title: Bioabsorbable bone fixation plates for X-ray imaging diagnosis by a radiopaque layer of barium sulfate and poly(lactic-co-glycolic acid).
abstract: Bone fixation systems made of biodegradable polymers are radiolucent, making post-operative diagnosis with X-ray imaging a challenge. In this study, to allow X-ray visibility, we separately prepared a radiopaque layer and attached it to a bioabsorbable bone plate approved for clinical use (Inion, Finland). We employed barium sulfate as a radiopaque material due to the high X-ray attenuation coefficient of barium (2.196 cm(2) /g). The radiopaque layer was composed of a fine powder of barium sulfate bound to a biodegradable material, poly(lactic-co-glycolic acid) (PLGA), to allow layer degradation similar to the original Inion bone plate. In this study, we varied the mass ratio of barium sulfate and PLGA in the layer between 3:1 w/w and 10:1 w/w to modulate the degree and longevity of X-ray visibility. All radiopaque plates herein were visible via X-ray, both in vitro and in vivo, for up to 40 days. For all layer types, the radio-opacity decreased with time due to the swelling and degradation of PLGA, and the change in the layer shape was more apparent for layers with a higher PLGA content. The radiopaque plates released, at most, 0.5 mg of barium sulfate every 2 days in a simulated in vitro environment, which did not appear to affect the cytotoxicity. The radiopaque plates also exhibited good biocompatibility, similar to that of the Inion plate. Therefore, we concluded that the barium sulfate-based, biodegradable plate prepared in this work has the potential to be used as a fixation device with both X-ray visibility and biocompatibility.
authors: Interdisciplinary Program in Bioengineering, College of Engineering, Seoul National University, Seoul, 152-742, Republic of Korea.
authors: Sung Yoon
authors: SY
authors: Choi
authors: Woojune
authors: W
authors: Hur
authors: Byeung Kyu
authors: BK
authors: Kim
authors: Catherine
authors: C
authors: Shasteen
authors: Myung Hun
authors: MH
authors: Kim
authors: La Mee
authors: LM
authors: Choi
authors: Seung Ho
authors: SH
authors: Lee
authors: Chun Gwon
authors: CG
authors: Park
authors: Min
authors: M
authors: Park
authors: Hye Sook
authors: HS
authors: Min
authors: Sukwha
authors: S
authors: Kim
authors: Tae Hyun
authors: TH
authors: Choi
authors: Young Bin
authors: YB
authors: Choy
mesh_terms: D020341:Absorbable Implants / Q000009:adverse effects; D065638:Absorption, Radiation; D000818:Animals; D001466:Barium Sulfate / Q000493:pharmacokinetics / Q000528:radiation effects / Q000633:toxicity; D001860:Bone Plates / Q000009:adverse effects; D020099:Coated Materials, Biocompatible / Q000528:radiation effects / Q000633:toxicity; D003287:Contrast Media / Q000493:pharmacokinetics / Q000528:radiation effects / Q000633:toxicity; D005552:Forelimb / Q000473:pathology / Q000601:surgery; D006811:Humerus / Q000000981:diagnostic imaging* / Q000601:surgery; D007739:L Cells; D019344:Lactic Acid / Q000493:pharmacokinetics / Q000528:radiation effects / Q000633:toxicity; D008297:Male; D008422:Materials Testing; D051379:Mice; D008855:Microscopy, Electron, Scanning; D011100:Polyglycolic Acid / Q000493:pharmacokinetics / Q000528:radiation effects / Q000633:toxicity; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011817:Rabbits; D011859:Radiography; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction; D014965:X-Rays
chemical_list: D020099:Coated Materials, Biocompatible; D003287:Contrast Media; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D001466:Barium Sulfate; D011100:Polyglycolic Acid; D019344:Lactic Acid
keywords: X-ray visibility; barium sulfate; biocompatibility; biodegradation; fixation system; poly(lactic-co-glycolic acid)