title: Development of resorbable nanocomposite tracheal and bronchial scaffolds for paediatric applications.
abstract: BACKGROUND
  Congenital tracheal defects and prolonged intubation following premature birth have resulted in an unmet clinical need for tracheal replacement. Advances in stem cell technology, tissue engineering and material sciences have inspired the development of a resorbable, nanocomposite tracheal and bronchial scaffold.
  
  
  METHODS
  A bifurcated scaffold was designed and constructed using a novel, resorbable nanocomposite polymer, polyhedral oligomeric silsesquioxane poly(ϵ-caprolactone) urea urethane (POSS-PCL). Material characterization studies included tensile strength, suture retention and surface characteristics. Bone marrow-derived mesenchymal stem cells (bmMSCs) and human tracheobronchial epithelial cells (HBECs) were cultured on POSS-PCL for up to 14 days, and metabolic activity and cell morphology were assessed. Quantum dots conjugated to RGD (l-arginine, glycine and l-aspartic acid) tripeptides and anticollagen type I antibody were then employed to observe cell migration throughout the scaffold.
  
  
  RESULTS
  POSS-PCL exhibited good mechanical properties, and the relationship between the solid elastomer and foam elastomer of POSS-PCL was comparable to that between the cartilaginous U-shaped rings and interconnective cartilage of the native human trachea. Good suture retention was also achieved. Cell attachment and a significant, steady increase in proliferation were observed for both cell types (bmMSCs, P = 0·001; HBECs, P = 0·003). Quantum dot imaging illustrated adequate cell penetration throughout the scaffold, which was confirmed by scanning electron microscopy.
  
  
  CONCLUSIONS
  This mechanically viable scaffold successfully supports bmMSC and HBEC attachment and proliferation, demonstrating its potential as a tissue-engineered solution to tracheal replacement.
authors: Division of Surgery and Interventional Science, London, UK; University College London Centre for Nanotechnology and Regenerative Medicine, London, UK.
authors: G Z
authors: GZ
authors: Teoh
authors: C
authors: C
authors: Crowley
authors: M A
authors: MA
authors: Birchall
authors: A M
authors: AM
authors: Seifalian
mesh_terms: D020341:Absorbable Implants; D001187:Artificial Organs; D001980:Bronchi / Q000166:cytology; D018929:Cell Culture Techniques / Q000379:methods; D049109:Cell Proliferation; D004847:Epithelial Cells / Q000166:cytology; D006801:Humans; D007223:Infant; D059630:Mesenchymal Stem Cells / Q000166:cytology; D053761:Nanocomposites / Q000627:therapeutic use*; D017646:Organosilicon Compounds / Q000627:therapeutic use; D011091:Polyesters / Q000627:therapeutic use; D011140:Polyurethanes / Q000627:therapeutic use; D012826:Silicone Elastomers / Q000494:pharmacology; D013314:Stress, Mechanical; D013536:Suture Techniques; D054457:Tissue Scaffolds; D014132:Trachea / Q000002:abnormalities* / Q000166:cytology
chemical_list: D017646:Organosilicon Compounds; D011091:Polyesters; D011140:Polyurethanes; D012826:Silicone Elastomers; C016240:polycaprolactone