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Ensemble Force Spectroscopy by Shear Forces
Published on: July 26, 2022
Direct force measurements between siRNA and chitosan molecules using force spectroscopy
Sailong Xu1, Mingdong Dong, Xiudong Liu
1Interdisciplinary Nanoscience Center, University of Aarhus, DK-8000 Aarhus, Denmark.
Biophysical Journal
|May 8, 2007
Summary
The interaction strength between small interfering RNA (siRNA) and chitosan is pH-dependent. Lower pH enhances siRNA-chitosan complex formation and nanoparticle stability, crucial for gene silencing delivery systems.
Area of Science:
- Biomaterials Science
- Nanotechnology
- Molecular Biology
Background:
- Chitosan/siRNA nanoparticles are key for gene silencing.
- Understanding siRNA-chitosan interactions is vital for optimizing these delivery systems.
- Force spectroscopy offers a method to quantify molecular interactions.
Purpose of the Study:
- To investigate the interaction strength between siRNA and chitosan.
- To determine the influence of pH on these interactions.
- To correlate interaction forces with nanoparticle stability for gene delivery.
Main Methods:
- Utilized atomic force microscopy (AFM) for force spectroscopy measurements.
- Measured interaction forces between siRNA and chitosan in phosphate-buffered saline (PBS).
- Evaluated interactions across a pH range (4.1 to 9.5).
Main Results:
- Adhesive interactions between siRNA and chitosan decreased with increasing pH.
- Distinct multimodal force distributions were observed at acidic pH.
- Negligible adhesive forces were detected at neutral and high pH.
- Strong pH dependence of siRNA-chitosan interactions was confirmed.
Conclusions:
- The pH-dependent nature of siRNA-chitosan interactions explains complex formation and nanoparticle stability.
- Force spectroscopy is a valuable tool for assessing siRNA-chitosan complexing ability.
- Findings can predict nanoparticle stability for siRNA delivery applications.
