Ballistic delivery and related particles, compositions, methods and systems

A method for controlled ballistic delivery of a biologically active cargo to the cornea of an individual comprising an epithelium layer and a stroma layer and an interface between the epithelium layer and the stroma layer, the method comprising

• ballistically delivering to the cornea a convex microparticle comprising the biologically active cargo optionally in combination with a carrier material, the convex microparticle having a diameter from 5 to 30 μm and a density from 1 g/cc up to less than 20 g/cc,
• the ballistically delivering performed at a velocity equal to or higher than 100 m/s to a set target region of the cornea from the epithelium layer to the stroma layer of the cornea of the individual
• wherein the ballistic delivery is controlled by selecting the density of the convex microparticle to correspond to the set target region such that:
• wherein when the convex microparticle has a density from 1.0 g/cc to 2.5 g/cc the set target region is a target region located within the epithelium of the cornea,
• wherein when the convex microparticle has a density higher than 2.5 g/cc to 7.8 g/cc the set target region is a target region located in the epithelium layer, in the stroma layer of the cornea and/or within the interface between epithelium layer and stroma layer of the cornea, and
• wherein when the convex microparticle has a density higher than 7.8 g/cc to less than 20 g/cc the set target region is a target region within the interface between the epithelium layer and the stroma layer of the cornea, or within the stroma layer of the cornea.