title: Challenges in the development of a reference standard and potency assay for the clinical production of RAFT tissue equivalents for the cornea.
abstract: OBJECTIVE
  To develop a reference standard and potency assay for Real Architecture For 3D Tissues (RAFT) tissue equivalents intended for use in limbal epithelial stem cell (LESC) therapy for the cornea.
  
  
  METHODS
  RAFT, a cell-seeded plastic compressed collagen construct with LESCs cultured on the surface, was manufactured with the goal of achieving GMP compliance. RAFTs were tested for reproducibility of manufacture (reference standard) and subsequently wounded and monitored for re-epithelialization (potency assay).
  
  
  RESULTS
  RAFT tissue equivalents produced with cells from different biological donors were capable of supporting multilayered epithelium in culture. The potency assay demonstrated re-epithelialization following wounding, indicating the potential efficacy of RAFT constructs.
  
  
  CONCLUSIONS
  We have presented our attempts at creating a reference standard and potency assay for the clinical manufacture of RAFT for the treatment of LESC deficiency. However, it remains challenging for adult stem cell therapies (including LESC therapy) to fully meet regulatory requirements when dealing with a limited source of autologous cells with inherent biological variation between donors.
authors.affiliation: Ocular Biology & Therapeutics, UCL Institute of Ophthalmology, London, UK.
authors.forename: Alvena K
authors.initials: AK
authors.lastname: Kureshi
authors.forename: Rosemary A L
authors.initials: RA
authors.lastname: Drake
authors.forename: Julie T
authors.initials: JT
authors.lastname: Daniels
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001681:Biological Assay / Q000379:methods* / Q000592:standards*; D048430:Cell Shape; D002478:Cells, Cultured; D003094:Collagen / Q000494:pharmacology; D003315:Cornea / Q000187:drug effects / Q000502:physiology*; D004847:Epithelial Cells / Q000166:cytology; D019573:Epithelium, Corneal / Q000166:cytology; D005455:Fluorescent Antibody Technique; D006801:Humans; D016850:Limbus Corneae / Q000166:cytology; D051379:Mice; D051381:Rats; D012015:Reference Standards; D023822:Tissue Engineering; D054457:Tissue Scaffolds; D014157:Transcription Factors / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism
chemical_list: C115051:TP63 protein, human; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D003094:Collagen