Radiolabeled oligosaccharides nanoprobes for infection imaging.

Breast milk oligosaccharides act as soluble receptors for different pathogens which protect the newborn child from infection. The differentiation between loosening of prosthesis due to infective pathology septic or otherwise aseptic plays an important role in the patient management. We have labeled hydroxypropyl-beta-cyclodextrin, oligosaccharide derivative, with technetium-99m (Tc-99m-HP beta CD). The quality control of Tc-99m-HP beta CD was done by ITLC and characterized by electron microscopy and H-1-nuclear magnetic resonance. The route of excretion of Tc-99m-HP beta CD nanoparticulate radiopharmaceutical was assessed in rats. Nanoparticles Tc-99m HP beta CD were injected in human subjects with clinically confirmed infected knee joints. Docking studies were done for ligand - protein interaction. The Tc-99m-HP beta CD was stable with good radiochemical yield (>98%) at pH 4.0 and 6.5. For single patient dose, 0.5-1.0mg HP beta CD quantity was sufficient. Tc-99m HP beta CD was observed to form nanoparticles of 60-180 mu m. The H-1 NMR studies revealed the binding of Tc-99m at C-8/H-8 position of HP beta CD. The excretion of Tc-99m HP beta CD showed renal route of excretion. Docking studies demonstrated the interaction between HP beta CD and bacterial maltose binding protein (MBP). The differentiation between septic and aseptic loosening was also evident on single photon emission tomography (SPET). In conclusion, these data indicated that Tc-99m HP beta CD is a promising radiopharmaceutical and may serve as molecular nanoprobe for infection imaging.