title: Prevention of radiation-induced bone pathology through combined pharmacologic cytoprotection and angiogenic stimulation.
abstract: Pathologic fractures and associated non-unions arising in previously irradiated bone are severely debilitating diseases. Although radiation is known to have deleterious effects on healthy tissue cellularity and vascularity, no clinically accepted pharmacologic interventions currently exist to target these destructive mechanisms within osseous tissues. We utilized amifostine-a cellular radioprotectant-and deferoxamine-an angiogenic stimulant-to simultaneously target the cellular and vascular niches within irradiated bone in a rat model of mandibular fracture repair following irradiation. Rats treated with combined therapy were compared to those undergoing treatment with singular amifostine or deferoxamine therapy, nontreated/irradiated animals (XFx) and non-treated/non-irradiated animals (Fx). 3D angiographic modeling, histology, Bone Mineral Density Distribution and mechanical metrics were utilized to assess therapeutic efficacy. We observed diminished metrics for all outcomes when comparing XFx to Fx alone, indicating the damaging effects of radiation. Across all outcomes, only the combined treatment group improved upon XFx levels, normalized all metrics to Fx levels, and was consistently as good as, or superior to the other treatment options (p<0.05). Collectively, our data demonstrate that pharmacologically targeting the cellular and vascular environments within irradiated bone prevents bone injury and enhances fracture healing.
authors.affiliation: University of Michigan, Ann Arbor, MI, USA.
authors.forename: Alexis
authors.initials: A
authors.lastname: Donneys
authors.affiliation: University of Michigan, Ann Arbor, MI, USA.
authors.forename: Noah S
authors.initials: NS
authors.lastname: Nelson
authors.affiliation: University of Michigan, Ann Arbor, MI, USA.
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Perosky
authors.affiliation: University of Michigan, Ann Arbor, MI, USA.
authors.forename: Yekaterina
authors.initials: Y
authors.lastname: Polyatskaya
authors.affiliation: University of Michigan, Ann Arbor, MI, USA.
authors.forename: Jose J
authors.initials: JJ
authors.lastname: Rodriguez
authors.affiliation: University of Michigan, Ann Arbor, MI, USA.
authors.forename: Christian
authors.initials: C
authors.lastname: Figueredo
authors.affiliation: University of Michigan, Ann Arbor, MI, USA.
authors.forename: Cheyenne A
authors.initials: CA
authors.lastname: Vasseli
authors.affiliation: University of Michigan, Ann Arbor, MI, USA.
authors.forename: Hannah C
authors.initials: HC
authors.lastname: Ratliff
authors.affiliation: University of Michigan, Ann Arbor, MI, USA.
authors.forename: Sagar S
authors.initials: SS
authors.lastname: Deshpande
authors.affiliation: University of Michigan, Ann Arbor, MI, USA.
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Kozloff
authors.affiliation: University of Michigan, Ann Arbor, MI, USA. Electronic address: sbuchman@med.umich.edu.
authors.forename: Steven R
authors.initials: SR
authors.lastname: Buchman
mesh_terms: D004999:Amifostine / Q000494:pharmacology / Q000627:therapeutic use*; D000792:Angiography; D000818:Animals; D001696:Biomechanical Phenomena / Q000187:drug effects; D015519:Bone Density / Q000187:drug effects; D001847:Bone Diseases / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000209:etiology / Q000517:prevention & control*; D019610:Cytoprotection / Q000187:drug effects*; D003676:Deferoxamine / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D011832:Radiation Injuries / Q000150:complications*; D017207:Rats, Sprague-Dawley
chemical_list: D003676:Deferoxamine; D004999:Amifostine
keywords: Amifostine; Deferoxamine; Nonunion; Osteoradionecrosis; Pathologic fracture; Radiotherapy