#$%^&*AU2020200576A120200213.pdf#####ABSTRACT The present invention provides, in part, a biodegradable compound of formula I, and subformulas thereof: Formula (I) or a pharmaceutically acceptable salt thereof, where each X independently is 0 or S, each Y independently is 0 or S, and each R, independently is defined herein； and a liposome composition comprising the cationic lipid of formula I or a sub-formula thereof, and methods of delivering agents, such as nucleic acids including mRNA, in vivo, by administering to a subject the liposome comprising the cationic lipid of formula I or a subformula thereof, where the agent is encapsulated within the liposome.
