In other words, anti-CEA SPIONPs belong to the so-called ‘ultrasmall

superparamagnetic iron oxides (USPIOs)’ [21]. An entire colorectal tumor implanted in an anesthetized mouse was scanned using the Sepantronium research buy SSB ICG-001 order scanning probe for 4 min. After each scanning, a scanning curve was obtained, as shown in the inset of Figure  2a. Among all scanning curves at a time point, the scanning curve with the largest I peak, the maximum intensity, was selected as a representative for comparison with other I peak at various times, as shown in Figure  2b. In Figure  2b, both I peak and the peak width of the scanning curve increased from the 0th hour, achieved the maximum at the 26th hour for mouse 1 and the 20th hour for mouse 2, and decreased to levels similar to those at the 0th hour. Therefore, the reliable area of the scanning path, ‘Area,’ was used to analyze the magnetism of the entire tumors by adding the

products of the scanning step Tipifarnib manufacturer and the intensities that were larger than the half of I peak. Here, the intensities that were smaller than the half of I peak were skipped because of the significant repeatability errors occurring under particular experimental conditions such as the arrangement of the mouse and mouse breath. Consequently, the maximum Area of mouse 1 and mouse 2 occurred separately at the 26th hour and the 20th hour. To prove the reliability of the SSB results by comparing them with the MRI results, the normalized parameter ΔArea/Areamax was used to express the magnetic enhancement using anti-CEA SPIONPs on a colorectal tumor, as shown in Figure  3. The examination of magnetic labeling of tumors by SSB, as shown in Figure  3, indicated that the accumulation of anti-CEA SPIONPs reached the highest level and gradually dissipated to the initial level at approximately the 72nd hour. Because anti-CEA SPIONPs showed not only the in-phase component of the AC susceptibility

for SSB examination but also the superparamagnetic properties for MRI contrast imaging, hence, the dynamic amount variation of anti-CEA SPIONPs binding to colorectal tumors could be verified below by the I normalized variation of the MR image with time. Figure 3 Comparison between ΔArea/Area max by SSB and I normalized by MRI for mouse 1 and mouse 2. Figure  4a shows the representative MR images for the colorectal tumors of mouse 1 and mouse 2 at various times. Here, the entire tumor was marked with a blue outline and selected for analysis, and the DI water in the tube was also used for comparison. Based on observation, the tumor of mouse 2 became significantly dark at the 24th hour and then recovered to brightness at the 0th hour. In addition, the normalized intensity, I normalized, was defined as the ratio of the average intensity of the selected region over that of DI water. The variation of I normalized for the entire tumor was analyzed, as shown in Figure  4b, indicating that I normalized for the entire tumor around the first day reached the minimum for mouse 2.