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2.1 Introduction
While the introduction of stem cell-based therapies has significantly widened the
horizons of regenerative medicine, notable problems still persist in harvesting the
relevant stem cells from the body, introducing them into an optimal microenviron-
ment, and ensuring sustainable differentiation into appropriate and functional tissue
once inside the body. Conventional methods of chemically inducing stem cells into
specific lineages is being challenged by the advances in biomaterial technology,
which suggests that engineered material properties are able to determine stem cell
fate [ 1 ]. Modern materials such as nanomaterials are designed to conjugate with, or
encapsulate the stem cells, to ensure that the artificial microenvironment of trans-
planted stem cells mimics the chemical and topographical cues that guide differen-
tiation in the extracellular matrix of the native stem cell niche—“convincing” the
cells to grow into appropriate, functional tissue. Another useful aspect of joining
stem cells with nanomaterials is that nanoparticles can often be imaged with routine
clinical imaging modalities such as magnetic resonance imaging (MRI), providing
more reliable methods of locating and tracking the transplanted cells.
Potential applications of nanotechnologies in stem cell research include [ 2 ]:
- Tracking of stem cell surface molecules and detailed examination of molecular
motion without photo-bleaching. - Noninvasive tracking of stem cells and progenitor cells transplanted in vivo.
- Stem cell delivery systems that enhance the survival of transplanted cells by
releasing pro-survival biomolecules. - Nano-patterned substrates that present covalently tethered biologically active
molecules (adhesion sites, growth factors, and synthetic peptides) for stem cell
differentiation and transplantation. - Intracellular delivery of DNA, RNA, proteins, peptides, and small drugs for stem
cell differentiation.
In this chapter we aim to present an introduction to nanotechnology and its most
explored uses in stem cell applications. Table 2.1 provides a summary of the most
common uses and types of nanoparticles in stem cell research, as well as some of
their known advantages and disadvantages [ 2 ].
2.2 Nanotechnology
The term “nanotechnology” implies that matter is manipulated on an atomic and/or
molecular scale. Nobel-prize winners Binnig and Rohrer developed the scanning
tunneling microscope in mid-1980’s, enabling scientists for the first time to image,
measure and manipulate atoms [ 3 ]. This led to a nano-revolution that has continued
for three decades in the fields of medicine, pharmacology, chemistry, environment,
H.A. Jensen et al.