Hydroxyl-functionalized and N-doped multiwalled carbon nanotubes decorated with silver nanoparticles preserve...

Area of Science:

• Materials Science
• Nanotechnology
• Biocompatibility Studies

Background:

• Silver nanoparticles (Ag-NPs) are widely explored for biomedical applications but often exhibit toxicity.
• Carbon nanotubes (CNTs) offer unique properties as scaffolds for nanomaterials.
• Functionalizing CNTs can alter their interaction with nanoparticles and biological systems.

Purpose of the Study:

• To investigate the biocompatibility of silver nanoparticles (Ag-NPs) anchored to different types of multiwalled carbon nanotubes (MWNTs).
• To evaluate the potential of these novel Ag-nanotube hybrid materials as drug delivery carriers and biosensors.

Main Methods:

• Synthesis of Ag-NPs anchored to pure MWNTs, carboxyl-functionalized MWNTs (COx-MWNTs), and nitrogen-doped MWNTs (CNx-MWNTs) using a novel chemical route.
• Characterization of Ag-NP size and anchoring on different MWNT substrates.
• Assessment of cellular viability and immune response in human keratinocyte cells (HaCaT) using MTS assays.

Main Results:

• Ag-NPs synthesized without thiol capping groups were strongly anchored to MWNTs, with sizes ranging from 7-12 nm.
• Hybrid Ag-nanotube materials showed marginal toxicity after 24 hours, with full cellular recovery at 48 hours.
• Pure MWNTs showed Ag-NP release after one week, decreasing cell proliferation, while COx-MWNTs and CNx-MWNTs demonstrated strong binding and no significant Ag-NP release.

Conclusions:

• Doped MWNTs (COx-MWNTs and CNx-MWNTs) strongly anchor Ag-NPs, significantly reducing their release and toxicity compared to free Ag-NPs.
• The strong interaction between Ag-NPs and doped nanotube surfaces enhances biocompatibility.
• COx-MWNTs and CNx-MWNTs anchored with Ag-NPs are promising candidates for advanced applications like drug delivery and biosensing.