Structuring gelatin methacryloyl - dextran hydrogels and microgels under shear.

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Soft Matter Physics

Background:

• Gelatin methacryloyl (GelMA) is a versatile semi-synthetic polymer extensively used in bioapplications.
• Tuning the microstructure of GelMA hydrogels is crucial for optimizing their performance.
• Existing methods for microstructure control are limited, necessitating novel approaches.

Purpose of the Study:

• To investigate the preparation of GelMA hydrogels with diverse microstructures.
• To explore the use of shear-induced self-assembly in aqueous two-phase systems (ATPS) for GelMA hydrogel fabrication.
• To establish structure-property relationships based on processing parameters.

Main Methods:

• Utilized an aqueous two-phase system (ATPS) composed of GelMA and dextran.
• Applied controlled preshear to ATPS followed by in situ UV-curing of the GelMA-rich phase.
• Characterized hydrogel microstructures using confocal laser scanning microscopy (CLSM).
• Investigated the influence of dextran concentration, preshear, and pH on microstructure formation.

Main Results:

• Achieved formation of GelMA string phases and aligned band structures by controlling dextran concentration and preshear.
• Demonstrated pH-dependent formation of multiple emulsions due to changes in GelMA charge density.
• Showed that preshearing of multiple emulsions leads to porous GelMA microgels.
• Confirmed the ability to create diverse microstructures, including aligned bands and porous networks.

Conclusions:

• Preshearing of ATPS offers a versatile method for fabricating GelMA hydrogels with controlled microstructures.
• The developed technique enables the creation of various architectures, such as aligned bands and porous microgels.
• This approach holds significant potential for developing advanced functional soft materials for bioapplications.