Photodynamic Therapy

Metal-organic frameworks (MOFs) have been used for photodynamic therapy (PDT) of cancers by integrating photosensitizers, which cause cytotoxic effects on cancer cells by converting tumor oxygen into reactive singlet oxygen (1O2). However, the PDT efficiency of MOFs is severely limited by tumor hypoxia. Herein, by decorating platinum nanozymes on photosensitizer integrated MOFs, we report a simple yet versatile strategy for enhanced PDT. The platinum nanoparticles homogeneously immobilized on MOFs possess high stability and catalase-like activity. Thus, our nanoplatform can facilitate the formation of 1O2 in hypoxic tumor site via H2O2-activated evolvement of O2, which can cause more serious damage to cancer cells. Our finding highlights that the composites of nanozymes and MOFs have the potential to serve as efficient agents for cancer therapy, which will open an avenue of nanozymes and MOFs toward biological applications.

Programmable Downregulation of Enzyme Activity Using a Fever and NIR‐Responsive Molecularly Imprinted Nanocomposite

A fever and NIR-responsive molecularly imprinted nanocomposite is designed for programmable downregulation of enzyme activity. The target enzyme can be captured specifically and its activity can be downregulated only when body temperature increases abnormally. Upon NIR irradiation, the temperature of the destination region can increase accordingly inducing a further decrease in the enzyme activity.

Light‐Mediated Reversible Modulation of ROS Level in Living Cells by Using an Activity‐Controllable Nanozyme

Nanozymes have shown great potential in bioapplications owing to their low cost, high stability, multiple activity, and biocompatibility. However, most of the known nanozymes are always at turn-on state, hindering their further applications. Herein, a simple and versatile method for constructing activity-controllable nanozymes is presented. To the best of our knowledge, this is the first report to utilize the light-driven isomerization of azobenzene (Azo) and host-guest interaction to reversibly photoregulating the activity of nanozyme. Gold nanoparticles as a typical catalase-mimic nanozyme are used in this design. The expanded Azo-modified mesoporous silica is employed as supported material to encapsulate and disperse Au nanoparticles, which further combines with cyclodextrin (CD). The catalytic activity of the nanozyme is blocked by CD and can be activated or inhibited reversibly by UV or visible light. The results indicated that the nanozyme can reversibly regulate reactive oxygen species (ROS) level in extracellular and intracellular environment for multiple cycles and change cell viability by simply changing the irradiated light. This is a general method and can be adapted to construct various smart nanozymes with highly spatiotemporal resolution.

Designed heterogeneous palladium catalysts for reversible light-controlled bioorthogonal catalysis in living cells

As a powerful tool for chemical biology, bioorthogonal chemistry broadens the ways to explore the mystery of life. In this field, transition metal catalysts (TMCs) have received much attention because TMCs can rapidly catalyze chemical transformations that cannot be accomplished by bio-enzymes. However, fine controlling chemical reactions in living systems like bio-enzymes is still a great challenge. Herein, we construct a versatile light-controlled bioorthogonal catalyst by modifying macroporous silica-Pd0 with supramolecular complex of azobenzene (Azo) and β-cyclodextrin (CD). Its catalytic activity can be regulated by light-induced structural changes, mimicking allosteric regulation mechanism of bio-enzymes. The light-gated heterogeneous TMCs are important for in situ controlling bioorthogonal reactions and have been successfully used to synthesize a fluorescent probe for cell imaging and mitochondria-specific targeting agent by Suzuki–Miyaura cross-coupling reaction. Endowing the bioorthogonal catalyst with new functions is highly valuable for realizing more complex researches in biochemistry.Fine controlling chemical reactions over transition metal catalysts in living systems like enzymes remains a challenge. Here, the authors develop a versatile light-controlled bioorthogonal catalyst by modifying macroporous silica-Pd0 with supramolecular complex of azobenzene and β-cyclodextrin.

Metal-Ion-Activated DNAzymes Used for Regulation of Telomerase Activity in Living Cells

Telomerase is a key regulator in cell metabolism, tissue renewal, and organismal lifespan. Here we develop a simple strategy to modulate cellular telomerase activity, and further control cell fate based on Mg2+ - and Zn2+ -activated DNAzymes in living cells. Through modulation of telomerase activity, we can regulate cell behavior, including cell migration, cell differentiation, cell senescence, and cell cycle. Our work provides a new way to modulate telomerase activity in living cells by using DNAzymes.

Hydrogen-producing hyperthermophilic bacteria synthesized size-controllable fine gold nanoparticles with excellence for eradicating biofilm and antibacterial applications

Herein, we employed the hydrogen-producing hyperthermophilic bacterial strain Caldicellulosiruptor changbaiensis for preparing uniform and size-tunable gold nanoparticles (AuNPs). Compared with the commonly used chemically synthesized nanoparticles, the biological synthesis of nanoparticles appears to be a suitable process since it has a low manufacturing cost of scalability, good biocompatibility, and better nanoparticles stabilization. The produced AuNPs possessed a unique property, whereby the smallest AuNPs exhibited the highest peroxidase activity over a broad pH range, even at neutral pH, which was quite different from the commonly chemical-synthesized ones. Also, when the size of AuNPs increased, the peroxidase activity of B-AuNPs at neutral pH decreased. Owing to the excellent antibacterial capability of ROS, the AuNPs exhibited striking antibacterial properties against both Gram-positive and Gram-negative bacteria, and moreover, the AuNPs showed excellent ability to disperse bacterial biofilms both in vitro and in vivo. Our studies indicate that living bacterial cells, as a biosynthesizer, can synthesize size-controllable AuNPs with improved bioactivity. This work may promote the design and synthesis of other types of metal nanoparticles with defined properties for future applications.