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Unformatted text preview: Regeneration of Central Nervous System Injuries by Application of a Bioactive Polymer Scaffold Seeded with Autologous Neural Stem Cells
Harold J. Ting Department of Biomedical Engineering, University of California at Davis, Davis CA Central Nervous Damage
Spinal Cord Injuries Degenerative Neurological Diseases (Parkinson's, Huntington's, Lou Gehrig's) Difficulties in CNS Repair
Inhibitory glycoproteins associated with myelin (myelin-associated glycoprotein, oligodendrocyte myelin glycoprotein) Developmentally repulsive cues (semaphorins, ephrins, etc) Blood-spine barrier "Reactive astrocytes" Possible Interventions Necessary Components for Successful CNS Defect Intervention Device Elements
Photolithographic Micropatterning Mitogen Loaded Microspheres Magnetically Aligned Collagen Polypyrrole Surface Treatment Autologous Nervous Stem Cells Surgical Implantation and Immobilization Biodegradability/Porosity
Collagen Gel Rod High biocompatibility, low inflammatory index Readily biodegradable, inert byproducts Reasonably porous, allows for diffusion of nutrients, wastes, gas exchange and cellular cues. Controlled Release of Growth Factors
Microspheres loaded with mitogen along a chemical gradient Surface modifications are highly regulated spatially, but remain porous. Electrical Activity
Polypyrrole is electrically conductive. Electric fields enhance nervous tissue migration and proliferation Transiently generates electric potentials Applied via Ink-Jet Printer technology. Oriented Nervous Substratum
Collagen gel is magnetically aligned along the axis of preferred axonal growth. Microspheres will establish a chemical gradient for NGF. Micropatterning will present a path of least resistance for cellular migration. Isolation of NSCs
Biopsies will be performed to isolate promising tissue samples. In the future, NCS's derived from non invasive regions may be developed. Unfortunately, currently highly invasive, though only minute amounts need be recovered. NCS can be derived from dermis, blood, or blood marrow but difficult to isolate from large populations of other cells. In the future, NCS's derived from these noninvasive regions may be developed. Incorporation of Support Cells
Isolated NSC's will be added to the fully synthesized polymer implant. These will then differentiate primarily into neuroglial cells due to mitotic cues (NGF and nanofiber substrate of implant) in the culture system. Implant walls will serve to delay astrocyte migration preventing additional glial cap formation, but after degradation will allow for later development of fully functional nervous tissue. References
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This note was uploaded on 09/18/2008 for the course BIM 202 taught by Professor Simon during the Spring '06 term at UC Davis.
- Spring '06