Biomaterials Commons^™

Evaluation Of Alternative Solvents For Electrospinning Occluded Scaffolds To Model Intracranial Atherosclerotic Disease In Blood Vessel Mimics, Olivia D. Rankin

Master's Theses

Intracranial atherosclerotic disease (ICAD) is characterized by a buildup of fatty plaque within the walls of arteries supplying the brain, resulting in vessel narrowing, restricted blood flow, and increased risk of ischemic stroke. While various treatments exist for ICAD, most are accompanied by high recurrent stroke rates and other adverse events, highlighting the need for further investigation and models for pre-clinical testing. Tissue engineered Blood Vessel Mimics (BVMs), consisting of a polymer scaffold sodded with human vascular cells, serve as physiologically relevant in vitro models for vascular device testing. This thesis focused on the application of alternative solvents to a …

Tetramethylbenzidine Loaded Pva Nanofibers Strip For Visual Detection Of Hydrogen Peroxide Via Cu2+ Catalysis And Its Applications, Samar A. Salim

Nanotechnology Research Centre

Background Advancements in sensor technology have facilitated the development of cost-effective and highly sensitive sensors which have significantly improved the detection of biological analytes in various fields. This study presents a novel approach for the detection of hydrogen peroxide (H₂O₂), a critical analyte in both biological and environmental systems. A simple and sensitive colorimetric sensing platform was developed based on polyvinyl alcohol (PVA) nanofibers loaded with tetramethylbenzidine (TMB). Results The nanofibers were characterized using scanning electron microscopy, confirming the formation of smooth, spindle-shaped fibers with diameters from 324 to 551 nm. The colorimetric detection method utilized TMB, which undergoes oxidation …

Enhancing Wound Healing With Synergistic Dual-Drug Electrospun Roflumilast And L-Arginine Loaded Pla/Pva Nanofibers Through Fabrication, Optimization, And In Vivo Assessment, Samar A. Salim

Nanotechnology Research Centre

Current trends in improved wound management emphasize the development of dual-drug-loaded electrospun nanofibrous scaffolds. Herein, electrospun dual-drug loaded PLA/PVA nanofibrous scaffolds, incorporating roflumilast, a selective phosphodiesterase-4 inhibitor with anti-inflammatory activity, and L-arginine, a precursor to nitric oxide with stimulating activity towards wound healing and tissue regeneration, were developed. A dual-spinneret electrospinning process enabled the coloading of drugs in PLA and PVA phases. Scaffolds were characterized by SEM, FTIR, and XRD, showing consistent fiber morphology, and amorphous drug formation. FTIR analysis was performed to confirm drug–polymer compatibility and successful incorporation of roflumilast and L-arginine within the PLA/ PVA nanofibrous matrix. Swelling …

Novel Electrospinning Techniques For Fabricating Scaffolds To Model Intracranial Atherosclerotic Disease In Tissue Engineered Blood Vessel Mimics, Isaac "Squeaky" Buentipo

Master's Theses

Novel Electrospinning Techniques for Fabricating Scaffolds to Model Intracranial

Atherosclerotic Disease in Tissue Engineered Blood Vessel Mimics

Isaac “Squeaky” Buentipo

Dr. Kristen Cardinal’s Tissue Engineering Lab at California Polytechnic State University specializes in fabricating customized vascular models, known as Blood Vessel Mimics (BVMs), for medical device testing. BVMs are simplified in vitro vascular models designed to bridge the gap between bench testing and in vivo evaluation of intravascular medical devices. BVMs are produced by combining a polymer scaffold with human vascular cells. Through novel scaffold fabrication techniques, such as silicone injection molding, silicone dip casting and electrospinning, the capabilities of …

Evaluation Of Polyvinyl Alcohol (Pva) For Electrospinning Utility In The Blood Vessel Mimic (Bvm) Lab, Logan Vandenbroucke

Master's Theses

Electrospinning has provided the opportunity to create extracellular matrix (ECM) mimicking scaffolds for the development of tissue-engineered constructs. Within Professor Kristen Cardinal’s Blood Vessel Mimic (BVM) Lab, at Cal Poly, there exists a constant demand for innovation and the expansion of polymer types and electrospinning capabilities for its BVM model. Along these lines, the BVM Lab has recently acquired two new electrospinning systems: the Spinbox, a commercially graded electrospinning system, and the Learn-By-Doing system, which was part of a recently completed thesis conducted by Jason Provol. Additionally, recently published literature has demonstrated polyvinyl alcohol (PVA) as a viable option for …

