RP-HPLC analysis using intact method was performed based on a previous protocol . In brief, the analysis was conducted using a BioResolve RP mAb polyphenyl 2.7 µm 2.1 × 150 mm column from Waters, Inc., USA, on an Agilent 1260 HPLC system. This system was equipped with a binary gradient pump, a temperature-controlled column compartment, an autosampler, and a diode array detector. The operational conditions were set as follows: a flow rate of 0.4 mL/min at 70 °C, with mobile phase A (MPA) comprising 0.1% trifluoroacetic acid (TFA) in water, and mobile phase B (MPB) containing 0.1% TFA in acetonitrile. Absorbance was monitored at 280 nm, using a reference wavelength of 450 nm. Separately, absorbance was monitored at 570 nm, using a reference wavelength of 543 nm. A volume of 20 μL of the modified proteinfied was injected into the system for each analysis. The elution profile included a 2-minute linear gradient from 5% to 30% MPB, a 22-minute linear gradient from 30% to 95% MPB, followed by a 3minute wash with 95% MPB, and concluded with a 8-minute re-equilibration at 5% MPB.