Chemistry Reference
In-Depth Information
pathogens and contaminants compared to naturally derived polymer gels such
as collagen and alginate.
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Moreover, they can be easily decorated with bio-
logical motifs, tailoring its properties for specific cell response. A key strategy in
the development of molecular gels for these purposes is to combat the innate
host immune response; this is a vital step towards the successful implantation of
fragile cells or tissues in regenerative medicine. Hence, the design and delivery
of biomedical gelators incorporating anti-inflammatory therapeutics prove to
address fundamental challenges in the biomedical applications of molecular
gels. The fields of tissue engineering and regenerative medicine are set to benefit
from the ongoing research in molecular gels, for many of the reasons already
previously discussed.
In pioneering work by Stupp and coworkers,
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rodent neural progenitor cells
(NPCs) were encompassed within a 3D network of nanofibres formed via self-
assembly of peptide-amphiphile 6.26 molecules. The self-assembly process was
triggered by mixing cell suspensions in media with (0.5-1% w/w H
2
O) aqueous
solutions of the molecules, with the cells surviving the growth of the fibres
around them during this process. NPCs were chosen owing to their potential
advantages in replacing lost central nervous system cells after degenerative or
traumatic injuries.
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The peptide-amphiphile gelator 6.26 incorporated the peptide sequence
IKVAV, an epitope found in laminin, and is known to promote neurite
sprouting and direct neurite growth. As a control for bioactivity, gelator 6.27
with the nonbioactive epitope EQS was also synthesised; forming a physically
similar gel (Figure 6.17).
The ability to have a dense population of biologically active factors (IKVAV)
incorporated in the nanofibres presenting themselves to the NPCs was
d
n
1
r
3
n
g
|
7
3
.
Figure 6.17
Examples of peptide amphiphiles (PA) used in tissue engineering. The PA
6.26 and control PA 6.27 used by Stupp and coworkers in the study on
the stimulation of neural progenitor cells (NPC).
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The KDL12 peptide
6.28 reported by Kisiday and coworkers is intended for cartilage repair
by supporting chondrocyte growth.
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