title: Chitosan sponges to locally deliver amikacin and vancomycin: a pilot in vitro evaluation.
abstract: BACKGROUND
  Open orthopaedic wounds are ideal sites for infection. Preventing infection in these wounds is critical for reducing patient morbidity and mortality, controlling antimicrobial resistance and lowering the cost of treatment. Localized drug delivery has the potential to overcome the challenges associated with traditional systemic dosing. A degradable, biocompatible polymer sponge (chitosan) that can be loaded with clinician-selected antibiotics at the point of care would provide the patient and clinician with a desirable, adjunctive preventive modality.
  
  
  OBJECTIVE
  We asked (1) if an adaptable, porous chitosan matrix could absorb and elute antibiotics for 72 hours for potential use as an adjunctive therapy to débridement and lavage; and (2) if the sponges could elute levels of antibiotic that would inhibit growth of Staphylococcus aureus and Pseudomonas aeruginosa?
  
  
  METHODS
  We fabricated a degradable chitosan sponge that can be loaded with antibiotics during a 60-second hydration in drug-containing solution. In vitro evaluation determined amikacin and vancomycin release from chitosan sponges at six time points. Activity tests were used to assess the release of inhibitory levels of amikacin and vancomycin.
  
  
  RESULTS
  Amikacin concentration was 881.5 microg/mL after 1 hour with a gradual decline to 13.9 microg/mL after 72 hours. Vancomycin concentration was 1007.4 microg/mL after 1 hour with a decrease to 48.1 microg/mL after 72 hours. Zone of inhibition tests were used to verify inhibitory levels of drug release from chitosan sponges. A turbidity assay testing activity of released amikacin and vancomycin indicated inhibitory levels of elution from the chitosan sponge.
  
  
  CONCLUSIONS
  Chitosan sponges may provide a potential local drug delivery device for preventing musculoskeletal infections.
authors.affiliation: University of Memphis, Memphis, TN, USA.
authors.forename: Scott P
authors.initials: SP
authors.lastname: Noel
authors.forename: Harry S
authors.initials: HS
authors.lastname: Courtney
authors.forename: Joel D
authors.initials: JD
authors.lastname: Bumgardner
authors.forename: Warren O
authors.initials: WO
authors.lastname: Haggard
mesh_terms: D000583:Amikacin / Q000032:analysis / Q000493:pharmacokinetics*; D000900:Anti-Bacterial Agents / Q000032:analysis / Q000493:pharmacokinetics*; D001672:Biocompatible Materials / Q000032:analysis / Q000493:pharmacokinetics*; D048271:Chitosan / Q000493:pharmacokinetics*; D004337:Drug Carriers / Q000737:chemistry; D008826:Microbial Sensitivity Tests; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000254:growth & development; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development; D013530:Surgical Wound Infection / Q000517:prevention & control; D014640:Vancomycin / Q000032:analysis / Q000493:pharmacokinetics*
chemical_list: D000900:Anti-Bacterial Agents; D001672:Biocompatible Materials; D004337:Drug Carriers; D014640:Vancomycin; D000583:Amikacin; D048271:Chitosan