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Posted: Jul 09, 2017
Vaccination with a dissolving microneedle array
(Nanowerk News) The effectiveness of a vaccine strongly depends on the ability of the vaccine components to reach and activate antigenpresenting cells, especially dendritic cells in the lymphoid organs. Vaccines do not reach lymphoid
APCs are ignored by the immune system, leading to unresponsiveness. On the other hand, vaccines are not confined to immune system access the systemic circulation and exert adverse effects systemically.
Researchers from Wayne State University now have demonstrated the utility of dissolving microneedle arrays designs for the lymph node delivery of amphiphilic vaccines released upon skin insertion (i.e. subcutaneous injection).
Microneedle administration of vaccines via the skin provides a cost-effective, easy, and safe approach without the need for trained personnel. It could even lead to self-administration of vaccines.
First, dissolving microneedle arrays generate no biohazardous sharp wastes because the microneedle arrays dissolve and disappear upon insertion. The pedestal part of microneedle arrays is also made of the water-soluble polymer so that it can easily be eliminated by dissolving in water.
This safety feature removes the risk of accidental needle-stick injury or intentional reuse of needles, which is common in some developing countries and is responsible for close to one million deaths per year due to transmission of hepatitis B, human immunodeficient virus (HIV), and other infectious diseases.
Second, the microneedle arrays delivery enhances the immune response through inflammatory cues and targeted delivery of antigen and adjuvant to the high density of antigen-presenting cells in lymph nodes.
This approach can greatly increase the safety profile of administered vaccines by effectively guiding them to draining lymph nodes, reducing systemic dissemination.
"Lymph node targeting vaccines delivered by microneedle arrays may provide not only practical advantages compared to hypodermic needles but also better humoral and cellular immunity," the authors conclude their report. "This strategy can be used as an effective platform for straightforward and robust transcutaneous self-administrative vaccines."