Biomedical Engineering Reference
In-Depth Information
nanoplatform, based on a polyacrylamide (PAA) nanoparticle core, with
encapsulated components for synergistic cancer detection, diagnosis and
treatment. This platform combined MRI contrast enhancement, photody-
namic therapy and specific targeting to tumor sites using F3 peptide [44].
F3 peptide, a 31-amino acid fragment of a high mobility group protein, was
shown to home to the vasculature of a number of tumor types by interacting
directly with endothelial cells [45-46]. In some human cancers F3 peptide
can interact directly with tumor cells, where it is specifically taken up at the
cell surface, then internalized into the cell and transported to the nucleus
[45-46]. The authors have shown that significant therapeutic benefit with
photodynamic therapy was obtained when an F3-targeted polymeric nano-
particle formulation consisting of encapsulated imaging agent (iron oxide)
and photosensitizer (Photofrin) was administered to glioma bearing rats.
Using these multifunctional nanoparticles the authors demonstrated that
nanoparticles could be targeted to intracerebral rat 9L gliomas and detected
using MRI [47]. F3-targeted nanoparticles provided a significantly increased
survival time over that of nontargeted Photofrin encapsulated nanoparticles
or Photofrin alone [47].
Tissue engineering brings together principles and innovations from en-
gineering and the life sciences for the improvement, repair or replacement
of tissue/organ function. Since its inception, this multidisciplinary field has
been governed by the generic concept of combining cell, scaffold (artificial
extracellular matrix) and bioreactor technologies, in the design and fabri-
cation of neo-tissues/organs. Microenvironment of organs and tissues is
composed of parenchymal cells and mesenchymal cells (support cells) im-
mersed in the extracellular matrix. The objective is to enable the body (cel-
lular components) to heal itself by introducing a tissue engineered scaffold
that the body recognizes as part of itself and uses this process to regenerate
neo-native functional tissues [48]. Furthermore the construction of organs
by regenerative therapy has been presented as a promising option to address
this deficit. Nanotechnology has the potential to provide instruments that
can accelerate progress in the engineering of organs. Achievement of the
more ambitious goals of regenerative medicine requires control over the un-
derlying nanostructures of the cell and extracellular matrix. Cells, typically
microns in diameter, are composed of numerous nanosized components
that all work together, to create a highly organized, self-regulating machine.
Cell-based therapies, especially those based on stem cells, have generated
considerable excitement in the media and scientific communities, and are
among the most promising and active areas of research in regenerative
medicine [49].
4.1 Nanoparticle drug delivery
Within past few years, rapid developments have been made to use nano-
materials in a wide variety of applications in various fields of medicine such
