Abstract
Purpose :
Recent reports have proposed the possibility of seeding retinal pigment epithelial (RPE) cells onto soft, polymeric scaffolds. Achieving good viabilities, differentiation and integration of RPE cells remains a challenge. Furthermore, there are no ideal biocompatible scaffolds for RPE transplantation to date. Therefore, the aim of this work is evaluate the potential of pectin-polyhydroxybutyrate (pec-PHB) nanofibers as scaffolds for RPE cell therapeutics in terms of their topography, thermal and mechanical properties.
Methods :
Pec-PHB mixtures of five different ratios of pectin to PHB were obtained by electrospinning. The mean fibre diameter ranges from 300 to 500 nm. Commercially available human RPE cell line (ARPE-19) was used for all the in vitro experiments. Cells were seeded at 1.00 ×104 cells cm-2 onto five different blends of pec-PHB nanofibers and coverslips served as positive control. Cell viability and proliferation were tested using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay at days 1, 3 and 7 post-seeding. Immunofluorescence was performed using rhodamine phalloidin to certify the growth and distribution of cells 24 hours post-seeding. The morphology and attachment of the cells were observed by scanning electron microscopy (SEM).
Results :
Quantification of cell proliferation using MTT assay revealed higher cell densities on pec-PHB10 and pec-PHB20 as compared to the other three groups seven days after seeding (one-way ANOVA, p < 0.05). The presence and distribution of F-actin on all groups was consistent with the pattern of expression observed on positive control. SEM analysis of cell morphology exhibited rounded and localized cells on pec-PHB10 and pec-PHB20 nanofibers, characteristic of RPE cells, as seen on positive controls. This morphology was however not retained in the other groups.
Conclusions :
ARPE-19 cells successfully adhered to all groups of pec-PHB nanofibers within 24 hours of seeding and were able to proliferate showing short-term biocompatibility. Pec-PHB10 and pec-PHB20 groups demonstrated superiority in providing favourable features for RPE cell growth. Continued research should thus be concentrated on these two blends to study the differentiation, long-term biocompatibility and subsequently integration.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.