Multi-Layered Microneedles Loaded with Microspheres.

Delivery of therapies into skin is attractive for medical indications including vaccination and treatment of dermatoses but is highly constrained by the stratum corneum barrier. Microneedle (MN) patches have emerged as a promising technology to enable non-invasive, intuitive, and low-cost skin delivery. When combined with biodegradable polymer formulations, MN patches can further enable controlled-release drug delivery without injection.

IOP Reduction in Nonhuman Primates by Microneedle Injection of Drug-Free Hydrogel to Expand the Suprachoroidal Space.

Purpose: Expansion of the suprachoroidal space (SCS) by a hydrogel injection has been shown to reduce intraocular pressure (IOP) in rabbits as a potential treatment for ocular hypertension in glaucoma. Here, we evaluate the safety and efficacy of this approach in hypertensive and normotensive eyes in nonhuman primates.

Methods: A microneedle was used to inject a hyaluronic acid-based hydrogel or saline solution (control) into the SCS of cynomolgus monkey eyes that were either normotensive (n = 7 experimental; n = 2 control eyes) or had induced ocular hypertension (n = 6 experimental; n = 3 control eyes).

Computational modelling of scleral photocrosslinking: from rat to minipig to human.

Selective scleral crosslinking has been proposed as a novel treatment to increase scleral stiffness to counteract biomechanical changes associated with glaucoma and high myopia. Scleral stiffening has been shown by transpupillary peripapillary scleral photocrosslinking in rats, where the photosensitizer, methylene blue (MB), was injected retrobulbarly and red light initiated crosslinking reactions with collagen. Here, we adapted a computational model previously developed to model this treatment in rat eyes to additionally model MB photocrosslinking in minipigs and humans.