Accession Number:

ADA618952

Title:

Dual-Purpose Bone Grafts Improve Healing and Reduce Infection

Descriptive Note:

Journal article

Corporate Author:

ARMY INST OF SURGICAL RESEARCH FORT SAM HOUSTON TX

Report Date:

2011-08-01

Pagination or Media Count:

7.0

Abstract:

Objective To determine if a dual-purpose bone graft can regenerate bone and reduce infection in highly contaminated bone critical size defects in rats. Methods Biodegradable polyurethane PUR scaffolds were loaded with recombinant human bone morphogenetic protein-2 BMP-2 and vancomycin Vanc. The release kinetics of the BMP-2 were tuned to take advantage of its mechanism of action ie, an initial burst to recruit cells and sustained release to induce differentiation of the migrating cells. The Vanc release kinetics were designed to protect the graft from contamination until it is vascularized by having a burst for a week and remaining well over the minimum inhibitory concentration for Staphylococcus aureus for 2 months. The bone regeneration and infection reduction capability of these dual-purpose grafts PURVancBMP-2 were compared with collagen sponges loaded with BMP-2 collagenBMP-2 and PURBMP-2 in infected critical size rat femoral segmental defects. Results The dual-delivery approach resulted in substantially more new bone formation and a modest improvement in infection than PURBMP-2 and collagenBMP-2 treatments. Conclusions The PUR bone graft is injectable, provides a more sustained release of BMP-2 than the collagen sponge, and can release antibiotics for more than 8 weeks. Thus, the dual-delivery approach may improve patient outcomes of open fractures by protecting the osteoinductive graft from colonization until vascularization occurs. In addition, the more optimal release kinetics of BMP-2 may reduce nonunions and the amount of growth factor required.

Subject Categories:

  • Anatomy and Physiology
  • Medicine and Medical Research
  • Microbiology
  • Pharmacology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE