Beschreibung:
During recent years, Super Paramagnetic Iron Oxide nano particles (SPIONs) have been raised a great deal of interest because of their use in a number of bio‐medical applications such as targeted drug delivery, sensitive diagnostic tools, contrast agents for Magnetic Resonance Imaging (MRI), protein purification studies and lab‐on‐a‐chip devices. We have been interested in the development of ligand bound SPIONs as contrast agents for MRI of breast tumors and their metastases (Leuschner et al., Breast Cancer Res. Treat. 99, 163‐176, 2006). The Luteinizing‐Hormone Releasing Hormone (LHRH) has been found to be an excellent targeting agent for breast tumors and their metastases and hence LHRH‐SPIONs have been shown to enhance the contrast efficiency in MRI. In order to modulate magnetic properties of SPIONs through gold coating, we have synthesized gold coated SPIONs and established an approach to bind LHRH to gold surface through cysteamine linkage as shown below.We have characterized the LHRH‐Au@SPIONs using TEM, X‐ray absorption spectroscopy and SQUID magnetometer. These particles are currently being evaluated for their cytotoxicity and inflammatory cytokine release using cell‐based assay systems. In addition to the toxicity results, investigations from their targeting ability in vitro using breast cancer cells followed by their MRI contrast efficiency will be presented.