Aptamer-Based Polyvalent Ligands for Regulated Cell Attachment on the Hydrogel Surface

Natural
biomolecules are often used to functionalize materials
to achieve desired cell-material interactions. However, their applications
can be limited owing to denaturation during the material functionalization
process. Therefore, efforts have been made to develop synthetic ligands
with polyvalence as alternatives to natural affinity biomolecules
for the synthesis of functional materials and the control of cell-material
interactions. This work was aimed at investigating the capability
of a hydrogel functionalized with a novel polyvalent aptamer in inducing
cell attachment in dynamic flow and releasing the attached cells in
physiological conditions through a hybridization reaction. The results
show that the polyvalent aptamer could induce cell attachment on the
hydrogel in dynamic flow. Moreover, cell attachment on the hydrogel
surface was significantly influenced by the value of shear stress.
The cell density on the hydrogel was increased from 40 cells/mm2 to nearly 700 cells/mm2 when the shear stress
was decreased from 0.05 to 0.005 Pa. After the attachment onto the
hydrogel surface, approximately 95% of the cells could be triggered
to detach within 20 min by using an oligonucleotide complementary
sequence that displaced polyvalent aptamer strands from the hydrogel
surface. While it was found that the cell activity was reduced, the
live/dead staining results show that ≥98% of the detached cells
were viable. Therefore, this work has suggested that the polyvalent
aptamer is a promising synthetic ligand for the functionalization
of materials for regulated cell attachment.