توصيفگر ها :
تخريب ماكولاي وابسته به سن , رتينيت پيگمنتوزا , اپيتليوم رنگ دانه اي شبكيه , غشاء بروخ , پلي كاپرولاكتون , غشاء آمنيوتيك
چكيده انگليسي :
Age-related macular degeneration (AMD) and retinitis pigmentosa (RP) are the two common retinal diseases. The diseases are characterized by the degeneration of a specific cell layer at the back of the eye, the retinal pigment epithelium (RPE), which is essential in retinal function. Cell transplantation may have the potential for retinal regeneration. However, several problems hinder the successful repair of the retina including [174] disorganized or misplaced grafts, as well as reflux of cells from the injection site, which might lead to serious complications including RPE cell stacking, cell death, and retinal fibrosis. Therefore, researchers were led to tissue engineering solutions, especially scaffold-based methods. But despite various artificial membranes that have been used as scaffolds for retinal pigment epithelium cells (RPE) for monolayer reconstruction, however, long-term cell viability and functionality are still largely unknown. This study is aimed to construct an ultrathin porous fibrous film with properties similar to the native Bruch’s membrane as carriers for the RPE cells. Therefore, Polycaprolactone (PCL) / human amniotic membrane powder (HAMP) random scaffolds containing different concentrations of HAMP in PCL (0, 2.84, 5.21, 7.21, 8.93, and 10.42% by weight) were fabricated using the electrospinning method, and their structural, physical, and mechanical properties were evaluated. Subsequently, the behavior of human RPE cells, ARPE-19, on these scaffolds were investigated. The results showed that with increasing the amount of HAMP, the diameter range of fibers increased (50 to 500 nm). Moreover, hydrophilicity and degradation rate significantly improved. All the electrospun scaffolds had a porosity above 85%. With cell culture on the substrates, none of the scaffolds had a toxic effect on the cells, and the cells adhered well on all scaffolds one day after culture. But after seven days, the rate of growth and proliferation of RPE cells on the PCL-30HAMP scaffold (HAMP concentration in PCL 7.21% by weight) was higher compared with the other scaffolds. Therefore, this scaffold was selected as the optimal scaffold and in the next step, by changing the type of collector, PCL-30HAMP solution was electrospun in the form of aligned fibers and the characteristics of this scaffold and the behavior of RPE cells on it were compared with the random scaffold. The results revealed that the aligned scaffold has a lower average fiber diameter, porosity, hydro¬philicity, and Young’s modulus, and also a higher maximum strain in failure compared with the random scaffold. None of these scaffolds had a toxic effect on the cells, and the cells adhered well to both scaffolds one day after culture. On the seventh day, the rate of cell proliferation and growth on both scaffolds was high; However, a more suitable cell sheet was formed on the random scaffold. Hence, the rest of the specialized cellular evaluations such as immunohistochemistry, real-time PCR, and functional assessments were performed on random scaffolds. The seeded cells on this scaffold showed an expression of RPE signature genes and functionally secreted VEGF and PEDF. Therefore, a HAMP-based substrate was fabricated for the growth of RPE cells for potential use as a scaffold for RPE cell transplantation.
