Biomaterials Commons^™

Contribution Of Collagen Type I To The Mechanical Properties Of Myocardial Tissues At The Micron Level, Adam Baker

All Dissertations

Collagen is a critical component of the organization and one of the key factors contributing to the mechanical stability of the myocardium. Where cardiomyocytes actuate to contract the heart and deliver blood to the lungs and the entire body, the local collagen network must be able to support the mechanical needs of the heart by enhancing rigidity, reducing the mechanical responsibility of cells, and increasing compliance to add loading capacity during diastole. At an organ-wide level, this has been measured and modeled in many ways. At the tissue level, the mechanical properties have been evaluated using techniques such as bi-axial …

Innovative 4d Printing Of Biomimetic Collagen-Tcp Scaffolds For Bone Regeneration, Karly Morgan Liebendorfer

Theses and Dissertations

Bone tissue engineering (BTE) is a promising alternative approach to autografts and allografts when treating various bone diseases and disorders. BTE enables the fabrication of biocompatible, biomimetic, and osteo-stimulating constructs for the repair and regeneration of damaged bone tissue. The native bone environment primarily consists of anisotropic type 1 collagen (organic) and hydroxyapatite nanocrystals (inorganic). Composite biomimetic scaffolds fabricated by combining collagen with bioceramics have shown immense promise for BTE applications. Prior work has reported on different biofabrication methods to synthesize collagen-based composite scaffolds for use in BTE applications. However, to date, a customizable 3D composite scaffold that resembles the …

Investigating The Effects Of Collagen Alignment And Tricalcium Phosphate Incorporation On Osteoblast Cell Response, Kathryn Elizabeth Bock

Theses and Dissertations

Every year, over 20 million people globally are affected by bone tissue loss due to disease or trauma. Bone tissue engineering (BTE) is touted as a promising approach to promote bone tissue repair and regeneration. In this realm, development of collagen-based scaffolds incorporated with a bioceramic is often attempted to generate tissue scaffolds that resemble the organic and inorganic composition of native bone. In addition, a variety of different collagen processing techniques have been employed to produce anisotropically aligned scaffolds that can provide the essential biochemical and structural cues to guide cell response. While there have been numerous studies on …

Study Of The Stability Of Heparin/Collagen Layer-By-Layer Coatings, Hector M. Apodaca Reyes

Chemical Engineering Undergraduate Honors Theses

Pairing heparin with collagen-based medical implants has opened a whole new area of research for enhancing the desired effect of current implants. In fact, heparin (HEP) and collagen (COL) layer-by-layer (LbL) coatings have shown impressive results in forming polyelectrolyte multilayers. It has been already seen on skin grafts, nerve guide conduits (NGCs), and drug delivery devices yielding promising results. Due to being a simple, cost-efficient, and versatile option to fabricate thin biomimetic films, this self-assembly technique is one of the most effective methods to immobilize extracellular matrix (collagen and heparin) onto medical devices and implants. Even though previous studies have …

Regenerative Medicine For Tendon/Ligament Injuries: De Novo Equine Tendon/Ligament Neotissue Generation And Application, Takashi Taguchi

LSU Doctoral Dissertations

Tendon and ligament injuries are debilitating conditions across species. Poor regenerative capacities of these tissues limit restoration of original functions. The first study evaluated the effect of cellular administration on tendon/ligament injuries in horses using meta-analysis. The cellular administration was effective in restoring ultrasonographic echogenicity and increasing vascularity during early phase of healing. Additionally, it improved microstructural organization of healed tissue in terms of cellularity and fiber alignment. However, the study did not support its use for increasing rate of return to performance, expression/deposition of tendon-specific genes/proteins, or mechanical properties.

The findings led to the second study that engineered implantable …

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 …

Computational Bone Mechanics Modeling With Frequency Dependent Rheological Properties And Crosslinking, Timothy G. Moreno

Master's Theses

Bone is a largely bipartite viscoelastic composite. Its mechanical behavior is determined by strain rate and the relative proportions of its principal constituent elements, hydroxyapatite and collagen, but is also largely dictated by their geometry and topology. Collagen fibrils include many segments of tropocollagen in staggered, parallel sequences. The physical staggering of this tropocollagen allows for gaps known as hole-zones, which serve as nucleation points for apatite mineral. The distance between adjacent repeat units of tropocollagen is known as D-Spacing and can be measured by Atomic Force Microscopy (AFM). This D-Spacing can vary in length slightly within a bundle, but …

Pneumatospinning Of Collagen Microfibers From Benign Solvents, Seth Polk, Nardos Sori, Nick Thayer, Yas Maghdouri-White, Anna A. Bulysheva, Michael P. Francis

School of Medical Diagnostics & Translational Sciences Publications

Introduction. Current collagen fiber manufacturing methods for biomedical applications, such as electrospinning and extrusion, have had limited success in clinical translation, partially due to scalability, cost, and complexity challenges. Here we explore an alternative, simplified and scalable collagen fiber formation method, termed 'pneumatospinning,' to generate submicron collagen fibers from benign solvents. Methods and results. Clinical grade type I atelocollagen from calf corium was electrospun or pneumatospun as sheets of aligned and isotropic fibrous scaffolds. Following crosslinking with genipin, the collagen scaffolds were stable in media for over a month. Pneumatospun collagen samples were characterized using Fourier-transform infrared spectroscopy, circular dichroism, …

Effects Of Protein-Coated Nanofibers On Conformation Of Gingival Fibroblast Spheroids: Potential Utility For Connective Tissue Regeneration, Gili Kaufman, Ryan A. Whitescarver, Laiz Nunes, Xavier-Lewis Palmer, Drago Skrtic, Wojtek Tutak

Engineering Technology Faculty Publications

Deep wounds in the gingiva caused bytrauma or surgery require a rapid and robust healing of connective tissues. Wepropose utilizing gas-brushed nanofibers coated with collagen and fibrin for that purpose. Our hypotheses are that protein-coated nanofibers will: (i) attract and mobilize cells in various spatial orientations, and (ii) regulate the expression levels ofspecific extracellular matrix (ECM)-associated proteins, determining the initial conformational nature ofdense and soft connective tissues. Gingival fibroblast monolayers and3D spheroids were cultured onECMsubstrate and covered with gas-blown poly-(DL-lactide-co-glycolide)(PLGA) nanofibers (uncoated/coated with collagen and fibrin). Cell attraction and rearrangement was followed byF-actin staining and confocal microscopy. Thicknesses ofthe cell …

Bi-Directional Fatigue Life Behavior Of Bovine Meniscus, Jaremy Creechley

Boise State University Theses and Dissertations

Meniscal injuries due to tissue tearing are prevalent in the U.S. yet the failure behavior of the meniscus is poorly understood. Clinical studies indicate that fatigue failure causes many of these tears. The highly circumferentially aligned fibers result in transversely isotropic material properties. Tears preferentially align bi-directionally to the fiber orientation. The aim of this study is to present the bi-directional fatigue life behavior of meniscal fibrocartilage. A novel fatigue life approach was developed to achieve this aim. Forty-eight bovine specimens were subjected to cyclic sinusoidal tension-tension stress at 2 Hz until rupture. Normalized peak tensile stresses were determined at …

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.