Patent ID: 8293214

Claim:
A compound of formula: M-S-T wherein: M represents a phospholipid capable of associating with an envelope of a gas-filled microvesicle; T represents a component comprising a targeting ligand selected from the group consisting of peptides, proteins and antibodies; and S represents a component comprising a group of formula (I): —R 1 —SO 2 -A-SO 2 —R 2 —X— (I) Where: R 1 and R 2 independently represent a moiety selected from the group consisting of: —(CH 2 ) m —, —R 3 —(CH 2 ) m —*, —(CH 2 ) m —NH—* and —(CH 2 ) m —NH—CO—(CH 2 ) n — where m and n are independently an integer of from 1 to 6, the symbol * identifies the bond linking to the respective SO 2 group and R 3 is an arylene group; A represents a moiety selected from the group consisting of —(CH 2 ) p —, —(CH 2 ) p —[O—(CH 2 ) q ] r , —(CH 2 ) s —, —(CH 2 ) p —R 4 —(CH 2 ) r —, —(CH 2 ) p —NH—R 4 —(CH 2 ) r —, —(CH 2 ) p —O—R 4 —(CH 2 ) r —, and —[(CH 2 ) p —NH] q —, where p and r are independently an integer of from 1 to 6, q is an integer of from 2 to 6, s is an integer of from 0 to 6 and R 4 is an arylene group; and X represents a bond or a group of formula: —Z—R 5 —SO 2 -A′-SO 2 —R 6 — where: Z represents a moiety of formula: —Z′—(CH 2 ) t —[O—(CH 2 ) u —] v —(CH 2 ) w —Z″— where: Z′ and Z″ represent a bond or a group formed by the reaction of two reactive binding moieties; t and v are independently an integer of from 1 to 6, u is an integer of from 2 to 6 and w is an integer of from 0 to 6; R 5 and R 6 independently represent a moiety selected from the group consisting of: —(CH 2 ) m′ —, —(CH 2 ) m′ —NH—* and —(CH 2 ) m′ —NH—CO—(CH 2 ) n′ — where m′ and n′ are independently an integer of from 1 to 6 and * indicates the bond linking to the respective SO 2 group; and A′ represents a moiety selected from the group consisting of: —(CH 2 ) p′ —, —(CH 2 ) p′ —[O—(CH 2 ) q′ ] r′ —(CH 2 ) s′ —, —(CH 2 ) p′ —R 7 —(CH 2 ) r′ —, —(CH 2 ) p′ —NH—R 7 —(CH 2 ) r′ —, —(CH 2 ) p′ —O—R 7 —(CH 2 ) r′ —, and —[(CH 2 ) p′ —NH] q′ —, where p′ and r′ are independently an integer of from 1 to 6, q′ is an integer of from 2 to 6, s′ is an integer of from 0 to 6 and R 7 is an arylene.