Incorporating dexamethasone release in hydrogel coated microdialysis probes

Microdialysis probes were used to study the influence of membrane modifications on glucose recovery. The microdialysis membranes were modified by adding a hydrogel coating. The coated probes were evaluated in vitro and in vivo for glucose permeability. It was found that percent glucose recovery was reduced by 25% in vitro using hydrogel coated probes compared to control probes. However, the glucose recoveries of the coated probes in vivo were more similar to that of control probe, with an average difference of 6%. From these results, it was concluded that the tissue resistance to glucose transport was much greater than the resistances of the hydrogel and biofouling. The hydrogel formulation was then changed to deliver a tissue modifying drug to reduce the tissue resistance. Dexamethasone was incorporated into the hydrogels to reduce inflammation. These hydrogels are capable of releasing drug up to 14 days. The dexamethasone hydrogels will be coated onto microdialysis probes in future in vivo studies to determine the effect of reduced inflammatory response on glucose recovery.