Photoswitched Cell Adhesion on Surfaces with RGD Peptides

Abstract

Coating of surfaces by RGD peptides is well-known. Herein we describe the possibility to switch cell adhesion properties by changing the distance and orientation of the RGD peptides to the surface. A set of RGD peptides of the type cyclo(-RGDfK-) was synthesized containing the photoswitchable 4-[(4-aminophenyl)azo]benzocarbonyl central unit as spacer between the acrylamide anchor and the RGD peptide. PMMA (poly methyl methacrylate) surfaces were coated with these peptides. Control of adhesion stimulation by irradiation with 366 or 450 nm light could be achieved.

Rapid Reversible Photoswitching of Integrin‐Mediated Adhesion at the Single‐Cell Level

“…[ 13 ] Several studies have employed RGD-functionalized azobenzenes for controlling adhesion with promising results, but more than one hour of illumination with UV light was required for switching. [14][15][16] Extended UV exposure is not suitable for bioapplications due to severe phototoxic damage to living cells, [ 17 ] whereas short UV exposure has proven successful in irreversible photoswitching approaches. [ 5 ] Here, we demonstrate a versatile approach that overcomes previous limitations and achieves rapid reversible photoswitching of cell adhesion by biofunctionalized azobenzene surfaces.…”

Using Azobenzene‐Embedded Self‐Assembled Monolayers To Photochemically Control Cell Adhesion Reversibly

“…A recent demonstration that azobenzene grafted on poly(methyl methacrylate) surfaces that allows some level of control of cell adhesion has encouraged us to design SAMs to reversibly control cell adhesion. [12] The motivation to carry out this reversible conversion on SAMs is that the molecularly well-defined nature of SAMs allows much flexibility in designing the surface for many avenues of future applications.…”

Solid‐phase synthesis of tailed cyclic RGD peptides using glutamic acid: unexpected glutarimide formation

“…As we know, aspartimide is easy to form when using the sequence of Asp-Gly in peptide synthesis. Our results indicate that the sequence of Glu(Gly)-OAll (7), as shown in Scheme 2, follows the same trend to form a cyclic imide, glutarimide (9). In the transition state (8), the attack of the NH group of Gly on the O-allyl protected α-carboxyl group of Glu is catalyzed by bases like piperidine.…”

“…To provide conjugating sites for their increasing applications in drug delivery, tumor imaging, surface modification and tissue engineering [7][8][9][10], a tailed cyclic peptide of c[RGDfE(tail)] was designed in our laboratory with c(RGDfE) linked to a tail consisting of a spacer and a linker, as shown in Figure 1. The spacer is used to increase the mobility of the c(RGDfE) ligand, which may lead to enhanced binding ability.…”