Refining the Design of Diblock Elastin-Like Polypeptides for Self-Assembly into Nanoparticles

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Drug Delivery Systems

Background:

• Elastin-like polypeptides (ELPs) are stimuli-responsive biopolymers.
• ELPs exhibit tunable phase transitions upon thermal stimulation.
• ELP-based carriers offer potential for targeted active molecule delivery.

Purpose of the Study:

• To design and investigate a library of ELP diblock copolymers.
• To explore the self-assembly and phase transition behavior of novel ELP diblocks.
• To establish controlled formation of unimers, micelles, and aggregates for cargo encapsulation.

Main Methods:

• Synthesis of ELP diblock copolymers with varying sequences (ELP-[M1V3-i]-[I-j]).
• Selective oxidation of methionine residues within the ELP diblock structures.
• Characterization of self-assembly and thermal phase transition properties.

Main Results:

• ELP-[M1V3-i]-[I-j] diblocks demonstrated similar self-assembly to monoblocks.
• Selective methionine oxidation unlocked distinct thermal phase transition regimes.
• Three regimes were observed: unimers, micelles, and aggregates, characteristic of well-defined ELP diblocks.

Conclusions:

• Designed ELP diblock copolymers exhibit controlled thermal phase transitions.
• Selective oxidation is a viable strategy to tune ELP diblock behavior.
• These findings pave the way for advanced ELP-based drug delivery systems.