Physicochemical characterization of siRNA-peptide complexes

Area of Science:

• Biochemistry
• Molecular Biology
• Nanotechnology

Background:

• Short interfering RNAs (siRNAs) are crucial for RNA interference (RNAi) but suffer from poor stability and low cellular uptake.
• Effective delivery carriers are needed to overcome siRNA degradation and improve transfection efficiency for therapeutic applications.

Purpose of the Study:

• To investigate Arginine-9 (R9), a cell-penetrating peptide, as a carrier for connective tissue growth factor (CTGF) siRNA.
• To characterize the physicochemical properties of siRNA-R9 complexes for potential breast cancer treatment.

Main Methods:

• Complexation and interaction studies using UV/vis spectroscopy and circular dichroism (CD).
• Characterization of complex size and surface charge via dynamic light scattering (DLS) and Zeta potential measurements.
• Assessment of salt effects on complex properties using UV/vis spectroscopy.

Main Results:

• siRNA and R9 readily formed stable complexes/aggregates.
• Complex surface charge changed with increasing peptide concentration, reaching a maximum hydrodynamic diameter of approximately 1 µm.
• Binding ratios of R9 to siRNA were determined using spectroscopy and light scattering techniques.

Conclusions:

• Physicochemical characterization provides a basis for controlling siRNA-peptide complex properties.
• R9 shows potential as a carrier for siRNA therapeutics, improving stability and delivery.
• This research supports the development of peptide-based siRNA delivery systems for cancer therapy.