Albumin-based nanoparticle trehalose lyophilisation stress-down to preserve structure/function and enhanced binding

Area of Science:

• Biomaterials Science
• Nanotechnology
• Pharmaceutical Sciences

Background:

• Albumin nanoparticles are promising drug delivery vehicles.
• Lyophilization is a common method for preserving nanoparticles but can affect their structure and function.
• Optimizing lyophilization conditions is crucial for maintaining nanoparticle integrity.

Purpose of the Study:

• To investigate the optimal lyophilization conditions for bovine serum albumin (BSA) nanoparticles.
• To preserve the structural integrity and functional properties of BSA nanoparticles during freeze-drying.
• To evaluate the effect of lyophilization on nanoparticle size, charge, surface chemistry, and binding affinity.

Main Methods:

• BSA nanoparticles were prepared using gamma irradiation.
• Nanoparticles were lyophilized in different solutions: buffer (PBS), miliQ water, and trehalose/miliQ solution.
• Particle size and zeta potential were measured using light scattering and Z-potential analysis.
• Surface amino acid (SH group) exposure was determined.
• Binding affinity with merocyanine 540 was assessed.

Main Results:

• Lyophilization in PBS resulted in aggregates (20–350nm) with a zeta potential of -37±8mV.
• Lyophilization with trehalose yielded nanoparticles of 70±2nm with a zeta potential of -20±5mV.
• Trehalose-preserved nanoparticles showed no significant change in SH group exposure compared to non-lyophilized controls.
• BSA nanoparticles lyophilized with trehalose exhibited enhanced binding affinity for merocyanine 540.

Conclusions:

• Lyophilization in 100μM trehalose solution is the optimal method for preserving BSA nanoparticle structure and function.
• Trehalose protects against aggregation and surface changes during lyophilization.
• This optimized lyophilization process enhances the binding capabilities of BSA nanoparticles for theragnostic applications.