Open Access. Powered by Scholars. Published by Universities.®

Biomedical Engineering and Bioengineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 16 of 16

Full-Text Articles in Biomedical Engineering and Bioengineering

Recent Advances In Bone Research 2022 Edition, Jean-Philippe Berteau, Laurent Pujo-Menjouet May 2022

Recent Advances In Bone Research 2022 Edition, Jean-Philippe Berteau, Laurent Pujo-Menjouet

Publications and Research

More and more scientific and engineering applications in bone research make pivotal advances in treating patients with orthopedics issues. Hence, bone research in the 21st century combines, inter alia, biology, chemistry, mathematics, and mechanics with complementary characteristics that help a holistic approach to bone-related pathologies. Nowadays, it is hard to connect new evidence when jargoning and money remain two significant obstacles to sharing knowledge. “Recent Advances In Bone Research” is a free book – no money involved at any stage - that combines the most recent efforts in bone research from several experts with different backgrounds, every expert seeks to …


Osteocyte Activity And Skeletal Muscle Relative Gene Expression Profiling After Short-Term Muscle Paralysis, Michelle Gelbs Jan 2021

Osteocyte Activity And Skeletal Muscle Relative Gene Expression Profiling After Short-Term Muscle Paralysis, Michelle Gelbs

Dissertations and Theses

Mechanical loading is essential for maintaining bone tissue. Reduced mechanical loading has been shown to have a negative effect on bone, and can result in the development of disuse osteoporosis. Disuse models of muscle inactivity and immobilization, like the Botox model used in this study, result in changes in the bone microarchitecture, the mechanisms behind which are not fully understood. In a previous four-week Botox disuse study, skeletally mature 20- week-old rats experienced degradation of intracortical bone, increased vascular porosity, and decreased osteocyte lacunar density in the tibiae. The focus of this study was to explicate a potential source of …


3d Printed Pla Scaffolds To Promote Healing Of Large Bone Defects, Jacob W. Cole, Tiera Martinelli, Mitchell T. Ryan, Sarah G. Seman, Daniel Sidle, Stephen R. Smith, Rocco J. Rotello, Timothy L. Norman Apr 2018

3d Printed Pla Scaffolds To Promote Healing Of Large Bone Defects, Jacob W. Cole, Tiera Martinelli, Mitchell T. Ryan, Sarah G. Seman, Daniel Sidle, Stephen R. Smith, Rocco J. Rotello, Timothy L. Norman

The Research and Scholarship Symposium (2013-2019)

One challenge modern medicine faces is the ability to repair large bone defects and stimulate healing. Small defects typically heal naturally, but large bone defects do not and current solutions are to replace the missing tissue with biologically inert materials such as titanium. This limits the amount of bone healing as the defect is not repaired but rather replaced. The focus of our research is to develop a method of using 3D printing to create biodegradable scaffolds which promote bone in-growth and replacement. To accomplish this we used poly lactic acid (PLA) filament and a desktop 3D printer. To promote …


Nanocellulose Fibers As A Potential Material For Orthopedic Implantation Application, David Gregg Holomakoff Aug 2017

Nanocellulose Fibers As A Potential Material For Orthopedic Implantation Application, David Gregg Holomakoff

Electronic Theses and Dissertations

The field of biomaterials is of immense importance and will continue to grow and develop in the coming years. Novel materials, as well as new approaches for use of existing materials, are sought after now more than ever. Current metal orthopedic implants have an over engineered stiffness and Young’s modulus, causing a phenomenon called stress shielding. Metal implants absorb the majority of force typically exerted on bone and the osteocytes within. When osteocytes fail to sense mechanical forces bones become less dense and weaken, causing possible fracture and other complications. A new orthopedic material is needed matching Young’s modulus of …


Densified Collagen-Fibril Biomaterials For Bone Tissue Engineering, Lauren E. Watkins Apr 2016

Densified Collagen-Fibril Biomaterials For Bone Tissue Engineering, Lauren E. Watkins

Open Access Theses

Millions of craniofacial bone defects occur annually as a result of trauma, congenital defects, disease, or tooth extraction. When present in the oral cavity, these defects are associated with adverse impacts on speech, mastication, and aesthetics. Thus, there is a clinical need for interventional strategies to restore and preserve alveolar bone mass to improve the success of future treatment options intended to reestablish functionality and aesthetics. Guided bone regeneration using bone grafts and a membrane represent the current standard of care for repairing alveolar bone defects, but face a number of limitations related to resorption time and structural integrity. Improvements …