Cellulose Materials For Drug Delivery Applications, Reham Mohamed

Mechanical Engineering Theses

Non-healing wounds are a growing global public health concern due to inadequate or ineffective therapeutic products available. Cellulose-based biopolymers are attractive wound dressing materials due to their biocompatibility, biodegradability, non-toxicity, and cost-effectiveness. This study aims to design and fabricate solid dosage formulations using carboxymethyl cellulose (CMC) and ethyl cellulose (EC) to facilitate multi-stage releases of phenytoin (PHT) and tetracycline hydrochloride (TCH) from plain carriers, fibers/films composites, and layer-by-layer fiber composites. Results from in vitro drug release assays demonstrated a time-dependent release up to 8 hours from PHT-loaded EC fibers, while TCH-loaded CMC films exhibited a rapid release within 5 minutes. …

Promotion Of Human Schwann Cell Proliferation Using Heparin/Collagen Coated Nerve Conduits, John Magness

Chemical Engineering Undergraduate Honors Theses

Often in the aftermath of an injury or surgery, the sense of touch and muscle control is lost in the affected area as nerves are damaged or severed and fail to grow back completely. The regeneration of the nerve cells can be promoted by treating the nerves with nerve conduits. Nerve conduits are hollow cylinders of bio-compatible materials that can be surgically implanted to the disconnected nerve to promote and direct the growth of nerves. The objectives of this research are to investigate the ability of nerve conduits treated with layer-by-layer coatings to promote the growth of Schwann cells, to …

Design Of An Affordable Rotating Drum Electrospinner For Classroom Education, Peder Solberg

The Journal of Undergraduate Research

Electrospinning is a technology used to generate small fibers down to nano-scale size. This method of fiber creation has been around for many years. However, in recent years electrospinning has found increased applications, especially in the area of tissue engineering due to its ability to create fibers with properties similar to the extracellular matrix in tissue. An electrospinning platform can illustrate concepts of engineering, electro-mechanical system design, manufacturing, and biomedical applications in one single package. Hence, it provides an excellent opportunity to integrate into secondary (middle and high school) and post-secondary (undergraduate) technology education.

Furthermore, just as integration of 3D …

Artificial Synthetic Scaffolds For Tissue Engineering Application Emphasizing The Role Of Biophysical Cues, Samerender Nagam Hanumantharao

Dissertations, Master's Theses and Master's Reports

The mechanotransduction of cells is the intrinsic ability of cells to convert the mechanical signals provided by the surrounding matrix and other cells into biochemical signals that affect several distinct processes such as tumorigenesis, wound healing, and organ formation. The use of biomaterials as an artificial scaffold for cell attachment, differentiation and proliferation provides a tool to modulate and understand the mechanotransduction pathways, develop better in vitro models and clinical remedies. The effect of topographical cues and stiffness was investigated in fibroblasts using polycaprolactone (PCL)- Polyaniline (PANI) based scaffolds that were fabricated using a self-assembly method and electrospinning. Through this …

Nano Fab Lab 63, Brian K. Deemer, Josh Clemons, Nick Brodine, Delaney Fitzsimmons

Mechanical Engineering

Lawrence Livermore National Laboratories (LLNL) has several steps in the production process for ceramic nanofiber tubes that they would like to improve - electrospinning, cutting, rolling, sealing and heat treating. We undertook the challenge to deliver LLNL with a semi-automated process that efficiently integrates the steps of cutting, rolling, and sealing to save time and improve control over end dimensions. In this document, we discuss the technical background of the manufacturing steps currently followed to create nanofiber tubes, identify which steps are incorporated in our prototype and explain how they will interface with one another, define the design requirements, present …

Identifying And Reducing Variability, Improving Scaffold Morphology, And Investigating Alternative Materials For The Blood Vessel Mimic Lab Electrospinning Process, Evan M. Dowey

Master's Theses

The work of the Cal Poly Tissue Engineering Lab is primarily focused on the fabrication, characterization, and improvement of “Blood Vessel Mimics” (BVMs), tissue engineered constructs used to evaluate cellular response to vascular medical devices. Currently, cells are grown onto fibrous, porous tubes made using an in-house electrospinning process from PLGA, a biocompatible co-polymer. The adhesion and proliferation of cells in a BVM is reliant on the micro-scale structure of the PLGA scaffold, and as such it is of great importance for the electrospinning process to consistently produce scaffolds of similar morphologies. Additionally, it has been shown that cell proliferation …

