Coated (A) and hollow (B) microneedles. Source: Leiden UniversityCoated (A) and hollow (B) microneedles. Source: Leiden University

For those who suffer from trypanophobia — fear of needles — an effective and painless vaccination delivery system is under development at Leiden University in the Netherlands. Nanoparticle-encapsulated vaccines are combined with microneedles to boost immune responses with a more patient-friendly delivery method.

The researchers developed hollow microneedles that inject the nanoparticle vaccines, as well as microneedles coated with vaccines. Trials with mice demonstrated the stronger the antibodies and immune cell responses, the better the vaccine worked. Smaller nanoparticles with controlled release properties correlated with a stronger effect for hollow microneedle use.

The non-invasive nature of microneedles is expected to increase patient acceptance and compliance. Immunization costs can be reduced since nanoparticulate vaccines can achieve an immune response comparable to a conventional vaccine, but with a smaller dose. Such transcutaneous immunizations can also lead to a strong immune response owing to the presence of immune-competent cells in the skin.

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