Microprojection arrays with microprojections having large surface area profiles
Inventors
Crichton, Michael • Kendall, Mark Anthony Fernance
Assignees
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Publication Number
US-11653939-B2
Publication Date
2023-05-23
Expiration Date
Abstract
A microprojection array comprising a substrate with a plurality of microprojections protruding from the substrate wherein the microprojections have a tapering hexagonal shape and comprise a tip and a base wherein the base has two substantially parallel sides with a slight draught angle of approximately 1 to 20 degrees up to a transition point at which point the angle increases to from about 20 degrees to about 70 degrees.
Core Innovation
The described invention relates to microprojection arrays for intradermal vaccine delivery. The arrays include a substrate with a plurality of microprojections protruding from the substrate, where the microprojections have a tapering hexagonal shape with a tip and a base. The base includes two substantially parallel sides with a draught angle that increases at a transition point, and the tip tapers to a distal line with specified length and width.
The geometry is further expressed through microprojection line arrangements and spacing, with high-density line arrangements disclosed for skin puncture. The document also discloses alternate tapering shapes, including octagonal tapering shapes, and emphasizes optional non-liquid vaccine coatings on at least one of the microprojections. The disclosed implementation is directed to applying the microprojection array to skin of a human for vaccine administration.
The document asserts that the tapering geometry and coating approach provide a larger effective skin-contact and surface area and reduced sensitivity to coating thickness relative to conical projections. The disclosure further asserts deeper skin penetration and distinct crack formation and cell death patterns, including bystander interactions, as compared with conical or cylindrical controls, and links these effects to improved immunogenicity, including dose-sparing performance.
Claims Coverage
The partial claims provided include one independent claim that covers a vaccine administration method using a microprojection array with a specific tapering hexagonal draught-angle geometry and at least one vaccine-coated microprojection, resulting in intradermal skin application. The dependent claims refine the independent claim by adding specific microprojection arrangement and application movement/rotation mechanics, and by introducing quantitative comparative performance aspects including projection speed, immunogenic response versus intramuscular injection, and cell-death response versus conical-microprojection controls.
Tapering hexagonal microprojection array with draught-angle transition geometry
A method where the microprojection array includes a substrate with microprojections having a tapering hexagonal shape with a tip and a base, wherein the base has two substantially parallel sides with a draught angle approximately 0 to 10 degrees up to a transition point where the draught angle increases approximately 20 degrees to 70 degrees.
Tip taper to distal line dimensions
Each tapering hexagonal microprojection has a tip that tapers to a distal line of approximately 25 μm long and 1-2 μm wide.
Vaccine coating on at least one microprojection
At least one microprojection is coated with a vaccine within the microprojection array applied to the skin.
Applying microprojection array by specified line arrangement and movement direction
The microprojection array has microprojections arranged in a line and is applied to skin by moving the array in a direction that has a component aligned with the line.
Rotational application of a circumferentially extending microprojection array
A circumferentially extending microprojection array is applied to skin by pressing perpendicular to the skin while rotating the microprojection array around an axis.
Controlled administration via projection speed range
The method administers the microprojection array to the skin by projecting it into the skin at a speed of between about 20 m/s to about 40 m/s.
Improved immunogenic response versus intramuscular injection
Administering the vaccine via the microprojection array produces a greater immunogenic response than administering the identical vaccine via intramuscular injection.
Enhanced cell death response versus conical microprojections at the same speed
A cell death response is compared between administering the microprojection array and administering a microprojection array having conical microprojections at the same speed, where the cell death response to the first array is 50% greater.
Across the independent claim and provided dependents, the coverage centers on administering a vaccine by applying a microprojection array to human skin in which the microprojections have a tapering hexagonal geometry with a defined draught-angle transition and tip taper to a distal line, and at least one microprojection is vaccine-coated. Provided dependents further specify line arrangement and movement alignment, circumferential rotation mechanics, projection speed, and comparative outcomes including greater immunogenic response versus intramuscular injection and greater cell death response versus conical controls at the same speed.
Stated Advantages
Larger effective skin-contact and surface area.
Reduced sensitivity to coating thickness relative to conical projections.
Deeper skin penetration.
Increased cell death and distinct crack formation patterns, including bystander interaction patterns, relative to conical or cylindrical controls.
Improved immunogenicity, including dose-sparing performance.
Documented Applications
Administration of a vaccine to a human by applying a microprojection array to the skin.
The document includes comparative immunogenicity and penetration context for intradermal delivery using the microprojection array versus intramuscular injection.
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