Highly-Strong and Highly-Tough Alginate Fibers with Photo-Modulating Mechanical Properties

Area of Science:

• Materials Science
• Biomaterials Engineering
• Polymer Chemistry

Background:

• Achieving high strength and toughness simultaneously in biomaterials remains a significant design challenge.
• Existing robust biomaterials lack dynamic mechanical responses to external stimuli like light at room temperature, limiting their applications.

Purpose of the Study:

• To fabricate novel photoresponsive alginate fibers capable of significant, reversible mechanical property modulation.
• To introduce a new design strategy for creating highly strong and tough photoresponsive biomaterials.

Main Methods:

• Fabrication of alginate fibers using azobenzene-containing surfactants as cross-linkers for polysaccharide chains.
• Utilizing the photoisomerization of azobenzene to induce reversible changes in mechanical properties.
• Characterization of mechanical properties, including breaking strength and toughness, under light stimulus.

Main Results:

• The fabricated alginate fibers demonstrated high mechanical strength and toughness, with reversible photo-modulation.
• Breaking strength and toughness were modulated from 732 MPa and 112 MJ m⁻³ to 299 MPa and 27 MJ m⁻³, respectively.
• Achieved record-high mechanical changes among smart biomaterials, with fast light response and good biocompatibility.

Conclusions:

• The developed photoresponsive alginate fibers offer a new class of smart biomaterials with tunable mechanical properties.
• The design strategy provides a pathway for creating advanced biomaterials suitable for diverse applications requiring light-responsiveness.
• These fibers exhibit excellent tolerance to pH and temperature, enhancing their potential for practical use.