Delivery device
A device for delivery of material to a biological subject, the device including a base and a number of projections extending from the base, each projection including a tip for penetrating tissue of the biological subject, at least a portion of at least one of the projections being coated with a non-liquid coating including the material. At least the tip of at least one of the coated projections may have a convex effective profile. The device may be for delivery of material to a dermal layer of the biological subject. In another aspect an applicator for applying the device to the biological subject applies a preload force to the tissue such that the force at least partially compresses a subcutaneous tissue layer of the biological subject prior to application of the device, and applies the device with a predetermined velocity, wherein tissue stiffness is maintained and/or the projections penetrate the tissue to a predetermined depth.
1. A device for delivery of a biochemical compound to a biological subject, the device comprising:
a) a base; and,
b) a number of solid, non-porous projections extending from the base, wherein each projection comprises a cylindrical support section which transitions into a coated, convex end section having a tip, wherein the transition forms a flat stepped surface profile between the end section and the cylindrical support section and wherein the cylindrical support section is wider at the transition than the coated end section and a discontinuity wherein the discontinuity is closer to the base than the flat stepped surface profile such that the flat stepped surface profile and the discontinuity of each projection interact with tissue of the biological subject to at least partially control penetration of the projections into the tissue thereby providing a physical adjuvant effect, when the device is applied to the tissue so that the projections penetrate the tissue,
wherein a cone angle measured from a centerline of each projection to an edge of the coated, convex end section having a tip varies along a length of at least one of the projections and wherein the cone angle increases along the length of the end section and wherein the cone angle is between 1° and 10° at the tip.
2. The device according to claim 1 , wherein the flat stepped surface profile is located at a distance from the tip of the end section, the distance being between 10 and 100 μm.
3. The device according to claim 1 , wherein at least one of the projections has a length between 200 μm and 250 μm.
4. The device according to claim 1 ,
wherein:
i) the number of projections is from about 1000 to 20000;
ii) at least one of the projections has a length of between 200 μm and 250 μm;
iii) at least one of the projections has a base width of between 20 μm and 50 μm;
iv) at least one of the projections has a tip radius of less than 5 μm; and
v) the projections are separated by a spacing of between 70 μm and 100 μm.
5. The device of claim 1 , wherein the coated, convex end section is coated with a first vaccine compound and wherein at least one of the projections is coated with a second vaccine compound.
6. The device of claim 1 , wherein the biochemical compound is sprayed onto the projections.
7. The device of claim 1 , wherein the base is 1 mm 2 to 100 mm 2 .
8. The device of claim 1 wherein the physical adjuvant effect is cell damage mediated by the projections.
9. The device according to claim 1 , wherein the flat stepped surface profile step is located at a distance from the tip of the end section, the distance being between 40 and 60 μm.