Thesis
An injectable hydrogel for the replacement of nucleus pulposus tissue and treatment of degenerative disc disease
Master of Science (M.S.), Drexel University
Aug 2009
DOI:
https://doi.org/10.17918/00008826
Abstract
Degenerative Disc Disease is a problem that affects the mechanical properties of the intervertebral disc due to the dehydration of the nucleus pulposus. Current operational treatment methods are simply aimed at relieving pain, rather than restoring mobility or biomechanical function. A preventative treatment of nucleus replacement is a promising alternative because it is non invasive and can potentially restore full motor function to the patient. Polyvinyl alcohol(PVA) I Polyvinyl pyrroliodone(PVP) I Polyethylene glycol (PEG) hydrogels can be utilized for its ability to be a melted solution at elevated temperatures, and gellation upon cooling to body temperature after implantation. Previous research has also indicated that these PVAIPVPIPEG hydrogels exhibit the required mechanical properties to serve as a full nucleus replacement. In this study, a series of gels consisting of different PEG concentrations were tested in an ex vivo environment to determine their set time and gelling characteristics. It was determined that all four tested solutions were found to set after 20 minutes. A 4 week study was conducted to determine the stability of these formulations using a swelling media of PBS, DI water, and a 0.12 MPa osmotic PEG solution. Of these, all four formulations were shown to be the most stable over the 4 week period in the PEG solution, and reached equilibrium after 1 week. The samples swollen in PEG also exhibited nearly the same characteristics as the gels which were implanted in the ex vivo model for a period of 3 days. Healthy nucleus tissue was extracted from calf spines and subjected to the same swelling study in order to make comparisons with the implanted gels. The nucleus tissue increased in volume by approximately 10-15% in the PBS and DI water solutions. However, the tissue volumes decreased by 30% in the PEG solution, indicating the osmotic pressures were not in equilibrium. Lastly, a set of control samples were tested that were not implanted into the ex vivo model. The higher densities and lower water content at every time point indicate the importance of these hydrogels setting in a biological environment in order to accurately determine their in vivo characteristics.
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Details
- Title
- An injectable hydrogel for the replacement of nucleus pulposus tissue and treatment of degenerative disc disease
- Creators
- David B. Cochran
- Contributors
- Anthony M. Lowman (Advisor) - Drexel University, Drexel University (1970-)
- Awarding Institution
- Drexel University
- Degree Awarded
- Master of Science (M.S.)
- Publisher
- Drexel University; Philadelphia, Pennsylvania
- Number of pages
- ix, 44 pages
- Resource Type
- Thesis
- Language
- English
- Academic Unit
- Chemical (and Biological) Engineering (1970-2026); College of Engineering (1970-2026); Drexel University
- Other Identifier
- 991021888742204721