Biomedical Engineering and Bioengineering Commons^™

A Model Microfluidics-Based System For The Human And Mouse Retina., Shawn Mishra, Ankush Thakur, Stephen Redenti, Maribel Vazquez

Publications and Research

The application of microfluidics technologies to the study of retinal function and response holds great promise for development of new and improved treatments for patients with degenerative retinal diseases. Restoration of vision via retinal transplantation therapy has been severely limited by the low numbers of motile cells observed post transplantation. Using modern soft lithographic techniques, we have developed the μRetina, a novel and convenient biomimetic microfluidics device capable of examing the migratory behavior of retinal lineage cells within biomimetic geometries of the human and mouse retina. Coupled computer simulations and experimental validations were used to characterize and confirm the formation …

Egf As A New Therapeutic Target For Medulloblastoma Metastasis, Jennifer Rico-Varela, Tanya Singh, Sean Mccutcheon, Maribel Vazquez

Publications and Research

Medulloblastoma (MB) is a malignant pediatric brain tumor known for its aggressive metastatic potential. Despite the well-documented migration of MB cells to other parts of the brain and spinal column, MB chemotaxis is poorly understood. Herein, we examined the in vitro migratory and cellular responses of MB-derived cells to external signaling of Epidermal Growth Factor (EGF), hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF-BB), and the stromal cellderived factors 1-alpha (SDF-1). Experiments utilized transwell assays and immunocytochemistry to identify receptor activation in MB migration, and used a microfluidic platform to examine directionality, trajectory, and gradient-dependence of motile cells. Data illustrates …

Carboxymethylcellulose Hydrogels Support Cns-Derived Tumor Cell Chemotactic Migration, Tanya Singh, Chandrasekhar Kothapalli, Devika Verma, Steven Nicoll, Maribel Vazquez

Publications and Research

The local microenvironment plays an important role in maintaining the dynamics of the extracellular matrix (ECM) and the cell-ECM relationship. ECM is a complex network of molecules with distinct mechanical and biochemical characteristics. When the mechanisms that are in place to maintain ECM homeostasis are deregulated, most likely, this is the onset of cancer. The ECM becomes highly disorganized and the cell-matrix relationship changes, thus promoting alternations in cell mechanisms and metastasis. Medulloblastoma (MB) is one of the most common, malignant pediatric brain tumors in the United States. In order to gain a better understanding between the cell-ECM relationship and …

Monitoring The Progression Of Spontaneous Articular Cartilage Healing With Infrared Spectroscopy, Megan P. O'Brien, Madhuri Penmatsa, Uday Palukuru, Paul West, Xu Yang, Mathias P. G. Bostrom, Theresa Freeman, Nancy Pleshko

Publications and Research

Objective. Evaluation of early compositional changes in healing articular cartilage is critical for understanding tissue repair and for therapeutic decision-making. Fourier transform infrared imaging spectroscopy (FT-IRIS) can be used to assess the molecular composition of harvested repair tissue. Furthermore, use of an infrared fiber-optic probe (IFOP) has the potential for translation to a clinical setting to provide molecular information in situ. In the current study, we determined the feasibility of IFOP assessment of cartilage repair tissue in a rabbit model, and assessed correlations with gold-standard histology.

Design. Bilateral osteochondral defects were generated in mature white New Zealand rabbits, and …

Contact Analysis For Coupling Of Plates And Screws In Fracture Fixation Of Cortical Bone, Gaffar Gailani, Rachid Moumni, Malek Brahimi

Publications and Research

Internal fixation is a common treatment for bone fracture. Bone fracture occurs due to different reasons such as motor vehicle accidents, falling,…etc. The treatment is performed by fixing plate and screws to the fracture site. Lack of stability of the implants (plates and screws) may lead to delay in healing or failure of treatment. Micro-motion between the implant and the bone may cause formation of fibrous tissue around the screw which will lead to implant loosening. On the other hands, firm fixing of the conventional implants (Dynamic Compression Plates) may lead to delay resorption and delay in healing. Recently, Locked …

