Single Polymer-drug Conjugate Carrying Two Drugs for Fixed-dose Codelivery

Abstract

Poly(ethyl glycol) (PEG2000) with carboxyl was purchased from Yare Biotech. Dichloromethane (DCM) and N,N-dimethylformamide (DMF) were dried by refluxing over CaH 2 and distilled prior to use. 9-fluorenylmethoxycarbonyl (Fmoc) and 2-(4,4-dimethyl-2,6-dioxocyclohexylidene)ethyl (Dde) protected amino acids, 2-chlorotrityl chloride (CTC) resin were purchased from GL Biochem (shanghai). O-(benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate (HBTU), thioanisole, trifluoroacetic acid (TFA), N-ethyldiisopropylamine (DIEA) and ninhydrin were purchased from GL Biochem. Dulbecco's modified Eagle's medium (DMEM), fetal bovine serum (FBS), penicillin-streptomycin, trypsin, Dubelcco's phosphate buffered saline (DPBS), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) were obtained from Gibco