Modulating The Innate Immune Response To Electrospun Scaffolds And Polymer Degradative Byproducts, Daniel Abebayehu

Theses and Dissertations

Implanted biomaterials often induce inflammation that frequently leads to the foreign body response, fibrosis, and the failure of the implant. Thus, it is important to evaluate how cells interact with materials to promote a more regenerative response. It is critical to determine how to modulate the response of tissue resident innate immune cells, as they are among the first cells to interact with implanted materials. Among tissue resident innate immune cells are mast cells, which are inflammatory sentinels that degranulate and orchestrate the fate of other cell populations, such as monocytes/macrophages and lymphocytes. Mast cells have also been reported to …

A 3d Biomimetic Scaffold Using Electrospinning For Tissue Engineering Applications, Samerender Nagam Hanumantharao

Dissertations, Master's Theses and Master's Reports

Electrospinning holds great promise for designing functional 3D biomimetic scaffolds for tissue engineering applications. The technique allows for the reproducible fabrication of 3D scaffolds with control over the porosity and thickness. In this work, a novel method for the synthesis of a 3D electroactive scaffold using electrospinning from polycaprolactone (PCL), Polyvinylidene Fluoride (PVDF) and Polyaniline (PANI) is reported. Additional scaffolds involving different morphologies of PCL, PCL-PVDF and PCL-PANI-PVDF were also fabricated and evaluated. The scaffolds were characterized using electron microscopy to visualize the morphologies. Infrared spectroscopy was used to confirm the presence of polymers and their respective phases in the …

Development Of An Electrospun And 3d Printed Cellular Delivery Device For Dermal Wound Healing, Ryan M. Clohessy

Theses and Dissertations

The goal of this research was to develop a system of individualized medicine that could be applied to dermal wounds serving as a wound dressing and synthetic extracellular matrix while delivering stem cells to the wound bed. First, fabrication parameters for electrospinning polymer fibers were determined. This involved evaluating fiber morphology with respect to polymer selection and solution concentration. Next, construct fabrication was examined to produce an integrated void space, or cargo area, suitable to maintain stem cells. In vitro studies to ensure stem cell viability and phenotype were conducted, and results supported the notion that cells could be administered …

Electrospinning Of Polycaprolactone Core-Shell Nanofibers With Anti-Cancer Drug, Sakib Iqbal, Mujibur Khan, Saheem Absar, Andrew Diamanduros, Samuel Chambers

GS4 Student Scholars Symposium

Encapsulation of a model anti-cancer drug, 5-Fluorouracul (5-FU) into biocompatible core-shell nanofibers of polycaprolactone (PCL) nanofibers was fabricated using a coaxial electrospinning process. Our work aims to solve these issues using a novel method of fabrication of fibers featuring confinement of drugs within a biodegradable core-shell structure, thereby permitting sustained release of drugs to specific sites of treatment, such as tissues affected with tumor cells. The coaxial electrospinning was performed using a sheath polymer solution consisting of a 14 wt% PCL solution and a 5 wt% solution of 5-FU as the core solution. Dimethylformamide (DMF) was used as the solvent …

Peracetic Acid Sterilization Of Electrospun Polycaprolactone Scaffolds, Suyog Yoganarasimha

Theses and Dissertations

Sterilization of tissue engineered scaffolds is an important regulatory issue and is at the heart of patient safety. With the introduction of new biomaterials and micro/nano structured scaffolds, it is critical that the mode of sterilization preserve these built-in features. Conventional sterilization methods are not optimal for engineered polymeric systems and hence alternate systems need to be identified and validated. PCL is polyester with a low melting point (heat labile), susceptible to hydrolysis and is popular in tissue engineering. Electrospinning generates some nanoscale features within the scaffold, the integrity of which can be affected by sterilization method. Chapter 1 explores …

Peracetic Acid: A Practical Agent For Sterilizing Heat-Labile Polymeric Tissue-Engineering Scaffolds, William R. Trahan

Theses and Dissertations

Advanced biomaterials and sophisticated processing technologies aim to fabricate tissue-engineering scaffolds that can predictably interact within a biological environment at a cellular level. Sterilization of such scaffolds is at the core of patient safety and is an important regulatory issue that needs to be addressed prior to clinical translation. In addition, it is crucial that meticulously engineered micro- and nano- structures are preserved after sterilization. Conventional sterilization methods involving heat, steam and radiation are not compatible with engineered polymeric systems because of scaffold degradation and loss of architecture. Using electrospun scaffolds made from polycaprolactone (PCL), a low melting polymer, and …

