Artificial Platelets for Efficient siRNA Delivery to Clear "Bad Cholesterol"

Area of Science:

• Biotechnology
• Biomedical Engineering
• Molecular Medicine

Background:

• Low-density lipoprotein cholesterol (LDL-C) is a primary risk factor for coronary heart disease.
• The low-density lipoprotein receptor (LDLR) regulates LDL-C levels, with its function modulated by Proprotein convertase subtilisin/kexin type 9 (PCSK9).
• Reduced PCSK9 activity leads to increased LDLR and lower plasma LDL-C.

Purpose of the Study:

• To develop and evaluate artificial platelets for efficient delivery of siRNA targeting PCSK9.
• To assess the efficacy of this novel delivery system in reducing PCSK9 mRNA and plasma LDL-C levels.
• To explore a potential RNA interference (RNAi) therapeutic strategy for hypercholesterolemia.

Main Methods:

• Development of bioinspired artificial platelets with biomimetic properties, high stability, and long circulation.
• In vitro delivery of siRNA targeting Pcsk9 using artificial platelets, measuring mRNA reduction.
• In vivo administration of artificial platelets in a model system to assess liver accumulation, Pcsk9 transcription, and plasma lipid levels (LDL-C, HDL-C, TGs).

Main Results:

• Artificial platelets successfully delivered siRNA targeting Pcsk9, achieving a 66% reduction in Pcsk9 mRNA in vitro.
• In vivo studies showed nanoparticles accumulating in the liver and reducing Pcsk9 transcription.
• A significant reduction of approximately 28% in plasma LDL-C concentrations was observed, with no significant impact on HDL-C or triglycerides.

Conclusions:

• Artificial platelets serve as an effective platform for siRNA delivery, enabling targeted RNAi therapeutics.
• This approach demonstrates a potential strategy for specifically lowering LDL-C by targeting PCSK9.
• The study presents a promising new therapeutic avenue for managing hypercholesterolemia.