title: Quantifying the effect of pore size and surface treatment on epidermal incorporation into percutaneously implanted sphere-templated porous biomaterials in mice.
abstract: The sinus between skin and a percutaneous medical device is often a portal for infection. Epidermal integration into an optimized porous biomaterial could seal this sinus. In this study, we measured epithelial ingrowth into rods of sphere-templated porous poly(2-hydroxyethyl methacrylate) implanted percutaneously in mice. The rods contained spherical 20-, 40-, or 60-μm pores with and without surface modification. Epithelial migration was measured 3, 7, and 14 days post-implantation utilizing immunohistochemistry for pankeratins and image analysis. Our global results showed average keratinocyte migration distances of 81 ± 16.85 μm (SD). Migration was shorter through 20-μm pores (69.32 ± 21.73) compared with 40 and 60 μm (87.04 ± 13.38 μm and 86.63 ± 8.31 μm, respectively). Migration was unaffected by 1,1' carbonyldiimidazole surface modification without considering factors of pore size and healing duration. Epithelial integration occurred quickly showing an average migration distance of 74.13 ± 12.54 μm after 3 days without significant progression over time. These data show that the epidermis closes the sinus within 3 days, migrates into the biomaterial (an average of 11% of total rod diameter), and stops. This process forms an integrated epithelial collar without evidence of marsupialization or permigration.
authors.affiliation: Department of Medicine/Division of Dermatology, University of Washington, Seattle, Washington, USA. underwoo@u.washington.edu
authors.forename: Robert A
authors.initials: RA
authors.lastname: Underwood
authors.forename: Marcia L
authors.initials: ML
authors.lastname: Usui
authors.forename: Ge
authors.initials: G
authors.lastname: Zhao
authors.forename: Kip D
authors.initials: KD
authors.lastname: Hauch
authors.forename: Marc M
authors.initials: MM
authors.lastname: Takeno
authors.forename: Buddy D
authors.initials: BD
authors.lastname: Ratner
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Marshall
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Shi
authors.forename: John E
authors.initials: JE
authors.lastname: Olerud
authors.forename: Philip
authors.initials: P
authors.lastname: Fleckman
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000378:metabolism; D002465:Cell Movement; D000078404:Epidermal Cells; D004817:Epidermis / Q000378:metabolism*; D020007:Implants, Experimental; D015603:Keratinocytes / Q000166:cytology / Q000502:physiology; D008297:Male; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D016062:Porosity; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D008689:Methacrylates; C005044:hydroxyethyl methacrylate