Aliuos Pooyan, Sen Aromita, Reich Uta, Dempwolf Wibke, Warnecke Athanasia, Hadler Christoph, Lenarz Thomas, Menzel Henning, Reuter Guenter
Department of Otorhinolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany.
J Biomed Mater Res A. 2014 Jan;102(1):117-27. doi: 10.1002/jbm.a.34686. Epub 2013 Apr 18.
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.
人工耳蜗（CI）通过电极阵列对听神经进行电刺激，从而恢复感音神经性听力损失患者的听力。术后结缔组织包裹导致电极 - 组织界面处的阻抗增加，进而使植入物的功耗更高。因此，减少人工耳蜗电极阵列周围结缔组织细胞的黏附和增殖具有重大临床意义。细胞与底物表面的黏附由细胞外基质（ECM）蛋白介导。蛋白质排斥聚合物（PRP）能够抑制非特异性蛋白质吸附。因此，通过用PRP包被电极载体可能实现细胞黏附的减少。本研究的目的是研究两种不同的PRP，即聚（二甲基丙烯酰胺）（PDMAA）和聚（2 - 乙基恶唑啉）（PEtOx）对成纤维细胞初始黏附强度和时间动态的影响。通过光化学接枝法将聚合物固定在玻璃板上。水接触角测量证明了PDMAA和PEtOx均具有亲水性表面性质（分别为45±1°和44±1°）。使用单细胞力谱法研究了NIH3T3成纤维细胞与表面相互作用5、30和180秒后的黏附强度。与玻璃表面相比，两种聚合物在所有不同的相互作用时间均显著降低了成纤维细胞的黏附，并且观察到较低的黏附动态速率。因此，PDMAA和PEtOx均表现出抗黏附特性，可作为植入物涂层以减少成纤维细胞与表面的非特异性ECM介导的黏附。
