Biomedical Engineering Reference
In-Depth Information
Fig. 9 Surface modification of cells with ssDNA-PEG-lipid. (a) Real-time monitoring of PEG-
lipid incorporation into a supported lipid membrane by SPR. (
i
) A suspension of small unilamellar
vesicles (SUV) of egg yolk lecithin (70
m
g/mL) was applied to a CH
3
-SAM surface. A PEG-lipid
solution (100
m
g/mL) was then applied. (
ii
) Three types of PEG-lipids were compared: PEG-
DMPE (C14), PEG-DPPE (C16), and PEG-DSPE (C18) with acyl chains of 14, 16, and 18
carbons, respectively. (b) Confocal laser scanning microscopic image of an CCRF-CEM cell
displays immobilized FITC-oligo(dA)
20
hybridized to membrane-incorporated oligo(dT)
20
-PEG-
lipid. (c) SPR sensorigrams of interaction between oligo(dA)
20
-urokinase and the oligo
(dT)
20
-PEG-lipid incorporated into the cell surface. (
i
) BSA solution was applied to block
nonspecific sites on the oligo(dT)
20
-incorporated substrate. (
ii
) Oligo(dA)
20
-urokinase (
solid
line
) or oligo(dT)
20
-urokinase (
dotted line
) was applied
4.2
Immobilization of Bioactive Substances on an Islet Surface
Cell transplantation has shown promise as a method for treating serious diseases.
Various kinds of pluripotent stem cells have been developed or identified, including
embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), and mesen-
chymal stem cells (MSCs). Moreover, the differentiation of stem cells to functional
cells has been extensively studied. Previous studies have demonstrated that the
transplantation of islet of Langerhans cells (islets) could successfully treat type 1
diabetes. Islets are insulin-secreting cells found in the pancreas. Over 200 patients
