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Hydrogels have emerged as a crucial class of materials within the field of tissue engineering. There is growing interest in matching the mechanical properties of hydrogel scaffolds to tissues in the human body and optimizing these properties for cell growth and differentiation. Gelatin methacrylate (GelMA) is a well-accepted, biocompatible hydrogel with tunable mechanical properties. However, the effects of various formulation parameters on its mechanical properties are not well understood. In this study, an array of GelMA scaffold fabrication parameters is evaluated by varying GelMA concentration and ultraviolet light exposure time. Our overarching goal is to characterize the mechanical properties through ultrasound and rheological measurements, providing a framework for GelMA scaffold selection. Pulse-echo ultrasound techniques were used to non-invasively determine the sound speed and attenuation of the scaffolds, revealing significant dependence on GelMA concentration. Steady shear rate and strain- and frequency-controlled oscillatory shear tests using a rotational rheometer (Model: DHR-2, TA Instruments) revealed a range in the levels of shear-thinning as well as viscoelasticity and showed moduli-dependence on both GelMA concentration and light exposure time. Together, this acoustic and rheological characterization can be used to inform the selection of GelMA scaffolds in tissue engineering applications.
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Development of GelMA-Based Hydrogel Scaffolds with Tunable Mechanical Properties for Applications in Peripheral Nerve Regeneration
Peripheral nerve injuries (PNIs) have a significant impact on the quality of life for patients suffering from trauma or disease. In injuries with critical nerve gaps, PN regeneration requires tissue scaffolds with appropriate physiological properties that promote cell growth and functions. Hydrogel scaffolds represent a promising platform for engineering soft tissue constructs that meet key physiological requirements. Nonetheless, ongoing innovation remains essential, as current designs continue to fall short of replicating the functional performance of autografts in bridging critical-sized nerve defects. In this study, gelatin methacrylate (gelMA)-based hydrogels are evaluated to fully characterize their pore structure, compressive stiffness, viscoelasticity, and 3D bioprintability. Hyaluronic acid (HA) and single-walled carbon nanotubes (SWCNTs) are explored as gelMA additives to modify viscoelastic and electrically conductive properties, respectively. Finally, Schwann cell (SC) and human umbilical vein endothelial cell (HUVEC) growth and functions are quantified to assess the biocompatibility of the hydrogel composites as materials for nerve scaffold fabrication. It was found that the microstructure and mechanical properties of gelMA-based hydrogels can be precisely controlled by modifying the concentrations of each component. The addition of HA led to altered viscoelastic properties of the cured structures and SWCNTs increased electrical conductivity, with both additives maintaining cytocompatibility while influencing the protein expression of both SCs and HUVECs. These composite hydrogels have potential in PNI regeneration applications.
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- PAR ID:
- 10644777
- Publisher / Repository:
- ACS Publications
- Date Published:
- Journal Name:
- ACS Biomaterials Science & Engineering
- Volume:
- 11
- Issue:
- 9
- ISSN:
- 2373-9878
- Page Range / eLocation ID:
- 5467 to 5481
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript
- Journal Article:
- https://doi.org/10.1021/acsbiomaterials.5c00023
