Engineered Chitosan-Derived Nanocarrier for Efficient siRNA Delivery to Peripheral and Central Neurons

Area of Science:

• Neuroscience
• Biotechnology
• Gene Therapy

Background:

• Neurological disorders can be targeted by gene therapy using small interfering RNA (siRNA) to silence genes like PTEN, which inhibits axonal growth.
• Current siRNA delivery methods to neurons face challenges including degradation and non-specific delivery, with chitosan systems showing low efficiency and neurotropism.

Purpose of the Study:

• To develop and evaluate a novel thiolated trimethyl chitosan (TMCSH)-based siRNA nanoparticle system for efficient and neurospecific delivery to neurons.
• To functionalize these nanoparticles with the tetanus neurotoxin heavy chain (HC) fragment to enhance neuronal targeting and transport.

Main Methods:

• siRNA nanoparticles were formulated using TMCSH and functionalized with the HC fragment.
• Physicochemical properties, biocompatibility, and electrophysiological effects were assessed.
• Neuronal delivery efficiency and neurospecificity were confirmed in diverse neuronal models (3D ex vivo, microfluidics).
• Retrograde axonal transport was visualized using live cell imaging.

Main Results:

• The HC-functionalized polyplexes exhibited suitable physicochemical properties and biocompatibility without adverse effects on neuronal electrophysiology.
• Demonstrated efficient and neurospecific delivery in various neuronal models.
• HC-functionalization significantly improved neuronal binding and accelerated retrograde axonal transport by fivefold.
• PTEN-targeting siRNA delivery successfully promoted axonal outgrowth in embryonic cortical neurons.

Conclusions:

• The developed HC-functionalized TMCSH-based siRNA polyplexes represent a promising platform for targeted neuronal gene delivery.
• This approach shows potential for clinical translation in treating neurological disorders by enabling effective siRNA delivery and promoting axonal regeneration.