According to the different reaction properties between chemical modifiers and proteins, modification reactions are mainly divided into acylation reactions, alkylation reactions, oxidation-reduction reactions, aromatic ring substitution reactions, etc., which chemically modify protein side chain groups such as amino, thiol, and carboxyl groups. Based on the different molecular weights, structures, and physicochemical properties of the modified compounds, including proteins, peptides, monoclonal antibody fragments, and small molecule compounds, the company adopts different polyethylene glycol modification techniques to modify these compounds. The modification methods include: 1. Random modification. Random modification of proteins often targets the ε - NH2 or α - NH2 of lysine. Due to the large amount of lysine in proteins, this modification causes multiple lysine residues to be modified in the protein, resulting in poly (lysine) as the product

Surface modification of gold nanoparticles is crucial in the field of biology, as it not only enhances their stability but also functionalizes their surface, making it easier to connect with biomolecules such as antibodies and enzymes. Commonly used thiol ligands are used to modify nano gold, such as glutathione (GSH), mercaptopropionic acid (MPA), cysteine, cysteine, dimercaptooctanoic acid (DHLA), and polyethylene glycol (PEG). Among them, the most common is mercapto polyethylene glycol (PEG-SH), which has the following advantages: 1. PEG is a polymer, and when PEG is modified onto nano gold particles, the stability of nano gold colloids will change from electrostatic stability to spatial stability, and the stable state is not easily affected by external factors; 2. PEG is antigen free, immunogenic, non-toxic, and has good biocompatibility; three

Polyethylene glycol modification, also known as PEGylation, is the chemical process of covalently coupling activated PEG to protein or peptide molecules. Since Davies modified bovine serum albumin with PEG in 1977, PEG modification technology is widely used for chemical modification of various proteins and peptides, and multiple PEG modified drugs have been launched or in clinical research. PEG modification has the advantages of prolonging half-life, reducing or disappearing immunogenicity, decreasing toxic side effects, and enhancing physical, chemical, and biological stability. Polymer polyethylene glycol (PEG) has irreplaceable advantages in protein modification due to its low toxicity, lack of antigenicity, good amphiphilicity, and biocompatibility, which have been recognized by the FDA. Polyethylene glycol modification technology couples polyethylene glycol with the modified drug through covalent bonds, improving the physicochemical properties and biological properties of the drug

Lipid nanoparticles (LNPs) are widely used as delivery vehicles for mRNA based COVID-19 vaccines. It has also shown good results in transmitting genetic information to the liver. However, accurately delivering packaged 'goods' to tissues outside of the liver remains a huge challenge. In a recent paper published in the Proceedings of the National Academy of Sciences (PNAS), Dr. Xu's team, along with partners from Harvard University and the University of Massachusetts, developed LNPs that can be precisely delivered to lung tissue. The treatment of mRNA transmitted through LNPs significantly reduced the disease burden of lymphangioleiomyomatosis in animal models. Research has shown that by altering the structure of lipid molecules that make up LNP, its tissue targeting specificity can be changed. Through screening the lipid molecule compound library, Dr. Xu

Lipid nanoparticles (LNPs)are delivery vehicles for currently two widely used mRNA COVID-19 vaccines. It has also shown good results in delivering genetic information to the liver. However, precise delivery of packaged goods into tissues other than the liver remains a challenge. Ina recent paperpublished recently in the Proceedings of the National Academy of Sciences (PNAS), Dr. Qiaobing Xu's group in the Department of Bioengineering at Tufts University, along with partners at Harvard Univer

药物载运系统是药学的重要研究内容之一。常见的药物载体有脂质体、病毒、脂质微球、多聚复合物及蛋白多肽类等。控释和靶向脂质体制剂是目前药物运载系统的研究热点。脂质体具有低毒、易制备、既能作为水溶性药物的载体又能作为脂溶性药物的载体、适用于多种给药途径、提高药物的稳定性、实现靶向性给药等优点。但是当脂质体进入体内后,由于血浆中的调理素对脂质体的特异性调理作用,以及网状内皮系统(RES)细胞与脂质体的非特异性疏水作用,使其易被RES细胞摄取、清除,在血液循环中的半衰期较短(一般为30min),主动靶向性和稳定性较差,其应用受