Biomedical Engineering and Bioengineering Commons^™

3d Printable And Computational Models Of The Bone Marrow Mechanical Environment, Alexander Regner

Boise State University Theses and Dissertations

Aged individuals and astronauts experience bone loss despite rigorous physical activity. Bone mechanoresponse is in part regulated by mesenchymal stem cells (MSCs). We reported that daily low intensity vibration (LIV) restores MSC proliferation in senescence and simulated microgravity models, suggesting reduced mechanical signal delivery to MSCs likely contributes to declining bone mechanoresponse. To this end, we have developed a 3D bone marrow analog which controls trabecular geometry, marrow mechanics and external stimuli.

Finite element (FE) models of hydrogels, representing bone marrow, were generated using instantaneous compression (1000% strain/s, 20% strain) and relaxation experiments (100s) of both gelatin and hyaluronin-based hydrogels. …

Decellularization Of Porcine Cartilage Promotes Chondrogenic Differentiation Of Human Chondrocytes, Roxanne Nicole Stone

Boise State University Theses and Dissertations

Knee osteoarthritis (knee OA) is the most common type of osteoarthritis (OA) and accounts for 70% of arthritis-related hospital admissions and 23% of clinical visits. Major limitations in both the current non-surgical and surgical methods are that they only relieve pain and show no evidence for restoring natural tissue anatomy. Leaders in the field propose that a stem cell treatment approach holds promise for the regeneration of a greater proportion of hyaline-like tissue at the repair site. (Cross et al., 2014; Escobar Ivirico, Bhattacharjee, Kuyinu, Nair, & Laurencin, 2017; Helmick et al., 2008; Toh, Foldager, Pei, & Hui, 2014).

It …

A Computational Framework To Model Mesenchymal Stem Cell Nucleus Mechanics Using Confocal Microscopy, Zeke Kennedy

Boise State University Theses and Dissertations

The mechanical properties of the cell nucleus are emerging as a key component in genetic transcription. It has been shown that the stiffness of the nucleus in part regulates the transcription of genes in response to external mechanical stimuli. The stiffness has been shown to change as a result of both disease and changes to the external environment. While the mechanical structure of the nucleus can be visually documented using a confocal microscope, it is currently impossible to test the stiffness of the nucleus without a mechanical testing apparatus such as an atomic force microscope. This is problematic in that …

Low Intensity Vibrations Restore Nuclear Yap Levels And Acute Yap Nuclear Shuttling In Mesenchymal Stem Cells Subjected To Simulated Microgravity, Matt Thompson

Boise State University Theses and Dissertations

The bone deterioration that astronauts experience in microgravity environments is known to occur in response to the lack of gravity-based tissue stress. Mechanical forces are crucial to maintain healthy bone mass by regulating the function of bone-making osteoblasts as well as the proliferation and differentiation of their progenitors, mesenchymal stem cells (MSC) which replenish osteoblastic cells. Regulation of proliferative function of MSCs in response to mechanical force is in part controlled by the “mechanotransducer” protein YAP (Yes-associated protein) which is shuttled into the nucleus in response to mechanical challenge to induce gene expression necessary for cell proliferation. Our group had …

Controlling Strain Energy Density In 3d Cellular Collagen Constructs During Complex Loads, Katherine Hollar

Boise State University Theses and Dissertations

Mechanical stimulation applied to damaged soft tissues, such as ligament, can promote tissue remodeling to accelerate healing. To help identify treatments that encourage ligament healing, bioreactors have been designed to subject 3D cellularized constructs to various loading conditions in order to determine the mechanical mechanisms that trigger cell-mediated repair. An innovative approach is to use a bioreactor to apply controlled states of biaxial stress to study the effects of strain energy density and distortion energy on cell activity. Tissue distortion has been linked to changes in the structure and function of ligament, yet the specific impact of distortion energy on …