Fluoro‐Photoacoustic Polymeric Renal Reporter for Real‐Time Dual Imaging of Acute Kidney Injury

Abstract

Photoacoustic (PA) imaging agents detect disease tissues and biomarkers with increased penetration depth and enhanced spatial resolution relative to traditional optical imaging, and thus hold great promise for clinical applications. However, existing PA imaging agents often encounter the issues of slow body excretion and low‐signal specificity, which compromise their capability for in vivo detection. Herein, a fluoro‐photoacoustic polymeric renal reporter (FPRR) is synthesized for real‐time imaging of drug‐induced acute kidney injury (AKI). FPRR simultaneously turns on both near‐infrared fluorescence (NIRF) and PA signals in response to an AKI biomarker (γ‐glutamyl transferase) with high sensitivity and specificity. In association with its high renal clearance efficiency (78% at 24 h post‐injection), FPRR can detect cisplatin‐induced AKI at 24 h post‐drug treatment through both real‐time imaging and optical urinalysis, which is 48 h earlier than serum biomarker elevation and histological changes. More importantly, the deep‐tissue penetration capability of PA imaging results in a signal‐to‐background ratio that is 2.3‐fold higher than NIRF imaging. Thus, the study not only demonstrates the first activatable PA probe for real‐time sensitive imaging of kidney function at molecular level, but also highlights the polymeric probe structure with high renal clearance.

Near-infrared fluorescent molecular probes for imaging and diagnosis of nephro-urological diseases

“…N-acetyl-b-D-glucosaminidase (NAG), g-glutamyl transferase (GGT) and caspase-3). [56][57][58][59][60][61][62]…”

Grafted semiconducting polymer amphiphiles for multimodal optical imaging and combination phototherapy

“…80,81 Different from uorescence imaging, PA imaging utilizes ultrasonic waves as the signal source and has a higher spatial resolution and deeper tissue penetration relative to uorescence imaging. [82][83][84] Considering the complementary advantages of uorescence and PA imaging, dual-modal imaging combining uorescence and PA imaging has also gained more and more attention. 85,86 Liu et al synthesized uorescent SPA1 with hyperbranched polyglycerol as the side chain.…”

Recent advances in engineered nanomaterials for acute kidney injury theranostics

“…Despite their attractive qualities, the excretion rate and signal specificity of PA imaging agents, such as carbon nanotubes and GNPs, have been found to be unfavorable [93]. Typically, these agents require passive accumulation in the injured region for an enhanced signal.…”