TY - JOUR T1 - <sup>68</sup>Ga-NOTA-UBI-29-41 as a PET Tracer for Detection of Bacterial Infection JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 622 LP - 627 DO - 10.2967/jnumed.115.161265 VL - 57 IS - 4 AU - Mónica Vilche AU - Ana Laura Reyes AU - Elena Vasilskis AU - Patricia Oliver AU - Henia Balter AU - Henry Engler Y1 - 2016/04/01 UR - http://jnm.snmjournals.org/content/57/4/622.abstract N2 - The cationic peptide 68Ga-NOTA-UBI-29-41 was synthesized and characterized. Biodistribution and PET/CT examinations were performed for evaluation of its biologic behavior. Differentiation of infection from sterile inflammation was investigated using microbiology methods at the sites of bacterial infections. Methods: Labeling of UBI-29-41 conjugated with NOTA with 68Ga was optimized at 20°C–100°C and pH 3.5–5.5. Radiochemical purity, stability up to 260 min, and binding to serum proteins were determined. In vitro binding to Staphylococcus aureus was evaluated from 9.14 × 107 to 1.17 × 1010 cfu/mL. Of 3 groups of Mus musculus Swiss male mice, the first was inoculated intramuscularly with 1.2 × 108 cfu of S. aureus to provoke infection, and the second, with 1.2 × 108 cfu of heat shock–treated S. aureus to generate sterile inflammation. The third mouse was not treated and served as a control. After 24 h, 68Ga-NOTA-UBI-29-41 was administrated intravenously, and biodistribution was performed at 30, 60, and 120 min. PET/CT dynamic studies (120 min) were acquired. Sinograms were reconstructed using 3D maximum-likelihood expectation maximization and analyzed with software. Infected or inflamed muscles were dissected, homogenized, and cultured in tryptic soy agar medium. Recovered S. aureus was calculated as cfu/g. Results: 68Ga-NOTA-UBI-29-41 showed high renal excretion (83.2% ± 7.3%) of injected dose and rapid blood clearance. More than 95% was bound in vitro to 5 × 109 cfu/mL. A significantly higher (P &lt; 0.05) accumulation of 68Ga-NOTA-UBI-29-41 was observed at sites of S. aureus inoculation in infected mice (ratio of target to nontarget, 5.0 at 60 min and 4.1 at 120 min) compared with animals with inflammation (ratio of target to nontarget, 1.6 at 60 min and 1.2 at 120 min). Conclusion: The difference in uptake of 68Ga-NOTA-UBI-29-41 in the infected muscles compared with the inflamed muscles was clearly observed in the PET/CT images and positively correlated with the degree of infection. ER -