Polarized, Cobblestone, Human Retinal Pigment Epithelial Cell Maturation on a Synthetic PEG Matrix

Abstract

Cell attachment is essential for the growth and polarization of retinal pigment epithelial (RPE) cells. Currently, surface coatings derived from biological proteins are used as the gold standard for cell culture. However, downstream processing and purification of these biological products can be cumbersome and expensive. In this study, we constructed a library of chemically modified nanofibers to mimic the Bruch's membrane of the retinal pigment epithelium. Using atmospheric-pressure plasmainduced graft polymerization with a high-throughput screening platform to modify the nanofibers, we identified three polyethylene glycol (PEG)grafted nanofiber surfaces (PEG methyl ether methacrylate, n = 4, 8, and 45) from a library of 62 different surfaces as favorable for RPE cell attachment, proliferation, and maturation in vitro with cobblestone morphology. Compared with the biologically derived culture matrices such as vitronectin-based peptide Synthemax, our newly discovered synthetic PEG surfaces exhibit similar growth and polarization of retinal pigment epithelial (RPE) cells. However, they are chemically defined, are easy to synthesize on a large scale, are cost-effective, are stable with longterm storage capability, and provide a more physiologically accurate environment for RPE cell culture. To our knowledge, no one has reported that PEG derivatives directly support attachment and growth of RPE cells with cobblestone morphology. This study offers a unique PEG-modified 3D cell culture system that supports RPE proliferation, differentiation, and maturation with cobblestone morphology, providing a new avenue for RPE cell culture, disease modeling, and cell replacement therapy.

Comparative studies between the murine immortalized brain endothelial cell line (bEnd.3) and induced pluripotent stem cell-derived human brain endothelial cells for paracellular transport

“…Next, we wanted to compare the expression of key endothelial phenotypic markers and tight junction protein expression between the two brain endothelial monolayers. The phase-contrast images of the bEnd.3 cells and ihBMECs ( Fig 3A ) show the typical cobblestone morphology, observed for endothelial and epithelial cells [ 38 , 39 ]. Both bEnd.3 cells and ihBMECs showed robust uptake of acetylated LDL ( Fig 3B ) and strong immuno-positivity for vWF ( Fig 3C ).…”

Development of an electrospun poly(ε-caprolactone)/collagen-based human amniotic membrane powder scaffold for culturing retinal pigment epithelial cells

“…Age-related macular degeneration (AMD) is the leading cause of visual impairment and blindness in individuals over 50 1 . Due to the increase of the aging population, the incidence and burden of AMD are expected to increase alarmingly in the coming years 2 . Retinitis pigmentosa (RP) prevalence is approximately 1 in 5000 individuals 3 , 4 .…”

Regenerating Eye Tissues to Preserve and Restore Vision

“…We envision that incorporating bioengineering approaches may better preserve retinal layering and integration in vivo . At the vanguard, adult RPESC- or PSC-derived RPE cells cultured with natural or synthetic scaffolds show key features of RPE monolayers that are preserved after transplantation in animal models, among which PLGA, parylene thin film, and polyester membranes are being developed for clinical studies (da Cruz et al, 2018; Kashani et al, 2018; Song and Bharti, 2016; Stanzel et al, 2014; Tian et al, 2017). Bringing together appropriately layered RPE with multi-layered neural retina is important for proper development and function of both, and represents a significant future challenge, as does connecting the output RGC axons with the brain via a rebuilt optic nerve.…”