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Gene-therapy Inspired Polycation Coating for Protection of DNA Origami Nanostructures
Published on: January 19, 2019
Polyamine/DNA polyplexes with acid-degradable polymeric shell as structurally and functionally virus-mimicking
Soo Kyung Cho1, Young Jik Kwon
1Medicinal Chemistry & Pharmacology Gateway Program, University of California, Irvine, CA 92697, USA.
Summary
Adding an acid-degradable polyketal shell to polyamine/DNA complexes significantly boosts gene delivery efficiency. These core-shell nanoparticles improve cellular uptake and intracellular trafficking for enhanced transfection.
Area of Science:
- Biotechnology
- Gene Delivery
- Nanomedicine
Background:
- Nonviral vectors offer safety advantages over viral vectors but suffer from low transfection efficiency.
- Bioavailable polyamines like protamine sulfate (PS) and spermine (SPM) interact well with nucleic acids but exhibit poor intracellular processing.
- Improving transfection efficiency is key to leveraging nonviral vector benefits.
Purpose of the Study:
- To enhance the transfection efficiency of polyamine/DNA complexes using an acid-degradable polyketal (PK) shell.
- To create core-shell nanoparticles mimicking viral vector structure for improved gene delivery.
- To investigate the impact of the PK shell on cellular uptake, intracellular trafficking, and transfection capability.
Main Methods:
- PS/DNA and SPM/DNA polyplexes were coated with an acid-degradable PK layer via surface-initiated photopolymerization.
- The resulting core-shell nanoparticles were characterized for their structure and gene-carrying capabilities.
- Transfection efficiency, cellular uptake, and intracellular DNA release were assessed using confocal microscopy and cell-based assays.
- The stability of lyophilized nanoparticles was also evaluated.
Main Results:
- Polyamine/PK core-shell nanoparticles demonstrated significantly enhanced transfection efficiency compared to polyamine/DNA polyplexes alone.
- Confocal microscopy confirmed efficient DNA release into the nucleus from PS/PK nanoparticles.
- SPM/PK nanoparticles showed substantially increased cellular uptake.
- Lyophilized polyamine/PK core-shell nanoparticles retained their transfection capability.
Conclusions:
- An acid-degradable PK shell effectively shields and then exposes polyamine/DNA polyplexes within the endosome.
- The PK shell significantly improves cellular internalization and intracellular trafficking, leading to enhanced gene transfection.
- These core-shell nanoparticles represent a promising strategy for improving nonviral gene delivery systems.
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