Biomaterials Commons^™

Development Of A Multilayered Association Polymer System For Sequential Drug Delivery, Sharath Kumar Chinnakavanam Sundararaj

Theses and Dissertations--Biomedical Engineering

As all the physiological processes in our body are controlled by multiple biomolecules, comprehensive treatment of certain disease conditions may be more effectively achieved by administration of more than one type of drug. Thus, the primary objective of this research was to develop a multilayered, polymer-based system for sequential delivery of multiple drugs. This particular device was designed aimed at the treatment of periodontitis, a highly prevalent oral inflammatory disease that affects 90% of the world population. This condition is caused by bacterial biofilm on the teeth, resulting in a chronic inflammatory response that leads to loss of alveolar bone …

Growth Plate Regeneration Using Polymer-Based Scaffolds Releasing Growth Factor, Amanda Clark

Theses and Dissertations--Biomedical Engineering

Currently growth plate fractures account for nearly 18.5% of fractures in children and can lead to stunted bone growth or angular deformation. If the body is unable to heal itself a bony bar forms, preventing normal bone growth. Clinical treatment involves removing the bony bar and replacing it with a filler substance, which causes poor results 60% of the time.

Using primarily poly(lactic-co-glycolic acid) (PLGA) as the scaffold material, the goal was to develop an implant that would support to the implant site, allow for cell ingrowth, and degrade away over time. Porous scaffolds were fabricated from PLGA microspheres using …

Quaternary Ammonium Silane-Functionalized, Methacrylate Resin Composition With Antimicrobial Activities And Self-Repair Potential, Shi-Qiang Gong, Li-Na Niu, Lisa K. Kemp, Cynthia K.Y. Yiu, Heonjune Ryou, Yi-Pin Qi, John D. Blizzard, Sergey Nikonov, Martha G. Brackett, Regina L.W. Messer, Christine D. Wu, Jing Mao, L. Bryan Brister, Frederick A. Rueggeberg, Dwayne D. Arola, David H. Pashley, Franklin R. Tay

Faculty Publications

The design of antimicrobial polymers to address healthcare issues and minimize environmental problems is an important endeavor with both fundamental and practical implications. Quaternary ammonium silane-functionalized methacrylate (QAMS) represents an example of antimicrobial macromonomers synthesized by a sol–gel chemical route; these compounds possess flexible Si–O–Si bonds. In present work, a partially hydrolyzed QAMS co-polymerized with 2,2-[4(2-hydroxy 3-methacryloxypropoxy)-phenyl]propane is introduced. This methacrylate resin was shown to possess desirable mechanical properties with both a high degree of conversion and minimal polymerization shrinkage. The kill-on-contact microbiocidal activities of this resin were demonstrated using single-species biofilms of Streptococcus mutans (ATCC 36558), Actinomyces naeslundii (ATCC …

Characterization Of Printed Skin Equivalents, Mayela R, Aldaz Cervantes, Maria Yanez, Thomas Boland

COURI Symposium Abstracts, Summer 2012

Severe burns, ulcerations, and cuts are some of the reasons people need bioengineered skin as a treatment for full-thickness wounds. When patients run out of donor sites in their own body, using the patient’s skin as a graft is no longer an option, and tissue-engineered constructs are the only possible replacement for damaged skin. The goal of this research is to develop a hydrogel-based skin graft that will be able to function as a skin replacement in full-thickness wounds while minimizing the possibility of rejection, being cost-effective, and possessing a longer shelf-life than the grafts currently in the market. Endothelial …

Propagation Of Ultrasound Through Freshly Excised Human Calvarium, Armando Garcia Noguera

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

The propagation of ultrasound through complex biological media, such as the human calvarium, poses a great challenge for modern medicine. Several ultrasonic techniques commonly used for treatment and diagnosis in most of the human body are still difficult to apply to the human brain, in part, because of the properties of the skull. Moreover, an understanding of the biomechanics of transcranial ultrasound may provide needed insight into the problem of blast wave induced traumatic brain injury (TBI). In the present study, the spatial variability of ultrasonic properties was evaluated for relevant frequencies of 0.5, 1, and 2.25 MHz. A total …

Development Of In Vitro Tissue Engineered Blood Vessel Mimics In Complex Geometries For Coronary Stent Testing, Robert Dalton Chavez

Master's Theses

Coronary heart disease is the leading cause of death in the United States and occurs when plaque occludes coronary arteries. Coronary stents, which may be used to treat coronary occlusions, are small metal tubes that are implanted in coronary arteries to restore blood flow. After stent implantation, endothelial cells grow over the stent so that blood contacts the endothelial cells instead of the stent surface; this event is known as re-endothelialization. Re-endothelialization prevents blood from clotting on the stent surface and is a good predictor of stent success. Blood vessel mimics (BVMs) are in vitro tissue engineered models of human …

Corrosion Of Stainless Steel 316l And Astm F75 Cobalt Chromium Alloy During Immersion Testing In Silver Salt Solutions, Meagan Higgins

