Local control of protein binding and cell adhesion by patterned organic thin films

Abstract

Control of the cell adhesion and growth on chemically patterned surfaces is important in an increasing number of applications in biotechnology and medicine, for example implants, in-vitro cellular assays, and biochips. This review covers patterning techniques for organic thin films suitable for site-directed guidance of cell adhesion to surfaces. Available surface patterning techniques are critically evaluated, with special emphasis on surface chemistry that can be switched in time and space during cultivation of cells. Examples from the authors' laboratory include the use of cell-repellent self-assembled monolayers (SAM) terminated by oligoethylene glycol (OEG) units and the lifting of the cell repellent properties by use of electrogenerated Br2/HOBr which can be performed with positionable microelectrodes. Structural changes of the SAM were analyzed by polarization-modulated infrared reflection absorption spectroscopy (PM IRRAS). Use of a soft array system of individually addressable microelectrodes enables formation of flexible and complex patterns in a short time and has the potential for further acceleration of probe-induced local manipulation of cell adhesion.

Biodegradable Polymeric Films and Membranes Processing and Forming for Tissue Engineering

“…The objectives of surface patterning on biocompatible film/membranes are (i) to study cell behaviors such as cell morphology change and cell adhesion and (ii) to control cell growth direction . The precise cells positioning leads to desired tissue structure which is useful for patterned TE applications such as corneal and retinal TE .…”

“…Cell migration pattern could be formed by coating BSA onto the surface using microelectrode. Moreover, by using microelectrochemically generated Bromine (Br 2 )/hypobromous acid (HOBr) on BSA layer, a co‐cultured cell pattern could be created based on the principle of cell repellent . Last of all, de‐wetting is a technique that generates two zones on the surface which are favorable and unfavorable zones for binder.…”

Modification and Patterning of Self‐Assembled Monolayers Using Electrogenerated Etchants and Homogeneous Scavenging Reactions in a Scanning Electrochemical Microscope

“…[13] This process has already been used to lift the cell-repellent properties of OEG-terminated SAM. [14][15][16][17] SECM-induced surface modification can be used advantageously to alter a pre-patterned surface dynamically to induce and study cell motility shown for cell-repellent protein layers [18][19][20] or to create spatially defined co-cultures of different cells on the same substrate shown for a microcontact-printed OEG-SAM and subsequent SECM modification. [14] The resolution of the etching processes of the SAM depends on the working distance d and the pulse time τ during which Br 2 is generated at the ME.…”

“…Br 2 can react with oligoethylene glycol (OEG)‐terminated SAMs, whereby OEG terminus is decomposed much faster than an alkyl spacer [13] . This process has already been used to lift the cell‐repellent properties of OEG‐terminated SAM [14–17] . SECM‐induced surface modification can be used advantageously to alter a pre‐patterned surface dynamically to induce and study cell motility shown for cell‐repellent protein layers [18–20] or to create spatially defined co‐cultures of different cells on the same substrate shown for a microcontact‐printed OEG‐SAM and subsequent SECM modification [14] .…”

Electrochemically assisted micro localized grafting of aptamers in a microchannel engraved in fluorinated thermoplastic polymer Dyneon THV

“…13 Within the last ten years, it was shown that polymers might be functionalized locally by SECM by generating reactive species at the tip that are prone to react with the material surface. [14][15][16][17][18] For example, it was demonstrated that SECM permits the localized reduction of uoropolymers by the electrogenerated radical anion of a redox mediator. Reduction of polytetrauoroethylene by an electrogenerated radical anion had been reported and results in its carbonization allowing further selective post-decoration of the carbonized patterns with metals, 19 organic 20 and polymeric entities.…”