title: [Experimental study of local administration of silver nanoparticles for the treatment of pyogenic spondylitis].
abstract: OBJECTIVE
  To establish a proper animal model of pyogenic spondylitis, to evaluate the efficacy of silver nanoparticles for treatment of spinal pyogenic infections, and to explore the distribution of the particles in the body of the animals.
  
  
  METHODS
  Staphylococcus aureus was inoculated into intervertebral discs of rabbits to establish a spinal pyogenic infection model. These rabbits were divided into Group A [0.1 mg/(kg.d)], Group B [1 mg/(kg.d)], and a Control group. Groups A and B were injected with different doses of silver nanoparticles solution daily at locally infected side. Two weeks later, bacterial cultures, radiographic outcomes, histopathology were analyzed. Atomic absorption spectrometry was utilized to measure silver contents in some vital organs of the rabbits to detect the distribution and accumulation of silver particles.
  
  
  RESULTS
  Staphylococcus aureus (100 CFU/mL), induced 100% pyogenic spondylitis. 1 mg/kg dose of silver nanoparticles solution could effectively inhibit the occurrence of spinal pyogenic infection with the effective rate of 75%. While the effect of 0.1 mg/kg dose of silver nanoparticles solution was less obvious, the efficiency was only 25%. Significant numbers of silver nanoparticles were observed to accumulate in the animal. In the 1 mg/kg group silver was deposited mainly in the spinal cord, liver, kidneys, spleen, and testicles, while in the 0.1 mg/kg group it accumulated only in the spinal cord.
  
  
  CONCLUSIONS
  Local administration of silver nanoparticles can effectively prevent and treat pyogenic spondylitis; the particles accumulate in the body commensurate with the administered drug concentration.
authors.affiliation: Department of Spine Surgery, Second Xiangya Hospital, Central South University, Changsha 410011,China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Qin
authors.initials: Q
authors.lastname: Tang
authors.forename: Lu
authors.initials: L
authors.lastname: Deng
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Wang
authors.forename: Jingying
authors.initials: J
authors.lastname: Gai
authors.forename: Ming
authors.initials: M
authors.lastname: Wang
authors.forename: Ming
authors.initials: M
authors.lastname: Yang
mesh_terms: D000818:Animals; D036502:Infusions, Intralesional; D008159:Lumbar Vertebrae; D008297:Male; D053768:Metal Nanoparticles / Q000008:administration & dosage*; D011817:Rabbits; D012834:Silver / Q000008:administration & dosage* / Q000494:pharmacology; D013166:Spondylitis / Q000188:drug therapy* / Q000382:microbiology; D013203:Staphylococcal Infections / Q000188:drug therapy*
chemical_list: D012834:Silver