Fig. 1

Study experimental design. Bleomycin was intratracheally delivered to mouse lungs to induce fibrosis, characterized by increased fibronectin expression. PEGylated FUD (PEG-FUD) peptide targets the N-terminal 70 kDa region of fibronectin and has been examined as an imaging probe for pulmonary fibrosis. To understand the temporal uptake of PEG-FUD in the bleomycin-induced model of pulmonary fibrosis, two approaches were utilized at various time points throughout this model. Top: precision-cut lung slices from fibrotic mouse lungs were incubated with radiolabeled peptide ([⁶⁴Cu]Cu-PEG-FUD) and radioactivity was quantified via gamma counting and autoradiography. Bottom: Fluorescently labeled peptide (Cy5-PEG-FUD) was delivered to mice subcutaneously, followed by relevant organ ex vivo IVIS fluorescence imaging and signal quantification. Figure was created in BioRender.com