Multilayer nanoarchitectonics of polypeptide capsules with size-selective permeability

Area of Science:

• Biomaterials Science
• Nanotechnology
• Polymer Chemistry

Background:

• Layer-by-Layer (LbL) assembly is a versatile technique for fabricating multilayered nanostructures.
• Liposomes serve as effective soft templates for creating complex capsule architectures.
• Biocompatible polypeptides offer promising building blocks for drug delivery and nanomedicine applications.

Purpose of the Study:

• To fabricate hollow nanocapsules using LbL assembly of polypeptides on liposomal templates.
• To characterize the morphology, integrity, and permeability of the resulting polypeptide capsules.
• To investigate the size-selective transport properties of the nanocapsule shells.

Main Methods:

• Fabrication of hollow nanocapsules via LbL assembly of poly(l-lysine) (PLL) and poly(glutamic acid) (PGA) on liposomes.
• Characterization using zeta potential, dynamic light scattering (DLS), and atomic force microscopy (AFM).
• Permeability studies using pH-sensitive dye (HPTS) and fluorescent probe (calcein) diffusion experiments.

Main Results:

• Successful fabrication of hollow polypeptide nanocapsules after template removal.
• Demonstrated size-selective permeability: rapid ion transport but restricted diffusion of larger molecules.
• Correlation of transport behavior with the hierarchical structure and hydration of polypeptide multilayers.

Conclusions:

• LbL assembly provides a method for creating biocompatible hollow nanocapsules with tunable size-selective permeability.
• The findings offer mechanistic insights into transport regulation in polypeptide multilayer shells.
• These results lay the groundwork for designing polypeptide-based carriers with controlled release functionalities.