Acetylated bacterial cellulose coated with urinary bladder matrix as a substrate for retinal pigment epithelium

This work evaluated the effect of acetylated bacterial cellulose (ABC) substrates coated with urinary bladder matrix (UBM) on the behavior of Retinal Pigment Epithelium (RPE), as assessed by cell adhesion, proliferation and development of cell polarity exhibiting transepithelial resistance and polygonal shaped-cells with microvilli. Acetylation of bacterial cellulose (BC) generated a moderate hydrophobic surface (around 65°) while the adsorption of UBM onto these acetylated substrates did not affect significantly the surface hydrophobicity. The ABS substrates coated with UBM enabled the development of a cell phenotype closer to that of native RPE cells. These cells were able to express proteins essential for their cytoskeletal organization and metabolic function (ZO-1 and RPE65), while showing a polygonal shaped morphology with microvilli and a monolayer configuration. The coated ABC substrates were also characterized, exhibiting low swelling effect (between 1.52.0 swelling/mm3), high mechanical strength (2048 MPa) and non-pyrogenicity (2.12 EU/L). Therefore, the ABC substrates coated with UBM exhibit interesting features as potential cell carriers in RPE transplantation that ought to be further explored.
The authors would also like to acknowledge José Ramalho for kindly supplying the RPE65 primary antibody. The authors acknowledge the Portuguese Foundation for Science and Technology (FCT, Portugal) for the financial support provided through the doctoral and posdoctoral grants SFRH/BD/63578/2009, SFRH/BD/64901/2009, SFRH/BPD/64958/2009 and SFRH/BPD/63148/2009 for Sara Gonc¸ alves, Jorge Padrão, João Pedro Silva, and Vitor Sencadas, respectively. The authors also acknowledge the projects PEst-OE/EQB/LA0004/2013, PEst-OE/EQB/LA0023/2013, PEST-C/FIS/UI607/2014, PTDC/BBB-BQB/2450/2012 and PTDC/SAU-ORG/118694/2010, co-funded by QREN, FEDER. Finally, the authors thank the FCT strategic project UID/BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124- FEDER-027462) and the project “BioInd—Biotechnology and Bioengineering for improved Industrial and Agro-Food processes”, REF. NORTE-07-0124-FEDER-000028 co-funded by the Programa Operacional Regional do Norte (ON.2-O Novo Norte), QREN, FEDER.