Integrin receptor MR imaging with targeted superparamagnetic liposome
QU Hai-yuan1, GUAN Li-ming1, CHEN Chun-yuan2, DENG Yi-hui3, LIU Yi1, XU Ke1
1. Department of Radiology, the First Hospital of China Medical University, Shenyang 110001, China; 2. The Shenyang Institute of Biology, Shenyang 110015, China; 3. School of Pharmacy, Shenyang Pharmaceucal University, Shenyang 110016, China
Abstract：Objective: The ability of αvβ3 integrin targeted superparamagnetic liposomes to detect tumor angiogenesis was evaluated by in vitro fluorescence microscopy and in vivo MR molecular imaging. Methods: SPIO or calcein loaded liposomes were conjugated with or without Arg-Gly-Asp(RGD) peptides. Human umbilical vein endothelial cells(HUVECs) were incubated with calcein loaded targeted and non-targeted liposome or PBS and analyzed by flow cytometry and confocal laser scanning microscopy. VX2 tumor bearing rabbits were injected I.V with the two liposome preparations. MRI scanning was performed and the contrast to noise ratios(CNR) of the tumor pre- and post-contrast agent injection were compared. Results: Binding and uptake of RGD-liposomes by HUVECs was significantly increased when compared with non-targeted liposomes. After the contrast agent injection, the signal intensity and CNR of tumor drop to the bottom at 15 hour and 2 hour respectively for the targeted group and non-targeted group. Conclusion: The RGD targeted super-paramagnetic liposome we prepared got high relaxivities. It can bind specifically with αvβ3 integrins and be detected by in vivo MR imaging by 1.5T clinical MR machine.
2009, Vol. 20 
