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 millable polyurethane rubber, preparation method and use thereof. Raw materials thereof comprise the following ingredients in part by weight: polyester diol 100 parts; micromolecular diol 2-10 parts; diisocyanate 5-20 parts; antioxidant 0.1-0.5 part; catalyst 0.03-0.08 part; peroxide 1-1.5 parts and/or sulfur 1-1.5 parts. By structural design and formula adjustment, the millable polyurethane rubber has better low temperature resistance and gas permeability compared with conventional millable polyurethane rubbers, by using special micromolecular diol, synthesizing with polyester diol at a specific ratio and vulcanizing with peroxide or sulfur, molecular strands of the polyurethane have excellent smoothness and strong interaction forces, the millable polyurethane rubber has at the same time characteristics such as time good low temperature compression set, low gas permeability and high mechanical strength and can be used in manufacturing of films in scuba suspension systems.