Swelling induced detachment of chondrocytes using RGD-modified poly(N-isopropylacrylamide) hydrogel beads

Abstract

Thermally sensitive poly(N-isopropylacrylamide, NIPAAm) hydrogel beads conjugated with a cell adhesive motif, GRGDY, were prepared and utilized as cell culture substrate for chondrocytes. They were produced to be uniform in size and distribution by using calcium alginate as a temporal mold. The RGD moieties were introduced, in a spatially selective manner, to the surface of the beads by conjugating GRGDY under the precollapsed state at a higher temperature above the lower critical solution temperature (LCST). These RGD-conjugated polyNIPAAm beads demonstrated a reversible swelling and deswelling behavior around the LCST, which enabled the chondrocytes attached on the surface of collapsed beads at 37 degreesC to readily detach when the temperature was shifted below 37 degreesC. The cell detachment percentage was largely affected by the temperature-dependent reswelling extent of the collapsed RGD-modified beads.