title: Effect of Surgical Technique on Corneal Implant Performance.
abstract: Our aim was to determine the effect of a surgical technique on biomaterial implant performance, specifically graft retention.
  
  
  
  Twelve mini pigs were implanted with cell-free, 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC)/N-hydroxysuccinimide (NHS) cross-linked recombinant human collagen type III (RHCIII) hydrogels as substitutes for donor corneal allografts using overlying sutures with or without human amniotic membrane (HAM) versus interrupted sutures with HAM. The effects of the retention method were compared as well as the effects of collagen concentration (13.7% to 15% RHCIII).
  
  
  
  All implanted corneas showed initial haze that cleared with time, resulting in corneas with optical clarity matching those of untreated controls. Biochemical analysis showed that by 12 months post operation, the initial RHCIII implants had been completely remodeled, as type I collagen, was the major collagenous protein detected, whereas no RHCIII could be detected. Histological analysis showed all implanted corneas exhibited regeneration of epithelial and stromal layers as well as nerves, along with touch sensitivity and tear production. Most neovascularization was seen in corneas stabilized by interrupted sutures.
  
  
  
  This showed that the surgical technique used does have a significant effect on the overall performance of corneal implants, overlying sutures caused less vascularization than interrupted sutures.
  
  
  
  Understanding the significance of the suturing technique can aid the selection of the most appropriate procedure when implanting artificial corneal substitutes. The same degree of regeneration, despite a higher collagen content indicates that future material development can progress toward stronger, more resistant implants.
authors.affiliation: Integrative Regenerative Medicine Centre and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: Monika Kozak
authors.initials: MK
authors.lastname: Ljunggren
authors.affiliation: Integrative Regenerative Medicine Centre and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: Rodolfo A
authors.initials: RA
authors.lastname: Elizondo
authors.affiliation: Integrative Regenerative Medicine Centre and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: Elle
authors.initials: E
authors.lastname: Edin
authors.affiliation: FibroGen Incorporated, San Francisco, CA, USA.
authors.forename: David
authors.initials: D
authors.lastname: Olsen
authors.affiliation: Integrative Regenerative Medicine Centre and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden ; Ottawa Hospital Research Institute-Vision Programme, Ottawa, Ontario, Canada.
authors.forename: Kimberley
authors.initials: K
authors.lastname: Merrett
authors.affiliation: Integrative Regenerative Medicine Centre and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden ; Ottawa Hospital Research Institute-Vision Programme, Ottawa, Ontario, Canada.
authors.forename: Chyan-Jang
authors.initials: CJ
authors.lastname: Lee
authors.affiliation: Integrative Regenerative Medicine Centre and Department of Biomedical Engineering, Linköping University, Linköping, Sweden.
authors.forename: Göran
authors.initials: G
authors.lastname: Salerud
authors.affiliation: FibroGen Incorporated, San Francisco, CA, USA.
authors.forename: James
authors.initials: J
authors.lastname: Polarek
authors.affiliation: Integrative Regenerative Medicine Centre and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Fagerholm
authors.affiliation: Integrative Regenerative Medicine Centre and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden ; Ottawa Hospital Research Institute-Vision Programme, Ottawa, Ontario, Canada.
authors.forename: May
authors.initials: M
authors.lastname: Griffith
keywords: biomaterials; biosynthetic cornea; corneal regeneration; corneal transplantation; recombinant human collagen
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