Biomedical Engineering Reference
In-Depth Information
Chapter 8
Biomimetic Nanostructures by
Electrospinning and Electrospraying
Elham Vatankhah
1
, Molamma P. Prabhakaran
1
, and Seeram Ramakrishna
1,2
1
Center for Nanofibers and Nanotechnology, Nanoscience and Nanotechnology Initiative,
Faculty of Engineering, National University of Singapore, Singapore
2
Department of Mechanical Engineering, Faculty of Engineering,
National University of Singapore, Singapore
Introduction
Many key functions of living organisms in human and animal bodies take place at a nanoscale
due to native nanometer-scaled biological features such as DNA, cell-surface receptors, and
proteins. Nanotechnology and stem-cell-based therapeutics for prevention, diagnosis, and
treatment of human diseases are among the newest avenues of biotechnological research [1].
The combination of stem cells with tissue-engineering principles enabled the development of
advanced stem-cell-based therapeutic strategies for treatment of human diseases [2]. There are
two major strategies for utilization of scaffolds in the delivery of stem cells to the damaged
tissue sites: either injection or implantation (Figure 8.1). The injection method involves the use
of injectable cell carriers, which are intended to facilitate cell attachment, differentiation, and
tissue regeneration in addition to their capability of filling complex defect shapes. The cells and
carriers can also be injected into a predesigned mold in order to engineer tissue of a required
anatomical shape
in vitro
prior to implantation. The general implantation strategy involves
seeding of cells onto three-dimensional scaffolds and implanting them either directly to the site
of injury, or after the cells being cultured
in vitro
for a definite period of time. The latter
strategy is chosen especially in cases where regeneration of a large defect is required [3].
In this chapter we focus on the application of nanofibers and nanoparticles for stem-cell
treatments and explain the role of a nanofibrous scaffold as the biomimetic architecture for
cellular interaction. Here, we also briefly review the role of electrospun nanofibers and elec-
trosprayed nanoparticles as cell carriers for injection and direct cell delivering.
Biomimetic Nanofibrous Scaffolds
The structural component of the stem-cell niche controlling stem-cell fate and function is
the extracellular matrix (ECM), which provides not only physical support for cell attach-
ment, migration, and division, but also biochemical signals to cells [4]. During embryonic
development, the special microenvironment of the ECM plays a critical role in regulating
