Figure 1.

Reaction schemes to prepare targeted PLGA NP.

Notes: (A) Carbodiimide method, where EDC/sulfo-NHS was used as the cross-linker. COOH terminated PLGA reacts with EDC/sulfo-NHS to form NHS-ester that reacts with antibody to obtain a stable amide bond. (B) Using BS3 spacer, where covalent amide bond is formed between ligand and BS3 molecules embedded on pre-activated NPs’ surface. This method is applicable for both ester and COOH terminated PLGA NPs.

Abbreviations: PLGA, poly(d, l-lactide co-glycolide); NP, nanoparticle; EDC, carbodiimide hydrochloride; NHS, N-hydroxysuccinimide; COOH, carboxylic acid; BS3, bis(sulfo-succinimidyl) suberate.