title: Evaluation of biomechanical strength, stability, bioactivity, and in vivo biocompatibility of a novel calcium deficient hydroxyapatite/poly(amino acid) composite cervical vertebra cage.
abstract: A new type of cervical vertebra cage was prepared using a novel composite, calcium deficient hydroxyapatite/poly(amino acid) (HA/PAA), and its mechanical properties, in vitro stability and bioactivity, and in vivo biocompatibility were characterized. The results showed that the axial compressive loads of the HA/PAA cage were in the range of 10058-10612 N and the lateral compressive loads were in the range of 1180-2363 N, and varied with the height of the cervical vertebra cages. After immersion in simulated body fluid (SBF) for 16 weeks, the axial compressive loads of the cage decreased from 10058 to 7131 N and the lateral compressive loads decreased from 1180 to 479 N. In addition, the weight loss decreased 6.01%, showing that HA/PAA composites had good stability during the incubation period. The pH value of SBF was also monitored during the whole soaking period; it fluctuated in the range of 6.9-7.4. Scanning electron microscope and energy dispersive spectrometer results showed the cage was bioactive with a new apatite layer attached on the surface. The histological evaluation revealed that new bone tissue bonded tightly with the surfaces of the implants, showing excellent biocompatibility. In conclusion, the HA/PAA cage showed sufficient strength, good stability, bioactivity, and biocompatibility, and has potential applications for clinical cervical vertebrae repair.
authors.affiliation: a College of Physical Science and Technology , Sichuan University , Chengdu 610041 , China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Xiong
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.forename: Chunguang
authors.initials: C
authors.lastname: Zhou
authors.forename: Xi
authors.initials: X
authors.lastname: Yang
authors.forename: Yueming
authors.initials: Y
authors.lastname: Song
authors.forename: Yan
authors.initials: Y
authors.lastname: Qing
authors.forename: Yonggang
authors.initials: Y
authors.lastname: Yan
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D000818:Animals; D001696:Biomechanical Phenomena; D018786:Bone Substitutes / Q000737:chemistry*; D002118:Calcium / Q000172:deficiency; D002574:Cervical Vertebrae; D019245:Compressive Strength; D017586:Diskectomy; D017886:Durapatite / Q000737:chemistry*; D005260:Female; D006041:Goats; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D013057:Spectrum Analysis
chemical_list: D000596:Amino Acids; D018786:Bone Substitutes; D017886:Durapatite; D002118:Calcium
keywords: bioactivity; biocompatibility; biomechanics; cervical vertebra cage; stability