Non-invasive detection of the early phase of kidney injury by photoacoustic/computed tomography imaging

Abstract

The early diagnosis of kidney diseases, which can remarkably impair the quality of life and are costly, has encountered great difficulties. Therefore, the development of methods for early diagnosis has great clinical significance. In this study, we used an emerging technique of photoacoustic (PA) imaging, which has relatively high spatial resolution and good imaging depth. Two kinds of PA gold nanoparticle (GNP)-based bioprobes were developed based on their superior photo detectability, size controllability and biocompatibility. The kidney injury mouse model was developed by unilateral ureteral obstruction for 96 h and the release of obstruction model). Giving 3.5 and 5.5 nm bioprobes by tail vein injection, we found that the 5.5 nm probe could be detected in the bladder in the model group, but not in the control group. These results were confirmed by computed tomography imaging. Furthermore, the model group did not show changes in the blood biochemical indices (BUN and Scr) and histologic examination. The 5.5 nm GNPs were found to be the critical point for early diagnosis of kidney injury. This new method was faster and more sensitive and accurate for the detection of renal injury, compared with conventional methods, and can be used for the development of a PA GNP-based bioprobe for diagnosing renal injury.

Recent advances in engineered nanomaterials for acute kidney injury theranostics

“…to distinguish between normal and injured kidneys. Moreover, no changes in either SCr or BUN were observed in the AKI murine model, which demonstrated the significance of the 5.5-nm GNP-based bioprobe as a more accurate and sensitive means of early AKI diagnosis [90]. Besides, PA imaging has been used to trace the distribution and excretion of the Au25(SG)18 nanocluster in the preclinical experiments [92].…”

“…Moreover, as it involves no ionizing radiation, PA imaging is safer than CT [89]. Recently, a type of PA gold NP(GNP)-based bioprobe was designed with excellent size controllability, biocompatibility, and photo detectability [90]. Investigations were conducted using an AKI murine model, which was established by unilateral ureteral obstruction for 4 d with subsequent release (UUO-R) [90].…”

“…Recently, a type of PA gold NP(GNP)-based bioprobe was designed with excellent size controllability, biocompatibility, and photo detectability [90]. Investigations were conducted using an AKI murine model, which was established by unilateral ureteral obstruction for 4 d with subsequent release (UUO-R) [90]. Research has shown that GNPs with sizes of over 10 nm will enter the spleen and the liver, whereas GNPs smaller than 5.5 nm will travel to the kidneys [91].…”

“…Accordingly, two differently sized (3.5-and 5.5-nm) bioprobes were injected via the tail vein; the 5.5-nm (HD: 8.2 nm) probe was detected in the bladder of the AKI mice, but it was not detected in the normal animals ( Fig. 5) [90]. Hence, 5.5-nm GNPs could be used Figure 5 PA imaging of the probes excreted in vivo in the kidneys of mice [90].…”

“…5) [90]. Hence, 5.5-nm GNPs could be used Figure 5 PA imaging of the probes excreted in vivo in the kidneys of mice [90]. Probes were intravenously administered in UUO-R models and in normal mice.…”