In vitro and in vivo affinity microdialysis sampling of cytokines using heparin-immobilized microspheres

Abstract

Heparin-immobilized microspheres were included in microdialysis sampling perfusion fluids under both in vitro and in vivo conditions to improve the recovery of different cytokines, acidic fibroblast growth factor, vascular endothelial growth factor, monocyte chemoattractant protein-1 (or CCL2), and regulation upon activation normal T cell express sequence (or CCL5). Different strategies to dissociate captured CCL2 and CCL5 from the immobilized heparin were attempted, and both cytokines could be quantitatively eluted from the beads using a phosphate buffer (pH 7.4) containing 25% (v/v) acetonitrile which did not interfere with the subsequent detection of cytokine using an ELISA assay. Using these heparin-immobilized microspheres, a two to fivefold increase of microdialysis relative recovery (RR) was achieved for the four cytokines from a quiescent solution. Enhanced microdialysis RR of CCL2 using the heparin-immobilized microspheres from microdialysis probes implanted into the peritoneal cavity of a rat was performed to test the in vivo application. This work suggests that the heparin-immobilized microspheres provide an alternative affinity agent to the previously used antibody-immobilized microspheres for enhanced microdialysis sampling of cytokines.

Using Glycosaminoglycan/Chemokine Interactions for the Long-Term Delivery of 5P12-RANTES in HIV Prevention

“…RANTES and its derivatives are known to have affinity interactions with various glycosaminoglycans(GAGs), with heparin having the strongest affinity, followed by various chondroitin sulfates 27 and uncleaved heparan sulfates 28–31 . These interactions have been explored in the application of biosensor and diagnostic development for cytokines 32, 33 . In this study, we characterized the affinity strength of different GAGs to 5P12-RANTES.…”

Microdialysis sampling techniques applied to studies of the foreign body reaction

“…Using the dual delivery/sample collection microdialysis technique, our laboratory has employed various strategies to advance the delivery and recovery of cytokines and other signaling molecules to better evaluate the FBR (Ao et al, 2004; Ao and Stenken, 2006; Duo and Stenken, 2011a; Duo and Stenken, 2011b; Mou et al, 2010; Wang and Stenken, 2009a). Modulation of the FBR is not only significant in biomaterials science, but moderating the effects of the FBR specifically upon implantation of a microdialysis sampling device will also be crucial to furthering drug development for a variety of fields in pharmaceutical and clinical research.…”

Non-invasive Characterization of Immune Responses to Biomedical Implants

“…63,64,98 It should be noted that microdialysis apparatus and various catheters have been employed to collect body fluids from implantation sites. 28,62,103 Unfortunately, these techniques can only be used on rats or larger animals. Due to the limited availability of specific antibodies to these species of animals, this system is rarely used to characterize tissue responses to biomaterial implants.…”