Lysine-functionalized nanodiamonds: synthesis, physiochemical characterization, and nucleic acid binding studies

Area of Science:

• Nanotechnology
• Biomaterials Science
• Molecular Biology

Background:

• Detonation nanodiamonds (NDs) are biocompatible nanomaterials with potential in bioimaging and drug delivery.
• NDs tend to aggregate in liquid, limiting their biomedical applications.
• Developing stable, functionalized NDs is crucial for their use as nonviral vectors.

Purpose of the Study:

• To covalently functionalize detonation nanodiamonds (NDs) with lysine.
• To create stable, nonviral nanoparticles for genetic material delivery.
• To investigate the potential of lysine-functionalized NDs as carriers for plasmid DNA and small interfering RNA.

Main Methods:

• Oxidation and lysine functionalization of NDs via amide bonds using a 1,3-diaminopropane linker.
• Characterization using Raman spectroscopy, FTIR, zeta potential, DLS, AFM, and TGA.
• Assessment of DNA and RNA binding capacity using gel electrophoresis and DLS.

Main Results:

• Successful lysine functionalization of NDs with a surface loading of 1.7 mmol g(-1).
• Formation of highly stable aqueous dispersions (zeta potential 49 mV, size ~20 nm).
• Demonstrated binding of plasmid DNA and small interfering RNA, forming nanosized "diamoplexes".

Conclusions:

• Lysine-substituted ND particles form stable aqueous formulations.
• These modified NDs show significant potential as carriers for genetic materials.
• The developed nanoparticles offer a promising solution for nonviral gene delivery.