Carbon Quantum Dots Assisted Virus Tracking: From Skin to Brain

Area of Science:

• Neurovirology
• Biomedical Engineering
• Infectious Diseases

Background:

• Herpes simplex virus 1 (HSV-1) infection can lead to severe neurological conditions like encephalitis and neurodegenerative diseases.
• The precise pathways HSV-1 uses to travel from peripheral infection sites to the brain are not fully understood.
• Understanding HSV-1 neuroinvasion is crucial for developing effective treatments and preventative strategies.

Purpose of the Study:

• To develop and utilize an innovative method for real-time tracking of HSV-1 neuroinvasion from the skin to the brain.
• To elucidate the primary routes HSV-1 takes to reach the central nervous system after peripheral infection.
• To investigate the impact of spinal cord injury on HSV-1 transport dynamics.

Main Methods:

• Development of a dual system combining carbon quantum dots (CQDs) for labeling HSV-1 and dissolving microneedles (dMN) for targeted delivery.
• Application of CQDs-labeled HSV-1 via dMN on skin and real-time in vivo imaging to monitor viral movement.
• Utilizing a microfluidic system to observe HSV-1 infection and transport in cultured neurons (SH-SY5Y cells).

Main Results:

• HSV-1 preferentially infects peripheral skin nerves and rapidly travels to the brain via the spinal cord within 10-30 minutes.
• Spinal cord injury significantly impedes HSV-1 transport from the skin to the brain, but not from the bloodstream.
• In vitro studies confirmed HSV-1's preference for infecting neurites and subsequent transport to neuronal cell bodies.

Conclusions:

• The combined CQDs and dMN approach provides a powerful tool for visualizing neurotropic virus transport in real-time.
• The spinal cord serves as a major and rapid route for HSV-1 entry into the brain from peripheral skin infections.
• This study offers critical insights into viral neuroinvasion mechanisms, potentially guiding future therapeutic interventions for HSV-1-associated neurological disorders.