Carbon dot-based polyplexes with cell penetration peptides for gene transfection

Area of Science:

• Biomaterials Science
• Nanotechnology
• Gene Therapy

Background:

• Developing efficient gene delivery vectors is crucial for therapeutic applications.
• Carbon nanomaterials and cell-penetrating peptides offer potential for enhanced gene transport.
• Optimizing polyplex formulations requires understanding their physicochemical properties and cellular interactions.

Purpose of the Study:

• To synthesize and characterize polyplexes using graphene oxide quantum dots (GO QDs) or carbon dots (CDs) with cell-penetrating peptides (CPPs) PF14 or PF221.
• To evaluate the gene delivery efficacy of these polyplexes carrying pGL3 plasmids or splice-correcting oligonucleotides (SCOs).
• To elucidate the cellular uptake mechanisms of the most effective polyplex formulations.

Main Methods:

• Synthesis of GO QDs via Hummers' method and acid fragmentation.
• Eco-friendly solvothermal synthesis of CDs using ascorbic acid.
• Characterization using X-ray diffraction (XRD), transmission electron microscopy (TEM), and zeta potential analysis.
• Gene transfection assays to assess delivery efficiency of pGL3 and SCO.
• Mechanistic studies using SCARA-specific inhibitors to determine uptake pathways.

Main Results:

• Successful synthesis and characterization of nanocomplexes with distinct properties.
• PF14-CD polyplexes demonstrated superior efficiency in delivering both pGL3 and SCO compared to GO QD and PF221-based systems.
• Cellular uptake of PF14-SCO-CD polyplexes was significantly inhibited by SCARA-specific inhibitors, indicating scavenger receptor class A-mediated endocytosis.

Conclusions:

• PF14-CD polyplexes represent a highly effective system for gene delivery.
• The primary mechanism for cellular uptake of these optimized polyplexes is scavenger receptor class A-mediated endocytosis.
• This study presents a promising nanocarrier model for efficient gene therapy applications.