Controlling Protein Immobilization over Poly(3-hydroxybutyrate) Microparticles Using Substrate Binding Domain from...

Area of Science:

• Biomaterials Science
• Protein Engineering
• Surface Chemistry

Background:

• Biointerface ligand decoration is essential for controlling nanoparticle biodistribution and enabling targeted delivery.
• Existing methods for functionalizing 3D polyester surfaces with ligands face challenges in efficiency and spatial orientation control.

Purpose of the Study:

• To develop and characterize hybrid proteins with enhanced anchoring efficiency and controlled spatial orientation on polyester surfaces.
• To evaluate the binding affinity of these novel proteins on poly(3-hydroxybutyrate) (PHB) microparticles and 2D surfaces.

Main Methods:

• Engineered hybrid proteins by fusing reporter proteins (sfGFP, mRFP1) and a receptor-binding domain (RBD) to a polyester substrate-binding domain (SBD).
• Assessed protein binding to poly(3-hydroxybutyrate) (PHB) microparticles and 2D surfaces using techniques to quantify protein content.
• Evaluated the internalization and cytotoxicity of RBD-SBD decorated microparticles in MRC5 cells.

Main Results:

• Proteins fused with SBD demonstrated significantly higher binding affinity and content on PHB interfaces compared to untagged proteins.
• The SBD tag effectively enhanced protein immobilization on both microparticle and 2D polyester surfaces.
• RBD-SBD decorated microparticles showed limited internalization and cytotoxicity in MRC5 cells.

Conclusions:

• The developed SBD-based protein system offers a robust strategy for efficient and oriented ligand functionalization of polyester biointerfaces.
• This approach holds significant potential for applications in targeted drug delivery and vaccine development.
• The system minimizes unwanted cellular interactions, paving the way for safer nanomedicine formulations.