Design of Mobile Supramolecular Biointerfaces for Regulation of Biological Responses - Biointerfaces: Where Material Meets Biology - page 356

biomaterials. 42 These exposed peptide sequences specifically bind to the
integrin b and a molecules, respectively, which exists on the most of the
plasma membrane. Cell adhesion on biomaterial surfaces is induced by this
type of molecular interaction between adsorbed protein and membrane
proteins. It is well known that cell adhesion via fibronectin molecules is not
initiated by significant conformational change of fibronectin, which is dif-
ferent with that of platelet-fibrinogen interaction. 43 By taking this advantage
into account, it could be hypothesized that the dynamic surfaces could in-
duce selective adhesion of HUVECs as well as eliminating platelet adhesion
by regulating degree of conformational change of the surface proteins. 44
Figure 12.10 shows the relative exposure ratio of cell-binding motif of sur-
face fibronectin on the dynamic surfaces. The total amount of exposed cell-
binding motifs remained at the highest level among the polymer surfaces,
which indicates that there are many cell-binding motifs on the dynamic
mPRX surface, even though the protein layer underwent moderate con-
formational changes. The relative amount of exposed cell-binding motifs
was then plotted with the amount of adhering HUVECs, as shown in
Figure 12.11. Being similar to the result of platelet adhesion, a strong
straightforward relationship is observed, which indicates that amount of
HUVEC adhesion is dominated by the density of the cell-binding motifs on
the polymer surfaces. An interesting point is that highly dynamic PRX sur-
face revealed a large amount of HUVEC adhesion while the adhesion level of
platelet was quite low. Taking the result of low platelet adhesion on the
mPRX surface into account, this cellular response seems out of the ordinary.
Usually, cell adhesive surfaces also induce strong platelet adhesion. Because

d n 3 r 4 n g | 3

.

Figure 12.10 Relative surface density of the cell-binding motifs on fibronectin
adsorbed surfaces. All the values are normalized to that of Cell Desk t .
Reproduced/adapted from ref. 44 with permission from Taylor &
Francis.