When 1 + 1 > 2: Nanostructured Composites For Hard Tissue Engineering Applications, Vuk Uskoković Dec 2015

When 1 + 1 > 2: Nanostructured Composites For Hard Tissue Engineering Applications, Vuk Uskoković

Pharmacy Faculty Articles and Research

Multicomponent, synergistic and multifunctional nanostructures have taken over the spotlight in the realm of biomedical nanotechnologies. The most prospective materials for bone regeneration today are almost exclusively composites comprising two or more components that compensate for the shortcomings of each one of them alone. This is quite natural in view of the fact that all hard tissues in the human body, except perhaps the tooth enamel, are composite nanostructures. This review article highlights some of the most prospective breakthroughs made in this research direction, with the hard tissues in main focus being those comprising bone, tooth cementum, dentin and enamel. …


Esem Analysis Of Mice Femurs With Varying Sost Levels, Patrick K. Mcclay Jun 2012

Esem Analysis Of Mice Femurs With Varying Sost Levels, Patrick K. Mcclay

Biomedical Engineering

This project’s goal was to analyze the properties of the cortical femur on 100 mice bones from Lawrence Livermore National Laboratory. Analysis was limited to imaging which determined the ratio of bone volume to total volume (BV/TV) and osteocyte lacunae density. Mice were altered to knock out their SOST gene: a negative regulator of bone formation. Twelve groups were created to differentiate their treatment, duration, and phenotype. Transgenic (TG) mice had an overexpression of the SOST gene: they carried a bacterial artificial chromosome. Mice with limb defects (DEF) were the offspring of two TG mice and carried twice the amount …


Cutting Rate Effect On Temperature During Cortical Bone Sawing, Hamid Khalili Parsa, Ger Reilly, Brendan Mccormack Jan 2006

Cutting Rate Effect On Temperature During Cortical Bone Sawing, Hamid Khalili Parsa, Ger Reilly, Brendan Mccormack

Conference Papers

When bone is cut the occurrence of thermal damage to the bone is of major concern to the surgeon. If the temperature exceeds 44°C for longer than 1 min, bone repair is impaired (Eriksson et al, 1984) and necrosis may occur. Repeated use of cutting blades may reduce the cutting efficiency (Wevers et al, 1987; Toksvig-Larsen et al, 1992). Wevers et al also found that there is a greater force required to cut cortical bone using a blunt saw compared to new one.


Indentation Fracture Of Bovine Cortical Bone: Acoustic Emission Technique, Ashkan Safari, Ger Reilly, Brendan Mccormack Jan 2006

Indentation Fracture Of Bovine Cortical Bone: Acoustic Emission Technique, Ashkan Safari, Ger Reilly, Brendan Mccormack

Conference Papers

Indentation cutting may result in microcracking and main crack growth which was previously reported. In this study, we recorded the AE signals produced by cracking processes during cutting on cortical bone, measuring the cutting force and correlating between load-displacement curves and AE activities.


Analysis Of Indentation Loading Of Cortical Bone Using Acoustic Emission Techniques, Ashkan Safari, Ger Reilly, Brendan Mccormack Dec 2005

Analysis Of Indentation Loading Of Cortical Bone Using Acoustic Emission Techniques, Ashkan Safari, Ger Reilly, Brendan Mccormack

Conference Papers

In this study, we recorded the number of Acoustic emission (AE) hits and related AE energy during indentation fracture of cortical bone using a PAC PCI-2 card and pico sensor. A threshold value of 43dB was used to filter premature trigger due to background noise. Registered AE hits had more than one count (threshold crossing). Amplifier gain was set at 40dB with a (0.1-1) MHz band pass filter. 8mm cubes of cortical bones were indented in the longitudinal direction at constant crosshead speed of 1 mm min-1 using a large 2D, 50˚ wedge indenter. We hypothesised that signals occurring as …


Detection Of Microcracks During Bone Cutting Using Acoustic Emission Techniques, Ashkan Safari, Ger Reilly, Brendan Mccormack Sep 2005

Detection Of Microcracks During Bone Cutting Using Acoustic Emission Techniques, Ashkan Safari, Ger Reilly, Brendan Mccormack

Conference Papers

Surgeons may use a number of cutting instruments such as osteotomes and chisels to cut bone during operative procedures. The initial loading of cortical bone during the cutting process results in the formation of microcracks in the vicinity of the cutting zone with main crack propagation to failure occurring with continued loading; microcracking acts as a stimulus for main crack formation and has also been shown to occur during the propagation of the main crack. It has also been reported that Acoustic Emission (AE) is generated due to microcrack formation and crack growth, prior to, and during final fracture in …


