title: A nanofibrillar surface promotes superior growth characteristics in cultured human retinal pigment epithelium.
abstract: BACKGROUND
  To evaluate the influence of surface topography on the proliferation of the retinal pigment epithelium (RPE) by comparing nanofibrillar and smooth substrates.
  
  
  METHODS
  Electrospun polyamide nanofibers (EPN) are an engineered surface mimicking native basement membranes. Commonly used plastic (polystyrene, PS) and glass substrates have a smooth topography. All were analyzed by scanning electron microscopy. RPE cultures were established from fetal and adult donors. Growth curves were established on the above substrates. Cell cycle and growth fractions were analyzed with 5-ethynyl-2'-deoxyuridine (EdU) and 4',6-diamidino-2-phenylindole (DAPI).
  
  
  RESULTS
  At a magnification of ×5,000, EPN showed randomly overlapping fibers and pores. The surface of glass was slightly studded yet regular, in contrast to ideally smooth PS. Polygonal cells grew on nanofibers in a colony-like distribution, while randomly spread spindle-shaped cell morphologies were seen on smooth surfaces. This was observed at all donor ages. Initial proliferation rates were higher on EPN, and similar final cell densities were reached in all age groups, compared to an age-related decline on PS. EdU/DAPI revealed faster cell cycles on EPN. Growth fractions were higher and maintained longer on EPN. Observed substrate differences in growth behavior were statistically significant.
  
  
  CONCLUSIONS
  Surface topography appears to induce distinct RPE proliferation characteristics.
authors.affiliation: University Eye Hospital Bonn, Bonn, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Thieltges
authors.forename: Boris V
authors.initials: BV
authors.lastname: Stanzel
authors.forename: Zengping
authors.initials: Z
authors.lastname: Liu
authors.forename: Frank G
authors.initials: FG
authors.lastname: Holz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018929:Cell Culture Techniques; D049109:Cell Proliferation; D005898:Glass; D006801:Humans; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures; D009757:Nylons; D011137:Polystyrenes; D055213:Retinal Pigment Epithelium / Q000254:growth & development*; D013499:Surface Properties; D023822:Tissue Engineering / Q000379:methods*; D055815:Young Adult
chemical_list: D009757:Nylons; D011137:Polystyrenes