title: Effects of μCT radiation on tissue engineered bone-like constructs.
abstract: High-resolution, non-destructive imaging with micro-computed tomography (μCT) enables in situ monitoring of tissue engineered bone constructs. However, it remains controversial, if the locally imposed X-ray dose affects bone development and thus could influence the results. Here, we developed a model system for μCT monitoring of tissue engineered bone-like constructs. We examined the in vitro effects of high-resolution μCT imaging on the cellular level by using pre-osteoblastic MC3T3-E1 cells embedded into three-dimensional collagen type I matrices. We found no significantly reduced cell survival 2 h after irradiation with a dose of 1.9 Gy. However, 24 h post-irradiation, cell survival was significantly decreased by 15% compared to non-irradiated samples. The highest dose of 7.6 Gy decreased survival of the pre-osteoblastic MC3T3-E1 cells by around 40% at 2 days post-irradiation. No significant increase of alkaline phosphatase (ALP) activity at 2 days post-irradiation was found with a dose of 1.9 Gy. However, ALP activity was significantly decreased after 7 days. Using our model system, the results indicate that μCT imaging with doses as low as 1.9 Gy, which is required to obtain a reasonable image quality, can induce irreparable damages on the cellular level.
authors.affiliation: Institute for Biomechanics, ETH Zurich, Zurich, Switzerland.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Kraehenbuehl
authors.forename: Martin
authors.initials: M
authors.lastname: Stauber
authors.forename: Martin
authors.initials: M
authors.lastname: Ehrbar
authors.forename: Franz
authors.initials: F
authors.lastname: Weber
authors.forename: Heike
authors.initials: H
authors.lastname: Hall
authors.forename: Ralph
authors.initials: R
authors.lastname: Müller
mesh_terms: D016475:3T3 Cells; D000818:Animals; D040761:Biomimetic Materials / Q000528:radiation effects*; D001842:Bone and Bones / Q000502:physiology* / Q000528:radiation effects*; D002470:Cell Survival / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D007928:Lethal Dose 50; D051379:Mice; D011829:Radiation Dosage; D023822:Tissue Engineering / Q000379:methods*; D014057:Tomography, X-Ray Computed