Novel siRNA formulation to effectively knockdown mutant p53 in osteosarcoma

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Cancer Research

Background:

• The tumor suppressor p53 is critical in osteosarcoma development.
• Targeting mutant p53 is a potential therapeutic strategy for osteosarcoma.

Purpose of the Study:

• To develop and optimize lipid-based nanoparticles for siRNA delivery.
• To achieve effective silencing of mutant p53 in a murine osteosarcoma cell line (318-1).

Main Methods:

• Nanoparticles were formulated using cholesterol, DOTAP, and either PLGA or PLGA-PEG.
• High-pressure homogenization was used for nanoparticle preparation.
• Optimization involved varying nanoparticle composition, siRNA concentration, cell density, incubation time, and storage conditions.

Main Results:

• PLGA or PLGA-PEG incorporation reduced particle size and cytotoxicity.
• Nanoparticles with 10% PLGA demonstrated the highest mutant p53 knockdown efficiency.
• Optimal silencing was achieved with a nanoparticle to siRNA ratio of 6.8:0.66 and 75 nM siRNA, maintaining high cell viability.
• Long-term storage led to a significant decrease in gene silencing efficiency.

Conclusions:

• The developed lipid-polymer nanoparticles show promise for targeting mutant p53 in osteosarcoma.
• Further evaluation in tissue culture and animal models is warranted for potential therapeutic applications.
• Formulation stability requires further investigation for clinical translation.