Coacervation of Elastin-Like Recombinamer Microgels

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Biophysics

Background:

• Biomicrogels show potential as drug carriers.
• Self-aggregation (coacervation) can lead to loss of activity, toxicity, and immunogenicity.
• Understanding coacervation is crucial for safe and effective biomicrogel applications.

Purpose of the Study:

• To investigate the coacervation behavior of elastin-like recombinamer microgels.
• To analyze the influence of concentration and temperature on microgel coacervation.
• To explore the simultaneous occurrence of volume phase temperature transition and coacervation.

Main Methods:

• Synthesis of elastin-like microgels via miniemulsion technique.
• Characterization using cryo-field emission scanning electron microscopy (cryo-FESEM) and cryo-transmission electron microscopy (cryo-TEM).
• Advanced analysis using novel proton (1H) high-resolution magic angle sample spinning (HRMAS) nuclear magnetic resonance (NMR) spectroscopy and relaxometry.

Main Results:

• Coacervation was confirmed in elastin-like microgels across various conditions.
• Proton (1H) NMR spectroscopy and relaxometry revealed simultaneous volume phase temperature transition and coacervation.
• Differential sensitivity of hydrophobic and hydrophilic amino acid side-chains to coacervation was observed.

Conclusions:

• Elastin-like microgels undergo coacervation, a process influenced by temperature and concentration.
• The study demonstrates the utility of (1H) HRMAS NMR and relaxometry for elucidating complex microgel behaviors.
• Findings highlight the distinct responses of glycine and proline residues during coacervation, offering insights into microgel structure-property relationships.