Selenium-Doped Carbon Quantum Dots Act as Broad-Spectrum Antioxidants for Acute Kidney Injury Management

Selenium-Doped Carbon Quantum Dots Efficiently Ameliorate Secondary Spinal Cord Injury via Scavenging Reactive Oxygen Species

Background

The excess production of reactive oxygen species (ROS) after traumatic spinal cord injury (TSCI) has been identified as a leading cause of secondary injury, which can significantly exacerbate acute damage in the injured spinal cord. Thus, scavenging of ROS has emerged as an effective route to ameliorate secondary spinal cord injury.

Purpose

Selenium-doped carbon quantum dots (Se-CQDs) with the ability to scavenge reactive oxygen species were prepared and used for efficiently ameliorating secondary injury in TSCI.

Methods

Water-soluble Se-CQDs were easily synthesized via hydrothermal treatment of l-selenocystine. The chemical structure, size, and morphology of the Se-CQDs were characterized in detail. The biocompatibility and protective effects of the Se-CQDs against H₂O₂-induced oxidative damage were investigated in vitro. Moreover, the behavioral test, bladder function, histological observation, Western blot were used to investigate the neuroprotective effect of Se-CQDs in a rat model of contusion TSCI.

Results

The obtained Se-CQDs exhibited good biocompatibility and remarkable protective effect against H₂O₂-induced oxidative damage in astrocytes and PC12 cells. Moreover, Se-CQDs displayed marked anti-inflammatory and anti-apoptotic activities, which thereby reduced the formation of glial scars and increased the survival of neurons with unscathed myelin sheaths in vivo. As a result, Se-CQDs were capable of largely improving locomotor function of rats with TSCI.

Conclusion

This study suggests that Se-CQDs can be used as a promising therapeutic platform for ameliorating secondary injury in TSCI.

Nanomedicines for Renal Management: From Imaging to Treatment

Nanomedicine has benefited from recent advances in chemistry and biomedical engineering to produce nanoscale materials as theranostic agents. Well-designed nanomaterials may present optimal biological properties, influencing circulation, retention, and excretion for imaging and treatment of various diseases. As the understanding of nanomedicine pharmacokinetics expands continuously, efficient renal clearance of nanomedicines can significantly increase the signal-to-background ratio for precision diagnosis and lower potential toxicity for improved treatment. Studies on nanomaterial-kidney interactions have led to many novel findings on the underlying principles of nanomaterial renal clearance, targeting, and accumulation. In return, the optimized nanomedicines confer significant benefits to the detection and treatment of kidney dysfunction.In this Account, we present an overview of recent progress in the development of nanomaterials for kidney theranostics, aiming to speed up translation and expand possible applications. We start by introducing biological structures of the kidney and their influence on renal targeting, retention, and clearance. Several key factors regarding renal accumulation and excretion, including nanomaterial types, sizes, and shapes, surface charges, and chemical modifications, are identified and discussed. Next, we highlight our recent efforts investigating kidney-interacting nanomaterials and introduce representative nanomedicines for imaging and treatment of kidney diseases. Multiple renal-clearable and renal-accumulating nanomedicines were devised for kidney function imaging. By employing renal-clearable nanomedicines, including gold nanoparticles, porphyrin polymers, DNA frameworks, and polyoxometalate clusters, we were able to noninvasively evaluate split renal function in healthy and diseased mice. Further engineering of renal-accumulating nanosystems has shifted attention from renal diagnosis to precision kidney protection. Many biocompatible nanomedicines, such as DNA origami, selenium-doped carbon quantum dots, melanin nanoparticles, and black phosphorus have all played essential roles in diminishing excessive reactive oxygen species for kidney treatment and protection. Finally, we discuss the challenges and perspectives of nanomaterials for renal care, their future clinical translation, and how they may affect the current landscape of clinical practices. We believe that this Account updates our current understanding of nanomaterial-kidney interactions for further design and control of nanomedicines for specific kidney diagnosis and treatment. This timely Account will generate broad interest in integrating nanotechnology and nanomaterial-biological interaction for state-of-the-art theranostics of renal diseases.

Reactive Oxygen Species (ROS)-Responsive Nanomedicine for Solving Ischemia-Reperfusion Injury

Ischemia-reperfusion injury (IRI) is a severe condition for most organs, which could occur in various tissues including brain, heart, liver, and kidney, etc. As one of the major hazards, reactive oxygen species (ROS) is excessively generated after IRI, which causes severe damage inside tissues and further induces the following injury via inflammatory response. However, current medical strategies could not thoroughly diagnose and prevent this disease, eventually leading to severe sequelae by missing the best time point for therapy. In the past decade, various nanoparticles that could selectively respond to ROS have been developed and applied in IRI. These advanced nanomedicines have shown efficient performance in detecting and treating a series of IRI (e.g., acute kidney injury, acute liver injury, and ischemic stroke, etc.), which are well-summarized in the current review. In addition, the nano-platforms (e.g., anti-IL-6 antibody, rapamycin, and hydrogen sulfide delivering nanoparticles, etc.) for preventing IRI during organ transplantation have also been included. Moreover, the development and challenges of ROS-responsive nanomedicine are systematically discussed for guiding the future direction.