Structural and mechanical properties of folded protein hydrogels with embedded microbubbles

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Protein Engineering

Background:

• Globular folded proteins offer robust mechanical properties and biological functions, making them suitable for advanced biomaterials.
• Protein-based hydrogels are explored for drug delivery, but controlling release remains a challenge.

Purpose of the Study:

• To investigate the incorporation and behavior of microbubbles (MBs) within a photo-activated, cross-linked bovine serum albumin (BSA) protein network.
• To assess the structural, mechanical, and release characteristics of this novel multi-composite system for drug delivery applications.

Main Methods:

• Circular dichroism (CD) to analyze protein folding.
• Rheology to characterize mechanical properties.
• Small-angle neutron scattering (SANS) for nanoscale structural analysis.
• Optical and confocal microscopy to visualize microbubble integration and diffusion.

Main Results:

• Microbubbles (MBs) were successfully embedded within the BSA protein hydrogel without altering protein folding.
• Ultrasound application effectively ruptured the MBs, indicating potential for burst drug release.
• The presence of MBs reduced the overall mechanical strength of the BSA hydrogel.
• Small-angle neutron scattering revealed changes in protein network clustering upon MB embedding.

Conclusions:

• Microbubbles can be effectively integrated into folded protein networks and ruptured using ultrasound.
• Understanding the nanoscale and mesoscale impact of embedded MBs is crucial for developing targeted drug delivery platforms.
• This study provides fundamental insights for designing advanced protein-based scaffolds for controlled therapeutic release.