Localized delivery of dexamethasone-21-phosphate via microdialysis implants in rat induces M(GC) macrophage polarization and alters CCL2 concentrations

by Keeler, Geoffrey David; Durdik, Jeannine M.; Stenken, Julie Ann

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Microdialysis sampling probes were implanted into the s.c. space on the dorsal side of male Sprague Dawley rats to locally deliver dexamethasone-21-phosphate (Dex) with the aim of altering in vivo macrophage polarization. Macrophage polarization is of significant interest in the field of biomaterials since wound-healing macrophages are a possible means to extend implant life as well as improve tissue remodeling to an implant. Quant. anal. of CCL2 in collected dialyzates, gene expression and immunohistochem. performed on the tissue surrounding the microdialysis implant were used to evaluate if Dex polarized macrophages. Dex infusion down-regulated IL-6 and CCL2 gene expression and decreased CCL2 concns. in dialyzates collected at the implant site. Dex appeared to have no significant effect on the gene regulation of CD163, a commonly used M2c macrophage surface marker; Arg2; and iNOS2. However, Dex infusion was effective at increasing the no. of CD163+ cells surrounding the implanted microdialysis probe. This work demonstrates the use of microdialysis sampling to deliver agents such as Dex to alter macrophage polarization in vivo while allowing the ability to collect cytokines in the surrounding microenvironment.

Journal
Acta Biomaterialia
Volume
12
Year
2015
Start Page
11
ISBN/ISSN
1742-7061
PMID
25449921
DOI
10.1016/j.actbio.2014.10.022