1525 chromatograph

Partial modification of PEG-b-PAsp with phenylboronic acid pinacol ester (PBE) was prepared according to the esterification reaction. First, PEG-b-PAsp was dissolved in anhydrous DMF at room temperature. According to the length of PAsp chain, PBE with proper molar ratio was added followed by DMAP addition, and the mixture solution was stirred at 40 °C for 12 h followed by being dialyzed against deionized water for 2 days in a dialysis bag with 3500DA cutoff. Finally, PEG-b-PAsp-g-PBE were obtained by lyophilizing the corresponding polymer solution (Hu et al., 2017 (link)). ¹H NMR spectra of the polymers were recorded on a Bruker 400 MHz nuclear magnetic resonance instrument using DMSO as the solvents. Gel permeation chromatography (GPC) was used to analyze the molecular weights and molecular weight distributions (Mw/Mn) of the polymers. GPC of PEG-b-PAsp was measured by a Waters 1525 chromatograph equipped with a Waters 2414 refractive index detector. The critical micelle concentration (CMC) of PEG-b-PAsp copolymers was determined according to the literature using pyrene as a hydrophobic fluorescent probe (Raimbault et al., 2018 ).

¹H NMR spectra of the polymers were recorded on a Bruker 400 MHz nuclear magnetic resonance instrument using DMSO as the solvents. Gel permeation chromatography (GPC) was used to analyze the molecular weights and molecular weight distributions (Mw / Mn) of the polymers. GPC of PEG-b-PAsp was measured at room temperature with a Waters 1525 chromatograph equipped with a Waters 2414 refractive index detector. H₂O was used as eluents with a low rate of 1.0 mL/min and narrowly distributed polyethyleneglycol was used as standard. The size and surface charge of the nanocarrier was investigated on Malvern ZetasizerNano ZS 90 zeta potential analyzer. Ultraviolet–visible (UV–vis) spectra were collected using a LAMBDA-35 spectrometer. CA4 loading content was calculated by measuring the UV–Vis absorbance at 290 nm.
Transmission electron microscopy (TEM) was performed on a JEOL-2100 with an accelerating voltage of 200 kV. TEM samples were prepared by drop-casting dispersion onto copper grids covered by carbon film. Confocal images were acquired using a Zeiss confocal laser scanning unit mounted on an LSM 710 fixed-stage upright microscope (CLSM).

¹H NMR spectra of the polymers were recorded on a Bruker 400 MHz nuclear magnetic resonance instrument using DMSO as the solvents. Gel permeation chromatography (GPC) was used to analyze the molecular weights and molecular weight distributions (Mw/Mn) of the polymers. GPC of PEG-b-PAsp was measured at room temperature with a Waters 1525 chromatograph equipped with a Waters 2414 refractive index detector. H₂O was used as eluents with a flow rate of 1.0 mL/min and narrowly distributed polyethylene glycol was used as standard. The size and surface charge of the nanocarrier was investigated on Malvern Zetasizer Nano ZS 90 zeta potential analyzer. Ultraviolet-visible (UV-vis) spectra were collected using a LAMBDA-35 spectrometer. Transmission electron microscopy (TEM) was performed on a JEOL-2100 with accelerating voltage of 200 kV. TEM samples were prepared by drop-casting dispersion onto copper grids covered by carbon film. Confocal images were acquired using a Zeiss confocal laser scanning unit mounted on an LSM 710 fixed-stage upright microscope (CLSM).