Defense Date
2026
Document Type
Dissertation
Degree Name
Doctor of Philosophy
Department
Nanoscience and Nanotechnology
First Advisor
Dr. Daeha Joung
Abstract
Traditional two-dimensional (2D) cell culture systems fail to reproduce the complex three-dimensional (3D) microenvironment of native tissues, where cells experience spatial confinement, mechanical forces, and dynamic structural cues that regulate organization, migration, and tissue formation. These limitations restrict the ability of conventional platforms to model in vivo physiology, disease progression, and therapeutic response.
Here, I present the development of extrusion-based 3D-printed magnetic origami scaffolds composed of iron oxide nanoparticle (Fe₃O₄)/cellulose acetate composites that enable remotely actuated, reversible folding to dynamically reconfigure cellular microenvironments. The scaffolds incorporate programmable microchannels (100–200 µm) and foldable hinges, allowing controlled pre- and post-folding culture with an intermediate extracellular matrix hydrogel layer that supports vertical cell proliferation between scaffold layers.
Using NIH/3T3 fibroblasts and A549 lung cancer cells in mono- and co-culture, I demonstrate that magnetic actuation enables temporal and spatial control of scaffold architecture, supporting studies of proliferation, vertical cell expansion, and intercellular interactions. Optimized channel geometry, hydrogel composition, and gravitational orientation promote homogeneous cell distribution and directed migration. Fibroblast expansion further facilitates cancer cell dissemination into initially unseeded regions via enhanced cell–cell and cell–matrix interactions while maintaining high viability (>94%).
I also investigate geometry-guided nematic ordering in microchannels by varying channel width (300–1200 µm). Quantitative orientation analysis reveals a critical confinement threshold (≤600 µm), where boundary effects dominate and strongly align cells along the channel axis. In wider channels, alignment decreases and organization becomes governed primarily by local cell–cell interactions rather than confinement.
Collectively, this work establishes a dynamic, magnetically actuated 3D culture platform and a quantitative framework for linking geometric confinement to emergent tissue organization, with implications for regenerative medicine, disease modeling, and biomimetic tissue engineering.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
4-24-2026