DTPA-Functionalized Nano-Porous MCM-41 Silica: A New Potential Nanoengineered Labeled Composite for Diagnostic Applications

Mesoporous silica, MCM-41, functionalized with diethylene triamine pentaacetic acid (DTPA) and 3-aminopropyltrimethoxysilane as an interface ligand, was investigated as a potential drug delivery system for radionuclides. The outstanding properties of Gallium-67 complexes, such as noninvasively detection of tumors, inflammation, and both acute and chronic infection, proposed that these compounds might potentially be good candidates as test drugs for drug delivery systems. In this work, [Ga-67] radionuclide was grafted on DTPA-functionalized MCM-41 with the direct method of modification, and the compounds were characterized by paper chromatography, FT-IR spectroscopy, low angle X-ray diffraction, and CHN and TGA/DTA analyses. The specific activity of the final compound was found to be 3 Ci/g, and the biological evaluations of the grafted complex, [Ga-67]-DTPA-NH-Propyl@MCM-41, were done in fibrosarcoma tumor-bearing Sprague-Dawley rats. DTPA-functionalized MCM-41 was found to be a good host for diagnostic radionuclides with the ability to form complex with DTPA. Considering the accumulation of the tracer in tumor, fast wash-out from normal tissues, appropriate half-life Ga-67 and less imposed radiation doses to patients (compare to non-targeted radiopharmaceutical), [Ga-67]-DTPA-NH-Propyl@MCM-41 can be a suitable radiopharmaceutical for imaging purposes.