Biomedical Engineering and Bioengineering Commons^™

Advanced Processing Techniques For Electrospun Nanofibers: Investigating Annealing And Laser Zone-Drawing Effects On Material Characteristics, Matthew D. Flamini

Theses and Dissertations

Electrospun nanofibers hold potential for a wide range of commercial and scientific applications; however, their properties must be optimized through post-processing treatments to achieve optimal performance. This dissertation investigates the effects of annealing and laser zone-drawing on electrospun nanofiber properties. Annealing polycaprolactone nanofibers at 70°C results in the highest rate of crystallization and molecular alignment, impacting long-term stability and mechanical properties. A multivariate linear model incorporating crystallinity and molecular alignment predicts the material properties resulting from annealing under different conditions. Laser zone-drawing experiments reveal that polylactide fiber thinning under laser irradiation primarily occurs due to drawing rather than ablation. Steady-state …

Enhancement Of Electrospun Nanofiber Properties Via Automated Track Post-Draw Processing, David Anthony Brennan

Theses and Dissertations

Electrospinning is an alternative manufacturing method, capable of producing fibers with nanoscale diameters from a wide range of different polymers in a process which is relatively simple and inexpensive in comparison to other forms of nanofiber production. This has made electrospinning the subject a great deal of research as a method of producing nanofibers for various high-performance applications. However, electrospun nanofiber tensile strength is weak in comparison to conventional fibers of the same material, preventing widespread use and marketization. This disparity in mechanical strength is attributed to poor polymer chain alignment in individual fibers, caused by the absence of a …

Electrospun Collagen Fibers For Tissue Regeneration Applications, Ying Li

Electronic Thesis and Dissertation Repository

Tissue engineering aims to regenerate damaged and deceased tissue by combining cells with scaffold made from an appropriate biomaterial and providing a conducive environment to guide cell growth and the formation or regeneration of new tissue or organ. While collagen, an important material of the extracellular matrix (ECM), is a natural choice as a scaffold biomaterial, the conducive environment can only be created by having the ability to control the geometry, organization, structural and mechanical properties of the scaffold. Moreover, degradability and degradation rate control of the scaffold has to be taken into consideration too. In this work, we aim …

Polysaccharide Fabrication Platforms And Biocompatibility Assessment As Candidate Wound Dressing Materials, Donald C. Aduba Jr., Hu Yang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Wound dressings are critical for wound care because they provide a physical barrier between the injury site and outside environment, preventing further damage or infection. Wound dressings also manage and even encourage the wound healing process for proper recovery. Polysaccharide biopolymers are slowly becoming popular as modern wound dressings materials because they are naturally derived, highly abundant, inexpensive, absorbent, non-toxic and non-immunogenic. Polysaccharide biopolymers have also been processed into biomimetic platforms that offer a bioactive component in wound dressings that aid the healing process. This review primarily focuses on the fabrication and biocompatibility assessment of polysaccharide materials. Specifically, fabrication platforms …

Molecular Combing Of Dna Nanofibers And Comparison To Electrospinning, Tanner L. Buresh

UCARE Research Products

The goal of these experiments was to create DNA nanofibers through the method of molecular combing (MC) and then compare the MC fibers to fibers created with electrospinning (ES). The experiment was designed and initial samples were created. After confirming that the method would succeed in creating DNA fibers, several parametric studies were performed in order to optimize the experiment and create the most uniform fibers possible. The parametric studies were done on the following variables: substrate material, pH level of DNA solution, and DNA solution concentration. After completion of all experiments, it was determined that although fibers could be …

Multi-Platform Arabinoxylan Scaffolds As Potential Wound Dressing Materials, Donald C. Aduba Jr

Theses and Dissertations

Biopolymers are becoming more attractive as advanced wound dressings because of their naturally derived origin, abundance, low cost and high compatibility with the wound environment. Arabinoxylan (AX) is a class of polysaccharide polymers derived from cereal grains that are primarily used in food products and cosmetic additives. Its application as a wound dressing material has yet to be realized. In this two-pronged project, arabinoxylan ferulate (AXF) was fabricated into electrospun fibers and gel foams to be evaluated as platforms for wound dressing materials. In the first study, AXF was electrospun with varying amounts of gelatin. In the second study, AXF …

Engineering Bacterial Cellulose Scaffold And Its Biomimetic Composites For Bone And Cartilage Tissue Regeneration, Pelagie Marlene Favi

Doctoral Dissertations

A very promising approach to quickly and safely restore normal function to extensively damages and diseases bone and cartilage tissues is the regeneration of these injured tissues using an engineered support scaffold. This dissertation research focuses on the development and evaluation of native bacterial cellulose (BC) and chemically modified BCs as potential biomaterials for bone and cartilage regeneration using equine-derived bone marrow mesenchymal stem cells (EqMSCs).

The ability of native BC scaffold to maintain cell proliferation, viability, and in vitro differentiation of the seeded EqMSCs for application in bone and cartilage tissue engineering was studied. BC morphology was characterized using …

Sol-Gel Derived Biodegradable And Bioactive Organic-Inorganic Hybrid Biomaterials For Bone Tissue Engineering, Bedilu A. Allo

Electronic Thesis and Dissertation Repository

Treatments of bone injuries and defects have been largely centered on replacing the lost bone with tissues of allogeneic or xenogeneic sources as well as synthetic bone substitutes, which in all lead to limited degree of structural and functional recovery. As a result, tissue engineering has emerged as a viable technology to regenerate the structures and therefore recover the functions of bone tissue rather than replacement alone. Hence, the current strategies of bone tissue engineering and regeneration rely on bioactive scaffolds to mimic the natural extracellular matrix (ECM) as templates onto which cells attach, multiply, migrate and function.

In this …

Novel Nanofiber Structures And Advanced Tissue Engineering Applications, Vince Beachley

All Dissertations

Extracellular matrix (ECM) nanofibers such as collagen and elastin make up an important component of natural tissues. These structural components serve to impart mechanical strength and provide locations for cell attachment and biomolecule storage. Cells respond to their structural environment in a wide variety of ways beyond physical support, and it has been demonstrated that this environment directly modulates cell behaviors such as, morphology, differentiation, ECM production, attachment, and migration. ECM nanofibers also play an important role as a template for tissue formation during development, remodeling, and regeneration. Nanofiber based tissue engineering strategies aim to mimic the geometry of the …

Nano Bubble Dynamics In Spider Spinning System, Ji-Huan He

Ji-Huan He

A possible mechanism in the spider-spinning process is illustrated and a nanobubble dynamical model is suggested. The spinning system consists of thousands of nano scale spigots and a bubble can be produced at the apex of each nano-spigot. Nano-effect enables the dragline silk to have of extraordinary strength and toughness, while the extremely small surface tension of nanobubbles enables the spider to use an awfully small force during the spinning procedure.