title: Mechanical properties of murine and porcine ocular tissues in compression.
abstract: Sub-retinal implantation of foreign materials is becoming an increasingly common feature of novel therapies for retinal dysfunction. The ultimate compatibility of implants depends not only on their in vitro chemical compatibility, but also on how well the mechanical properties of the material match those of the native tissue. In order to optimize the mechanical properties of retinal implants, the mechanical properties of the mammalian retina itself must be carefully characterized. In this study, the compressive moduli of eye tissues, especially the retina, were probed using a dynamic mechanical analysis instrument in static mode. The retinal compressive modulus was lower than that of the sclera or cornea, but higher than that of the RPE and choroid. Compressive modulus remained relatively stable with age. Conversely, apparent retinal softening occurred at an early age in mice with inherited retinal degeneration. Compressive modulus is an important consideration for the design of retinal implants. Polymer scaffolds with moduli that are substantially different than that of the native tissue in which they will ultimately reside will be less likely to aid in the differentiation and development of the appropriate cell types in vitro and will have reduced biocompatibility in vivo.
authors.affiliation: Department of Chemical and Biochemical Engineering, The University of Iowa, Iowa City, IA, USA; Department of Pharmaceutics and Experimental Therapeutics, The University of Iowa, Iowa City, IA, USA; Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, IA, USA; The Stephen A. Wynn Institute for Vision Research, University of Iowa, Iowa City, IA, USA.
authors.forename: Kristan S
authors.initials: KS
authors.lastname: Worthington
authors.affiliation: Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, IA, USA; The Stephen A. Wynn Institute for Vision Research, University of Iowa, Iowa City, IA, USA.
authors.forename: Luke A
authors.initials: LA
authors.lastname: Wiley
authors.affiliation: Department of Chemical and Biochemical Engineering, The University of Iowa, Iowa City, IA, USA.
authors.forename: Alexandra M
authors.initials: AM
authors.lastname: Bartlett
authors.affiliation: Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, IA, USA; Howard Hughes Medical Institute, University of Iowa, Iowa City, IA, USA; The Stephen A. Wynn Institute for Vision Research, University of Iowa, Iowa City, IA, USA.
authors.forename: Edwin M
authors.initials: EM
authors.lastname: Stone
authors.affiliation: Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, IA, USA; The Stephen A. Wynn Institute for Vision Research, University of Iowa, Iowa City, IA, USA.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Mullins
authors.affiliation: Department of Pharmaceutics and Experimental Therapeutics, The University of Iowa, Iowa City, IA, USA.
authors.forename: Aliasger K
authors.initials: AK
authors.lastname: Salem
authors.affiliation: Department of Chemical and Biochemical Engineering, The University of Iowa, Iowa City, IA, USA.
authors.forename: C Allan
authors.initials: CA
authors.lastname: Guymon
authors.affiliation: Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, IA, USA; The Stephen A. Wynn Institute for Vision Research, University of Iowa, Iowa City, IA, USA. Electronic address: budd-tucker@uiowa.edu.
authors.forename: Budd A
authors.initials: BA
authors.lastname: Tucker
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D001696:Biomechanical Phenomena; D002829:Choroid / Q000502:physiology*; D003315:Cornea / Q000502:physiology*; D004129:Dimethylpolysiloxanes; D055119:Elastic Modulus / Q000502:physiology*; D008422:Materials Testing; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D012160:Retina / Q000502:physiology*; D012162:Retinal Degeneration / Q000503:physiopathology*; D012590:Sclera / Q000502:physiology*; D013314:Stress, Mechanical; D034421:Sus scrofa; D054457:Tissue Scaffolds
chemical_list: D004129:Dimethylpolysiloxanes; C013830:baysilon
keywords: implant; retinal degeneration; retinal modulus; transplantation