Synthesis of monodisperse drug microparticles and high-velocity bombardment as a strategy to traverse epithelial layers and treat pathologies of the cornea

Certain diseases (e.g. Keratoconus) weaken the human cornea, our eyes' protective window and primary focusing lens. Corneal cross-linking therapy (CXL) involves removing the epithelium, applying a photosensitizer solution to the cornea, and using UV light to cross-link collagen and reinforce tissues that display viscoelastic creep. CXL could have shorter recovery times and better outcomes if patients' epithelial layers are left intact, but this barrier prevents sufficient and uniform delivery of photosensitizer to the inner, diseased layer (the stroma). As a means of attaining sufficient mass flux and uniform delivery of cross-linking agent, our group has developed technology to embed solid, monodisperse spheres (10-50 um) composed of photosensitizer (Eosin Y) in sub-epithelial layers. A vibrating orifice aerosol generator is used to discharge drug solution into a temperature/humidity controlled column to synthesize glassy microparticles made of Eosin Y. Highly controlled pneumatic devices have been developed to accelerate microparticles without emitting damaging, pressurized gas. It has been shown that not only can this be a viable therapy, but also that there exist novel, nonlinear impact mechanics when particles embed in fibrous biomatter at high strain rates.