Avvance drx 400 nmr spectrometer

The transactivating transcriptional activator (TAT) peptide (YGRKKRRQRRRC) with purity ≥97% was purchased from ChinaPeptides Co., Ltd. (Shanghai, China). Taxol injection was obtained from Yangtze River Pharmaceutical (Group) Co., Ltd. (Jiangsu, China). Hochest33342 and 4% paraformaldehyde were provided by Solarbio Science and Technology Co., Ltd. (Beijing, China). Acetonitrile for high-performance liquid chromatography (HPLC) was obtained from Tedia Company, Inc (Fairfeld, OH, USA). Anhydrous pyridine, 1-(2-Hydroxyethyl)-1H-pyrrole-2,5-dione (HEMI), PEG (Mw2000) and D, L-lactide were obtained from Aladdin Bio-Chem Technology Co., LTD (Shanghai, China). Dulbecco’s Modified Eagle Medium (DMEM) (high glucose) cell culture medium, penicillin/streptomycin stock solutions, fetal bovine serum (FBS) and Trypsin were all bought from Gibco BRL (Gaithersberg, MD, USA). Protonic nuclear magnetic resonance (¹H-NMR) (400 MHz) was used to confirm the obtained compounds (Bruker AVVANCE DRX-400 NMR spectrometer, Bruker, Switzerland). In addition, gel permeation chromatography (GPC) (Waters 1515–2414, Waters, USA) was used to analyze all polymers by using tetrahydrofuran as the mobile phase (flow rate: 1 mL/min) at 30 °C. Polystyrene was used as standards.

¹H NMR spectra were recorded at 400 MHz (Bruker AVVANCE DRX-400 NMR spectrometer, Bruker, Switzerland). CDCl₃ and DMSO-d₆ were used as deuterated solvents. Chemical shifts (δ, ppm) were determined with internal solvent signal as reference (CHCl₃: δ = 7.26, DMSO-d₆: δ = 2.50). Monomer conversion during polymerization was determined based on the concentration of residual monomer using gas chromatography (GC) (FULI9720 series, RBX-5 capillary column 30 m × 0.32 mm × 1.0 μm). The column temperature was 150 °C (15 min). N₂ was used as the eluent at a flow rate of 1.0 mL min⁻¹. Gel permeation chromatography (GPC) (Waters 1515–2414, Waters, Milford, MA, USA) was used to determine the number- and weight-average molecular weights (M_n and M_w) and polydispersity (M_w/M_n) of copolymers in THF at 30 °C with 1 mL min⁻¹ flow rate. Polystyrene standards were used to calibrate the instrument. Transmission electron microscopy (TEM) images were taken with a Hitachi HT7700 instrument operating at an accelerating voltage of 120 KV. The particle size and polydispersity index (PDI) of polymeric nanoparticles were determined by dynamic light scattering (DLS) equipped with a Malvern Nano ZS90 Zetasizer, a 632.8 nm He-Ne laser, and a 173° backscatter detector.

¹H NMR spectra were recorded at 400 MHz (Bruker AVVANCE DRX-400 NMR spectrometer, Bruker, Switzerland). CDCl₃ and DMSO-d₆ were used as deuterated solvents. Chemical shifts (δ, ppm) were determined with internal solvent signal as reference (CHCl₃: δ = 7.26, DMSO-d₆: δ = 2.50). Gel permeation chromatography (GPC) (Waters 1515-2414, Waters, Milford, MA, USA) was used to determine the number- and weight-average molecular weights (M_n and M_w) and polydispersity (M_w/M_n) of copolymers in THF at 30 °C with 1 mL/min flow rate. Polystyrene standards were used to calibrate the instrument. Transmission electron microscopy (TEM) images were taken with a Hitachi HT7700 instrument operating at an accelerating voltage of 120 KV. The particle size and polydispersity index (PDI) of polymeric nanoparticles were determined by dynamic light scattering (DLS) equipped with a Malvern Nano ZS90 Zetasizer, a 632.8 nm He-Ne laser, and a 173° backscatter detector.