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Updated: Jan 17, 2026

Understanding the Changes in Mitochondrial Morphology through Dynamic and Three-dimensional Fluorescence Micrographs
Published on: August 15, 2025
Metformin nanoparticles mitigate cerebral ischemia reperfusion injury by improving mitochondrial dysfunction and
Lin Deng1, Ting Cai2, Jiayu Li2
1Department of Anesthesiology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang, 150001, China.
Background:
Cerebral ischemia reperfusion injury (CIRI) is a serious condition that lacks highly effective treatment methods. After CIRI, microglia in the cortex of mice show high expression of CD44, which offers a potential target for the development of targeted drug-delivery systems to treat ischemic brain injury.
Objective:
This study aimed to design a targeted drug-delivery system for ischemic brain injury, and explore the underlying molecular mechanisms on CIRI.
Methodology:
Hyaluronic acid-PEG-DSPE@metformin (HA@MET) nanoparticles were designed to specifically target the CD44 receptor on microglia. HA@MET was used to intervene in a CIRI mouse model, and then the infarct size and neurological scores were measured. Moreover, experiments on the expression of autophagy-related proteins (Beclin-1, Atg5, Sirt3), the production of reactive oxygen species (ROS), the activation of the NLRP3 inflammasome and the release of associated inflammatory factors (Caspase-1, IL-6, IL-1β) were performed.
Results:
In the CIRI mouse model, HA@MET treatment led to a significant reduction in infarct size and an improvement in neurological scores, indicating a strong therapeutic effect on ischemic brain injury. Mechanistically, HA@MET inhibited the expression of key autophagy proteins Beclin-1 and Atg5, while increasing the expression of Sirt3 protein. This action alleviated excessive mitochondrial autophagy and promoted the clearance of damaged mitochondria. After entering microglia, HA@MET released metformin, which decreased ROS production and inhibited the activation of the NLRP3 inflammasome, resulting in reduced concentrations of inflammatory factors (Caspase-1, IL-6, IL-1β) and alleviating the inflammatory responses associated with CIRI.
Conclusions:
This study provides new perspectives and potential therapeutic targets for the treatment of ischemic brain injury. HA@MET, as a targeted drug-delivery system, shows promise in treating CIRI through multiple mechanisms, including regulating mitochondrial autophagy and inhibiting inflammation.

