Hydrogel Coating Optimization to Augment Engineered Soft Tissue Mechanics in Tissue-Engineered Blood Vessels.

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Soft tissue engineering faces challenges with insufficient mechanical strength in cell-only constructs and biomaterials.
• Limited extracellular matrix (ECM) production in cell culture further compromises construct integrity.
• Developing robust biomaterials is crucial for simulating native tissue mechanics and integration.

Purpose of the Study:

• To explore ECM-based hydrogel coatings for enhancing soft tissue engineering, specifically vascular applications.
• To evaluate the efficacy of cells in supplementing the mechanical strength of hydrogel coatings.
• To assess the impact of natural crosslinkers on hydrogel properties.

Main Methods:

• Tested fibrin, collagen, and gelatin hydrogels with and without fibroblasts as coatings on engineered artery tunica adventitia.
• Investigated the use of genipin, a natural crosslinker, to stabilize and strengthen hydrogels.
• Assessed tensile strength and cell viability of coated constructs after 14 days in culture.
• Evaluated the effect of fibrin hydrogel coating on the burst pressure of engineered blood vessels.

Main Results:

• Gelatin crosslinked with genipin showed the highest tensile strength, but fibrin gel best supported cell viability.
• Fibrin hydrogel coating without genipin was optimal, balancing mechanical strength and cell viability.
• Engineered vessels coated in fibrin hydrogel with cells achieved the highest tensile strength (11.9 ± 2.91 kPa).
• Fibrin hydrogel coating significantly increased the burst pressure of engineered vessels to 229 ± 23.8 mmHg.

Conclusions:

• Fibrin hydrogel coating, particularly with cells, offers a promising approach to enhance the mechanical properties of engineered soft tissues.
• The findings demonstrate potential for improving engineered blood vessels, though further optimization is needed for clinical application.
• The study highlights the importance of balancing mechanical reinforcement with cellular support in tissue engineering strategies.