CRISPR/Cas9 system, which can perform gene editing efficiently and conveniently, has been favored and widely used in many fields, and its delivery method has attracted the attention of a large number of researchers at home and abroad. Extracellular vesicles (EVs), as natural nanoscale vectors from a wide range of sources, are an attractive delivery vector for the CRISPR/Cas9 system. Compared with conventional viral vectors or non-viral vectors, EVs have obvious advantages in terms of safety, capacity, penetration, targeting and modification potential, and are expected to be the best vectors for delivering the CRISPR/Cas9 system. The common delivery strategies and loading modes of CRISPR/Cas9 system are summarized, EVs are compared with other vectors, and the advantages of EVs in delivering CRISPR/Cas9 system, as well as the domestic and international research progress and applications are reviewed, with a view to providing assistance for the development of the gene editing delivery field.

OBJECTIVE: To investigate the role of Kupffer cells in acetaminophen (APAP)-induced drug-induced liver injury by using Cre/iDTR system to specifically reject Kupffer cells. METHODS: 1 μg of diphtheria toxin (DT) was injected intraperitoneally, and the clearance efficiency of hepatic Kupffer cells after injection was detected by flow cytometry. Then, Clec4fCre/iDTR mice were divided into 4 groups, namely, control group, DT injection group, APAP injection group and DT and APAP injection group, and 300 mg/kg APAP was injected intraperitoneally after 18 h of starvation to establish the model of acute drug-induced liver injury.

Messenger RNA (mRNA) vaccines, as a revolutionary biological product, have shown great potential in the prevention and treatment of infectious diseases. Compared with novel DNA vaccines, mRNA vaccines avoid the risk of genome integration, and their cell-free production significantly accelerates development and improves production efficiency compared with protein vaccines, which have been widely used. mRNA vaccines are able to encode multiple antigens, adapt to a variety of pathogen variants, and effectively stimulate strong immune responses with the dual functions of encoding antigens and adjuvants. However, further optimization of mRNA stability, immunogenicity and safety, as well as improvement of the efficiency of the delivery system, especially the application of lipid nanoparticles (LNPs), remain key challenges for the development of this technology. Globally, the successful application of mRNA vaccines in diseases such as neocollagenic infections has driven a new direction in vaccine development, heralding their potential role in the prevention and treatment of a wider range of diseases. Recent advances in sequence optimization strategies and delivery systems for mRNA vaccines as well as their applications in infectious diseases are reviewed, aiming to provide a comprehensive reference for future research and applications.

Abstract L-alanyl-L-glutamine (Ala-Gln) is an important dipeptide, which can be decomposed into L-glutamine (L-Gln) in vivo, and this amino acid has irreplaceable physiological and biochemical effects. The traditional chemical synthesis of Ala-Gln has the disadvantages of high pollution, low conversion rate, low purity, and the generation of toxic by-products, which limits its large-scale application. With the rapid development of biology, researchers have analyzed the synthesis mode of Ala-Gln and carried out targeted modification of bacterial strains, which opens a new era of green and efficient production of Ala-Gln. We mainly review the application of Ala-Gln, the research progress of Ala-Gln synthesis by traditional chemical and biological methods, and aim to explore how to use synthetic biology, genomics and other disciplines to modify the metabolic pathway of Ala-Gln to produce Ala-Gln efficiently, and to provide a theoretical basis for the industrialization of Ala-Gln.