Uv 3101pc spectroscope

The ultraviolet–visible (UV–vis) spectra of cRGD, PEG, and cRGD-PEG were recorded on a UV-3101PC spectroscope (Shimadzu, Japan). Electrospray-ionization mass spectrometry (LCQ Orbitrap XL, USA) was used to characterize the molecular weights of Por-R₆-CHO and its intermediate products. The gel permeation chromatography (GPC, Agilent 1200 Series, USA) with tetrahydrofuran as mobile phase was applied to determine the outflow time of cRGD-PEG, cPRP and cPRP at pH 5.0. The cPRP ¹H nuclear magnetic resonance (NMR) spectra were generated under different pH conditions using a Bruker DRX 600 MHz NMR spectrometer (USA) and hexadeuterated dimethyl sulfoxide (DMSO-d6). Transmission electron microscopy (TEM, Thermo Scientific Talos L120C, USA) was used to evaluate the morphology of the GNA002-loaded nanoparticles. The diameter, zeta potential, and PDI of the cPRP nanoparticles were measured by dynamic light scattering (DLS, Zetasizer Nano ZS, UK). High-performance liquid chromatography (HPLC, AB Sciex Quadrupole 5500, USA) was performed using a C18 4.6 × 250-mm column to determine the GNA002 concentration in the GNA002@cPRP nanoparticles.