title: Inhibition of fibroblast adhesion by covalently immobilized protein repellent polymer coatings studied by single cell force spectroscopy.
abstract: Cochlea implants (CI) restore the hearing in patients with sensorineural hearing loss by electrical stimulation of the auditory nerve via an electrode array. The increase of the impedance at the electrode-tissue interface due to a postoperative connective tissue encapsulation leads to higher power consumption of the implants. Therefore, reduced adhesion and proliferation of connective tissue cells around the CI electrode array is of great clinical interest. The adhesion of cells to substrate surfaces is mediated by extracellular matrix (ECM) proteins. Protein repellent polymers (PRP) are able to inhibit unspecific protein adsorption. Thus, a reduction of cell adhesion might be achieved by coating the electrode carriers with PRPs. The aim of this study was to investigate the effects of two different PRPs, poly(dimethylacrylamide) (PDMAA) and poly(2-ethyloxazoline) (PEtOx), on the strength and the temporal dynamics of the initial adhesion of fibroblasts. Polymers were immobilized onto glass plates by a photochemical grafting onto method. Water contact angle measurements proved hydrophilic surface properties of both PDMAA and PEtOx (45 ± 1° and 44 ± 1°, respectively). The adhesion strength of NIH3T3 fibroblasts after 5, 30, and 180 s of interaction with surfaces was investigated by using single cell force spectroscopy. In comparison to glass surfaces, both polymers reduced the adhesion of fibroblasts significantly at all different interaction times and lower dynamic rates of adhesion were observed. Thus, both PDMAA and PEtOx represented antiadhesive properties and can be used as implant coatings to reduce the unspecific ECM-mediated adhesion of fibroblasts to surfaces.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany.
authors.forename: Pooyan
authors.initials: P
authors.lastname: Aliuos
authors.forename: Aromita
authors.initials: A
authors.lastname: Sen
authors.forename: Uta
authors.initials: U
authors.lastname: Reich
authors.forename: Wibke
authors.initials: W
authors.lastname: Dempwolf
authors.forename: Athanasia
authors.initials: A
authors.lastname: Warnecke
authors.forename: Christoph
authors.initials: C
authors.lastname: Hadler
authors.forename: Thomas
authors.initials: T
authors.lastname: Lenarz
authors.forename: Henning
authors.initials: H
authors.lastname: Menzel
authors.forename: Guenter
authors.initials: G
authors.lastname: Reuter
mesh_terms: D000178:Acrylamides / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000494:pharmacology; D003054:Cochlear Implants; D005109:Extracellular Matrix / Q000737:chemistry; D006801:Humans; D051379:Mice; D041681:NIH 3T3 Cells; D010080:Oxazoles / Q000737:chemistry / Q000494:pharmacology; D011108:Polymers / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000178:Acrylamides; D020099:Coated Materials, Biocompatible; D010080:Oxazoles; D011108:Polymers; C429790:poly(N,N-dimethylacrylamide); C071857:polyethyloxazoline
keywords: PDMAA; PEtOx; cell adhesion; cochlear implants (CI); single cell force spectroscopy (SCFS)