Amino-dPEG®₁₂-Tris(-dPEG®₂₄-t-butyl ester)₃

Amino-dPEG®12-Tris(dPEG®24-t-butyl ester)3, product number QBD-11449, is a branched, four-arm, single molecular weight, discrete-length polyethylene glycol (dPEG®) product. Built around a tris core, the product consists of a carboxylate-reactive, medium-length (40 atoms) amino-dPEG®12 tail joined to one side of the tris core and three, equally long (76 atoms) tert-butyl-ester-protected dPEG®24 branches. The total length from the terminal, carboxylate-reactive amine tail to the carbonyl carbons on the branches is 126 atoms (102.8 Å, average).

Amino-dPEG®12-Tris(dPEG®24-t-butyl ester)3 increases the hydrodynamic volume and water solubility of conjugates made with it. The increased hydrodynamic volume protects conjugates from renal clearance and can shield them from the immune system.

The tert-butyl-ester-protected dPEG®24 branches can be deprotected with trifluoroacetic or formic acid. Once deprotected, the free carboxylic acids can be used for charge modification of the conjugate molecule or further functionalized for additional reactions. In addition to conjugate charge modification, potential uses for this product include PK/BD optimization of biomolecules, surface coating and passivation to prevent non-specific interactions, dendrimer construction, and payload delivery (cytotoxins, targeting molecules, etc.).