| 主权项 |
1. A composition, the composition comprising a sterol; a neutral lipid; a PEG or a PEG-modified lipid; and a lipid of formula (I) wherein, each Xa and Xb, for each occurrence, is independently C1-6 alkylene; n is 0, 1, 2, 3, 4, or 5; A for each occurrence is NR2 or a cyclic moiety optionally substituted with 1-3 R; B is NR or a cyclic moiety optionally substituted with 1-2 R; each R is independently H, alkyl,provided that at least one R is R1, for each occurrence, is independently H, R3, R2, for each occurrence, is independently, alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, or heteroalkynyl; each of which is optionally substituted with one or more substituent; R3, for each occurrence, is independently, alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, or heteroalkynyl; each of which is optionally substituted with one or more substituent (e.g., a hydrophilic substituent); Y, for each occurrence, is independently O, NR4, or S; and R4, for each occurrence is independently H alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, or heteroalkynyl; each of which is optionally substituted with one or more substituent. |
