Biomedical Engineering Faculty, Amirkabir University of Technology, Tehran, Iran.
Biomedical Engineering Faculty, Amirkabir University of Technology, Tehran, Iran.
Mater Sci Eng C Mater Biol Appl. 2021 Jul;126:112180. doi: 10.1016/j.msec.2021.112180. Epub 2021 May 13.
Many research groups have investigated the various kinds of scaffolds to mimic the natural Bruch's membrane (BM) and support the retinal pigmented epithelial cells to form an organized cellular monolayer. While using prosthetic BM is identified as a promising treatment of age-related macular degeneration (AMD), a degenerative and progressive retinal disease, the effects of different signals such as electrical and morphological cues on the retinal pigmented epithelial (RPE) cells are still unknown. In this study, a laminated and conductive hydrogel/fiber composite scaffold by adding conductive polyaniline (PANi) to the scaffold's nanofibrous phase was prepared. This hybrid scaffold offers the closest morphology to the native structure of the human Bruch's membrane by imitating the inner and outer collagenous layer and induces the electrical signal to the scaffold to assess the electrical cue on behaviors of polarized retinal pigmented epithelial cells in the retina. The electrospun nanofibrous phase consisted of gelatin-Polyaniline in different ratios incorporated into the hydrogel precursor, a blend of gelatin and 4-armed PEG. We used a novel dual crosslinking process by incorporating the exposure of gamma irradiation and glutaraldehyde vapor treatment to construct the scaffold's hydrogel phase. The results showed the best composition was the sample which included the 40/60, Polyaniline/gelatin nanofiber sheets ratio because this scaffold revealed a 2.66 ± 0.33 MPa, Young's modulus and 1.84 ± 0.21 S/cm, electrochemical conductivity, which are close to the main features of native Bruch's membrane. In addition, this scaffold showed good biocompatibility by reaching 83.47% cell viability.
许多研究小组已经研究了各种支架，以模拟天然的布鲁赫膜（BM）并支持视网膜色素上皮细胞形成有组织的细胞单层。虽然使用人工 BM 被认为是治疗年龄相关性黄斑变性（AMD）的一种有前途的方法，AMD 是一种退行性和进行性视网膜疾病，但不同信号（如电和形态线索）对视网膜色素上皮（RPE）细胞的影响尚不清楚。在这项研究中，通过向支架的纳米纤维相中添加导电聚苯胺（PANi）来制备层状和导电水凝胶/纤维复合材料支架。这种混合支架通过模拟内层和外层胶原层来提供最接近人类布鲁赫膜天然结构的形态，并向支架诱导电信号，以评估电信号对视网膜极化的视网膜色素上皮细胞行为的影响。电纺纳米纤维相由不同比例的明胶-聚苯胺掺入水凝胶前体中制成，水凝胶前体是明胶和 4 臂 PEG 的混合物。我们使用了一种新的双重交联过程，通过结合伽马辐照和戊二醛蒸汽处理的暴露来构建支架的水凝胶相。结果表明，最佳组成是包括 40/60、聚苯胺/明胶纳米纤维片比例的样品，因为该支架显示出 2.66±0.33 MPa 的杨氏模量和 1.84±0.21 S/cm 的电化学电导率，这与天然布鲁赫膜的主要特征接近。此外，该支架的细胞活力达到 83.47%，显示出良好的生物相容性。
