Patent ID: 8729258

Claim:
A compound having a structure according to Formula III: wherein L 1 , L 2 , L 3 , L 4 , L 5 , L 6 , L 7 , L 8 , L 9 and L 10 are linker groups independently selected from substituted or unsubstituted ethyl; R 1 , R 2 , R 3 and R 4 are members independently selected from H, an enzymatically labile group, a hydrolytically labile group, a metabolically labile group and a single negative charge; R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 , R 14 , R 15 and R 16 are H; L 11 is a linker moiety selected from substituted or unsubstituted heteroalkyl and substituted or unsubstituted alkyl; and X is a reactive functional group selected from an amine, a carboxylic acid, a maleimidyl, a thiazolidyl, a substituted or unsubstituted NHS ester, a sulfonated NHS ester, a succinimidyl, an isocyanate, and an isothiocyanate moiety.