Date of Award
5-12-2024
Degree Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Biomedical and Chemical Engineering
Advisor(s)
James Henderson
Second Advisor
Sandra Hewett
Abstract
Although biomaterials surface modification and smart materials science are heavily studied areas, the interface of the two has received substantially less investigation. Without this fundamental understanding, progress in biomaterials science at the interface of cells and dynamic functional materials will be hindered, preventing innovation in diverse biomedical applications. Thus, the goal of this dissertation is to acquire a fundamental understanding on the dynamic effects of shape-memory polymer (SMP) activation on biopolymer surface coatings, and to explore the potential biomedical application of this novel, material platform. To better understand the synergistic effects of surface modification and dynamic, shape memory activation, the work in this dissertation involves coating the surface of a thermo-responsive SMP with silk fibroin (SF) surface coatings. These two biomaterials are appropriately combined such that SMPs undergo heat-induced contraction to enable the SF coatings to buckle into a wrinkled state, resulting in SMP-triggered silk wrinkled surface topographies. The design rationale, processing, and application focused characterization of the SF-SMP material platform is investigated in both two-dimensional (2D) and three-dimensional (3D) materials systems. First, this dissertation describes the development of the SF-SMP wrinkling platform under dry and physiologically relevant conditions (cell-compatible), and how its wrinkling characteristics (e.g., wavelength and amplitude) are affected by SMP strain magnitude, film thickness, shape recovery temperature, and cell culture medium. We envision these biopolymer wrinkled surfaces to have potential application in cell mechanobiology, wound healing, and tissue engineering. Next, this dissertation, describes the extent towards translating the SF-SMP wrinkling system to complex, biomimetic and bioinspired 3D architectures. A simple experimental method was designed to create tunable silk wrinkled surfaces on porous, shape-memory log-pile scaffolds. We envision this will serve as a potential strategy for engineering biomimetic cellular microenvironments that can progress understanding and regulation of cell-material interaction in developing tissue engineered constructs. Then, we explore the potential biomedical application of the SF-SMP wrinkling platform in the second half of the dissertation. To determine the potential antifouling properties of the SMP-triggered silk wrinkled surfaces, we investigated the effects of the mechanically actuated silk wrinkling approach on bacterial biofilm formation. We determined the extent to which the silk wrinkle wavelengths and amplitude would reduce or prevent biofilm formation; and the extent to which silk wrinkling of a 3D material platform would affect the formation of biofilms. To determine the feasibility of the silk wrinkled topographies to be useful to serve as an appropriate material platform for guided peripheral nerve regeneration, we created a topographical functionalized nerve guidance conduits (NGCs) that consists of intraluminal micro- and nano-scale silk wrinkles. Here we determined the effects of the wrinkled topographical features on neuronal viability, neuronal adhesion, neurite outgrowth, and neuronal alignment. Ultimately, by investigating this novel material combination, it will enable us to develop new, bioinspired material platforms for optimized surface properties and cell surface interactions; thus, advancing the biomaterials science field and enabling innovation in various biomedical applications.
Access
Open Access
Recommended Citation
Oguntade, Elizabeth, "Fabrication and Characterization of 2D and 3D Shape-Memory Actuated Silk Wrinkled Surface Topographies for Biomedical Applications" (2024). Dissertations - ALL. 1905.
https://surface.syr.edu/etd/1905
