Inflammation imaging by silica nanoparticles with antibodies orientedly immobilized.

Tomoaki Shirai, Hiroshi Kohara, Yasuhiko Tabata

Department of Biomaterials, Institute for Frontier Medical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan.

Journal of drug targeting 2012 Jul

filter terms:

The objective of this study is to design fluorescent nanoprobes for inflammation imaging. An antibody against CD11b expressed on the surfaces of mouse macrophages (anti-CD11b), was fluorescently labeled. Protein G, which has an ability to bind the Fc region of antibody, was conjugated onto the surface of silica nanoparticles (SiNP). Then, the fluorescent-labeled anti-CD11b was orientedly immobilized to the SiNP surface through the specific protein G-antibody interaction. After the intravenous injection of anti-CD11b orientedly immobilized SiNP to the mouse model of acute interstitial nephritis, unilateral ureteral obstruction (UUO) of one kidney, the fluorescent intensity at the UUO and non-treated, normal kidneys was assessed. The anti-CD11b orientedly immobilized SiNP were accumulated in the UUO kidney to a significantly great extent compared with the normal, non-inflamed kidney. The fluorescence intensity of inflamed kidney 6 and 12 h after injection of the anti-CD11b orientedly immobilized SiNP were significantly higher than that of anti-CD11b randomly immobilized SiNP or free anti-CD11b injection. Histological experiments revealed that the anti-CD11b orientedly immobilized SiNP were associated with macrophages infiltrated into the inflammation site. It is concluded that the anti-CD11b orientedly immobilized SiNP are promising nanoprobes to image the inflammation site at a high intensity.

Citation

Tomoaki Shirai, Hiroshi Kohara, Yasuhiko Tabata. Inflammation imaging by silica nanoparticles with antibodies orientedly immobilized. Journal of drug targeting. 2012 Jul;20(6):535-43