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Holland, Nolan B.; Lee, Moo-Yeal
Elastin-like polypeptide (ELP) based, temperature responsive triblocks are an attractive alternative to current cell encapsulation hydrogels (bioinks) used in bioprinting, due to their natural physiological properties and their potential for higher cell viability. Many cell encapsulating hydrogels in current use, require UV light to initiate crosslinking which can be damaging to the encapsulated cells. Other materials irreversibly gel with a change in temperature potentially clogging the bioprinting instruments. ELP based hydrogels utilize temperature dependent gelation, but gel reversibly. Elastin is a natural material in human tissue which many protein scaffolds are made of. We are studying an ELP triblock consisting of a long hydrophilic center ELP segment with a short, temperature responsive ELP segment at each end. When a solution of these ELP triblocks is brought to a transition temperature, the end segments become hydrophobic and phase separate. This results in a crosslinked hydrogel network of hydrophobic ELP nodes connected by hydrophilic ELP segments. The ELP hydrogel's properties are dependent on concentration, temperature, pH and salt concentration of the solution. We have characterized the gelation behavior through temperature dependent and time dependent complex modulus profiles of the ELP hydrogel measured using a rheometer with cone and plate geometry. This study is an important step in designing a temperature responsive solution that gels between room and physiological temperature.
Waskewicz College of Engineering
Martin, Ryan and Deyling, James, "Design and Characterization of Protein-Based Bioink" (2016). Undergraduate Research Posters 2016. 49.