Influenza nucleoprotein DNA vaccination by a skin targeted, dry coated, densely packed microprojection array (Nanopatch) induces potent antibody and CD8(+) T cell responses.

DNA vaccines have many advantages such as thermostability and the ease and rapidity of manufacture; for example, in an influenza pandemic situation where rapid production of vaccine is essential. However, immunogenicity of DNA vaccines was shown to be poor in humans unless large doses of DNA are used. If a highly efficacious DNA vaccine delivery system could be identified, then DNA vaccines have the potential to displace protein vaccines.

CXCL1 gene silencing in skin using liposome-encapsulated siRNA delivered by microprojection array.

The barrier morphology of skin provides major obstacles for the application of siRNA for gene silencing, which current delivery technologies do not effectively overcome. Emerging technologies utilise microprojection array devices to penetrate into the skin epidermis and dermis for delivery of drug payloads. Delivery of siRNA by such devices has been proven in principle, yet requires optimisation for clinical applications.

Dry-coated live viral vector vaccines delivered by nanopatch microprojections retain long-term thermostability and induce transgene-specific T cell responses in mice.

The disadvantages of needle-based immunisation motivate the development of simple, low cost, needle-free alternatives. Vaccine delivery to cutaneous environments rich in specialised antigen-presenting cells using microprojection patches has practical and immunological advantages over conventional needle delivery. Additionally, stable coating of vaccine onto microprojections removes logistical obstacles presented by the strict requirement for cold-chain storage and distribution of liquid vaccine, or lyophilised vaccine plus diluent.

Nanopatch targeted delivery of both antigen and adjuvant to skin synergistically drives enhanced antibody responses.

Many vaccines make use of an adjuvant to achieve stronger immune responses. Alternatively, potent immune responses have also been generated by replacing the standard needle and syringe (which places vaccine into muscle) with devices that deliver vaccine antigen to the skin's abundant immune cell population. However it is not known if the co-delivery of antigen plus adjuvant directly to thousands of skin immune cells generates a synergistic improvement of immune responses.

Rapid kinetics to peak serum antibodies is achieved following influenza vaccination by dry-coated densely packed microprojections to skin.

A rapid time to peak serum antibody response following vaccination is particularly important for influenza: the time window between the availability of appropriate antigen and the start of the seasonal epidemic is very short. In this paper, influenza vaccine was delivered to both the epidermis and dermis of mouse skin using densely packed microprojection arrays for vaccination. We found that, after vaccination, around 75% and 90% of the delivered influenza vaccine migrated away from the ear skin within just 2 days and 1 week - respectively.

Improving the reach of vaccines to low-resource regions, with a needle-free vaccine delivery device and long-term thermostabilization.

Dry-coated microprojections can deliver vaccine to abundant antigen-presenting cells in the skin and induce efficient immune responses and the dry-coated vaccines are expected to be thermostable at elevated temperatures. In this paper, we show that we have dramatically improved our previously reported gas-jet drying coating method and greatly increased the delivery efficiency of coating from patch to skin to from 6.5% to 32.