A Rapid Corneal Healing Microneedle for Efficient Ocular Drug Delivery

Abstract

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.

Highly Sensitive and Reliable Internal-Standard Surface-Enhanced Raman Scattering Microneedles for Determination of Bacterial Metabolites as Infection Biomarkers in Skin Interstitial Fluid

“…To check the sensing ability of pyocyanin in real ISF, hyaluronic acid (HA) MNs (10 × 10 array, 650 μm height) were prepared to release the loaded pyocyanin (1 mM) into mouse ISF since HA MNs are widely used as carriers to deliver cargo to ISF. , After inserting into the mouse dermis for 20 min, HA needles dissolved completely together with the in situ release of pyocyanin to ISF (Figure a). Then, IS-SERS-MNs were inserted at the same location for sensing.…”

Emerging Wearable Chemical Sensors Enabling Advanced Integrated Systems toward Personalized and Preventive Medicine

“…Solid microneedles are generally used to pretreat the skin by creating micrometer-size pores, through which the drug is delivered with passive diffusion. − Coated microneedles, as indicated by the name, are microneedles coated with water-soluble drug formulations that will be released to the skin after insertion. − Hollow microneedles generally provide special conduits for drug delivery into the skin. When the microneedles are entirely made of biodegradable or water-soluble materials with drugs encapsulated within the microneedle matrix, they would completely degrade or dissolve in the skin to release the drugs after the insertion. − The earliest investigations of controlled drug delivery were primarily focused on mechanical force-driven drug release, which is simple and easily accessible. For instance, the release of the drug can be promoted by an applied tensile strain due to the increased surface area for diffusion and compression induced by Poisson’s ratio on the microdepots .…”

Advances in microneedle patches for long-acting contraception

“…Dissolvable MN patches are generally made of water-soluble polymers and can achieve rapid dissolution within a short time after skin insertion, thus avoiding biohazardous waste and residual drugs [42]. Dissolvable MN patches are generally made of natural polysaccharides, such as hyaluronic acid (HA) [43], dextran [44], and chitosan [45], or water-soluble polymers, such as polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) [46]. Dissolvable MN patches have good solubility and can dissolve rapidly after contacting interstitial fluid (ISF) in the skin [47,48], thereby achieving transdermal delivery of different types of drugs, including contraceptives (Figure 1).…”