SUMMARY: Tissue-specific delivery of stem cells holds the potential to regenerate damaged heart tissue and to restore its functions after Myocardial Infarction. In this study we describe a novel cell encapsulation technique for target delivery of stem cells to damaged heart tissue. This research is conducted in collaboration with OHRI and UOttawa.
BACKGROUND/ISSUE(S)/OBJECTIVES: Heart failure is the number one cause of death in developed countries. Stem cell transplantation has drawn a lot of attention as a promising therapy for heart disease. However, extensive cell attrition, and loss at the site of transplantation present a limit to therapeutic efficacy. We have hypothesized that by encapsulating the cells in naturally-derived materials, e.g., collagen and alginate, cells viability, and target delivery can be enhanced. Our main objective is to develop encapsulation techniques for effective delivery of stem cells. The other objective is to develop characterization techniques for safety evaluation of such systems at nano and micro scales.
DESIGN/METHOD/DESCRIPTION: Novel collagen-alginate microspheres loaded with GFP-BOEC cells (green florescence expressing -blood outgrowth endothelial cells) were developed. The method involves the gelation of a hybrid collagenalginate- cell solution using a drop-wise technique in a calcium chloride bath. Microspheres were washed and transferred to a Petri dish containing culture medium and incubated at 37°C. Microspheres formation, and morphology (shape and size) and viability of the cells were monitored using a Nikon inverted light microscope.
OUTPUTS/RESULTS: Light microscopy images suggest successful formation of hybrid collagen-alginate microspheres in a size range of about 1000-2000 μm. The images also show that cells fluoresce an apple green when excited with near UV light implying that most of the cells are viable.
IMPACTS/OUTCOMES/CONCLUSIONS/IMPLICATIONS/NEXT STEPS: Preliminary results from these experiments reveal that GFP-BOEC cells can be encapsulated in collagen-alginate microspheres. The results suggest that cells are viable over a period of three days. Also, light microscopy techniques were successfully utilized for physical (i.e., shape and size) and biological (i.e., viability) characterizations of microspheres. The next steps will include the use of Mesenchymal Stem Cells instead of GFP-BOEC, fine-tuning of material formulations, and further characterizations, i.e., scanning electron microscopy (SEM). We anticipate that this work will help us to better understand new emerging technologies such as nanotechnology, stem cells therapeutics, and tissue engineering that will ultimately benefit the regulatory process of medical products that are based on such technologies.