Assessment of collagen-induced arthritis using cyanine 5.5 conjugated with hydrophobically modified glycol chitosan nanoparticles: correlation with 18F-fluorodeoxyglucose positron emission tomography data.
OBJECTIVE
To evaluate the potential and correlation between near-infrared fluorescence (NIRF) imaging using cyanine 5.5 conjugated with hydrophobically modified glycol chitosan nanoparticles (HGC-Cy5.5) and (18)F-fluorodeoxyglucose-positron emission tomography ((18)F-FDG-PET) imaging of collagen-induced arthritis (CIA).


METHODS
We used 10 CIA and 3 normal mice. Nine days after the injecting collagen twice, microPET imaging was performed 40 minutes after the intravenous injection of 9.3 MBq (18)F-FDG in 200 µL PBS. One day later, NIRF imaging was performed two hours after the intravenous injection of HGC-cy5.5 (5 mg/kg). We assessed the correlation between these two modalities in the knees and ankles of CIA mice.


RESULTS
The mean standardized uptake values of (18)F-FDG for knees and ankles were 1.68 ± 0.76 and 0.79 ± 0.71, respectively, for CIA mice; and 0.57 ± 0.17 and 0.54 ± 0.20 respectively for control mice. From the NIRF images, the total photon counts per 30 mm(2) for knees and ankles were 2.32 ± 1.54 × 10(5) and 2.75 ± 1.51 × 10(5), respectively, for CIA mice, and 1.22 ± 0.27 × 10(5) and 0.88 ± 0.24 × 10(5), respectively, for control mice. These two modalities showed a moderate correlation for knees (r = 0.604, p = 0.005) and ankles (r = 0.464, p = 0.039). Moreover, both HGC-Cy5.5 (p = 0.002) and (18)F-FDG-PET (p = 0.005) imaging also showed statistically significant differences between CIA and normal mice.


CONCLUSIONS
NIRF imaging using HGC-Cy5.5 was moderately correlated with (18)F-FDG-PET imaging in the CIA model. As such, HGC-Cy5.5 imaging can be used for the early detection of rheumatoid arthritis.
Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736, Korea.
Ji Hyeon
JH
Cha
Sang Hoon
SH
Lee
Sheen-Woo
SW
Lee
Kyeongsoon
K
Park
Dae Hyuk
DH
Moon
Kwangmeyung
K
Kim
Sandip
S
Biswal
D000818:Animals; D000843:Ankle Joint / Q000000981:diagnostic imaging; D001169:Arthritis, Experimental / Q000000981:diagnostic imaging*; D002232:Carbocyanines / Q000008:administration & dosage; D048271:Chitosan / Q000008:administration & dosage; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage; D007275:Injections, Intravenous; D007719:Knee Joint / Q000000981:diagnostic imaging; D008297:Male; D051379:Mice; D018613:Microscopy, Confocal; D053758:Nanoparticles; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D018709:Statistics, Nonparametric
C098793:CY5.5 cyanine dye; D002232:Carbocyanines; D019275:Radiopharmaceuticals; C118638:glycol-chitosan; D019788:Fluorodeoxyglucose F18; D048271:Chitosan