Microprojection arrays to immunise at mucosal surfaces

Area of Science:

• Biomedical Engineering
• Immunology
• Drug Delivery Systems

Background:

• The buccal mucosa offers accessible antigen presenting cells (APCs) for immunotherapeutics.
• Topical delivery faces challenges like degradation, poor APC access, and salivary clearance.
• Existing methods struggle with consistent, targeted delivery within the buccal mucosa.

Purpose of the Study:

• To develop and evaluate a microprojection array (Nanopatch) for targeted immunotherapeutic delivery into the buccal mucosa.
• To overcome limitations of topical delivery for enhanced vaccine efficacy.
• To achieve consistent and repeatable delivery of vaccines to APCs within the buccal mucosa.

Main Methods:

• Utilized Nanopatches (110 μm projections) with a clip applicator for mechanical delivery.
• Applied Nanopatches with a dry-coated influenza vaccine to mouse buccal mucosa.
• Measured vaccine depth using fluorescent dyes and CryoScanning Electron Microscopy (CryoSEM).

Main Results:

• Nanopatches delivered vaccine to a depth of 47.8±14.8 μm, near APCs.
• Systemic immune responses were comparable to systemic methods and superior to oral delivery.
• Confirmed Nanopatch delivery into the mucosa, not via ingestion.

Conclusions:

• Nanopatches provide rapid, accurate, and consistent immunotherapeutic release into the buccal mucosa.
• This minimally-invasive approach enhances vaccine delivery and immune response.
• The Nanopatch technology shows potential for broad human application in immunotherapy.