Volume 109, Issue 11 pp. 2255-2268
RESEARCH ARTICLE

Comparative efficacy of resorbable fiber wraps loaded with gentamicin sulfate or gallium maltolate in the treatment of osteomyelitis

Taneidra W. Buie

Taneidra W. Buie

Department of Biomedical Engineering, The University of Texas, Austin, Texas, USA

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Michael Whitely

Michael Whitely

Department of Orthopaedic Trauma, US Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, Texas, USA

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Joshua McCune

Joshua McCune

Department of Biomedical Engineering, The University of Texas, Austin, Texas, USA

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Ziyang Lan

Ziyang Lan

Department of Biomedical Engineering, The University of Texas, Austin, Texas, USA

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Anupriya Jose

Anupriya Jose

Department of Biomedical Engineering, The University of Texas, Austin, Texas, USA

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Annika Balakrishnan

Annika Balakrishnan

Department of Biomedical Engineering, The University of Texas, Austin, Texas, USA

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Joseph Wenke

Joseph Wenke

Department of Orthopaedic Trauma, US Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, Texas, USA

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Elizabeth Cosgriff-Hernandez

Corresponding Author

Elizabeth Cosgriff-Hernandez

Department of Biomedical Engineering, The University of Texas, Austin, Texas, USA

Correspondence

Elizabeth Cosgriff-Hernandez, Department of Biomedical Engineering, The University of Texas, 107 W. Dean Keeton, BME 3.503D, 1 University Station, C0800, Austin, TX 78712, USA.

Email: [email protected]

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First published: 05 May 2021
Citations: 2

Funding information: National Science Foundation Graduate Research Fellowship Program and the National Institutes of Health, Grant/Award Number: R03 AI136060

Abstract

The high incidence of osteomyelitis associated with critical-sized bone defects raises clinical challenges in fracture healing. Clinical use of antibiotic-loaded bone cement as an adjunct therapy is limited by incompatibility with many antimicrobials, sub-optimal release kinetics, and requirement of surgical removal. Furthermore, overuse of antibiotics can lead to bacterial modifications that increase efflux, decrease binding, or cause inactivation of the antibiotics. Herein, we compared the efficacy of gallium maltolate, a new metal-based antimicrobial, to gentamicin sulfate released from electrospun poly(lactic-co-glycolic) acid (PLGA) wraps in the treatment of osteomyelitis. In vitro evaluation demonstrated sustained release of each antimicrobial up to 14 days. A Kirby Bauer assay indicated that the gentamicin sulfate-loaded wrap inhibited the growth of osteomyelitis-derived isolates, comparable to the gentamicin sulfate powder control. In contrast, the gallium maltolate-loaded wrap did not inhibit bacteria growth. Subsequent microdilution assays indicated a lower than expected sensitivity of the osteomyelitis strain to the gallium maltolate with release concentrations below the threshold for bactericidal activity. A comparison of the selectivity indices indicated that gentamicin sulfate was less toxic and more efficacious than gallium maltolate. A pilot study in a contaminated femoral defect model confirmed that the sustained release of gentamicin sulfate from the electrospun wrap resulted in bacteria density reduction on the surrounding bone, muscle, and hardware below the threshold that impedes healing. Overall, these findings demonstrate the efficacy of a resorbable, antimicrobial wrap that can be used as an adjunct or stand-alone therapy for controlled release of antimicrobials in the treatment of osteomyelitis.

DATA AVAILABILITY STATEMENT

The data that support the findings of this study are available from the corresponding author upon reasonable request.

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