Fragmenting Bulk Hydrogels and Processing into Granular Hydrogels for Biomedical Applications.

Area of Science:

• Biomaterials science
• Hydrogel engineering
• Biomedical engineering

Background:

• Granular hydrogels are jammed microgel assemblies with beneficial properties like injectability and tunable porosity.
• Existing microgel fabrication methods (emulsions, photolithography) can be resource-intensive and costly.
• There is a need for accessible and scalable microgel fabrication techniques for diverse hydrogel types.

Purpose of the Study:

• To present a novel, simple, and scalable method for fabricating microgels and granular hydrogels.
• To demonstrate the utility of these granular hydrogels as 3D printing inks for biomedical applications.
• To establish a versatile platform adaptable to various hydrogel compositions.

Main Methods:

• Fabrication of microgels via extrusion fragmentation of bulk hydrogels through sequentially smaller needles.
• Processing of microgels into granular hydrogels using centrifugation or vacuum-driven filtration.
• Optional post-crosslinking for enhanced hydrogel stability.
• Demonstration of granular hydrogels as extrusion printing inks, using photocrosslinkable hyaluronic acid (HA) as an example.

Main Results:

• Successful fabrication of microgels and subsequent granular hydrogels using the extrusion fragmentation method.
• The technique is rapid, low-cost, and highly scalable.
• Granular hydrogels exhibited suitability as extrusion printing inks for 3D printing applications.
• The methodology proved adaptable for photocrosslinkable hyaluronic acid and is broadly applicable to other hydrogel types.

Conclusions:

• Extrusion fragmentation offers a simple, cost-effective, and scalable approach to microgel and granular hydrogel fabrication.
• The developed granular hydrogels are promising for biomedical applications, particularly as 3D printing inks.
• This adaptable method facilitates the use of diverse hydrogel materials in regenerative medicine and tissue engineering.