In recent years, an increasing number of viruses have triggered outbreaks that pose a severe threat to both human and animal life, as well as caused substantial economic losses. It is crucial to understand the genomic structure and epidemiology of these viruses to guide effective clinical prevention and treatment strategies. Nanopore sequencing, a third-generation sequencing technology, has been widely used in genomic research since 2014. This technology offers several advantages over traditional methods and next-generation sequencing (NGS), such as the ability to generate ultra-long reads, high efficiency, real-time monitoring and analysis, portability, and the ability to directly sequence RNA or DNA molecules. As a result, it exhibits excellent applicability and flexibility in virus research, including viral detection and surveillance, genome assembly, the discovery of new variants and novel viruses, and the identification of chemical modifications. In this paper, we provide a comprehensive review of the development, principles, advantages, and applications of nanopore sequencing technology in animal and human virus research, aiming to offer fresh perspectives for future studies in this field.

Fruits are a rich source of polysaccharides, and an increasing number of studies have shown that polysaccharides from fruits have a wide range of biological functions. Here, we thoroughly review recent advances in the study of the bioactivities, structures, and structure-activity relationships of fruit polysaccharides, especially highlighting the structure-activity influencing factors such as extraction methods and chemical modifications. Different extraction methods cause differences in the primary structures of polysaccharides, which in turn lead to different polysaccharide biological activities. Differences in the degree of modification, molecular weight, substitution position, and chain conformation caused by chemical modification can all affect the biological activities of fruit polysaccharides. Furthermore, we summarize the applications of fruit polysaccharides in the fields of pharmacy and medicine, foods, cosmetics, and materials. The challenges and perspectives for fruit polysaccharide research are also discussed.

The synergistic effects of ultrafine grinding and enzymolysis (cellulase and Laccase hydrolysis) alone or combined with carboxymethylation or acetylation on the hypoglycemic and antioxidant activities of oil palm kernel fibre (OPKEF) were studied for the first time. After these synergistic modifications, the microstructure of OPKEF became more porous, and its soluble fibre and total polyphenols contents, and surface area were all improved (P < 0.05). Superfine-grinding and enzymolysis combined with carboxymethylation treated OPKEF exhibited the highest viscosity (13.9 mPa∙s), inhibition ability to glucose diffusion (38.18%), and water-expansion volume (3.58 mL∙g-1). OPKEF treated with superfine-grinding and enzymolysis combined with acetylation showed the highest surface hydrophobicity (50.93) and glucose adsorption capacity (4.53 μmol∙g-1), but a lower α-amylase-inhibition ability. Moreover, OPKEF modified by superfine-grinding and enzymolysis had the highest inhibiting activity against α-amylase (25.78%). Additionally, superfine-grinding and enzymolysis combined with carboxymethylation or acetylation both improved the content and antioxidant activity of OPEKF\'s bounding polyphenols (P < 0.05).

Nucleic acid aptamers, often termed \"chemical antibodies,\" are short, single-stranded DNA or RNA molecules, which are selected by SELEX. In addition to their high specificity and affinity comparable to traditional antibodies, aptamers have numerous unique advantages such as wider identification of targets, none or low batch-to-batch variations, versatile chemical modifications, rapid mass production, and lack of immunogenicity. These characteristics make aptamers a promising recognition probe for scientific research or even clinical application. Aptamer-functionalized nanomaterials are now emerged as a promising drug delivery system for various diseases with decreased side-effects and improved efficacy. In this review, the technological strategies for generating high-affinity and biostable aptamers are introduced. Moreover, the development of aptamers for their application in biomedicine including aptamer-based biosensors, aptamer-drug conjugates and aptamer functionalized nanomaterials is comprehensively summarized.

