Polymer encapsulation is now an accepted route into cellular therapies via implantation of therapeutically active allogeneic and xenogeneic cells. Although many methods are currently used for encapsulation of cells, no single method is capable of producing large volumes of mono-disperse beads, containing cells completely covered by the polymer of choice. The overall aim of this project was to develop a microfluidic method to encapsulate dopamine releasing cells in an alginate matrix, determine their viability in vitro and investigate implantation into a rodent model of Parkinson's disease. During the course of this study a novel microfluidic method was developed. Two cell types were encapsulated a human test line and a therapeutic cell line derived from rat brain tumour cells (PC 12). Cell viability, measured using an adapted trypan blue exclusion method, was observed to be minimally affected by the encapsulation process. Confocal images of cells encapsulated within alginate beads were collected in addition to long term viability data, up to 90 days post-encapsulation. Dopamine was still detected after PC 12 cell encapsulation through use of an ELISA. Modifications to the developed microfluidic method allowed beads of an appropriate size (<250microm in diameter) to be implantated into a rodent brain via a cannula. Upon implantation of alginate beads into rats' brains there was no evidence of beads after 7 days. Attempts were made to stabilise alginate beads further by addition of barium as a cross-linking agent and polycation secondary coating. Beads were observed to be more stable and remained visible within brain tissue for 14 days. Imaging of fluorescent alginate beads revealed that beads produced using the developed microfluidic method were homogeneous in nature. The work presented here represents the first microfluidic method to be developed which is capable of encapsulating viable cells. Moreover, the viability measurements carried out were the first such experiments to be performed on cells encapsulated using microfluidic methods. Although the structure of alginate beads produced using more commonplace methods has been shown, this has not previously been reported for beads produced using a microfluidic technique.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:584748 |
| Date | January 2009 |
| Creators | Workman, Victoria |
| Publisher | Cardiff University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://orca.cf.ac.uk/55884/ |
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