Acetonitrile for high performance liquid chromatography

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.