NIR-Responsive Functionalized Nanoflower for Acute Spinal Cord Injury.

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Neuroscience

Background:

• Spinal cord injury (SCI) pathogenesis involves reactive oxygen species (ROS) and M1 macrophages.
• Therapies targeting ROS elimination and M1 macrophage repolarization are needed for SCI.
• Current treatments face challenges in crossing the blood-spinal cord barrier (BSCB).

Purpose of the Study:

• To develop a Prussian blue-based nanoflower (KPBF) with antioxidant and photothermal properties.
• To enhance KPBF's ability to penetrate the BSCB for targeted SCI treatment.
• To evaluate KPBF's efficacy in repolarizing M1 macrophages and alleviating neuroinflammation in SCI.

Main Methods:

• Development of a Prussian blue-based nanoflower (KPBF).
• Incorporation of CKLVFFAED peptide for enhanced BSCB penetration.
• Assessment of KPBF's antioxidant activity, ROS scavenging, and M1 macrophage repolarization.
• Evaluation of NIR photothermal effects on SCI lesions in mice.
• Analysis of neuroinflammation markers and SCI recovery in treated mice.

Main Results:

• KPBF demonstrated antioxidant enzyme-like biofunctions, reducing ROS.
• Near-infrared (NIR) irradiation with KPBF effectively heated SCI lesions.
• CKLVFFAED peptide modification enabled significant KPBF penetration across the BSCB.
• KPBF successfully repolarized M1 macrophages, reducing neuroinflammation in SCI mice.
• KPBF treatment promoted acute SCI recovery.

Conclusions:

• KPBF serves as a versatile nanotherapeutic system for acute SCI.
• The developed KPBF exhibits potent antioxidant and immunoregulation activities.
• KPBF's ability to cross the BSCB and target M1 macrophages offers a promising therapeutic strategy for SCI.