Comparisons of Release of Several Antibiotics from Antimicrobial Polymer-Coated Allograft Bone Void Filler

Abstract

Osteomyelitis remains a significant complication in orthopedic surgeries. Although infection rates remain steady at 1-3% for primary orthopedic surgeries, overall numbers of orthopedic procedures are increasing, corresponding to earlier and more frequent surgical intervention for an active, aging population. To address this dangerous surgical complication, degradable polycaprolactone (PCL) polymer/antibiotic solutions were coated over allograft bone void filler. Local in vitro release of ciprofloxacin, vancomycin, oxacillin, tobramycin, or rifampicin from a polymer-controlled, antibiotic-releasing bone graft void filler and monitored in vitro allowed the criterion for successful local antibiotic-releasing devices to be expanded. Although each antibiotic exhibited a different release profile based on their formulation and chemical structure, allowing the potential for engineering combinatorial therapy with microbicidal activity, bacterial killing activity in vitro was demonstrated efficacious out to a clinically relevant 8-week time point. In addition to proposing an expanded criterion for successful local antibiotic-releasing devices, this study demonstrates that allograft bone can act as a local, controlled drug release matrix in bone sites. This combination device provides osteoconductive potential in bone voids while mitigating the potential for operatively sourced opportunistic infectious complications during orthopedic repairs as well as primary and revision arthroplasties