Methods To Assess Shear-Thinning Hydrogels for Application As Injectable Biomaterials

Area of Science:

• Biomaterials Science
• Biomedical Engineering
• Rheology

Background:

• Injectable hydrogels are increasingly used for localized delivery of therapeutics and tissue bulking.
• Evaluating hydrogel properties like viscosity, moduli, and injection force is critical for successful application.
• Shear-thinning hydrogels exhibit property changes under mechanical load, requiring specific assessment methods.

Purpose of the Study:

• To describe quantitative rheological tests for evaluating injectable hydrogels.
• To present methods for measuring injection force using specialized equipment.
• To provide a framework for assessing shear-thinning hydrogels for biomedical applications, with a focus on cardiac delivery.

Main Methods:

• Utilized rheological testing to assess hydrogel properties under shear stress.
• Employed force sensors and mechanical testing machines to quantify injection forces.
• Applied these methods to injectable, shear-thinning hydrogels for cardiac applications in animal models (mouse, rat, pig).

Main Results:

• Established protocols for characterizing the rheological behavior of injectable hydrogels.
• Quantified injection forces required for hydrogel delivery, crucial for consistent administration.
• Demonstrated successful hydrogel delivery and retention in myocardial infarction models.

Conclusions:

• The described rheological and injection force measurement methods are vital for the design and assessment of injectable hydrogels.
• These methods ensure predictable performance and retention of hydrogels in target tissues.
• The findings support the broader application of shear-thinning hydrogels in regenerative medicine and drug delivery.