An Experimental Technique For Measurement Of Heat Generated During Bone Sawing, Hamid Khalili Parsa, Ger Reilly, Brendan Mccormack Sep 2005

An Experimental Technique For Measurement Of Heat Generated During Bone Sawing, Hamid Khalili Parsa, Ger Reilly, Brendan Mccormack

Conference Papers

Orthopaedic bone cutting processes such as osteotomy and hip arthroplasty involve the cutting of one with the aid of various manual and powered cutting instruments including manual and powered bone saws. The extent of surgically induced bone necrosis at the point of the cutting tool and the bone is mainly due to the frictional heat generated by bone cutting. Bone necrosis has an impact on bone regeneration, and the rate of healing of the bone post operation. The threshold temperature for impaired regeneration of bone is in the range of 44°C to 47°C. Overheating also affects the sharpness life of …


Sequential Labelling And Acoustic Emission Analysis Of Damage Occurring In Cortical Bone During Indentation Cutting, Ger Reilly, Ashkan Safari, David Taylor, Brendan Mccormack Jul 2005

Sequential Labelling And Acoustic Emission Analysis Of Damage Occurring In Cortical Bone During Indentation Cutting, Ger Reilly, Ashkan Safari, David Taylor, Brendan Mccormack

Conference Papers

When a surgeon uses a wedge shaped blade or an osteotome to cut cortical bone during an operative procedure the bone will fail by a process of microcracking and primary crack propagation. It has previously been observed that crack propagation is dependent on the direction of cutting relative to the main axis of the bone. It has also been observed that microcracks occurring during fracture release acoustic signals that facilitate real-time monitoring of a cutting process. In these novel studies, we labelled damage accumulation during cutting of cortical bone using sequential chelating dyes and we correlated recorded AE signals during …


An Investigation Of The Heat Affected Zone In Cortical Bone Sawing, Hamid Khalili Parsa, Ger Reilly, Brendan Mccormack, Andrew Macey Jan 2005

An Investigation Of The Heat Affected Zone In Cortical Bone Sawing, Hamid Khalili Parsa, Ger Reilly, Brendan Mccormack, Andrew Macey

Conference Papers

Surgical procedures such as osteotomy and hip replacement involve the cutting of bone with the aid of various manual and powered cutting instruments including manual and powered bone saws. Frictional rubbing between the blade of the saw and the bone results in the generation of localised heating of the cut bone and increased cutting forces (Ark et al, 1997). Overheating in localised areas can cause bone necrosis and have an impact on the rate of healing of the bone post operation and overheating also affects the sharpness life of the blade. A review of the literature indicates that work has …


Validation Of Energy Dispersive X-Ray Spectrometry As A Method To Standardize Backscattered Electron Images Of Bone, E. G. Vajda, R. D. Bloebaum, J. G. Skedros Jan 1996

Validation Of Energy Dispersive X-Ray Spectrometry As A Method To Standardize Backscattered Electron Images Of Bone, E. G. Vajda, R. D. Bloebaum, J. G. Skedros

Cells and Materials

The use of backscattered electron (BSE) imaging as a tool for the qualitative measurement of mineral content in bone has been well documented. The challenge still remains to develop BSE imaging as a tool for quantitative mineral content analysis in bone. The limiting factor has been the ability to standardize the BSE signal within and between laboratories. Energy dispersive x-ray spectrometry (EDX) has been proposed as a method to standardize the BSE operating environment. The goal of this study is to investigate the relationship between EDX-determined wt.% Ca measurements and BSE graylevels. A comparison with traditional ash content measurements will …


Perturbations Of Periosteel Bone During Healing: Effect Of Non-Weight Bearing, Helen E. Gruber, Mary E. Kirchen, John R. Sweeney, William E. Anderson, G. June Marshall Jan 1996

Perturbations Of Periosteel Bone During Healing: Effect Of Non-Weight Bearing, Helen E. Gruber, Mary E. Kirchen, John R. Sweeney, William E. Anderson, G. June Marshall

Cells and Materials

Weight bearing (WB) is an important factor influencing bone remodelling. The present study evaluates the effects of weight bearing and non-weight bearing (S) (achieved by tail suspension and hindlimb elevation) on the healing of a fibular osteotomy in adult male rats. After 9, 18 or 36 days under WB or S conditions, periosteum near the callus formed at the osteotomy site was compared to periosteum of the contralateral fibula (which did not receive an osteotomy) or to periosteum of fibula of control animals which did not receive an osteotomy. Data show that periosteal bone healing is sensitive to alterations in …