Lectin and antibody-based histochemical techniques for cardiovascular tissue engineering.

Tissue engineering holds immense potential for treatment of cardiovascular diseases by creating living structures to replace diseased blood vessels, heart valves, and cardiac muscle. In a traditional approach, scaffolds are seeded with stem cells and subjected to stimuli in bioreactors that mimic physiologic conditions or are directly implanted into target sites in animal models. The expected results are significant cell changes, extensive remodeling of the scaffolds and creation of surrogate structures that would be deemed acceptable for tissue regeneration. Histochemical techniques are increasingly becoming essential tools in tissue engineering research. In our studies, we used lectin and antibody-based techniques to characterize novel collagen and elastin scaffolds and to ensure efficient removal of xenoantigens. Scaffolds were implanted in animals and infiltrated host cells were identified using antibodies to activated fibroblasts, macrophages, and lymphocytes. Stem cell-seeded scaffolds were subjected to mechanical strains and tested for differentiation into cardiovascular cells using antibody-based double immunofluorescence methods. Finally, living heart valves were constructed from scaffolds and stem cells, subjected to conditioning in a bioreactor and stem cell differentiation evaluated by immunofluorescence. Overall, these techniques have proven to be outstanding companions to biochemical, molecular biology and cell analysis methods used in tissue engineering research and development.