Hydrolytically Degradable PEGylated Polyelectrolyte Nanocomplexes for Protein Delivery.

Area of Science:

• Polymer Chemistry
• Biomaterials Science
• Nanotechnology

Background:

• Developing effective protein delivery vehicles is crucial for therapeutics.
• Covalent modification of proteins can alter their activity and immunogenicity.
• Biodegradable and biocompatible materials are needed for advanced drug delivery systems.

Purpose of the Study:

• To synthesize novel polyphosphazene polyelectrolytes for self-assembly into PEGylated nanoparticles.
• To evaluate these nanoparticles for non-covalent PEGylation of therapeutic proteins.
• To assess the impact of PEGylation on protein stability, activity, and antigenicity.

Main Methods:

• Synthesis of oppositely charged polyphosphazene polyelectrolytes with grafted poly(ethylene glycol) (PEG) chains.
• Formulation of supramolecular assemblies (nanocomplexes) under physiological conditions.
• Characterization of nanocomplexes using zeta potential, enzyme-linked immunosorbent assay (ELISA), and gel permeation chromatography (GPC).

Main Results:

• Successfully synthesized biodegradable polyphosphazene polyelectrolytes that self-assemble into stable, PEGylated nanocomplexes (<100 nm).
• Demonstrated significant reduction in l-asparaginase (L-ASP) antigenicity and improved thermal/proteolytic stability upon encapsulation.
• Confirmed that encapsulation did not compromise L-ASP enzymatic activity and that polyphosphazenes exhibit controlled hydrolytic degradability.

Conclusions:

• Novel hydrolytically degradable polyphosphazene polyelectrolytes enable spontaneous self-assembly into PEGylated nanoparticulates.
• These systems offer a simple, effective approach for non-covalent modification of therapeutic proteins.
• The developed technology has potential for improving protein-based therapeutics by reducing immunogenicity and enhancing stability.