Optimization of PEGylation conditions for BSA nanoparticles using response surface methodology

Area of Science:

• Biomaterials Science
• Nanotechnology
• Pharmaceutical Sciences

Background:

• Polyethylene glycol (PEG)ylation enhances nanoparticle circulation half-life, reduces immunogenicity, and promotes tumor accumulation via the enhanced permeability and retention effect.
• Bovine serum albumin (BSA) nanoparticles offer a biodegradable platform for drug delivery applications.

Purpose of the Study:

• To optimize the PEGylation process for BSA nanoparticles using response surface methodology.
• To investigate the effect of process variables on PEGylation efficiency and characterize the resulting nanoparticles.

Main Methods:

• BSA nanoparticles were prepared using a phase separation method.
• PEGylation was achieved by chemically coupling succinimidyl-phenylacetate (SPA) activated mPEG to the free amino groups of BSA nanoparticles.
• Response surface methodology was employed to optimize PEGylation conditions, with PEGylation efficiency as the response variable.

Main Results:

• Optimal PEGylation conditions were determined as 32.5 g/l PEG concentration, 10 min incubation time, 27°C incubation temperature, and pH 7 for 5 mg BSA nanoparticles in 1 mL buffer.
• PEG concentration significantly impacted PEGylation efficiency, while pH had a minimal effect.
• PEGylated nanoparticles exhibited a mean diameter of 217 nm and a zeta potential of -14 mV, compared to -31.7 mV for non-PEGylated nanoparticles.
• Drug release from PEGylated nanoparticles was slower than from non-PEGylated counterparts.

Conclusions:

• Optimized PEGylation significantly reduces the negative surface charge of BSA nanoparticles.
• The reduced surface charge and the presence of a PEG layer on PEGylated nanoparticles likely contribute to slower drug release kinetics.
• PEGylated BSA nanoparticles show promise for improved drug delivery, particularly for tumor targeting due to enhanced circulation and reduced immunogenicity.