Bound Volume Number

1

Document Type

Honors Capstone Project

Date of Submission

Spring 5-1-2015

Capstone Advisor

James H. Henderson, Associate Professor, Department of Biomedical and Chemical Engineering

Honors Reader

Carlos A. Castañeda, Assistant Professor, Department of Biology & Chemistry

Capstone Major

Biology

Audio/Visual Component

no

Keywords

Shape memory polymers, bioengineering, Thermoplastic polyurethane

Capstone Prize Winner

no

Won Capstone Funding

yes

Honors Categories

Sciences and Engineering

Subject Categories

Biochemistry | Biological Phenomena, Cell Phenomena, and Immunity | Medical Biochemistry | Medicinal-Pharmaceutical Chemistry

Abstract

Shape memory polymers (SMPs) are a class of “smart” materials that can transform between two distinct conformations through external stimuli, such as heat or electricity. Their usage in bioengineering has led to a promising field of research that lies at the interface of cell and mechanobiology, potentially providing insight into cancer therapies and tissue development—two processes that exist in dynamic environments in vivo. The present work involves creating new, shape changing, scaffolds for studies to analyze cell migration upon changes to the environmental topography. Specifically, this Capstone has been primarily focused on the development of a “half and half” fibrous scaffold, entailing 50% aligned and 50% random fiber alignments separated by a clear interface, to model and better understand how the migratory patterns of both human fibrosarcoma cells (cell line: HT-1080) and murine mesenchymal stem cells (cell line: C3H10T1/2) respond to this architectural change. For example, it is thought that upon metastasis, cancerous cells are able to reorganize the collagen fibers in the extracellular matrix, and use this reorganized architecture as a guide to invade other tissue areas.

Thermoplastic polyurethane (TPU) SMPs were prepared by electrospinning 700-900nm diameter fiber to serve as a cellular scaffold. Through the development of these scaffolds, we are interested in investigating two related, and simultaneously-tested, hypotheses comprised of static and dynamic polymers (each containing static unaligned, and aligned [control] scaffolds, in addition to a thermoplastic 50/50 unaligned-aligned [experimental]—“Half and Half”—scaffold). In the development of these experimental scaffolds, we have attempted to develop a scaffold that demonstrates the aforementioned properties. Through four primary methods to trigger the recovery in only half of the scaffold, we have made progress in minimizing imperfections that result from this process, some of which include: thermal buckling and incomplete recovery. Upon finalizing the protocol used to develop these experimental groups, we will analyze the cells’ migratory rate and how that rate is influenced by time. We anticipate that cells will preferentially migrate faster on scaffolds with aligned fibers than on scaffolds with unaligned fibers, due to the presence of a consistent track for the cells to migrate. Simultaneously, we also will examine whether cells seeded on randomly-oriented fibers will sense these fibers and in the direction of increased orientation.

Creative Commons License

Creative Commons Attribution 3.0 License
This work is licensed under a Creative Commons Attribution 3.0 License.

 
 

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