title: The improved biological performance of a novel low elastic modulus implant.
abstract: BACKGROUND
  The mismatch of the elastic modulus between implants and bone tissue can lead to stress shielding, bone resorption and poor osseointegration. Compared with normal bone tissue, this problem is much more serious in osteoporosis. The purpose of this study was designed to find out whether the novel Ti-24Nb-4Zr-7.9Sn (TNZS) implant with low elastic modulus and high strength was suitable for biomedical material, especially in osteoporosis.
  
  
  METHODS
  In vitro study, the viability and Alkaline phosphatase (ALP) activity of osteoblasts on the TNZS and Ti-6V-4V (TAV) were observed. In vivo study, 30 adult female New Zealand rabbits were selected and divided randomly into two groups: sham-operation (SHAM, n=6) and ovariectomised in combination with methylprednisolone treatment (OVX+MP, n=24). Two implants were then placed in the tibia of each OVX + MP group rabbit, one in each side (left: TAV; right: TNZS). The OVX + MP group rabbits were sacrificed at 4 and 12 weeks after the implantation. The osteoporotic bone responses to the TNZS and TAV implants were evaluated by pull-out test, Micro-CT analyses and histological observation.
  
  
  RESULTS
  Compared with the TAV group, the TNZS group showed a significant increase (P<0.05) in cell viability and ALP activity, new bone formation and pull-out force.
  
  
  CONCLUSIONS
  The novel TNZS implants show good biological performance both in vitro and in vivo, which suggests that the alloys are suitable for biomedical applications, especially in osteoporosis.
authors: Institute of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
authors: Lei
authors: L
authors: Shi
authors: Lei
authors: L
authors: Shi
authors: Ling
authors: L
authors: Wang
authors: Yonghong
authors: Y
authors: Duan
authors: Wei
authors: W
authors: Lei
authors: Zhen
authors: Z
authors: Wang
authors: Jing
authors: J
authors: Li
authors: Xiangli
authors: X
authors: Fan
authors: Xiaokang
authors: X
authors: Li
authors: Shujun
authors: S
authors: Li
authors: Zheng
authors: Z
authors: Guo
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000497:Alloys / Q000494:pharmacology; D000818:Animals; D001696:Biomechanical Phenomena / Q000187:drug effects; D015519:Bone Density / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D055119:Elastic Modulus / Q000187:drug effects / Q000502:physiology*; D005260:Female; D020007:Implants, Experimental; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D011817:Rabbits; D013499:Surface Properties; D013977:Tibia / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology; D055114:X-Ray Microtomography
chemical_list: D000497:Alloys; D000469:Alkaline Phosphatase