Characterizing The Reproducibility Of The Properties Of Electrospun Poly(D, L-Lactide-Co-Glycolide) Scaffolds For Tissue-Engineered Blood Vessel Mimics, Toni M. Pipes

Master's Theses

“Blood vessel mimics” (BVMs) are tissue-engineered constructs that serve as in vitro preclinical testing models for intravascular devices. The Cal Poly Tissue Engineering lab specifically uses BVMs to test the cellular response to stent implantation. PLGA scaffolds are electrospun in-house using the current “Standard Protocol” and used as the framework for these constructs. The performance of BVMs greatly depends on material and mechanical properties of the scaffolds. It is desirable to create BVMs with reproducible properties so that they can be consistent models that ultimately generate more reliable results for intravascular device testing. Reproducibility stems from the consistency of the …

Tissue Engineering Scaffold Fabrication And Processing Techniques To Improve Cellular Infiltration, Casey Grey

Theses and Dissertations

Electrospinning is a technique used to generate scaffolds composed of nano- to micron-sized fibers for use in tissue engineering. This technology possesses several key weaknesses that prevent it from adoption into the clinical treatment regime. One major weakness is the lack of porosity exhibited in most electrospun scaffolds, preventing cellular infiltration and thus hosts tissue integration. Another weakness seen in the field is the inability to physically cut electrospun scaffolds in the frontal plane for subsequent microscopic analysis (current electrospun scaffold analysis is limited to sectioning in the cross-sectional plane). Given this it becomes extremely difficult to associate spatial scaffold …

Shelf Life Study Of Electrospun Plga Copolymers, Sean Youra, Nick Hudson

Biomedical Engineering

Poly(lactic-co-glycolic acid) (PLGA) is one of the most commonly used copolymers for electrospinning in tissue engineering applications. However, most research has not focused on the copolymer itself in regards to how long it can be used effectively and if varying the concentrations of polylactic acid (PLA) and polyglycolic acid (PGA) affect the resulting properties. Electrospinning is the method we use to create the three-dimensional constructs, or “scaffolds”, for the blood vessel mimic (BVM) in the tissue engineering lab. The aim of our project was to investigate if the morphology and mechanical properties of the scaffolds changed over time when they …

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. …

An Investigation Of Process Parameters To Optimize The Fiber Diameter Of Electrospun Vascular Scaffolds Through Experimental Design, Steffi Wong

Biomedical Engineering

No abstract provided.

Assessment Of Electrospinning As An In-House Fabrication Technique For Blood Vessel Mimic Cellular Scaffolding, Colby M. James

Master's Theses

Intravascular devices, such as stents, must be rigorously tested before they can be approved by the FDA. This includes bench top in vitro testing to determine biocompatibility, and animal model testing to ensure safety and efficacy. As an intermediate step, a blood vessel mimic (BVM) testing method has been developed that mimics the three dimensional structure of blood vessels using a perfusion bioreactor system, human derived endothelial cells, and a biocompatible polymer scaffold used to support growth of the blood vessel cells. The focus of this thesis was to find an in-house fabrication method capable of making cellular scaffolding for …

Preparation And Characterization Of Electrospun Poly(D, L-Lactide-Co-Glycolide) Scaffolds For Vascular Tissue Engineering And The Advancement Of An In Vitro Blood Vessel Mimic, Tiffany Richelle Pena

Master's Theses

PREPARATION AND CHARACTERIZATION OF ELECTROSPUN POLY(D,L-LACTIDE-CO-GLYCOLIDE) SCAFFFOLDS FOR VASCULAR TISSUE ENGINEERING AND THE ADVANCEMENT OF AN IN VITRO BLOOD VESSEL MIMIC

Tiffany Richelle Peña

Currently, an estimated 1 in every 3 adult Americans are affected by one or more cardiovascular complications. The most common complication is coronary artery disease, specifically atherosclerosis. Outcomes of balloon angioplasty treatments have been significantly improved with the addition of drug eluting stents to the process. Although both bare metal and drug eluting stents have greatly increased the effectiveness of angioplasty and decreased the occurrence of restenosis, several complications still exist. For this reason, the stent …