Open Access. Powered by Scholars. Published by Universities.®
Biomedical Engineering and Bioengineering Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Institution
- Publication
- Publication Type
- File Type
Articles 1 - 6 of 6
Full-Text Articles in Biomedical Engineering and Bioengineering
Poly(Vinyl Alcohol) Nanocomposite Hydrogels For Intervertebral Disc Prostheses, Elaine Wong
Poly(Vinyl Alcohol) Nanocomposite Hydrogels For Intervertebral Disc Prostheses, Elaine Wong
Electronic Thesis and Dissertation Repository
Spinal fusion is currently the gold standard for surgical intervention of intervertebral disc (IVD) diseases leading to neck and back pain failing conservative treatments. However, fusion removes motion between the vertebrae and can result in adjacent level degeneration. Total disc replacement (TDR) is an emerging treatment alternative that preserves motion, but materials found in clinically available devices bear little resemblance to the properties of the native IVD. Poly(vinyl alcohol) (PVA) hydrogels are biocompatible, have mechanical behaviour similar to natural tissues, and properties that can be tuned by varying polymer concentration and physical crosslinking through freeze-thaw cycling. Furthermore, their properties can …
Effect Of Applied Uniaxial Stress On Rate And Mechanical Effects Of Cross-Linking In Tissue-Derived Biomaterials, Debbie Chachra, Paul Gratzer, Christopher Pereira, J. Lee
Effect Of Applied Uniaxial Stress On Rate And Mechanical Effects Of Cross-Linking In Tissue-Derived Biomaterials, Debbie Chachra, Paul Gratzer, Christopher Pereira, J. Lee
Debbie Chachra
Conformational changes in collagen fibrils, and indeed the triple helix, can be produced by application of mechanical stress or strain. We have demonstrated that the rate of cross-linking in glutaraldehyde and epoxide homobifunctional reagents can be modulated by uniaxial stress (strain). Two poly(glycidyl ether) epoxides were used: Denacol® EX-810 (a small bifunctional reagent), and Denacol EX-512 (a large polyfunctional reagent). To prevent any possible effect from being masked by saturation of cross-linking sites, bovine pericardium was cross-linked to such an extent that the increase in collagen denaturation temperature, Td, was one-half of the maximal rise achievable with …
The Effect Of Different Hormone Replacement Therapy Regimens On The Mechanical Properties Of Rat Vertebrae, Debbie Chachra, M. Kasra, Carla Vanin, N. Maclusky, R. Casper, Marc Grynpas
The Effect Of Different Hormone Replacement Therapy Regimens On The Mechanical Properties Of Rat Vertebrae, Debbie Chachra, M. Kasra, Carla Vanin, N. Maclusky, R. Casper, Marc Grynpas
Debbie Chachra
The purpose of this study was to examine the effects of estrogen replacement, in concert with three different progestin regimens, on the mechanical properties of rat lumbar vertebrae. Ninety-two Sprague-Dawley rats (11 months old) were divided into six groups for treatment. The first group was an intact control, the second group (OVX) was ovariectomized only, and the third group (estrogen-only) was ovariectomized and received continuous estrogen through a 17-estradiol implant. The remaining groups were ovariectomized and received estrogen and progestin (norethindrone, NET) therapy; 3 g of NET was injected daily (estrogen plus continuous NET), or 6 g of NET was …
Mechanical Properties Of Bone Due To Sost Expression: A 3-Point Bending Assessment Of Murine Femurs, Kainoa John Peterson
Mechanical Properties Of Bone Due To Sost Expression: A 3-Point Bending Assessment Of Murine Femurs, Kainoa John Peterson
Master's Theses
Sclerostin, a protein coded for by the SOST gene, is an osteocyte-expressed negative regulator of bone formation. The absence of SOST in the genome may have an effect on bone formation both during skeletal maturation and full maturity. This study attempts to determine significant differences in the mechanical properties of bone that expresses SOST compared to bone that does not. One hundred femur samples from 6, 8, and 12 month old mice were obtained from Lawrence Livermore National Labs and loaded until failure using three-point bending. Results showed significant differences in treatment group effects for cross sectional area, yield force, …
The Influence Of Heterogeneous Meninges On The Brain Mechanics Under Primary Blast Loading, Linxia Gu, Mehdi S. Chafi, Shailesh Ganpule, Namas Chandra
The Influence Of Heterogeneous Meninges On The Brain Mechanics Under Primary Blast Loading, Linxia Gu, Mehdi S. Chafi, Shailesh Ganpule, Namas Chandra
Department of Mechanical and Materials Engineering: Faculty Publications
In the modeling of brain mechanics subjected to primary blast waves, there is currently no consensus on how many biological components to be used in the brain–meninges–skull complex, and what type of constitutive models to be adopted. The objective of this study is to determine the role of layered meninges in damping the dynamic response of the brain under primary blast loadings. A composite structures composed of eight solid relevant layers (including the pia, cerebrospinal fluid (CSF), dura maters) with different mechanical properties are constructed to mimic the heterogeneous human head. A hyper-viscoelastic material model is developed to better represent …
A New Tool To Assess The Mechanical Properties Of Bone Due To Collagen Degradation, C. Wynnyckyj, S. Omelon, K. Savage, M. Damani, Debbie Chachra, Marc Grynpas
A New Tool To Assess The Mechanical Properties Of Bone Due To Collagen Degradation, C. Wynnyckyj, S. Omelon, K. Savage, M. Damani, Debbie Chachra, Marc Grynpas
Debbie Chachra
Current clinical tools for evaluating fracture risk focus only on the mineral phase of bone. However, changes in the collagen matrix may affect bone mechanical properties, increasing fracture risk while remaining undetected by conventional screening methods such as dual energy x-ray absorptiometry (DXA) and quantitative ultrasound (QUS). The mechanical response tissue analyzer (MRTA) is a non-invasive, radiation-free potential clinical tool for evaluating fracture risk. The objectives of this study were two-fold: to investigate the ability of the MRTA to detect changes in mechanical properties of bone as a result of treatment with 1 M potassium hydroxide (KOH) and to evaluate …