Researchers recently devised a coating containing interleukin-4 (IL-4) that can be applied on soft contact lenses in layers. The researchers found that the coating releases cytokines, which further activate an anti-inflammatory cell population. These cells can decrease inflammation and the associated dry eye disease.

In the study, presented as part of ARVO’s 2020 online meeting, the lenses coated with IL-4 were incubated in solution containing enzymes that mimic those produced by ocular macrophages in vivo. The researchers cultured macrophages and then incubated them with either coated/uncoated contact lenses or cytokines known to cause either the anti- or pro-inflammatory phenotypes.

Alcian blue staining confirmed successful application of the coating. In vitro drug release assays showed that the lens coating was capable of a sustained release of drug over the course of days that was mainly enzyme driven. The study’s in vitro culture experiments, staining for intracellular arginase and assessment of arginase activity both showed that the IL-4 released from the lens device was capable of reducing inflammation. The researchers noted that the IL-4 coated lenses did not cause any appreciable production of nitric oxide, which is the marker of the pro-inflammatory M1 macrophage phenotype responsible for perpetuation dry eye.

The researchers believe that their strategy for IL-4 delivery to “reprogram” M1 macrophages to the anti-inflammatory M2 phenotype can help mitigate the inflammation that fuels dry eye.