Figure 14.

Imaging brain cancer with peptide or antisense radiopharmaceuticals and BBB drug delivery technology. (A) Structure of [¹¹¹In]-DTPA-EGF-PEG³⁴⁰⁰-biotin bound to the OX26/SA conjugate. (B) Film autoradiogram of coronal section of nude rat brain bearing a U87 glioma removed 2 h after IV injection of the BBB-targeted EGF peptide radiopharmaceutical. (C) A section parallel to that shown in (B) was examined by immunohistochemistry using the 528 MAb against the human EGFR. Panels B and C reproduced with permission [804], Copyright© 1999 American Association Cancer Research. (D) Structure of [¹¹¹In]-DTPA-O₂-18-mer PNA antisense to nucleotides 20–37 of the rat GFAP mRNA. The carboxyl terminus of the PNA incorporates a lysine (Lys) residue and biotin is conjugated to the ε-amino group of the Lys; O = 9-atom linker. The biotinyl PNA is bound by the OX26/SA conjugate. (E) Confocal microscopy of an intra-cranial RG-2 tumor in rats that is immune-stained with an antibody to caveolin-1α (red) and an antibody to GFAP (green). (F) Film autoradiogram of coronal section of tumor-bearing rat brain removed 6 h after the IV injection of the biotinyl GFAP-PNA-OX26/SA conjugate. (G) Film autoradiogram of coronal section of tumor-bearing rat brain removed 6 h after the IV injection of the biotinyl CAV-PNA-OX26/SA conjugate. Panels (E–G) reproduced with permission [806], Copyright© 2004 SNMMI.