Institute of Biotechnology, RWTH Aachen University, Aachen, Germany.
DWI - Leibniz-Institute for Interactive Materials, Aachen, Germany.
Biomater Sci. 2022 Jun 14;10(12):3282-3295. doi: 10.1039/d1bm01946e.
: Visual prostheses, epiretinal stimulating arrays, are a promising therapy in treating retinal dystrophies and degenerations. In the wake of a new generation of devices, an innovative method for epiretinal fixation of stimulator arrays is required. We present the development of tailor-made bioadhesive peptides (peptesives) for fixating epiretinal stimulating arrays omitting the use of traumatic retinal tacks. : Binding motifs on the stimulating array (poly[chloro--xylylene] (Parylene C)) and in the extracellular matrix of the retinal surface (collagens I and IV, laminin, fibronectin) were identified. The anchor peptides cecropin A (CecA), KH1, KH2 (author's initials) and osteopontin (OPN) were genetically fused to reporter proteins to assess their binding behavior to coated microtiter plates fluorescence-based assays. Domain Z (DZ) of staphylococcal protein A was used as a separator to generate a bioadhesive peptide. Following ISO 10993 "biological evaluation of medical materials", direct and non-direct cytotoxicity testing (L-929 and R28 retinal progenitor cells) was performed. Lastly, the fixating capabilities of the peptesives were tested in proof-of-principle experiments. : The generation of the bioadhesive peptide required evaluation of the N- and C-anchoring of investigated APs. The YmPh-CecA construct showed the highest activity on Parylene C in comparison with the wildtype phytase without the anchor peptide. eGFP-OPN was binding to all four investigated ECM proteins (collagen I, laminin > collagen IV, fibronectin). The strongest binding to collagen I was observed for eGFP-KH1, while the strongest binding to fibronectin was observed for eGFP-KH2. The selectivity of binding was checked by incubating eGFP-CecA and eGFP-OPN on ECM proteins and on Parylene C, respectively. Direct and non-direct cytotoxicity testing of the peptide cecropin-A-DZ-OPN using L-929 and R28 cells showed good biocompatibility properties. Proof-of-concept experiments in post-mortem rabbit eyes suggested an increased adhesion of CecA-DZ-OPN-coated stimulating arrays. : This is the first study to prove the applicability and biocompatibility of peptesives for the fixation of macroscopic objects.
: 视觉假体，即视网膜刺激器阵列，是治疗视网膜营养不良和变性的有前途的疗法。随着新一代设备的出现，需要一种创新的方法来固定视网膜刺激器阵列，而无需使用创伤性视网膜钉。我们介绍了定制生物胶粘剂肽（peptesives）的开发，用于固定视网膜刺激器阵列，而无需使用创伤性视网膜钉。: 识别了刺激器阵列（聚[氯-对二甲苯]（Parylene C））和视网膜表面细胞外基质（胶原蛋白 I 和 IV、层粘连蛋白、纤维连接蛋白）上的结合基序。作者将抗菌肽 Cecropin A（CecA）、KH1、KH2（作者的首字母）和骨桥蛋白（OPN）与报告蛋白基因融合，以评估它们在涂覆的微量滴定板上的结合行为-荧光测定法。葡萄球菌蛋白 A 的结构域 Z（DZ）被用作分离物，以生成生物胶粘剂肽。根据 ISO 10993“医疗器械的生物学评价”，进行了直接和非直接细胞毒性测试（L-929 和 R28 视网膜祖细胞）。最后，在原理验证实验中测试了 peptesives 的固定能力。: 生物胶粘剂肽的生成需要评估所研究 AP 的 N 和 C 锚定。与没有锚肽的野生型植酸酶相比，YmPh-CecA 构建体在与 Parylene C 结合时显示出最高的活性。eGFP-OPN 与所有四种研究的 ECM 蛋白（胶原蛋白 I、层粘连蛋白>胶原蛋白 IV、纤维连接蛋白）结合。eGFP-KH1 与胶原蛋白 I 的结合最强，而 eGFP-KH2 与纤维连接蛋白的结合最强。通过分别在 ECM 蛋白和 Parylene C 上孵育 eGFP-CecA 和 eGFP-OPN，检查了结合的选择性。使用 L-929 和 R28 细胞对肽 Cecropin-A-DZ-OPN 进行直接和非直接细胞毒性测试表明其具有良好的生物相容性。在死后兔眼的概念验证实验中，用 CecA-DZ-OPN 涂层的刺激器阵列的粘附性增加。: 这是第一项证明 peptesives 适用于固定宏观物体及其生物相容性的研究。
