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SUMMARY:Nanofibre-reinforced hydrogels : tough biomimetic scaffolds for co
 rneal tissue engineering - Khaow Tonsomboon
DTSTART:20140211T140000Z
DTEND:20140211T143000Z
UID:TALK50564@talks.cam.ac.uk
CONTACT:Anna Walczyk
DESCRIPTION:Fracture toughness has occasionally been neglected in the deve
 lopment of tissue engineering scaffolds. In fact\, almost all recent corne
 al scaffolds’ developments aim to achieve transparent scaffolds with the
  tensile strength and elastic modulus closely-matched to those of native c
 ornea despite the fact that cornea is normally subjected to below-ultimate
 -strength cyclic tensile loadings due to intraocular pressure\, ocular mus
 cle contractions and eye blink. Similarly to other soft collagenous tissue
 s\, toughening mechanisms in cornea are not well understood\, but the lame
 llar structure of orthogonally aligned collagen fibrils in corneal stroma 
 is thought to account for its toughness. To examine this\, transparent lam
 inates of gelatin nanofibers in alginate gel\, mimicking the corneal lamel
 lar structure\, were created in a three-step process. First\, stacks of or
 thogonally aligned gelatin nanofibers were created by electrospinning foll
 owed by chemical cross-linking. Next\, dehydrated cross-linked gelatin fib
 ers were swollen in alginate solution\, forming fiber-reinforced hydrogel 
 composites. Finally\, the resulting structures were subjected to cycles of
  dehydration and chemical cross-linking to increase their mechanical prope
 rties and optical transparency. Fracture toughness and time-independent te
 nsile behaviors of the orthogonally-aligned fiber-reinforced hydrogels wer
 e characterized using trouser tearing and uniaxial tensile tests. Their be
 haviors were compared to those of pure hydrogels and hydrogels reinforced 
 with uniaxially-aligned gelatin fibers. Relative orientation of fibers in 
 adjacent layers was found to significantly affect the overall fracture tou
 ghness and time-independent tensile behaviors of the fiber-reinforced hydr
 ogels and is therefore a key to achieve tough biomimetic scaffolds for cor
 neal tissue engineering. 
LOCATION:Cambridge University Engineering Department\, Oatley meeting room
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