Plasma polymer coatings to aid retinal pigment epithelial growth for transplantation in the treatment of age related macular degeneration

Abstract

Subretinal transplantation of functioning retinal pigment epithelial (RPE) cells grown on a synthetic substrate is a potential treatment for age-related macular degeneration (AMD), a common cause of irreversible vision loss in developed countries. Plasma polymers give the opportunity to tailor the surface chemistry of the artificial substrate whilst maintaining the bulk properties. In this study, plasma polymers with different functionalities were investigated in terms of their effect on RPE attachment and growth. Plasma polymers of acrylic acid (AC), allyl amine (AM) and allyl alcohol (AL) were fabricated and characterised using X-ray photoelectron spectroscopy (XPS) and water contact angle measurements. Octadiene (OD) hydrocarbon films and tissue culture polystyrene were used as controls. Wettability varied from hydrophobic OD to relatively hydrophilic AC. XPS demonstrated four very different surfaces with the expected functionalities. Attachment, proliferation and morphological examination of an RPE cell line and primary RPE cells were investigated. Both cell types grew on all surfaces, with the exception of OD, although the proliferation rate of primary cells was low. Good epithelial morphology was also demonstrated. Plasma polymerised films show potential as cell carrier surfaces for RPE cells in the treatment of AMD.

Bacterial Cellulose As a Support for the Growth of Retinal Pigment Epithelium

“…hydroxyl and hydrocarbon) on RPE cell adhesion and growth was evaluated in the literature. 58 The cell culture results after 10 days with the ARPE-19 immortalized cell line and the primary human RPE cells indicated no statistical difference between different surfaces, except for the hydrophobic surface with the hydrocarbon chemical functionality, which had a significantly lower number of cells adhered comparing to the unmodified tissue culture polystyrene (TCP) and the other modified PP surfaces. In our study, all substrates were hydrophilic; however different cell responses were obtained.…”

“…6 Since permeation coefficients did not differ between BC conditions, it was expected the presence of porous structures in all BC substrates, which was confirmed through SEM analysis of BC, ABC, CBC and CMBC substrates (Figure 3). BC's porosity is an advantageous feature when comparing to other non-biodegradable biomaterials that have been proposed such as polydimethylsiloxane 57 , polypropylene 58 and the already patented for RPE transplantation parylene (patent publication number: US20120009159 A1; publication date: 12 Jan 2012). All the referred biomaterials are non-porous, and a nonbiodegradable substrate has to meet the passive diffusion requirements to be a BM substitute, which BC's was shown herein to possess.…”

Enhancing RPE Cell-Based Therapy Outcomes for AMD: The Role of Bruch's Membrane

“…Natural membranes including biologically-derived basal lamina, amniotic membrane, Descemet's membrane and lens capsule have been used as substrates for RPE cells. 121,172 Additionally, artificial Bruch's membrane substrates including parylene films, 173,174 plasma polymers, 175 polyamide nanofibres, 176 polyester membranes, 177 polyimide, 178 and modified polytetrafluoroethylene 175 have been proposed. 179 However, the use of some types of artificial membranes carries the risk of biological contamination and disease transmission.…”

Biomaterials for ocular reconstruction

“…This could be achieved by modifying a surface to enable attachment of a LEC monolayer that maintains an epithelial phenotype. Several groups have studied the effects of changing surface chemistry with the addition of various functional groups such as amine, carboxyl and hydroxyl groups, to encourage cell attachment in various cell types [78][79][80]. The cellular response could also be controlled by incorporating ECM molecules such as glycosaminoglycan [70,81,82].…”

“…This can be achieved using plasma polymerisation to manipulate the surface chemistry without changing the fundamental physical properties of the underlying material. Good epithelial cell morphology was found on surfaces coated with acrylic acid (AC), allyl amine (AM) and allyl alcohol (AL) using plasma polymerisation and thus these surface modifications show potential as cell carrier surfaces for RPE cells [136].…”