Ballistic delivery of compounds to inner layers of the cornea is limited by tough mechanical properties of stromal tissue

The barrier characteristics of the cornea are interrogated using impact micro-particles into ex vivo porcine cornea. Using a commercial gene gun (BioRad; PDS1000), microparticles were accelerated and made to embed in target materials: either ballistic gelatin as reference or corneal tissue. Statistical analysis penetration polydisperse spherical (5–22 μm dia.) with density 2.5 g/cc, 4.2 7.8 g/cc (soda-lime glass, barium-titanate glass stainless steel; more limited examination 1.1 polyethylene 19.2 tungsten) spanned almost two decades kinetic energy. Penetration profiles show that particle embedding depth is sensitive size density. In cornea, weak function density, stroma an effective stopping medium for high velocity microparticles. Despite water content tissue (76% w/w) compared stratum corneum skin (40% w/w), resistance comparable what seen previous research low polymer particles therapeutic agent payload, it demonstrated bulk material can be ballistically delivered central 1 cm2 epithelium even layer bioavailability compound.