Eeded on glass slides and fixed after 4 days, stained with (A) ZO-1 or (B) Na+/K+-ATPase (green) counterstained with DAPI (blue). Primary hCECs seeded onto RAFT stained with either (C and E) ZO-1, (D and F) Na+/K+-ATPase (green) counterstained with DAPI (blue). (C and D) fixed after 4 days in culture or (E and F) after 14 days. Scale bars 50 mm. doi:10.1371/journal.pone.0050993.gpurchase Ergocalciferol Endothelial Cell Density and Cell Size on RAFTCell density of hCECs was measured by counting cell numbers in at least 4 fields of view from 4 different RAFT constructs seeded with cells. The number of cells per 25033180 mm2 was then calculated. The average size of hCECs and hCECL cells was calculated by taking the area of field of view and dividing by average cell number per field to determine approximate cell area in mm26 SEM. An unpaired t-test was performed to determine statistical significance with values deemed to be significant if p,0.05.Electron Microscopy Analysis of Endothelial Cells on RAFTRAFT constructs were examined using transmission electron microscopy (TEM). RAFT constructs were fixed with 2 paraformaldehyde and 2 glutaraldehyde in 0.1 M sodium cacodylate buffer, pH 7.4 (Electron Microscopy Sciences (EMS), Hatfield, PA, USA) at 4uC overnight. Constructs were then washed in sodium cacodylate buffer and post-fixed in 1 osmium tetroxide and potassium ferrocyanide (EMS) to enhance membrane contrast. After extensive rinsing with distilled water, tissues were dehydrated in a graded series of ethanol, and embedded inAraldite (EMS). Semi-thin sections of 0.5? mm were cut with a GNF-7 biological activity Reichert-Jung Ultracut E Ultramicrotome (C. Reichert Optische Werke AG, Vienna, Austria), counterstained with toluidine blue/ basic fuchsin and examined using an Axioplan, Zeiss light microscope (Carl Zeiss, Germany). The ultra-thin sections of 60?80 nm thickness were cut and collected on copper grids, double stained with uranyl acetate and lead citrate for 20 min each, then viewed and imaged at 100 kV on a Philips EM 2085 transmission electron microscope (FEI Electron Optics BV, Eindoven, Netherlands). For scanning electron microscopy (SEM), specimens were immersed in a fixative containing 2 glutaraldehyde, 2 paraformaldehyde and 0.1 M sodium cacodylate (pH 7.4) overnight at 4uC. They were then transferred and stored in sodium cacodylate buffer (EMS). Before processing, the samples were washed twice in distilled water and were secondary fixed in 1 osmium tetroxide (FMB, Singapore), for 2 hours at room temperature. Following this, samples were dehydrated, critical point dried (Bal-Tec, Liechtenstein, Germany) and mounted on SEM stubs using carbon adhesive tabs and finally sputter coated with a thin layer of gold (10 nm; Bal-Tec). Samples were imagedPC Collagen for Endothelial TransplantationFigure 7. Scanning electron microscope characterisation of RAFT with hCECs. (A) Representative micrograph of the surface of RAFT constructs. (B) Representative low magnification SEM 
image showing confluent monolayer of hCECs on RAFT. (C) Higher magnification image showing cell borders between cells and (D) at high magnification over-lapping finger-like projections onto juxtaposed cells. Scale bars A 5 mm, B 50 mm, C 10 mm, D 2 mm. doi:10.1371/journal.pone.0050993.gwith a field-emission SEM (XL 30 FEG SEM; FEI Company/ Philips, Eindoven, The Netherlands) at 10 kV.full surgical procedure (Fig. 2H), suggesting the material has suitable mechanical properties to enable transplantation.Results Ease of H.Eeded on glass slides and fixed after 4 days, stained with (A) ZO-1 or (B) Na+/K+-ATPase (green) counterstained with DAPI (blue). Primary hCECs seeded onto RAFT stained with either (C and E) ZO-1, (D and F) Na+/K+-ATPase (green) counterstained with DAPI (blue). (C and D) fixed after 4 days in culture or (E and F) after 14 days. Scale bars 50 mm. doi:10.1371/journal.pone.0050993.gEndothelial Cell Density and Cell Size on RAFTCell density of hCECs was measured by counting cell numbers in at least 4 fields of view from 4 different RAFT constructs seeded with cells. The number of cells per 25033180 mm2 was then calculated. The average size of hCECs and hCECL cells was calculated by taking the area of field of view and dividing by average cell number per field to determine approximate cell area in mm26 SEM. An unpaired t-test was performed to determine statistical significance with values deemed to be significant if p,0.05.Electron Microscopy Analysis of Endothelial Cells on RAFTRAFT constructs were examined using transmission electron microscopy (TEM). RAFT constructs were fixed with 2 paraformaldehyde and 2 glutaraldehyde in 0.1 M sodium cacodylate buffer, pH 7.4 (Electron Microscopy Sciences (EMS), Hatfield, PA, USA) at 4uC 
overnight. Constructs were then washed in sodium cacodylate buffer and post-fixed in 1 osmium tetroxide and potassium ferrocyanide (EMS) to enhance membrane contrast. After extensive rinsing with distilled water, tissues were dehydrated in a graded series of ethanol, and embedded inAraldite (EMS). Semi-thin sections of 0.5? mm were cut with a Reichert-Jung Ultracut E Ultramicrotome (C. Reichert Optische Werke AG, Vienna, Austria), counterstained with toluidine blue/ basic fuchsin and examined using an Axioplan, Zeiss light microscope (Carl Zeiss, Germany). The ultra-thin sections of 60?80 nm thickness were cut and collected on copper grids, double stained with uranyl acetate and lead citrate for 20 min each, then viewed and imaged at 100 kV on a Philips EM 2085 transmission electron microscope (FEI Electron Optics BV, Eindoven, Netherlands). For scanning electron microscopy (SEM), specimens were immersed in a fixative containing 2 glutaraldehyde, 2 paraformaldehyde and 0.1 M sodium cacodylate (pH 7.4) overnight at 4uC. They were then transferred and stored in sodium cacodylate buffer (EMS). Before processing, the samples were washed twice in distilled water and were secondary fixed in 1 osmium tetroxide (FMB, Singapore), for 2 hours at room temperature. Following this, samples were dehydrated, critical point dried (Bal-Tec, Liechtenstein, Germany) and mounted on SEM stubs using carbon adhesive tabs and finally sputter coated with a thin layer of gold (10 nm; Bal-Tec). Samples were imagedPC Collagen for Endothelial TransplantationFigure 7. Scanning electron microscope characterisation of RAFT with hCECs. (A) Representative micrograph of the surface of RAFT constructs. (B) Representative low magnification SEM image showing confluent monolayer of hCECs on RAFT. (C) Higher magnification image showing cell borders between cells and (D) at high magnification over-lapping finger-like projections onto juxtaposed cells. Scale bars A 5 mm, B 50 mm, C 10 mm, D 2 mm. doi:10.1371/journal.pone.0050993.gwith a field-emission SEM (XL 30 FEG SEM; FEI Company/ Philips, Eindoven, The Netherlands) at 10 kV.full surgical procedure (Fig. 2H), suggesting the material has suitable mechanical properties to enable transplantation.Results Ease of H.
