BME Seminar: Sam Kim
Monday, April 3rd, 2023 - 12:00 p.m.
Sam Kim
Ph.D. Candidate
Biomedical Engineering
"Genetically Engineered Artificial Protein Polymers for Functional Regenerative Tissue Scaffolds"
Keating 103
Live Zoom Link | Passcode: BearDown
Hosts: Dr. Beth Hutchinson and Dr. Shang Song
(Instructor permission required for enrolled students to attend via Zoom)
Persons with a disability may request a reasonable accommodation by contacting the Disability Resource Center at 621-3268 (V/TTY).
Abstract: The ability to control stem cell fate is important for tissue engineering and regenerative medicine, as it enables researchers to direct stem cell differentiation into specific cell types, which is crucial for generating functional tissues to potentially treat injuries and degenerative diseases. Hydrogels are excellent tissue scaffolds because of their high-water content, which resembles the natural extracellular matrix and provides a supportive environment for stem cell differentiation and tissue regeneration. However, material properties of a scaffold, such as its elasticity and geometry, can regulate cell behavior and differentiation, resulting in different outcomes post cell differentiation. To achieve precise control over stem cell fate, it is necessary to develop hydrogels with tunable mechanical properties that can modulate cell behavior.
Due to their unique physicochemical and biological properties, artificial proteins are promising building blocks for hydrogel materials, providing a mean to control the mechanical properties. By utilizing the concept of polymer networks and genetic engineering, these biomolecules can be constructed into tunable protein polymers that mimics the nano-mechanics of natural proteins and self-assembles into a polymeric material. However, proper translation of protein nano-mechanics to macroscale material properties remains a challenge due to topological defects. These defects are attributed to weak and nonspecific crosslinking junctions of the polymer network, which limits the overall material from reaching its potential mechanical properties. To overcome this, we investigated protein crosslinking junctions to determine optimal design components for producing biopolymer networks with the goal of translating protein nano-mechanics to bulk material properties. To achieve this, we designed streptavidin, a mechanically and thermally stable tetramer, into artificial protein polymers to stabilize the crosslinking junction and evaluate whether the single streptavidin nano-mechanics can be fully harnessed in macroscale materials. Our results consist of various streptavidin-based protein polymer designs that provide valuable insight into the design principles necessary to enhance crosslinking junctions and improve the overall mechanical properties of hydrogel scaffolds composed of well-organized, polymer networks.