Melanin-Inspired Maleimide Coatings on Various Substrates for Rapid Thiol Functionalization

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Bioconjugation

Background:

• Developing robust and versatile surface coatings is crucial for advanced bioengineering applications.
• Existing methods like polydopamine coatings often require harsh conditions and long reaction times.
• There is a need for efficient and mild surface functionalization techniques.

Purpose of the Study:

• To develop a substrate-independent maleimide film for rapid and efficient thiol immobilization.
• To create a melanin-inspired coating using tyrosine-conjugated maleimide (Tyr-Mal) and tyrosinase.
• To demonstrate the advantages of the new film over existing surface platforms.

Main Methods:

• Preparation of tyrosine-conjugated maleimide (Tyr-Mal) as a coating precursor.
• Formation of a melanin-inspired maleimide (Mel-Mal) film on various substrates under mild aqueous conditions (pH 7.4) via enzymatic reaction mimicking melanogenesis.
• Immobilization of thiol-containing molecules onto the Mel-Mal film via Michael addition reaction.

Main Results:

• A substrate-independent Mel-Mal film was successfully formed under mild aqueous conditions (pH 7.4).
• The Mel-Mal film enabled rapid (< 30 min) and efficient surface thiol immobilization.
• The developed platform showed significant improvements in reaction kinetics and usability compared to polydopamine films.

Conclusions:

• The Mel-Mal film offers a significant advancement for surface functionalization, particularly for thiol conjugation.
• Its mild reaction conditions and rapid kinetics make it suitable for sensitive applications like living cell surfaces.
• This platform holds promise for applications in cell surface engineering, microarrays, and high-throughput screening.