Organized shells on clay nanotubes for controlled release of macromolecules

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Halloysite nanotubes (HNTs) are natural aluminosilicate clay minerals with a hollow tubular structure.
• Layer-by-layer (LbL) assembly is a versatile technique for fabricating thin films and coatings.
• Controlled drug release systems are crucial for improving therapeutic efficacy and reducing side effects.

Purpose of the Study:

• To investigate the use of halloysite clay nanotubes as nanotemplates for layer-by-layer (LbL) shell assembly.
• To evaluate the controlled release of drug macromolecules from these LbL-coated halloysite nanostructures.
• To explore the influence of shell properties on drug release kinetics.

Main Methods:

• Utilizing tubular halloysite clay as a core nanostructure.
• Assembling polyelectrolyte shells (chitosan and gelatin) onto halloysite nanotubes via LbL assembly.
• Loading drug macromolecules (dexamethasone) into the halloysite lumen.
• Investigating the effect of polymeric shell thickness and molecular weight on drug release rates.

Main Results:

• LbL nanoshells on halloysite nanotubes enabled controlled, sustained release of loaded drug macromolecules.
• The number of polymeric bilayers and polymer molecular weight significantly influenced the drug release rate.
• Three bilayer shells (chitosan/gelatin, 15 nm thickness) demonstrated optimal encapsulation and retarded release of dexamethasone.
• The combination of lumen encapsulation and polyelectrolyte shell formation provided a novel controlled release formulation.

Conclusions:

• Halloysite nanotubes serve as effective nanotemplates for creating drug delivery systems.
• LbL assembly provides tunable control over drug release kinetics from halloysite-based nanocarriers.
• This novel formulation offers a promising approach for the controlled release of bioactive agents.