Biomedical Engineering and Bioengineering Commons^™

Study Of Porosity Of Gelatin-Alginate Hydrogels To Model Brain Matter For Studying Traumatic Brain Injuries, Apolline Vincent

Honors Scholar Theses

Traumatic brain injuries (TBIs) affect brain tissue and neuronal signaling, leading to many side effects including death. Research on TBIs is limited by the lack of accurate brain matter models to study the physiological and cellular reaction. Alginate-gelatin hydrogels have been designed and modified to mimic the mechanical properties of the brain to act as an accurate in vitro model. This Honors thesis aims to verify the porous microstructure of gelatin-alginate hydrogels through Scanning Electron Microscopy (SEM) to understand how gelatin and alginate affect the microstructure. I measured the pore sizes of each hydrogel using ImageJ, compared the average pore …

Impact Of Angiogenic And Osteogenic Factors In The Presence Of Biodegradable Piezoelectric Films, Jayla Millender

Honors Scholar Theses

One of the most common causes of bone graft rejection is lack of a vascular network connecting the graft to the existing native tissue – allowing for nutrient flow. Under current grafting techniques, the existing blood vessel network in the patient slowly invades the implant in order to supply the injured site with its necessary nutrients. The purpose of this research is to determine if a synthetic bone graft with a stable microvascular network can be developed in vitro. I hypothesize that the use of indirect angiogenic factors such as sonic hedgehog homolog and hypoxia-inducible factor-1 in combination with the …

Hydrolytic Degradation Study Of Polyphosphazene-Plga Blends, Riley Blumenfield

Honors Scholar Theses

The synthesis and in vitro degradation analysis of thin films of poly[(glycineethylglycinato)₇₅(phenylphenoxy)₂₅phosphazene]
(PNGEG₇₅PhPh₂₅) and poly[(ethylphenylalanato)₂₅(glycine-
ethylglycinato)₇₅phosphazene] (PNEPA₂₅GEG₇₅) blended with poly(lactic-co-glycolic acid) (PLGA) was conducted to determine the blends’ potential for use as scaffolding materials for tissue regeneration applications. The samples were synthesized with glycylglycine ethyl ester (GEG) acting as the primary substituent side group, with cosubstitution by phenylphenol (PhPh) and phenylalanine ethyl ester (EPA) to make the final product [1]. Blends of 25% polyphosphazene, 75% PLGA and 50% polyphosphazene, 50% PLGA were …

Development Of A Sonically Powered Biodegradable Nanogenerator For Bone Regeneration, Avi Patel

Honors Scholar Theses

Background: Reconstruction of bone fractures and defects remains a big challenge in orthopedic surgery. While regenerative engineering has advanced the field greatly using a combination of biomaterial scaffolds and stem cells, one matter of difficulty is inducing osteogenesis in these cells. Recent works have shown electricity’s ability to promote osteogenesis in stem cell lines when seeded in bone scaffolds; however, typical electrical stimulators are either (a) externally housed and require overcomplex percutaneous wires be connected to the implanted scaffold or (b) implanted non-degradable devices which contain toxic batteries and require invasive removal surgeries.

Objective: Here, we establish a biodegradable, piezoelectric …

Distribution And Localization Of Novel Iodine Nanoparticles In The Human Glioma 1242 Growing In The Brains Of Mice, Benjamin Billings

Honors Scholar Theses

Observing and designing the in vivo distribution and localization of therapeutic nanoparticles is an essential aspect of developing and understanding novel nanoparticle- based medical treatments. This study investigates novel PEGylated Iodine-based nanoparticles (INPs), an alternate composition to the more widely researched gold nanoparticles (AuNPs), which may help avoid adverse effects associated with AuNPs, such as potential toxicity and skin discoloration, when used in similar applications. Determining the localization of the novel INPs within murine brains containing human glioma U-1242MG cells is critical in assisting the development of radiation dose enhancement therapy for this aggressive cancer. Radiation dose enhancement utilizes the …

Effect Of Silk-Based Hydrogel Topography On Intestinal Epithelial Cell Morphology And Wound Healing In Vitro, Marisa E. Boch

Honors Scholar Theses

Recent advances in the field of biomaterials have suggested that cells cultured on substrates resembling the native tissue mechanical properties, matrix and growth factor composition, and topography can adopt phenotypes that more closely resemble the in vivo tissue compared to cells cultured on non-mimetic constructs. Understanding the effect of culture substrate on in vitro tissue formation is important for bioengineering applications that include mechanistic studies of healthy tissue function and development of disease models. In this work, Caco-2 adenocarcinoma cells were seeded on flat and crypt-like topographies of 3D-printed cytocompatible hydrogels derived from silk fibroin protein. Silk hydrogels were selected …

Patient-Derived Hydrogel As A Sacrificial Matrix For Efficient Cell Loading, Shalmli U. Joshi

Honors Scholar Theses

The field of tissue engineering focuses on delivering patient-derived stem cells to the body through the use of degradable biomaterials, such as hydrogels, which are infused into engineered scaffolds. Hydrogels act as templates to support and guide cells towards the regeneration of new tissue. In this study, we introduce a completely intraoperative procedure for obtaining a fibrin hydrogel for tissue engineering applications. In the past, fibrin hydrogel has been commonly formed by combining fibrinogen protein with animal-derived thrombin. Instead, we have developed an automated, and therefore reproducible, protocol to isolate and form fibrin hydrogel without the use of animal-derived thrombin. …

Design And Development Of Two Component Hydrogel Ejector For Three-Dimensional Cell Growth, Thomas Dunkle, Jessica Deschamps, Connie Dam

Honors Scholar Theses

Hydrogels are useful in wound healing, drug delivery, and tissue engineering applications, but the available methods of injecting them quickly and noninvasively are limited. The medical industry does not yet have access to an all-purpose device that can quickly synthesize hydrogels of different shapes and sizes. Many synthesis procedures that have been developed result in the formation of amorphous hydrogels. While generally useful, amorphous hydrogels exhibit limited capability in tissue engineering applications, especially due to their viscous properties. This endeavor aims to modulate the appropriate gelation parameters, optimize the injection process, and create a prototype that allows for the extrusion …

Finite Element Analysis Of The Application Of Ultrasound-Generated Acoustic Radiation Force To Biomaterials, Nicole J. Piscopo

Honors Scholar Theses

While most bone fractures can heal simply by being stabilized, others can take a longer time to rejoin or they could fail to merge back together completely. Numerous studies have shown the positive effects that ultrasonic therapy have had on delayed-union and non-union bone fracture repair but little is known as to what specific biological mechanisms are at play. Ultrasound may be a valuable tool for bone tissue regeneration at these fracture sites using a tissue engineering approach, however, more must be understood about its impact on stimulating tissues to heal before this can be a reality. For that reason, …

Design Of A Simple Device For Accurate Measurement Of Human Blood Viscosity In Oxygenated And Deoxygenated Conditions, Catherine E. Oliver, Jessica Hockla, Divya Kamireddi

Honors Scholar Theses

The purpose of this research is to design, fabricate, and test a simple device that can accurately measure the viscosity of whole blood in both an oxygenated and a deoxygenated environment. The ideal device is easy to operate, inexpensive to fabricate, and is usable outside of a laboratory setting. The microfluidic rheometer presented here was fabricated using a wet chemical etching method. Using the channel dimensions, the known viscosity of a reference fluid, and the velocity of fluid flow of the sample and a reference fluid through the microchannels the unknown viscosity of a sample fluid is calculated.

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 …