Fig. 1. (a) TEM images of unloaded (left) and Ru1-containing (right) PLGA nanoparticles. For unloaded PLGA nanoparticles (left) uranyl acetate contrast stain was employed. For Ru1-loaded particles (right), no TEM contrast stain was used, thereby allowing direct visualisation of Ru1 contrast within the PLGA core. (b) Coomassie blue stained SDS-PAGE gel of free hEGF (1 μg, left lane) or PLGA nanoparticles (1 mg) added to hEGF in the presence (middle lane) or absence (right lane) of NHS/EDC crosslinking agents. Nanoparticles were separated from unreacted hEGF by centrifugation before loading. *hEGF-PLGA, #hEGF. (c) Release kinetics of hEGF-PLGA-Ru1 showing biphasic release profile of Ru1. (d) Representative instant thin layer chromatograms (iTLC) of purified ¹¹¹In-hEGF-PLGA and ¹¹¹In-hEGF-PLGA-Ru1 nanoparticles in citrate buffer using EDTA (0.5 M, pH = 7.6) as the mobile phase.