METHODS TO QUANTIFY ANTIBODY CONJUGATION TO ELECTROSPRAYED PLGA NANOPARTICLES VIA CARBODIIMIDE CHEMISTRY

The active targeting of polymeric nanoparticles (NPs) using antibodies enhances drug delivery by reducing systemic exposure and toxicity while improving bioavailability. Strategies like carbodiimide chemistry and physical adsorption have been widely studied, but methods for confirming antibody attachment and quantification remain inconsistent. This study evaluates the reliability of commonly used techniques, including the bicinchoninic acid (BCA) assay, Fourier-transformed infrared spectroscopy (FTIR), zeta potential, and enzyme-linked immunosorbent assay (ELISA). PLGA NPs were generated via one-step continuous electrospraying (ES). The BCA assay demonstrated a correlation between 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride (EDC) and N-hydroxy succinimide (NHS) concentrations and optical density, highlighting its utility in conjugation quantification. ELISA was then used to compare non-covalent (adsorption) and covalent (carbodiimide) binding methods. The findings confirm that carbodiimide chemistry results in higher antibody amount and activity than adsorption, reinforcing its suitability for targeted NP delivery.