Polysaccharide-based polyelectrolyte complex nanoparticles from chitosan, heparin, and hyaluronan.

Area of Science:

• Materials Science
• Biotechnology
• Nanotechnology

Background:

• Polyelectrolyte complex nanoparticles (PCN) are formed by electrostatic interactions between polycations and polyanions.
• Chitosan, heparin, and hyaluronan are biocompatible polysaccharides with potential applications in drug delivery and tissue engineering.
• Controlling PCN formation is crucial for tailoring their properties for specific applications.

Purpose of the Study:

• To investigate the formation of PCN using chitosan-heparin and chitosan-hyaluronan at varying charge mixing ratios.
• To analyze the effect of charge mixing ratio on PCN size, zeta potential, morphology, and stability.
• To understand the behavior of PCN when adsorbed onto surfaces and subjected to drying.

Main Methods:

• Preparation of PCN by mixing polycation and polyanion solutions at different charge mixing ratios (n(+)/n(-)) ranging from 0.08 to 19.2.
• Characterization of PCN in solution using dynamic light scattering for size and zeta potential measurements.
• Evaluation of PCN morphology and surface behavior using scanning electron microscopy (SEM) after adsorption and drying.

Main Results:

• Colloidally stable, nonstoichiometric PCN were successfully formed in solution under most conditions.
• PCN formation was inhibited by flocculation at charge mixing ratios close to 1.
• Surface adsorption and drying led to varied morphologies, including discrete nanoparticles, aggregation, or coalescence depending on the formulation.

Conclusions:

• The charge mixing ratio significantly influences the formation, stability, and surface morphology of chitosan-based PCN.
• Nonstoichiometric ratios favor the formation of stable PCN in solution.
• Surface behavior of PCN is highly dependent on the initial formulation and processing conditions, impacting their potential for surface-based applications.