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Updated: Jun 15, 2026
Optical Clearing and Imaging of Immunolabeled Kidney Tissue
Published on: July 22, 2019
Renal-Clearable Biomass-Derived Carbon Dots with Red Fluorescence for Masked Cryptic Kidney Injury Imaging
Aisha Zhang1,2, Yuanyuan Wang3, Xiaolu Sui1,2
1Department of Nephrology, The Second Affiliated Hospital of Shenzhen University, Shenzhen 518101, China.
Abstract:
Masked cryptic kidney injury (MCKI), an early stage of acute kidney injury (AKI), is challenging to detect and diagnose, especially in the modern context where toxic substances, such as surfactants, are increasingly misused. Consequently, there is an urgent need for methods for the visual diagnosis of MCKI. In this study, we synthesized environmentally friendly spirulina-derived carbon dots (SpiCDs) using spirulina as a biobased raw material through a simple hydrothermal process. These SpiCDs, with their ultrasmall size, enable efficient renal clearance. In cellular experiments, SpiCDs rapidly entered SDS-damaged cells, facilitating dynamic monitoring of the cell membrane damage process. In vivo animal experiments demonstrated that SpiCDs were efficiently excreted through the kidneys and began to accumulate in the bladder within 10 min after tail vein injection. The detection of red fluorescence in excreted urine confirmed the renal metabolic pathway of the SpiCDs. Furthermore, in an MCKI model induced by SDS, SpiCDs showed accelerated excretion and earlier accumulation in the bladder, indicating an increased sensitivity to kidney injury. These results suggest that SpiCDs provide a promising approach for the early diagnosis of MCKI, offering insights into its visual detection and monitoring.
Insights
Environmentally friendly spirulina-derived carbon dots (SpiCDs) offer a new way to visually detect masked cryptic kidney injury (MCKI). These nanoparticles aid in early diagnosis by showing clear signs of kidney damage in urine.
Area of Science:
- Biomaterials Science
- Nanotechnology
- Medical Diagnostics
Background:
- Masked cryptic kidney injury (MCKI), an early stage of acute kidney injury (AKI), is difficult to detect, especially with increased misuse of toxic substances like surfactants.
- Current diagnostic methods lack the sensitivity for early-stage MCKI, necessitating novel visual detection approaches.
Purpose of the Study:
- To develop and evaluate spirulina-derived carbon dots (SpiCDs) as a visual diagnostic tool for early detection of MCKI.
- To assess the biocompatibility, renal clearance, and diagnostic potential of SpiCDs in cellular and in vivo models.
Main Methods:
- Synthesis of spirulina-derived carbon dots (SpiCDs) via a hydrothermal process.
- In vitro studies using sodium dodecyl sulfate (SDS)-damaged cells to monitor membrane damage.
- In vivo animal studies involving tail vein injection of SpiCDs to track renal excretion and bladder accumulation.
- Induction of MCKI in an animal model using SDS to evaluate SpiCDs' sensitivity.
Main Results:
- SpiCDs demonstrated ultrasmall size, efficient renal clearance, and rapid entry into SDS-damaged cells.
- In vivo, SpiCDs were quickly excreted via kidneys, accumulating in the bladder within 10 minutes, with red fluorescence in urine confirming renal metabolism.
- In the MCKI model, SpiCDs exhibited accelerated excretion and earlier bladder accumulation, signifying heightened sensitivity to kidney injury.
Conclusions:
- SpiCDs are a promising, environmentally friendly tool for the visual diagnosis of MCKI.
- The study highlights the potential of SpiCDs for dynamic monitoring of kidney injury and early detection.
- SpiCDs offer a novel approach for real-time, visual assessment of kidney health.
