Drug Delivery and Translational Research - Featured Article: August 2023
Read the featured article from the August 2023 issue! (this opens in a new tab)
Summary:
The discovery of proteins that neutralize vascular endothelial growth factors can inhibit the process of angiogenesis to restore eyesight in individuals with retinal vascular disorders. However, a safe and effective means to deliver these protein drugs to the target posterior segment is currently lacking. To this end, we developed dissolving bilayer microneedles (MNs) possessing the potential to deliver proteins to the back of the eye in an efficient and minimally invasive manner. A model protein, ovalbumin (OVA), was incorporated into MNs fabricated from different polymers, including hyaluronic acid, polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP). Optimized PVA/PVP MNs demonstrated robust permeation of porcine sclera with > 75% of the needle length penetrating the sclera while dissolving within 150 s. SDS-PAGE and OVA-specific ELISA revealed that the bioactivity of OVA was retained during the manufacture of MNs. In hen’s egg-chorioallantoic membrane test, MNs fabricated from all chosen polymers were classified as non-irritants. Furthermore, ex vivo permeation studies showed that optimized MNs mediated the penetration of 86.99 ± 7.37% of OVA through the sclera, twice that of the needle-free patch (42.16 ± 3.95%), highlighting the capability of MNs to circumvent physical barriers and promote protein delivery to the posterior segment of the eye. Overall, a novel, efficient, and safe intraocular protein delivery system was successfully established.