NANOTECHNOLOGY: A TOOLKIT FOR CELL BEHAVIOR - 3D Bioprinting and Nanotechnology in Tissue Engineering and Regenerative Medicine - page 1

CHAPTER

1

NANOTECHNOLOGY:
A TOOLKIT FOR CELL
BEHAVIOR

Christopher O'Brien 1 , Benjamin Holmes 1 and Lijie Grace Zhang 1,2
1 Department of Mechanical and Aerospace Engineering, The George Washington University,
Washington DC, USA
2 Department of Medicine, The George Washington University, Washington DC, USA

1.1 INTRODUCTION
Scientists and researchers have been fascinated with the details of life at small scales ever since Robert
Hooke saw the evidence of small structures in cork that he coined cells. This spurred the creation of
the compound microscope and the quest of the late 1600s to discover how life operates beneath our
very own eyes. That quest has continued even to this day as scientists look for smaller and smaller
constituents that contribute to life as we know it; from proteins to functional groups, everything has
an important role. The collective scientific gaze looked for finer and finer components to life, and for a
short while now has focused on the prevalence of the nano world.
One hundred to one thousand times smaller than Hooke's observed cork cells, researchers have
determined that materials and features of less than 100 nm in at least one dimension can have pro-
found effects on the behavior of cells and further tissue and organ regeneration ( Zhang and Web-
ster, 2009 ). When examining nature, using nanotechnology for tissue regeneration becomes obvious. In
fact, human cells create and continually interact directly with their natural nanostructured environment,
called extracellular matrix (ECM). This momentous discovery spurred many researchers to attempt to
more effectively mimic natural biology by creating novel nanobiomaterials and designing nanocom-
posite scaffolds for improved tissue and organ regenerations ( Biggs et al . , 2007 ; Jang et al . , 2010 ;
Chopra et al., 2012 ). Decreasing material size to the nano scale dramatically increases surface rough-
ness and the surface area to volume ratio of materials, and may lead to a higher surface reactivity and
many superior physiochemical properties (i.e. mechanical, electrical, optical, catalytic, and magnetic prop-
erties) ( Zhang and Webster, 2009 ). The excellent properties of nanobiomaterials make them hold great
potential for a wide range of biomedical applications, particularly advanced tissue/organ regeneration.
With the exponential growth in the human population and the similarly rapid increase in lifespan
worldwide, there is an enormous market for various tissue and organ transplantations and engraftments.
Current treatment options for damaged tissues and organs are nonideal, and often involve severe tissue/
organ shortages, painful surgeries, and long recovery times without offering a complete restoration