Abstract
In vitro cell culture models representing the physiological and pathological features of the outer retina are urgently needed. Artificial tissue replacements for patients suffering from degenerative retinal diseases are similarly in great demand. Here, we developed a co-culture system based solely on the use of human induced pluripotent stem cell (hiPSC)-derived cells. For the first time, hiPSC-derived retinal pigment epithelium (RPE) and endothelial cells (EC) were cultured on opposite sides of porous polylactide substrates prepared by breath figures (BF), where both surfaces had been collagen-coated by Langmuir–Schaefer (LS) technology. Small modifications of casting conditions during material preparation allowed the production of free-standing materials with distinct porosity, wettability and ion diffusion capacity. Complete pore coverage was achieved by the collagen coating procedure, resulting in a detectable nanoscale topography. Primary retinal endothelial cells (ACBRI181) and umbilical cord vein endothelial cells (hUVEC) were utilised as EC references. Mono-cultures of all ECs were prepared for comparison. All tested materials supported cell attachment and growth. In mono-culture, properties of the materials had a major effect on the growth of all ECs. In co-culture, the presence of hiPSC-RPE affected the primary ECs more significantly than hiPSC-EC. In consistency, hiPSC-RPE were also less affected by hiPSC-EC than by the primary ECs. Finally, our results show that the modulation of the porosity of the materials can promote or prevent EC migration. In short, we showed that the behaviour of the cells is highly dependent on the three main variables of the study: the presence of a second cell type in co-culture, the source of endothelial cells and the biomaterial properties. The combination of BF and LS methodologies is a powerful strategy to develop thin but stable materials enabling cell growth and modulation of cell-cell contact. Statement of significance: Artificial blood-retinal barriers (BRB), mimicking the interface at the back of the eye, are urgently needed as physiological and disease models, and for tissue transplantation targeting patients suffering from degenerative retinal diseases. Here, we developed a new co-culture model based on thin, biodegradable porous films, coated on both sides with collagen, one of the main components of the natural BRB, and cultivated endothelial and retinal pigment epithelial cells on opposite sides of the films, forming a three-layer structure. Importantly, our hiPSC-EC and hiPSC-RPE co-culture model is the first to exclusively use human induced pluripotent stem cells as cell source, which have been widely regarded as an practical candidate for therapeutic applications in regenerative medicine.
Original language | English |
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Pages (from-to) | 327-343 |
Number of pages | 17 |
Journal | Acta Biomaterialia |
Volume | 101 |
DOIs | |
Publication status | Published - 2020 |
Publication type | A1 Journal article-refereed |
Funding
Outi Melin, Hanna Pekkanen and Paula Puistola, are thanked for skilful technical assistance. The Zeiss LSM780 confocal microscope maintained by Tampere University imaging core was used in imaging. This work was supported by the Finnish Diabetes Foundation (KJ-U), the Eye and Tissue Bank Foundation (KJ-U), Evald and Hilda Nissi Foundation (KJ-U), the Academy of Finland (Centre of Excellence Body-on-Chip, MKe), the Competitive State Research Financing of the Expert Responsibility area of Tampere University Hospital (SMi), Business Finland (HSk, KA-S, PKa, MKe, SMi). The funders had no role in study design, data collection and analysis, decision to publish, or in the preparation of the manuscript.
Keywords
- Blood-retinal barrier
- Breath figures
- Co-culture
- Polylactide
- hiPSC-RPE
- hiPSC-endothelial cells
Publication forum classification
- Publication forum level 2