Biomedical Engineering Reference
In-Depth Information
found that two pairs of partially independent antagonistic surface character-
istics, namely (i) amino-rich vs. carboxylic-rich surfaces and (ii) hydrophilic
vs. hydrophobic surfaces, controlled the cell attachment, with the former pro-
moting adhesion (Fig. 2.8). This complex relationship means that one cannot
predict the attachment of cells based only on hydrophobicity or hydrophilic-
ity of the surface. However, surfaces designed for biomolecular recognition
mechanisms (e.g. neuropeptide-functionalized) were the most effective for at-
tachment of neuronal cells, and those designed with very high hydrophobicity
were the most effective for repelling neuronal cells. This discussion is illustra-
tive of the specific issues raised by cell attachment (i.e. neuronal cells) but
these conclusions cannot, however, be extrapolated to other types of cells due
to the diverse nature of cellular membranes types and receptors.
In addition to determining whether attachment will occur, it is also nec-
essary to examine the effect that cell confinement will have on cell behavior.
Several studies (e.g. [47]) have studied this relationship. Microcontact print-
ing of SAMs has been used to fabricate substrates with micrometer-scale
islands of bovine and human endothelial cell extracellular matrix separated
by nonadhesive regions. The size and geometry of the islands were found
to control cell shape, with immediate impact on the control of apoptosis as
well as growth. Progressive restriction of cell extension by culturing cells on
smaller and smaller micropatterned adhesive islands regulated a transition
Fig. 2.8.
Mechanisms of immobilization of neuronal cells on photoresist surfaces.
The vertical bar on the left of each diagram represents the relative repelling effect
of the respective surface. Neuropeptide-functionalized surfaces are found to be the
most effective for immobilization of neuronal cells, while highly hydrophobic and
negatively charged surfaces are the most repelling (Reprinted with permission from
[46]. Copyright 1999 Academic Press Inc Elsevier Science)
