The Effect of Aligned and Random PCL-Human Amniotic Membrane Powder Scaffolds on Retinal Tissue Engineering

One promising treatment for degenerative retinal diseases such as age-related macular degeneration (AMD) is the delivery of retinal pigment epithelial (RPE) cells using degradable scaffolds. Tough-aligned scaffolds are promising candidates for some applications of tissue engineering, such as peripheral nerve regeneration. However, aligned scaffolds have not been investigated in retinal tissue engineering so far. Here, a comparison was made between aligned and random scaffolds fabricated from polycaprolactone (PCL) and human amniotic membrane powder (HAMP) as a scaffold for RPE cells. The effects of alignment on mechanical properties, porosity, hydrophilicity, degradation of the scaffolds, and the cellular interaction of RPE cells were investigated. The results revealed that the aligned scaffold has a lower average fiber diameter, porosity, hydrophilicity, and Young's modulus and also a higher maximum strain in failure compared with the random scaffold. However, the proliferation of RPE cells increased on the random scaffold compared to the aligned 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 showed an expression of RPE signature genes and functionally secreted VEGF and PEDF. Therefore, a HAMP-based substrate was fabricated for potential use as a scaffold for RPE cell transplantation.