Supplementary Data

β-actin IL-13Rα2 65 kDa 42 kDa G26-H2 G26-V2 SnB19-pcDNA SnB19-asIL-13Rα2 Figure S1A

Phage clones (pfu/ml) 10 9 Pep-1Pep-2Pep-3M13KE Figure S1B DTT (-) DTT (+) O.D. - A 405 nm

Concentration (µg/ml) Figure S1C IL-13R  2-Fc IgG-Fc BSA Pep-1-L Pep-1-DSC Pep-1-L (C/S) Control Pep-1-L Control Pep-1-DSC O.D. - A 405 nm

1 µg/ml5 µg/ml U-251 MG Pep-1-DSC Pep-1-L Figure S2 A

Pep-1-L B T98G cells Pep-1-DSC Figure S2 1 µg/ml5 µg/ml

Scrambled Pep-1-L U-251 MG cells C No peptide 1 µg/ml Figure S2 5 µg/ml

Figure S2 D

Figure S3A Strep- Cys5.5 Strep- Cys5.5 Strep- Cys min2 hr8 hr 24 hr72 hr Pep-1-DSC Ctrl. Pep-1-DSC SalinePep-1-DSC Ctrl. Pep-1-DSC SalinePep-1-DSC Ctrl. Pep-1-DSC Saline 48 hr Pep-1-DSC Ctrl p = * Total NIR Radiant efficiency (x 10 ) 10

Luciferin Figure S3B Pep-1-DSC Ctrl. Strep- Cy5.5 Saline hr

Figure S4 A B i.ii.iii. i.ii.iii.