Embryonic stem cells (ESCs) can differentiate into all somatic cells, and as such, are a promising cell source for therapeutic applications. In vitro, ESCs spontaneously differentiate via the aggregation of cells into embryoid bodies (EBs), which recapitulate aspects of early embryogenesis and harbor a unique reservoir of cues critical for tissue formation and morphogenesis. Embryonic healing responses employ similar intrinsic machinery used for tissue development, and these morphogenic cues may be captured within the EB microenvironment. Recent studies have shown that when injected into injury or defect models in vivo, ESCs synthesize and secrete extracellular factors that ultimately contribute to repair, suggesting that these molecules may be as important for regenerative therapies as functional differentiation of the cells. The overall objective of this project was to develop novel acellular matrices derived from differentiating ESCs undergoing morphogenesis. The central hypothesis was that embryonic matrices contain complex mixtures of extracellular factors that, when isolated, retain bioactivity and enhance wound healing in an adult environment.
The overall objective was accomplished by: (1) investigating the production of extracellular matrix (ECM) by differentiating ESCs as a function of differentiation time; (2) assessing the ability of solvents to efficiently decellularize EBs; and (3) evaluating the healing response elicited by acellular matrices derived from EBs in a murine dermal wound healing model. Endogenous ECM synthesis by EBs varied with time and was associated with specific differentiation events. Novel techniques were developed to effectively remove cell components from EBs in order to extract complex, bioactive acellular matrices. EB-derived acellular matrices significantly enhanced the healing of excisional dermal wounds in mice, indicating the potency of extracellular factors synthesized by ESCs. All together, these studies demonstrate that acellular matrices derived from ESCs retain morphogenic factors capable of influencing tissue repair. In addition, this work lays the foundation for future studies to further examine the functional role of endogenous matrix molecules on ESC differentiation and to evaluate the utility of a stem cell-derived matrix for a variety of regenerative medicine applications.
| Identifer | oai:union.ndltd.org:GATECH/oai:smartech.gatech.edu:1853/37170 |
| Date | 10 November 2009 |
| Creators | Nair, Rekha |
| Publisher | Georgia Institute of Technology |
| Source Sets | Georgia Tech Electronic Thesis and Dissertation Archive |
| Detected Language | English |
| Type | Dissertation |
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