Alexafluor488 or cy3 labeled secondary antibodies

Oleylamine (approximate C18-content 80–90%), oleic acid (technical grade 90%), xylene (98%), manganese (II) acetate (98%), CCK-8 and fluorescein isothiocyanate (FITC) were obtained from Sigma-Aldrich. S-2-(4-isothiocyanatobenzyl)-1, 4, 7-triazacyclononane-1, 4, 7-triacetic acid (p-SCN-Bn-NOTA) was purchased from Macrocyclics, Inc. (Dallas, TX). TRC105 was supplied by TRACON Pharmaceuticals Inc. (San Diego, CA). DSPE-PEG₅₀₀₀-NH₂ and SCM-PEG₅₀₀₀-Mal were purchased from Creative PEGworks (Winston Salem, NC). AlexaFluor488- or Cy3-labeled secondary antibodies (Jackson Immunoresearch Laboratories, Inc., West Grove, CA), rat anti-mouse CD31 primary antibody (BD Biosciences, San Diego, CA), and PD-10 desalting columns (GE Healthcare, Piscataway, NJ) were all acquired from commercial sources. All buffers and water were of Millipore grade. All other reaction buffers and chemicals were obtained from Thermo Fisher Scientific (Fair Lawn, NJ).

VEGF₁₂₁ was provided by GenScript Corp. (Piscataway, NJ). S-2-(4-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid (p-SCN-Bn-NOTA) was purchased from Macrocyclics, Inc. (Dallas, TX). Chelex 100 resin (50-100 mesh) and fluoresce in isothiocyanate (FITC) were purchased from Sigma-Aldrich (St. Louis, MO). Succinimidyl carboxymethyl PEG maleimide (SCM-PEG-Mal; molecular weight: 5 kDa; Creative PEGworks, Winston Salem, NC), rat anti-mouse CD31 primary antibody (BD Biosciences, San Diego, CA), AlexaFluor488- or Cy3-labeled secondary antibodies (Jackson Immunoresearch Laboratories, Inc., West Grove, CA), Bevacizumab (Avastin, Genentech, San Francisco, CA) and PD-10 desalting columns (GE Healthcare, Piscataway, NJ) were all acquired from commercial sources. Water and all buffers were of Millipore grade and pre-treated with Chelex 100 resin to ensure that the aqueous solution was free of heavy metal. All other reaction buffers and chemicals were obtained from Thermo Fisher Scientific (Fair Lawn, NJ).