Abstract: A novel type of cationic lipid and PEGylated derivative thereof, a cationic liposome and a cationic liposome-nucleic acid pharmaceutical composition containing the cationic lipid and formulation thereof include an ionizable lipid compound of the general formula (1). This compound is slightly ionized or neutral at physiological pH but undergoes greater ionization under acidic conditions, exhibiting lower toxicity in the systemic circulation and improved endosomal escape ability. The compound's polar head contains an ionizable tertiary amine group along with a side chain containing functional groups, while the tail chains may include linking groups that are easily degraded. Cationic liposomes containing the compound have a better ability to complex with nucleic acid drugs, higher stability in serum, no apparent cytotoxicity, and high transfection efficiency.

Abstract: A novel cationic lipid having a structure as represented by general formula (1), which specifically relates to a nitrogen-containing cationic lipid, and also relates to a liposome containing the cationic lipid, a liposome pharmaceutical composition containing said cationic lipid, preparation and application thereof. A cationic liposome containing the cationic lipid represented by formula (1), can improve the loading rate and transport rate of drugs, particularly nucleic acid drugs. The terminus of the novel cationic lipid can contain a fluorescent group or a targeting group, so that the cationic liposome pharmaceutical composition containing the cationic lipid can have fluorescent or targeting function.

Abstract: The monofunctional branched poly(ethylene glycol) (PEG) has a general formula shown in formula (1), and the bio-related substance modified by the monofunctional branched PEG has a general formula shown in formula (2), wherein X1 and X2 are each independently a hydrocarbon group having 1 to 20 carbon atoms, n1 and n2 are each independently an integer selected from 1 to 1000, n3 is an integer selected from 11 to 1000, L1, L2 are each independently a linking group, p is 0 or 1, q is 0 or 1, R1 is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, D is a bio-related substance, Z is a linking group, and Z can react with the bio-related substance to form a residue group L3. The PEG-modified bio-related substance maintains good biological activity, and has better solubility and a longer half-life in vivo.

Abstract: The monofunctional branched poly(ethylene glycol) (PEG) has a general formula shown in formula (1), and the bio-related substance modified by the monofunctional branched PEG has a general fomula shown in formula (2), wherein X1 and X2 are each independently a hydrocarbon group having 1 to 20 carbon atoms, n1 and n2 are each independently an integer selected from 1 to 1000, n3 is an integer selected from 11 to 1000, L1, L2 are each independently a linking group, p is 0 or 1, q is 0 or 1, R1 is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, D is a bio-related substance, Z is a linking group, and Z can react with the bio-related substance to form a residue group L3. The PEG-modified bio-related substance maintains good biological activity, and has better solubility and a longer half-life in vivo.