Multifunctional dendronized peptide polymer platform for safe and effective siRNA delivery

Area of Science:

• Biomaterials Science
• Nanotechnology
• Molecular Biology

Background:

• RNA interference (RNAi) therapeutics require efficient and safe delivery systems.
• Current delivery vectors often face challenges with stability, toxicity, and efficacy in biological fluids.

Purpose of the Study:

• To design and synthesize a novel biodegradable dendronized polypeptide (denpol) platform for enhanced small interfering RNA (siRNA) delivery.
• To optimize denpol architecture for improved siRNA binding, cellular uptake, and endosomal escape.
• To evaluate the in vitro efficacy and safety profile of the developed denpol system.

Main Methods:

• Synthesis of biodegradable dendronized polypeptides (denpols) incorporating multifunctional amino acids.
• Systematic and combinatorial tuning of denpol structure to optimize siRNA complexation and delivery.
• In vitro transfection of NIH 3T3 cells with siRNA using denpol carriers.
• Assessment of cellular toxicity and comparison with commercial transfection agents (e.g., Lipofectamine).
• Intracellular trafficking studies using fluorescence microscopy to elucidate delivery mechanisms.

Main Results:

• Identified several denpol candidates demonstrating effective siRNA delivery to NIH 3T3 cells with minimal toxicity.
• The lead denpol candidate exhibited significantly higher transfection efficiency compared to Lipofectamine in serum-containing media.
• Amphiphilicity of denpols was found to be crucial for cellular uptake.
• Histidine's buffering capacity was shown to facilitate endosomal escape, enhancing transfection.

Conclusions:

• The developed biodegradable denpol platform offers a promising and efficient system for siRNA delivery.
• The denpol system demonstrates superior performance in serum-containing media and exhibits low cytotoxicity.
• This novel carrier holds potential for advancing RNAi-based therapeutics.