Dual delivery of an antibiotic and a growth factor addresses both the microbiological and biological challenges of contaminated bone fractures.
BACKGROUND
Open fractures are plagued by high complication rates, among which infection and nonunion are the most common, leading to higher morbidity and poor patient outcomes. Despite meticulous surgical care and employment of adjunctive therapies, infection rates remain at 20%, due to the limitations of conventional therapies.


METHODS
Persistent bacteria often survive initial debridement and treatment with antibiotics. Thus, the bone graft subsequently implanted to promote healing can be the nidus for infection. The principles of biofilm theory and the "race to the surface" have been applied to develop dual-purpose bone grafts that are protected by a sustained release of an antibiotic, thereby preventing bacterial colonization. A simultaneous sustained release of a recombinant human growth factor allows the defect to become vascularized and heal.


CONCLUSIONS
Current therapies fail to meet the challenges of open fractures. Tissue engineering and drug delivery approaches can address the challenges of healing large bone defects while protecting the implant from infection. When combined as an adjunctive therapy with existing clinical practices for management of open fractures, dual-purpose bone grafts that release both an antibiotic and a growth factor at biologically relevant time scales can potentially reduce infection rates and improve patient outcomes.
United States Army Institute of Surgical Research, Extremity Trauma & Regenerative Medicine Task Area, 3400 Rawley E. Chambers Ave. Fort Sam Houston, TX 78234, USA. joseph.wenke@us.army.mil
Joseph C
JC
Wenke
Scott A
SA
Guelcher
D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001424:Bacterial Infections / Q000150:complications / Q000188:drug therapy*; D055396:Bone Morphogenetic Protein 2 / Q000627:therapeutic use*; D016025:Bone Transplantation; D050723:Fractures, Bone / Q000188:drug therapy* / Q000382:microbiology; D005597:Fractures, Open / Q000188:drug therapy* / Q000382:microbiology; D006801:Humans; D011994:Recombinant Proteins / Q000627:therapeutic use; D016212:Transforming Growth Factor beta / Q000627:therapeutic use*
D000900:Anti-Bacterial Agents; D055396:Bone Morphogenetic Protein 2; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2