Development of self-assembling mixed protein micelles with temperature-modulated avidities

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Protein Engineering

Background:

• Elastin-like polypeptides (ELPs) are stimuli-responsive biopolymers that undergo reversible phase transitions.
• ELPs can be engineered into complex architectures like diblock copolymers for advanced applications.
• Controlling protein-ligand interactions with stimuli-responsive materials is crucial for targeted delivery.

Purpose of the Study:

• To design and characterize ELP-based mixed micelles capable of temperature-modulated fibrinogen binding.
• To investigate the potential of these engineered micelles for in vivo depot applications.
• To demonstrate temperature-triggered release of bound fibrinogen.

Main Methods:

• Synthesis of ELP diblock copolymers with varying transition temperatures.
• Formation and characterization of mixed micelles using dynamic light scattering (DLS), multiangle light scattering (MALS), and fluorescence resonance energy transfer (FRET).
• Functionalization with fibrinogen-binding (GPRP) and control (GPSP) peptide sequences.

Main Results:

• Formation of stable ∼55 nm mixed micelles from ELP diblocks.
• Successful fusion of peptide sequences to ELP blocks, conferring specific binding properties.
• Demonstrated temperature-dependent binding and release of fibrinogen at 32 °C and 42 °C.
• Engineered micelles showed disengagement of fibrinogen at elevated temperatures.

Conclusions:

• Engineered ELP mixed micelles offer a modular platform for temperature-controlled protein interactions.
• The system demonstrates potential for developing stimuli-responsive in vivo depot systems.
• Temperature-triggered release of fibrinogen highlights the utility for targeted drug delivery applications.