Direct Laser Writing of Selectively Degradable Polypeptide Hydrogel Microstructures by Proteolytic Enzymes

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Additive Manufacturing

Background:

• Developing materials with controlled degradation is crucial for additive manufacturing.
• Hydrogels are versatile for microstructures but often lack tunable degradation.
• Proteolytic enzymes offer a pathway for selective biomaterial breakdown.

Purpose of the Study:

• To create star polypeptide cross-linkers for direct laser writing of hydrogel microstructures.
• To achieve on-demand, tunable degradation of these microstructures using enzymes.
• To demonstrate selective degradation of printed hydrogels via amino acid-enzyme interactions.

Main Methods:

• Synthesis of star polypeptide cross-linkers with l-lysine and l-alanine.
• Direct laser writing (DLW) for fabricating hydrogel microstructures.
• Multimaterial printing combining hydrogels with photoresists.
• Selective degradation studies using thermolysin and trypsin.

Main Results:

• Successfully fabricated complex hydrogel microstructures using DLW.
• Demonstrated selective degradation of specific microstructure sections.
• Showcased enzyme-specific degradation based on polypeptide composition.
• Confirmed tunable degradability by controlling cross-linker formulation.

Conclusions:

• Star polypeptide cross-linkers enable tunable degradation in 3D printed hydrogels.
• Direct laser writing facilitates the creation of complex, degradable microstructures.
• Enzyme-mediated degradation offers precise control over material breakdown for advanced applications.