The Synthesis And Characterization Of Dual-Modified Carboxymethylcellulose For Bioadhesive Applications, Fabrice Bernard

Dissertations and Theses

Reparative medical techniques, in conjunction with existing and emerging tissue adherents and sealants, offer practicing physicians a wide variety of tools to improve the functionality, performance, and safety of surgical interventions. Carboxymethylcellulose (CMC) is a plant-derived polymer that is cytocompatible, biocompatible, biodegradable, and inexpensive. The need for a non-toxic but strongly adherent material motivated the development of an injectable bioadhesive system containing CMC modified with functional methacrylate and aldehyde groups that could potentially be used as an annulus fibrosus sealant or as a supplement to existing wound closure materials. After modification, the polymer was characterized via NMR spectroscopy, Schiff’s base …

Assessment Of Injection Behavior Of Commercially-Available Bone Bsms For Subchondroplasty Procedures, Dinely A. Colon

Dissertations and Theses

Subchondroplasty is a procedure that utilized bone substitutes materials (BSMs) or bone cement to correct bone defects in the subchondral bone. The two main materials used to compose BSMs are poly-methyl-methacrylate (PMMA) and calcium phosphate cement (CaP). Currently, there is no optimal bone material substitute in the market that can provide both the adequate mechanical support and the right viscosity to reach the affected area in the subchondral bone. In addition, there is also no established parameter for their proper use, based on the defect size and location. PMMA possesses comparable mechanical properties to bone (i.e. 96 MPa in compressive …

Morphology Of Brain Sulci Trabeculae And Its Effect On Brain During Impacts, Sharlin Anwar

Dissertations and Theses

Traumatic brain injury (TBI) is an intracranial injury caused by direct contact or non-contact head impacts to the brain. TBI is a major problem that accounts for high incidents of hospitalizations each year. Thus, it is important to understand and predict the occurrence of TBI in an impact. It has been shown that the subarachnoid space (SAS) trabeculae play an important role in damping the effect of an impact, thus reducing the injuries. However, the influence of sulci parameters and the sulci trabeculae in TBI due to impact is unexplored. Studies have shown that inclusion of sulci in brain models …

Calibration And Validation Of An In Vitro Ultrasound Device To Deliver Targeted Thermal Enhancement Of Hmsc Osteogenesis, Dionne Dawkins

Dissertations and Theses

Osteoarthritis (OA) is a disease that affects millions of people annually, often the elderly, and limits their physical abilities. Current methods of treating OA are often very invasive, and expensive, costing the Medicare system billions of dollars annually. A minimally invasive therapy that can be localized to the affected area that provides both relief and a short recovery time is optimal for treating the disease. For targeted therapy and clinical use, therapeutic ultrasound in the 0.7 MHz to 3 MHz frequency range can provide relief and is convenient, portable and localized. Low-intensity pulsed ultrasound (LIPUS) has been proven in clinical …

Chemotaxis Of Central Nervous System-Derived Tumor Cells Within Controlled Microenvironments, Jennifer Rico Varela

Dissertations and Theses

Medulloblastoma (MB) is a malignant pediatric brain tumor known for its aggressive metastatic potential. Despite the well-documented migration of MB cells to other parts of the brain and spinal column, MB chemotaxis is poorly understood. Herein, we examined the in vitro migratory and cellular responses of MB-derived cells to external signaling of Epidermal Growth Factor (EGF), hepatocyte growth factor (HGF), platelet-derived growth factor (PDGF-BB), and the stromal cell-derived factors 1-alpha (SDF-1). Experiments utilized transwell assays and immunocytochemistry to identify receptor activation in MB migration, and used a microfluidic platform to examine directionality, trajectory, and gradient- dependence of motile cells. Data …