title: The Effect of Vancomycin and Gentamicin Antibiotics on Human Osteoblast Proliferation, Metabolic Function, and Bone Mineralization.
abstract: METHODS
  The present study investigates the effect of vancomycin and gentamicin antibiotics on primary human osteoblasts. Osteoblasts were incubated with vancomycin, gentamicin, or with povidone-iodine (PVI), at concentrations advocated for wound irrigation. Osteoblast proliferation, metabolic function, and bone mineralization were measured.
  
  
  OBJECTIVE
  The aim of the study was to model gentamicin and vancomycin wound irrigation in vitro and to examine the effect on osteoblast viability and cellular function in comparison to 0.35% PVI.
  
  
  BACKGROUND
  Vancomycin, gentamicin, and dilute PVI are employed as wound irrigants in spinal surgery to reduce infection. We have, however, recently demonstrated that 0.35% PVI has a detrimental effect on osteoblast cellular function and bone mineralization. Studies to determine the effects of antibiotic wound irrigation solutions on osteoblasts and bone mineralization are therefore warranted.
  
  
  METHODS
  Primary human osteoblasts were exposed for 20 minutes to phosphate buffered saline (PBS) control, vancomycin (35 or 3.5 mmol/L), gentamicin (34 or 3.4 mmol/L), or 0.35% PVI for 3 minutes. Cellular proliferation was measured during 7 days by MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay. Osteoblast metabolic function was determined using a Seahorse XFe24 Bioanalyzer. Mineralized bone nodules were quantified using Alizarin red.
  
  
  RESULTS
  At concentrations advocated for wound irrigation, both gentamicin (3.4 mmol/L) and vancomycin (3.5 mmol/L) induced a transient 15% to 20% reduction in osteoblast proliferation, which returned to control values within 72 hours. This was in marked contrast to the effect of 0.35% PVI, which resulted in a sustained reduction in osteoblast proliferation of between 40% and 50% during 7 days. Neither gentamicin nor vancomycin at concentrations up to 10× clinical dose had any effect on osteoblast oxygen consumption rate, or significantly affected mineralized bone nodule formation.
  
  
  CONCLUSIONS
  Vancomycin and gentamicin solutions, at concentrations advocated for intrawound application in spinal surgery, have a small but transient effect on osteoblast proliferation, and no effect on either osteoblast metabolic function or bone nodule mineralization.
  
  
  METHODS
  N/A.
authors.affiliation: MRC-ARUK Centre for Musculoskeletal Ageing Research, Institute of Inflammation and Ageing, Queen Elizabeth Hospital, University of Birmingham, Birmingham, United Kingdom.
authors.forename: Ashleigh M
authors.initials: AM
authors.lastname: Philp
authors.affiliation: MRC-ARUK Centre for Musculoskeletal Ageing Research, Institute of Inflammation and Ageing, Queen Elizabeth Hospital, University of Birmingham, Birmingham, United Kingdom.
authors.forename: Saroop
authors.initials: S
authors.lastname: Raja
authors.affiliation: MRC-ARUK Centre for Musculoskeletal Ageing Research, Institute of Inflammation and Ageing, Queen Elizabeth Hospital, University of Birmingham, Birmingham, United Kingdom.
authors.forename: Andrew
authors.initials: A
authors.lastname: Philp
authors.affiliation: The Royal Orthopaedic Hospital NHS Foundation Trust, Bristol Road South, Northfield, Birmingham, United Kingdom.
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Newton Ede
authors.affiliation: MRC-ARUK Centre for Musculoskeletal Ageing Research, Institute of Inflammation and Ageing, Queen Elizabeth Hospital, University of Birmingham, Birmingham, United Kingdom.
authors.forename: Simon W
authors.initials: SW
authors.lastname: Jones
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D005839:Gentamicins / Q000494:pharmacology*; D006801:Humans; D010006:Osteoblasts / Q000187:drug effects*; D010012:Osteogenesis / Q000187:drug effects*; D011206:Povidone-Iodine / Q000627:therapeutic use; D013530:Surgical Wound Infection / Q000188:drug therapy; D013778:Tetrazolium Salts / Q000627:therapeutic use; D013844:Thiazoles / Q000627:therapeutic use; D014640:Vancomycin / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins; D013778:Tetrazolium Salts; D013844:Thiazoles; C070380:3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium; D014640:Vancomycin; D011206:Povidone-Iodine