Biomedical Engineering and Bioengineering Commons^™

Bioadhesive Hydrogel Composite Cell Carrier For The Repair Of The Degenerated Intervertebral Disc, Thomas Richard Christiani

Theses and Dissertations

Lower back pain (LBP) affects the worldwide population and can be attributed to the degeneration of the intervertebral disc (IVD). The IVD is composed of a central nucleus pulposus (NP), a peripheral annulus fibrosus (AF), and adjacent cartilage endplates (CEPs). IVD degeneration is characterized by proteoglycan loss, tissue dehydration, and decreased hydrostatic pressure. In this work, the use of an injectable bioadhesive hydrogel composite for replacement of the degenerated NP was investigated.

Results indicate that the composite exhibits similar mechanical properties to the NP, adheres to AF tissue, and supports encapsulated mesenchymal stem cell (MSC) differentiation toward an NP-like phenotype …

Analysis Of Cellular Interactions Within A Collagen Hydrogel, Austin N. Worden

Theses and Dissertations

Evidence has arisen over the past several years that use of a three- dimensional (3D) culture system provides a distinct advantage over two- dimensional (2D) systems when cellular interactions are examined in a more natural environment. Changes in morphology, speed, and directionality of cells tested in both planar and 3D matrices have all demonstrated that using 3D system is advantageous. The changes to the cellular migration patterns were shown to be dependent on several variables within the surrounding substrate including cellular content, physical environment, and the matrix chemical milieu. We have taken advantage of using collagen hydrogels as a 3D …

Modified Pamam Dendrimers In Tunable Drug-Delivery Systems: A Sustained-Release Dendrimer Hydrogel For Anti-Glaucoma Drugs And Surface-Engineered Macrophages As Nanoparticle Carriers For Targeted Anti-Cancer Therapy, Christopher A. Holden

Theses and Dissertations

Two specific drug-delivery applications were sought in this work using polyamidoamine (PAMAM) dendrimers. One drug-delivery system used a novel dendrimer hydrogel (DH) for sustained delivery of anti-glaucoma drugs. In this work, PAMAM G3.0 dendrimers were covalently bonded with poly(ethylene glycol) (PEG­₁₂₀₀₀) molecules which were subsequently acrylated, resulting in photocurable DH conjugates. For pharmacological studies, DH were loaded with a solution of intraocular pressure lowering drugs, brimonidine and timolol maleate, and were characterized for in vitro release and ex vivo transport and uptake. DH formulations were shown to increase the loading of drug molecules, increase transcorneal drug delivery, and …

An Injectable Stem Cell Delivery System For Treatment Of Musculoskeletal Defects, Shirae Leslie

Theses and Dissertations

The goal of this research was to develop a system of injectable hydrogels to deliver stem cells to musculoskeletal defects, thereby allowing cells to remain at the treatment site and secrete soluble factors that will facilitate tissue regeneration. First, production parameters for encapsulating cells in microbeads were determined. This involved investigating the effects of osmolytes on alginate microbead properties, and the effects of alginate microbead cell density, alginate microbead density, and effects of osteogenic media on microencapsulated cells. Although cells remained viable in the microbeads, alginate does not readily degrade in vivo for six months. Therefore, a method to incorporate …

Synthesis And Characterization Of Clickable Dendrimer Hydrogels For Ocular Drug Delivery, Jingfei Tian

Theses and Dissertations

Topical medication is a standard treatment for glaucoma. However, frequent dosing makes the therapy inconvenient and patient unfriendly. There is a great need to develop new topical formulations that provide long lasting noninvasive drug release. In this thesis, novel clickable dendrimer hydrogels for anti-glaucoma drug delivery were synthesized and characterized. Polyamidoamine (PAMAM) dendrimers have been widely applied for drug delivery. The physical characteristics they possess include monodispersity, water solubility, encapsulation ability, and a large number of surface groups. Polycationic PAMAM dendrimer G3 was surface modified with alkyne-PEG5-acid and then reacted with polyethylene glycol bisazide (PEG-BA, 1100 gmol-1) through click chemistry …