Figure 5.
In vivo detection of CD163 by MRI in the glycerol model of rhabdomyolysis (A) Schematic representation of the nanoparticles administered in mice. Nanoparticles consisted of a gold-coated iron oxide core covered with thiol ligands bearing mannose and a carboxylic acid. ProtG was covalently linked through a peptide bond to the carboxylic moieties and anti-CD163 (NP-CD163) or IgG antibodies (NP-IgG) were subsequently grafted on them. (B) TEM micrograph of NP-CD163 and (C) UV-Vis spectra of gold-coated NPs before and after IgG antibodies conjugation. (D) Graph showing the normalized T2 values obtained from MRI images of mouse peritoneal macrophages incubated with NP-CD163 or NP-IgG (as control) in presence of dexamethasone for 24h (DXM, a CD163 inducer). Mean±SD of 3 independent experiments. * p<0.05 vs. NP-CD163 without dexamethasone. The corresponding MRI phantoms are shown below the graph. (E) Representative magnetic resonance images obtained pre (0h) and post (48h) nanoparticles injection in mice with rhabdomyolysis. Graph showing the contrast-to-noise-ratio (CNR) of the kidney cortex with respect to muscle pre- and post-nanoparticle injection (F) and normalized-enhancement-ratio (NER) of the kidney cortex with respect to muscle 48 hours after nanoparticle injection (G) in mice with rhabdomyolysis and control. * p<0.05 vs pre-nanoparticle injection. † p<0.05 vs healthy mice or mice with rhabdomyolysis and injected with NP-IgG. (H) Detection of nanoparticles in mice by using TEM. Left panels shows 4000x magnification of renal cortex. White arrows show the presence of infiltrating macrophages in the kidney of mice 5 days after i.m. injection of glycerol. Central panel shows 12000 x magnification of macrophages. The rectangle shows the region of interest for which high-magnification images are shown in the right panels (120000 x magnification). Black arrows show the presence of nanoparticles in mice with rhabdomyolysis and injected with NP-CD163, but not in those mice treated with NP-IgG.