Date of Submission

8-2025

Document Type

Thesis

Degree Name

Master of Science in Biomedical Engineering

Department

Chemistry and Chemical Engineering

Advisor

Shue Wang, Ph.D.

Committee Member

Huan Gu, Ph.D.

Committee Member

Anna Kloc, Ph.D.

Keywords

Bone-related Diseases, Osteogenesis, Mesenchymal Stem Cell (MSC), Bone Regeneration, Adipogenesis

MeSH

Bone Diseases, Osteogenesis, Mesenchymal Stem Cells, Bone Regeneration, Adipogenesis

LCSH

Osteal manifestations of general diseases, Bones--Growth, Mesenchymal stem cells, Bone regeneration

Abstract

Bone-related diseases (e.g., osteoporosis) are primarily treated with pharmacologic therapies that often exhibit limited efficacy and substantial side effects. Currently, bone marrow derived mesenchymal stem cells (MSCs) have become one of most important cell options in bone regeneration due to readily available sources, strong proliferation abilities, weak immune rejection responses, and strong osteogenic differentiation potential. While identifying the most effective approach to enhance osteogenic differentiation of MSCs for bone regeneration is challenging, understanding the regulatory mechanisms is crucial for improving therapeutic efficacy. Recent research has focused on developing strategies to enhance osteogenesis, which involve biophysical and biochemical stimulation. Mechanical and chemical environment of a given cell may impact on the differentiation fate and commitment. The impact of specific mechanical stresses is being studied to help produce consistent and specific differentiation in vitro. Shear stress, stiffness, and compression all have possible impacts on the differentiation and phenotype of cells. The introduction of specific chemical signals and biochemical markers may invoke similar changes in cell behavior. Uncontrolled differentiation and phenotypic behavior limit the capabilities of hMSCs in regenerative medicine. Therein, the ability to control the differentiation of many cells is crucial for regenerative tissue engineering. Cellular behavior also changes between two- and three-dimensional environments. Attached cells on a two-dimensional plate behave differently than three-dimensional cell spheroids. Growing cells on top of and within three dimensional substrates creates an opportunity to study cellular behavior in an environment closer to the human body. Hydrogel substrates can be used to develop scaffolds for regenerative tissue engineering. The gels can also be used to help simulate environments closer to that of the human body.

Here, we studied how biophysical cues—matrix stiffness and shear stress – regulate mesenchymal stem cell (MSC) behavior, including morphology, cytoskeletal organization, proliferation, and differentiation, using engineered 3D culture systems and a novel lncRNA nanobiosensor. By developing a 3D collagen cushion (~300 μm thick), we examined how varying stiffness (Ezcol vs. Telocol collagen) influences MSC responses. Our findings revealed that stiffer Telocol substrates promoted MSC proliferation, increased cell perimeter, and expanded cell area. YAP immunostaining demonstrated nuclear translocation in both gels under osteogenic conditions, suggesting stiffness-dependent mechanotransduction. Future work will explore the role of lncRNAs in mediating these stiffness-driven differentiation processes.

Additionally, we explored shear stress’s impact on adipogenic differentiation, building on prior studies linking shear stress to osteogenesis. Using a novel lncRNA nanobiosensor, we identified MALAT1 as a key regulator in shear-mediated adipogenic commitment. These results highlight how mechanical cues—stiffness and shear—orchestrate MSC fate, with MALAT1 emerging as a critical mediator. Understanding these mechanisms is vital for advancing MSC based therapies in regenerative medicine, offering new strategies to control stem cell behavior through tailored biophysical microenvironments.

Download

Share

COinS