Tissue/biomaterial interface characteristics of four elastomers. A transmission electron microscopical study.
The tissue/biomaterial interface reactions of four elastomers--selected as candidates for scaffolding for tympanic membrane tissue in a total alloplastic middle ear prosthesis--were studied at the electron microscopical level after implantation in the rat middle ear. Time-dependent changes in the phagocyte/polymer interface suggested degradation of porous implants made of Estane polyether urethane, polypropylene oxide, and a poly(ethylene oxide hydantoin) and poly(tetramethylene terephthalate) segmented polyether polyester copolymer (HPOE/PBT copolymer), but not of dense Silastic silicone rubber implants. Silastic was always encapsulated in fibrous tissue. Contact between fibrous tissue and HPOE/PBT copolymer or Estane was established in the third month, but fibrous tissue was never seen close to polypropylene oxide. Bone made contact only with Estane and HPOE/PBT copolymer implants. The bone/copolymer interface showed an electron-dense layer morphologically similar to that seen between bone and hydroxyapatite ceramic, suggesting that with respect to bone HPOE/PBT copolymer behaves like a bioactive implant material. The electron-dense layer was absnet at the bone/Estane interface. Estane and especially HPOE/PBT copolymer seem to be suitable as alloplastic tympanic membrane because of their interface behavior with respect to fibrous tissue and bone.
Bakker
D
D
Ear, Nose & Throat Department, University Hospital, Leiden, The Netherlands.
van Blitterswijk
C A
CA
Hesseling
S C
SC
Daems
W T
WT
Grote
J J
JJ
D000818:Animals; D001672:Biocompatible Materials; D008297:Male; D008422:Materials Testing; D008854:Microscopy, Electron; D019736:Prostheses and Implants; D051381:Rats; D011919:Rats, Inbred Strains; D012408:Rubber; D014432:Tympanic Membrane / Q000648:ultrastructure
D001672:Biocompatible Materials; D012408:Rubber