Encapsulation of Protein-Polysaccharide HIP Complex in Polymeric Nanoparticles

Area of Science:

• Biotechnology
• Materials Science
• Pharmaceutical Sciences

Background:

• Hydrophobic ion pairing (HIP) complexation is typically limited to smaller proteins (<20 kDa).
• Developing effective nanoparticulate formulations for larger macromolecules like bovine serum albumin (BSA) remains a challenge.
• There is a need for advanced drug delivery systems capable of encapsulating and stabilizing large biomolecules.

Purpose of the Study:

• To formulate and characterize a nanoparticulate-based formulation of a macromolecule using hydrophobic ion pairing (HIP) complexation.
• To investigate the feasibility of HIP complexation for a high molecular weight protein, bovine serum albumin (BSA) (66.3 kDa).
• To prepare and optimize nanoparticles encapsulating the BSA-HIP complex and assess structural integrity.

Main Methods:

• Hydrophobic ion pairing (HIP) complex formation between bovine serum albumin (BSA) and dextran sulphate (DS).
• Fourier-transform infrared (FTIR) spectroscopy to confirm ionic interactions.
• Nanoparticle preparation using PLGA polymer and characterization of size and surface morphology.
• Circular dichroism (CD) and intrinsic fluorescence assays to evaluate BSA's secondary and tertiary structures.

Main Results:

• Optimized HIP complex formation between BSA and dextran sulphate (DS).
• Successful preparation of nanoparticles with significant BSA entrapment using minimal PLGA.
• FTIR confirmed ionic interactions between BSA and DS.
• CD and fluorescence assays demonstrated that HIP complexation and nanoparticle preparation preserved BSA's native structure.

Conclusions:

• The hydrophobic ion pairing (HIP) approach is effective for complexing high molecular weight proteins like BSA with polymers such as dextran sulphate (DS).
• Nanoparticle formulation using this HIP complex successfully entrapped BSA without compromising its secondary and tertiary structures.
• This study validates a novel method for developing macromolecule-loaded nanoparticles, applicable to larger biomolecules for potential therapeutic applications.