Measurement of intracellular hydrogen peroxide induced by biomaterials implanted in a rodent air pouch

Biomaterials elicit an inflammatory response that is undoubtedly a factor in their healing and in the complications associated with their use. Herein, we report the modification of a rat air pouch in which we measured the production of intracellular hydrogen peroxide by inflammatory cells adherent to the surfaces of silicone elastomer (SE) and expanded polytetrafluoroethylene (ePTFE). We used the fluorescent probe dichlorofluorescein diacetate (DCFH-DA) to measure the intracellular production of hydrogen peroxide 2 and 7 days after implantation. After 2 days, host cells adherent to ePTFE produced almost 3.5 times more hydrogen peroxide than did cells adherent to SE (P < .001). By 7 days, the H2O2 production of cells adherent to ePTFE had decreased while that on cells adherent to SE was unchanged. These data indicate that the air pouch is a good alternative to other in vivo models for studies of the biological reactions induced by biomaterials.