A Rapid Corneal Healing Microneedle for Efficient Ocular Drug Delivery

Fungal keratitis (FK) remains a serious clinical problem worldwide, so the ultimate goal of the treatment is to develop a minimally invasive, safe, and effective method for ocular drug delivery. Here, a minimally invasive delivery system is reported for treating FK by using a dissolving microneedle (MN)-array patch based on Poly(D,L-lactide) (PLA) and hyaluronic acid (HA). By altering the concentration of PLA, MN patches with excellent properties are modified and optimized. The 30% PLA-HA MN patches penetrate the corneal epithelial layer reversibly with no apparent ocular irritation as well as a short recovery time of less than 12 h, and increase the residence time by 2.5 h in the conjunctival sac, thereby offering higher drug bioavailability. Remarkably, the rabbit model of FK shows that the topical MN(+) patch medication exerts superior therapeutic effects compared with the conventional eye drop formulation, and also presents comparable therapeutic efficacy with that of the clinical mainstay strategy (i.e., intrastromal injection). Therefore, the MN patch, acting as an ocular drug delivery system with high efficacy and ability of rapid corneal healing, promises a cost-effective household solution for the treatment of FK, which may also lead to a new approach for treating FK in clinics.