Materials Engineering

This study evaluates the potential effects of silver salts on biocompatible metals used for prostheses during the chemical reduction process to produce a silver antimicrobial layer on the metal’s surface. Samples of two biocompatible metals were obtained: Stainless Steel 316L and ASTM F75 Cobalt Chromium Alloy. Three different silver salts were also acquired: silver nitrate, silver sulfadiazine, and silver chloride. Specimens of each metal were cut to size using a 4-1/2 inch aluminum oxide, 40 grit, cut off wheel for metal, attached to a Dewalt Angle Grinder. The biocompatible metal samples were then subject to either Solution 1, water with …

Design Of Experimentation To Systematically Determine The Interaction Between Electrospinning Variables And To Optimize The Fiber Diameter Of Electrospun Poly (D, L-Lactide-Co-Glycolide) Scaffolds For Tissue Engineered Constructs, Yvette S. Castillo

Master's Theses

Cardiac disease causes approximately a third of the deaths in the United States. Furthermore, most of these deaths are due to a condition termed atherosclerosis, which is a buildup of plaque in the coronary arteries, leading to occlusion of normal blood flow to the cardiac muscle. Among the methods to treat the condition, stents are devices that are used to restore normal blood flow in the atherosclerotic arteries. Before advancement can be made to these devices and changes can be tested in live models, a reliable testing method that mimics the environment of the native blood vessel is needed. Dr. …

The Characterization Of Biofilm Attachment To Metal Interfaces: Effects Of Substratum Properties, Marcel D. Mendes

Master's Theses

Bacteria are among the most abundant microorganisms on earth, and can be found in essentially every environment. When a clean surface is exposed to media containing planktonic bacteria, the bacterial cells will attach to the surface and aggregate to form what is known as a biofilm. Biofilms have been shown to negatively affect many industries including medical, industrial, and food science applications. While biofilms have been well characterized from a microbiology perspective, there has been much less research from a materials science standpoint. It is hypothesized that the material properties of the substratum (such as the micro-structure) have a significant …

Growth And Expression Of Halorhodopsin For Application In A Protein-Based Artificial Retina, Megan Ryan Gillespie

Honors Scholar Theses

Halorhodopsin (HR), a light-activated chloride ion pump, demonstrates potential for use as the scaffolding in an artificial retina. Retinal implants are needed to restore vision to people afflicted with ophthalmic diseases, such as age-related macular degeneration (AMD) and retinitis pigmentosa (RP). A protein-based chloride ion-patch would be utilized by the eye to create an influx of chloride ions, similar to ion concentrations in healthy retinas during the conversion of light stimuli to electrochemical signals. This protein-based retinal prosthesis will directly stimulate the bipolar cells of the retina, replacing the function of damaged photoreceptor cells. Other alternative treatments for AMD and …

Evaluation Of Decellularization Procedures For Porcine Arteries, Charles Clapp

Biomedical Engineering

Coronary artery disease has become the leading cause of death in the United States, with over 425,000 deaths in 2006. Stenting has evolved into the preferred preventative technique for myocardial infarction by opening up an occluded artery, due to its low invasiveness compared to the alternative of coronary artery bypass grafting. Bare metal stents have been improved by coating with anti-proliferative drugs to advance their effects, but even drug eluting stents still have a risk of restenosis, thrombus formation, and necessary revascularization. Continual advancement in stent design necessitates faster, effective pre-clinical evaluation techniques. Kristen Cardinal, Ph.D., developed the blood vessel …

Investigation Of A New Material For Heart Valve Tissue Engineering, Claire Brougham, Nian Shen, Allison Cudsworth, Thomas Flanagan, Stefan Jockenhoevel, Fergal O'Brien

Conference Papers

No abstract provided.

Mineralization Potential Of Electrospun Pdo-Hydroxyapatite-Fibrinogen Blended Scaffolds, Isaac Rodriguez, Parthasarathy A. Madurantakam, Jennifer M. Mccool, Scott A. Sell, Hu Yang, Peter C. Moon, Gary L. Bowlin

Biomedical Engineering Publications

The current bone autograft procedure for cleft palate repair presents several disadvantages such as limited availability, additional invasive surgery, and donor site morbidity. The present preliminary study evaluates the mineralization potential of electrospun polydioxanone:nano-hydroxyapatite : fibrinogen (PDO : nHA : Fg) blended scaffolds in different simulated body fluids (SBF). Scaffolds were fabricated by blending PDO : nHA : Fg in the following percent by weight ratios: 100 : 0 : 0, 50 : 25 : 25, 50 : 50 : 0, 50 : 0 : 50, 0 : 0 : 100, and 0 : 50 : 50. Samples were immersed …

A Preliminary Study On The Potential Of Manuka Honey And Platelet-Rich Plasma In Wound Healing, Scott A. Sell, Patricia S. Wolfe, Andrew J. Spence, Isaac A. Rodriguez, Jennifer M. Mccoll, Rebecca L. Petrella, Koyal Garg, Jeffery J. Ericksen, Gary L. Bowlin

