Characterization of CS-LO-PEG-HER Nanoparticles

A series of analytical methods were used to confirm the successful formation of CS-LO-PEG-HER NPs. The loading of LO and, functionalization of mAb (Anti-HER) were analyzed by FTIR (Fourier-transform infrared spectroscopy; PerkinElmer Paragon 500, Waltham, MA, USA) and NMR (Nuclear Magnetic Resonance; FT-NMR, Bruker, 600 MHz, MA, USA). For the FTIR analysis, the nanoparticle samples, including CS, PEG6000, LO, HER, CS-LO NPs, CS-LO-PEG NPs, and CS-LO-PEG-HER NPs, were prepared as KBr pellets using the standard sample preparation method, and the IR scanning was performed from the 400–4000 cm⁻¹. To determine the size and zeta potential of nanoparticles, DLS (Dynamic light scattering; zeta potential particle size analyzer Malvern, Eindhoven, The Netherland) and ELS (Electrophoretic light scattering) analysis were used. For the DLS/ELS analysis, 10 µg of each NPs was dissolved in 3 mL of DI water, sonicated for 2 min, and filtered using a 2 µm syringe filter. The filtered nanoparticle suspension was used for DLS analysis. Transmission electron microscopic (JEOL-JSM 1200EX, Tokyo, Japan) analysis was used to observe the morphology of nanoparticles. For TEM analysis, 10 µg of each NPs was dissolved in 1 mL of ethanol, sonicated for 2 min, and negative stained with 2% uranyl acetate then loaded into a copper grid for TEM observation [27 (link)].