title: Nanotextured substrates with immobilized aptamers for cancer cell isolation and cytology.
abstract: BACKGROUND
  The detection of a small number of circulating tumor cells (CTCs) is important, especially in the early stages of cancer. Small numbers of CTCs are hard to detect, because very few approaches are sensitive enough to differentiate these from the pool of other cells. Improving the affinity of a selective, surface-functionalized molecule is important given the scarcity of CTCs in vivo. There are several proteins and aptamers that provide such high affinity; however, using surface nanotexturing increases this affinity even further.
  
  
  METHODS
  The authors report an approach to improve the affinity of tumor cell capture by using novel aptamers against cell membrane overexpressed epidermal growth factor receptors (EGFRs) on a nanotextured polydimethylsiloxane (PDMS) substrate. Surface-immobilized aptamers were used to specifically capture tumor cells from physiologic samples.
  
  
  RESULTS
  The nanotexturing of PDMS increased surface roughness at the nanoscale. This increased the effective surface area and resulted in a significantly higher degree of surface functionalization. The phenomenon resulted in increased density of immobilized EGFR-specific RNA aptamer molecules and provided significantly higher efficiency to capture cancer cells from a mixture. The data indicated that CTCs could be captured and enriched, leading to higher yield yet higher background.
  
  
  CONCLUSIONS
  A comparison between glass slides, plain PDMS, and nanotextured PDMS functionalized with aptamers demonstrated that a 2-fold approach of using aptamers on nanotextured PDMS can be important for cancer cytology devices, and especially for the idea of a "lab-on-chip," toward higher yield in capture efficiency.
authors.affiliation: Department of Bioengineering, University of Texas at Arlington, Texas 76019, USA.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Wan
authors.forename: M Arif Iftakher
authors.initials: MA
authors.lastname: Mahmood
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.forename: Peter B
authors.initials: PB
authors.lastname: Allen
authors.forename: Young-Tae
authors.initials: YT
authors.lastname: Kim
authors.forename: Robert
authors.initials: R
authors.lastname: Bachoo
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Ellington
authors.forename: Samir M
authors.initials: SM
authors.lastname: Iqbal
mesh_terms: D052157:Aptamers, Nucleotide / Q000235:genetics; D001932:Brain Neoplasms / Q000473:pathology*; D002469:Cell Separation / Q000379:methods*; D002478:Cells, Cultured; D003581:Cytodiagnosis; D003584:Cytological Techniques / Q000379:methods; D004129:Dimethylpolysiloxanes; D066246:ErbB Receptors / Q000235:genetics; D005347:Fibroblasts / Q000473:pathology; D005909:Glioblastoma / Q000473:pathology*; D006801:Humans; D019344:Lactic Acid; D049329:Nanostructures; D036103:Nanotechnology / Q000379:methods; D009369:Neoplasms / Q000175:diagnosis* / Q000473:pathology; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D009757:Nylons; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer
chemical_list: D052157:Aptamers, Nucleotide; D004129:Dimethylpolysiloxanes; D009757:Nylons; C085707:poly(dimethylsiloxane)-polyamide copolymer; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D066246:ErbB Receptors