SEM images showing that human cord blood HSCs adhered to a functionalized nanofiber matrix nanofibers and formed colonies after 10 days of expansion culture.
Stem cells reside in vivo in a highly specialized microenvironment called the stem cell niche. This niche provides a complex array of biochemical and physical signals in a temporal and spatial fashion, engaging and instructing stem cells to proliferate, migrate and differentiate into adult cells that make up all the tissues in the human body. Understanding its molecular and structural components and their respective functions is critical to the development of effective methodologies for stem cell expansion and differentiation. It has long been recognized that the in vivo physical features of the extracellular matrix possesses characteristic nanoscale fibrous morphology. To understand how nanotopography of the matrix affects hematopoietic stem cell proliferation and phenotype maintenance, we have developed a functionalized nanofiber platform prepared by electrospinning. Using such a nanofiber platform, we have demonstrated that the topography and surface biochemical nature of the electrospun fiber synergistically improve the self-renewal, maintenance and engraftment property of human cord blood derived hematopoietic stem cells. A unique set of aminated nanofibers supported the highest level of expansion of hematopoietic stem cells compared with standard tissue culture method. This study showed that these functionalized nanofibers provided anchorage to hematopoietic stem cells and enhanced their phenotype maintenance.
This technology now has been adapted by Arteriocyte, Inc., a biotech company in Cleveland, Ohio for the expansion of hematopoietic stem cells. These nanofiber-expanded cells have shown promise for stem cell-based angiogenesis therapy in treating ischemic diseases.