2.1.1. Synthesis of c(RGDfC) Peptide and DSPE-PEG5000-c(RGDfC)

Ultrapure water (Mili-Q, r > 18 MΩ·cm) was used in all the experiments. Acetonitrile (ACN), acetic acid (AcOH), dicholoromethane (DCM), diethyl ether (Et₂O), dimethylformamide (DMF), chloroform (CHCl₃), and methanol (MeOH) were obtained from Sigma-Aldrich (Saint-Quentin Fallavier, France) and were used without further purification.

The synthesis of c(RGDfC) peptide required N,N,N′,N′-tetramethyl-O-(1H-benzotriazol-1-yl)uronium hexafluorophosphate (HBTU) (Iris Biotech GmbH, Germany) and acetic anhydride (Sigma-Aldrich, Saint-Quentin Fallavier, France), and N–methylmorpholine (NMM), N–methylpyrrolidinone (NMP), N,N-diisopropylethylamine (DIPEA), piperidine and tetrakis(triphenylphosphine)palladium(0) (Pd(PPh₃)₄) (Alfa Aesar, Haverhill, MA, USA) as reagents. Fmoc–L–Asp–OAll, Fmoc–Gly–OH, Fmoc–L–Arg(Pbf)–OH, Fmoc–L–Cys (Trt)–OH, Fmoc–D–Phe–OH and 2CTC resin (2-chlorotrityl chloride resin, 100–200 mesh, 1.0–2.0 mmol/g loading) were obtained from Iris Biotech GmbH (Marktredwitz, Germany). Trifluoroacetic acid (TFA) was purchased from Sigma-Aldrich (Saint-Quentin Fallavier, France) and triisopropylsilane (TIPS) from Alfa Aesar (Haverhill, MA, USA).

The synthesis of DSPE-PEG₅₀₀₀-c(RGDfC) required DSPE-PEG₅₀₀₀-Mal (≥95%, Biochempeg Scientific Inc., Watertown, MA, USA), and phosphate-buffered saline (pH 7.4) and 1 kDa dialysis membrane (Sigma-Aldrich, Saint-Quentin Fallavier, France).