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Minocycline microspheres did not significantly improve outcomes after collagenase injection of tendon.

Authors :
Allen AD
Bassil AM
Berkoff DJ
Al Maliki M
Draeger RW
Weinhold PS
Source :
Journal of orthopaedics [J Orthop] 2019 Jun 03; Vol. 16 (6), pp. 580-584. Date of Electronic Publication: 2019 Jun 03 (Print Publication: 2019).
Publication Year :
2019

Abstract

Background: Tetracycline antibiotics inhibit matrix metalloproteinases and pro-inflammatory cytokines implicated in the pathogenesis of tendinopathy, while microsphere formulations allow sustained release of drug contents. The purpose of this study was to evaluate the ability of a local minocycline microsphere injection to restore normal tendon properties in a rat model of collagenase-induced patellar tendinopathy.<br />Methods: A total of 22 rats were randomly assigned to the control (n = 11) or minocycline (n = 11) group and received bilateral patellar tendon injections of collagenase. After 7 days, the minocycline group received the minocycline microsphere treatment and the control group received phosphate buffered solution. Pain was assessed via activity monitors and Von Frey filament testing. At 4 weeks post-collagenase injections, animals were euthanized.<br />Results: Cage crossings significantly decreased among all rats 2-3 days following each injection period, however, tactile allodynia measures did not reflect this injury response. Biomechanical properties, interleukin-1 beta levels, and glycosaminoglycan content did not differ between groups. While not statistically significant, levels of leukotriene B <subscript>4</subscript> were lower in the minocycline group compared to controls ( p  = 0.061), suggesting a trend.<br />Conclusions: Our study further characterizes the collagenase model of tendinopathy by demonstrating no evidence of central sensitization with collagenase-induced injury. We found no adverse effect of intratendinous injections of minocycline-loaded poly-lactic-co-glycolic acid microspheres, although no therapeutic effect was observed. Future studies involving a more substantial tendon injury with a greater inflammatory component may be necessary to more thoroughly evaluate the effects of minocycline on tendon pathology.<br /> (© 2019 Prof. PK Surendran Memorial Education Foundation. Published by Elsevier, a division of RELX India, Pvt. Ltd. All rights reserved.)

Details

Language :
English
ISSN :
0972-978X
Volume :
16
Issue :
6
Database :
MEDLINE
Journal :
Journal of orthopaedics
Publication Type :
Academic Journal
Accession number :
31660026
Full Text :
https://doi.org/10.1016/j.jor.2019.06.007