Recently, numerous studies have been conducted on renewable polymers derived from different natural sources, exploring their suitability for diverse biomedical applications. Lignin as one of the main components of lignocellulosic has garnered significant attention as a promising alternative to petroleum-based polymers. This interest is primarily due to its cost-effectiveness, biocompatibility, eco-friendly nature, as well as its antioxidant and antimicrobial properties. These characteristics could be more beneficial when incorporating lignin into the formulation of value-added products. Although lignin has a chemical structure that is suitable for various applications, these characteristics require modifications to guarantee that the resultant materials display the desired biological, chemical, and physical properties when applied in the creation of biodegradable hydrogels, particularly for biomedical purposes. This study delineates the recent modification approaches that have been employed in the creation of lignin-based hydrogels. These strategies encompass both chemical and physical interactions with other polymers. Additionally, this review encompasses an examination of the current applications of lignin hydrogels, spanning their use as scaffolds for tissue engineering, carriers for pharmaceuticals, materials for wound dressings and biosensors, and elements in flexible and wearable electronics. Finally, we delve into the challenges and constraints associated with these materials, discuss the necessary steps required to attain the appropriate properties for the development of innovative lignin-based hydrogels, and derive conclusions based on the presented findings.

Small interfering RNA (siRNA) delivery by nanocarriers has been identified as a promising strategy in the study and treatment of cancer. Short nucleotide sequences are synthesized exogenously to create siRNA, which triggers RNA interference (RNAi) in cells and silences target gene expression in a sequence-specific way. As a nucleic acid-based medicine that has gained popularity recently, siRNA exhibits novel potential for the treatment of cancer. However, there are still many obstacles to overcome before clinical siRNA delivery devices can be developed. In this review, we discuss prospective targets for siRNA drug design, explain siRNA drug properties and benefits, and give an overview of the current clinical siRNA therapeutics for the treatment of cancer. Additionally, we introduce the siRNA chemical modifications and delivery systems that are clinically sophisticated and classify bioresponsive materials for siRNA release in a methodical manner. This review will serve as a reference for researchers in developing more precise and efficient targeted delivery systems, promoting ongoing advances in clinical applications.

The chemical modifications (CMs) of protein is an important technique in chemical biology, protein-based therapy, and material science. In recent years, there has been rapid advances in the development of CMs of peptides and proteins, providing new approaches for peptide and protein functionalization, as well as drug discovery. In this review, we highlight the methods for chemically modifying tyrosine (Tyr) residues in different regions, offering a comprehensive exposition of the research content related to Tyr modification. This review summarizes and provides an outlook on Tyr residue modification, aiming to offer readers assistance in the site-selective modification of macromolecules and to facilitate application research in this field.

Licorice, a widely used traditional Chinese medicine, contains more than 300 flavonoids and more than 20 triterpenoids, which have potential medicinal value and can prevent the growth of tumor cells by blocking the cell cycle, affecting the regulation of the apoptosis gene of tumor cells, and inhibiting tumor cell angiogenesis. However, many of the compounds in licorice still have the drawbacks of poor solubility, significant toxic side effects, and low antitumor activity. This article reviews the structural modification of effective antitumor active ingredients in licorice, thus providing a theoretical basis for further investigation of licorice and the development of new antitumor drugs.

Chitin is a natural polymeric polysaccharide extracted from marine crustaceans, and chitosan is obtained by removing part of the acetyl group (usually more than 60 %) in chitin\'s structure. Chitosan has attracted wide attention from researchers worldwide due to its good biodegradability, biocompatibility, hypoallergenic and biological activities (antibacterial, immune and antitumor activities). However, research has shown that chitosan does not melt or dissolve in water, alkaline solutions and general organic solvents, which greatly limits its application range. Therefore, researchers have carried out extensive and in-depth chemical modification of chitosan and prepared a variety of chitosan derivatives, which have expanded the application field of chitosan. Among them, the most extensive research has been conducted in the pharmaceutical field. This paper summarizes the application of chitosan and chitosan derivatives in medical materials over the past five years.

Gene silencing is an important biological strategy for studying gene functions, exploring disease mechanisms and developing therapeutics. 8-17 DNAzyme is of great potential for gene silencing, due to its higher RNA-cleaving activity. However, it is not generally used in practice, due to its divalent cation dependence and poor understanding of its cellular mechanisms. To address these issues, we have explored its activity in vitro and in cells and found that it can cleave RNA substrates under the simulated physiological conditions, and its gene-silencing activity is additionally enhanced by its RNase H compatibility, offering both cleavage and antisense activities in cells. Further, chemical modifications can facilitate its stability, substrate binding affinity and gene-silencing activity. Our research results suggest that this DNAzyme can demonstrate high levels of activities for both actions in cells, making it a useful tool for exploring biomedical applications.