Lipid particle, nucleic acid transfer carrier, compound for manufacturing nucleic acid transfer carrier, method for manufacturing lipid particle, and gene transfer method

A lipid particle comprising, as constituents:

• a phospholipid having one or more amino groups and one or more nitrogen-containing heterocyclic groups;
• a neutral lipid not containing a nitrogen-containing heterocyclic group;
• a sterol;
• and
• a nucleic acid,
• wherein the phospholipid having one or more amino groups and one or more nitrogen-containing heterocyclic groups is a lipid represented by the following Formula (I) or a salt thereof,
• in Formula (I), X represents an oxygen atom or a sulfur atom;
• Y represents a hydrophobic group;
• each of W and V independently represents a single bond, —O—, —NH—, —CO—, or a linking group as a combination of these;
• each of R1 and R2 independently represents a hydrogen atom or an alkoxycarbonyl group having 1 to 4 carbon atoms;
• each of R3 and R4 independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, an alkoxycarbonyl group having 1 to 4 carbon atoms, an aminoalkyl group having 1 to 4 carbon atoms, a guanidinoalkyl group having 1 to 4 carbon atoms, or an imidazolylalkyl group having 4 to 7 carbon atoms;
• each of R5 and R6 independently represents a hydrogen atom, an amino group, or an alkoxycarbonyl group having 1 to 4 carbon atoms;
• when n is 1, at least one of R5 and R6 represents an amino group;
• when n is an integer from 2 to 4, at least one of the plural R5s and plural R6s contained in Formula (I) represents an amino group;
• l represents an integer from 2 to 4;
• m represents an integer from 0 to 4;
• and n represents an integer from 1 to 4.