Near-infrared-traceable DNA nano-hydrolase: specific eradication of telomeric G-overhang in vivo

Functionalized antibacterial peptide with DNA cleavage activity for enhanced bacterial disinfection

Antibiotics are commonly used to treat bacterial infections, but the misuse and abuse of antibiotics have given rise to a severe problem of the drug resistance of bacteria. Solving this problem has been a vitally important task in the modern medical arena. Antibacterial peptide (AMPs) has become a promising candidate drug to replace antibiotics because of their broad-spectrum antibacterial activity and their difficulty in making bacteria resistant. However, its wider clinical application is limited by the shortcomings of high cytotoxicity and low antibacterial efficiency. In this paper, we constructed an antibacterial peptide (Cu-GGH-KKLRKIAFK, abbreviated as Cu-GGH-AMP) with a DNA cleavage function. The peptide has two functional regions, the C-terminal antibacterial peptide PaDBS1R6F10 (KKLRLKIAFK) and the N-terminal Cu-GGH complex. PaDBS1R6F10 is a unique antibacterial peptide, which shows lower tendency to produce bacterial resistance than traditional antibiotics. Cu-GGG complexes are formed by chelating Cu with the classical amino terminal Cu (II)- and Ni (II) -Binding (ATCUN) motif GGH. In the presence of ascorbic acid, Cu-GGH can efficiently catalyze the oxidative cleavage of bacterial DNA, thus playing a synergistic antibacterial role with antibacterial peptides. The in vitro and in vivo experiments demonstrated this functionalized antibacterial peptide possesses excellent antibacterial and anti-skin infection capability, as well as the activity of promoting wound healing.

Orthogonal light-triggered multiple effects based on photochromic nanoparticles for DNA cleavage and beyond

Efficient and spatiotemporally controllable cleavage of deoxyribonucleic acid (DNA) is of great significance for both disease treatment (e.g. tumour, bacterial infection, etc) and molecular biology applications (e.g. gene editing). The recently developed light-induced cleavage strategy based on catalytic nanoparticles has been regarded as a promising strategy for DNA controllable cleavage. Although the regulation based on orthogonal light in biomedical applications holds more significant advantages than that based on single light, nanoparticle-mediated DNA cleavage based on orthogonal light has yet to be reported. In this article, for the first time, we demonstrated an orthogonal light-regulated nanosystem for efficient and spatiotemporal DNA cleavage. In this strategy, tungsten oxide (WO₃) nanoparticles with photochromic properties were used as nano-antennae to convert the photoenergy from the orthogonal visible light (405 nm) and near-infrared light (808 nm) into chemical energy for DNA cleavage. We verified that only the orthogonal light can trigger high cleavage efficiency on different types of DNA. Moreover, such an orthogonal light-response nano-system can not only induce significant apoptosis of tumour cells, but also effectively eliminate bacterial biofilms.

Nuclease-like metalloscissors: Biomimetic candidates for cancer and bacterial and viral infections therapy

Despite the extensive and rapid discovery of modern drugs for treatment of cancer, microbial infections, and viral illnesses; these diseases are still among major global health concerns. To take inspiration from natural nucleases and also the therapeutic potential of metallopeptide antibiotics such as the bleomycin family, artificial metallonucleases with the ability of promoting DNA/RNA cleavage and eventually affecting cellular biological processes can be introduced as a new class of therapeutic candidates. Metal complexes can be considered as one of the main categories of artificial metalloscissors, which can prompt nucleic acid strand scission. Accordingly, biologists, inorganic chemists, and medicinal inorganic chemists worldwide have been designing, synthesizing and evaluating the biological properties of metal complexes as artificial metalloscissors. In this review, we try to highlight the recent studies conducted on the nuclease-like metalloscissors and their potential therapeutic applications. Under the light of the concurrent Covid-19 pandemic, the human need for new therapeutics was highlighted much more than ever before. The nuclease-like metalloscissors with the potential of RNA cleavage of invading viral pathogens hence deserve prime attention.

A Topologically Engineered Gold Island for Programmed In Vivo Stem Cell Manipulation

E ven a well-designed system can only control stem cell adhesion, release, and differentiation, while other cell manipulations such as in situ labeling and retention in target tissues, are difficult to achieve in the same system. Herein, native ligand cluster-mimicking islands, composed of topologically engineered ligand, anchoring point AuNP, nuclease mimetics Ce IV complexes and magnetic core Fe 3 O 4 , are designed to facilitate comprehensive cell manipulations in a programmable manner. Three islands with different amounts of AuNPs are constructed, which means tunable interligand spacing within a cluster. These nanostructures are chemically coupled to a substrate using DNA tethers. Under tissue-penetrative magnetic field, this integrated system promotes stem cell adhesion, proliferation, mechanosensing, differentiation, detachment, in situ effective magnetic labeling and retention both in vitro and in vivo , offering fascinating opportunities for biomimetic matrix in regenerative medicine.