Electrospun mini-MiSp spidroin/poly(L-lactide-co-ε-caprolactone) nanofibrous scaffolds for ARPE-19 cells

Abstract

Age-related macular degeneration, a type of retinal degenerative disease, is the primary cause of severe visual impairment and irreversible blindness in people older than 50, due to age-related deterioration of the photoreceptors and the retinal pigment epithelium (RPE), which could be restored by cell therapy. However, the success of cell therapy depends on biocompatible scaffolds, which serve as carriers for the growth of RPE cells for repairing damaged or diseased retinas. In this study, the plasmid pET-SUMO-R2C for expressing a mini-spidroin, fusing the second repetitive region to the C-terminal domain of the minor ampullate spidroin gene from the spider Araneus ventricosus, was constructed and named R2C. The spidroin R2C was expressed, purified and wet spun into silk-like fibers, possessing a Young’s modulus of 3.51 ± 0.92 GPa and toughness of 24.67 ± 9.51 MPa. The spidroin R2C, mixed with poly(L-lactide-co-ε-caprolactone) (PLCL) at a ratio of 3:1, was electrospun into nanofibrous scaffolds, composed of nanometric fibers with a diameter of 751.70 ± 19.48 nm. After co-culturing with the R2C/PLCL scaffolds, the transcriptomic differences of the ARPE-19 cells were analyzed, showing that fourteen genes that are mainly related to inflammation, tumors and keratinization were upregulated more than three times, while seven genes that are mostly related to substance transport and homeostasis were downregulated more than three times. The R2C/PLCL scaffolds have the potential to be further studied to serve as a suitable carrier for RPE transplantation in the future.