Ellmer School of Nursing Faculty Publications

Aim. The purpose of this study was to determine the in vitro response of cells critical to the wound healing process in culture media supplemented with a lyophilized preparation rich in growth factors (PRGF) and Manuka honey. Materials and Methods. This study utilized cell culture media supplemented with PRGF, as well as whole Manuka honey and the medical-grade Medihoney (MH), a Manuka honey product. The response of human fibroblasts (hDF), macrophages, and endothelial cells (hPMEC) was evaluated, with respect to cell proliferation, chemotaxis, collagen matrix production, and angiogenic potential, when subjected to culture with media containing PRGF, MH, Manuka honey, …

The Use Of An In Vitro 3d Melanoma Model To Predict In Vivo Plasmid Transfection Using Electroporation, Benadette Marrero, Richard Heller

Bioelectrics Publications

A large-scale in vitro 3D tumor model was generated to evaluate gene delivery procedures in vivo. This 3D tumor model consists of a "tissue-like" spheroid that provides a micro-environment supportive of melanoma proliferation, allowing cells to behave similarly to cells in vivo. This functional spheroid measures approximately 1 cm in diameter and can be used to effectively evaluate plasmid transfection when testing various electroporation (EP) electrode applicators. In this study, we identified EP conditions that efficiently transfect green fluorescent protein (GFP) and interleukin 15 (IL-15) plasmids into tumor cells residing in the 3D construct. We found that plasmids …

Effect Of Extracellular Matrix (Ecm) Protein Micropatterns On The Behavior Of Human Neuroblastoma Cells, Ishwari Poudel

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Recent advances in patterning techniques and emerging surface microtechnologies have allowed cell micropatterning to control spatial location of the cells on a surface as well as cell shape, attachment area, and number of contacting neighbor cells. These parameters play important roles in cell cellular behaviors. Cell micropatterning has thus become one of the most important strategies for biomedical applications, such as, tissue engineering, diagnostic immunoassays, lab-on-chip devices, bio-sensing, etc., and cell biology studies as well. For neuronal cells, there have been attempts to distribute neuronal cells on specific patterns to control cell-to-cell interaction. However, there have been very limited understanding …

Differential Gene Expression To Investigate The Effects Of Low-Level Electrochemical Currents On Bacillus Subtilis., Robert Szkotak, Tagbo H R Niepa, Nikhil Jawrani, Jeremy L. Gilbert, Marcus B. Jones, Dacheng Ren

Biomedical and Chemical Engineering - All Scholarship

With the emergence and spread of multidrug resistant bacteria, effective methods to eliminate both planktonic bacteria and those embedded in surface-attached biofilms are needed. Electric currents at uA-mA/cm2 range are known to reduce the viability of bacteria. However, the mechanism of such effects is still not well understood. In this study, Bacillus subtilis was used as the model Gram-positive species to systematically investigate the effects of electrochemical currents on bacteria including the morphology, viability, and gene expression of planktonic cells, and viability of biofilm cells. The data suggest that weak electrochemical currents can effectively eliminate B. subtilis both as planktonic …

Impact Isolation Of Training Shoes, Nicci Daly, Stephen Tiernan

Conference Papers

ABSTRACT The increase in popularity of physical activities from fun runs to competitive marathons has lead to a huge industry in sports footwear, which is now worth $20bn annually. There is a resultant increase in injuries, largely due to the repeated and prolonged nature of the impact forces experienced by the leg. Clinical data indicates that the knee is the most common site of running related injury, followed by the lower leg and foot. The complexity of the ankle structure means that injuries are acute and the success rates of replacements are very low. Therefore research in this area is …

Improved Manufacturing Methods Of Bovine Femur Samples For Ultrasonic Testing And Assessment Of Materials Through Contract Angle Measurement, Kevin Mathew Lopez Galang

Biomedical Engineering

At California Polytechnic State University of San Luis Obispo (Cal Poly), the Biomedical Engineering department (BMED) requires its students to take the course listed as “BMED 420: Principles of Biomaterial Designs.” BMED 420 has a required laboratory section every week throughout the duration of the course that is meant to be a supplemental tool for learning. During the lab sections, students perform experiments and exercises that are currently being implemented in the industry. Despite accuracy of the methods and experiments relative to their use in the industry, there is always room for improvement. The objective of this project will illustrate …

Targeted Multistage Delivery Of Nanoparticles To The Bone Marrow, Aman Mann

Dissertations and Theses (Open Access)

Bone marrow is a target organ site involved in multiple diseases including myeloproliferative disorders and hematologic malignancies and metastases from breast and prostate. Most of these diseases are characterized with poor quality of life, and the treatment options are only palliative due to lack of delivery mechanisms for systemically injected drugs which results in dose limitation to protect the healthy hematopoietic cells. Therefore, there is a critical need to develop effective therapeutic strategies that allow for selective delivery of therapeutic payload to the bone marrow. Nanotechnology-based drug delivery systems provide the opportunity to deliver drugs to the target tissue while …