Targeted Drug delivery: Vaccination through the skin without pain

Novel vaccines for Vaccination through the skin

Researchers have succeeded, nano-particles further so that they can be absorbed by cells of the human skin. With this new technology, specifically vaccines could be introduced into the skin cells.

Protection against diseases

Vaccinations are a very effective agent against various infectious diseases. Previously it was associated with the Vaccination, it is always the needle. But years ago, scientists reported that it might be possible in the future, vaccines through the skin to administer. And indeed, scientists managed from Australia recently, to develop a tool, the pain should allow for free Vaccination without the needle. German researchers now report new insights into how vaccines via the skin or administered could be.

Still, vaccines are administered via injection. However, in the future, vaccination may be carried out also through the skin. (Photo: Adam Gregor/fotolia.com)

Nano particles developed more

Researchers at the Max-Planck-Institute for colloid and interface research in Potsdam succeeded, nano-particles further so that they can be taken up by special cells of the human skin.

In a communication of the Institute is explained, to coordinate these so-called Langerhans cells, the immune response and to alert the body when pathogens or tumors occur in the organism.

The professionals that could be introduced into active compounds with this new technology platform is now specifically, for example, vaccines or medicines, in Langerhans cells, in order to achieve a controlled immune response.

Reaction throughout the body

According to the scientists, the skin is a particularly attractive place for the application of many drugs that affect the immune system.

The appropriate target cells only a few micrometers in the skin below their surface. The Langerhans cells are located in this top layer of skin, the Epidermis.

These cells can lead to local application of a drug to a reaction in the entire body of the patient.

Experts the germ defense

For the development of a targeted drug TRANS-ports, which delivers the drug directly to Langerhans cells, is exploited of their natural function:

As a professional, Antigen-presenting cells to detect pathogens and to take these and present the components of these Pathogens to effector cells of the immune system, the T-cells.

For the detection and recording of the Langerhans cells use receptors on their surface, the browse the environment to Pathogens. Pathogens to be detected on the basis of sugar structures on their surface.

Events changed, a Protein from the family of C-type Lectins, such a Receptor on Langerhans cells and is used for the detection of viruses and bacteria.

The specific Expression of the Langerins on Langerhans cells allows for targeted delivery of therapeutics to at the same time side effects to minimize.

The research team around Dr. Christoph Rademacher, Max-Planck-Institute for colloid and boundary surface research could make now, the Knowledge of the underlying detection mechanisms with atomic resolution advantage.

The scientists managed to develop a synthetic, sugar-like substance, which binds well to specific events changed on the surface of Langerhans cells.

In collaboration with a scientific Team of the laboratory for Langerhans cell research, Medical University of Innsbruck nano were developed particles that can be absorbed by this interaction in Langerhans cells of human skin.

In order for the researchers to lay the foundations for further developments, for example, in order vaccines directly through the skin to the exact immune cells to deliver later for the activation of the immune system of the whole body is responsible.

On the Basis of these findings, in the future, possibly novel vaccines against infections or immune therapies for the treatment of cancer or auto-immune diseases develop.

The researchers ‘ findings were published in the journal “ACS Central Science”.

Langerhans cells can activate the immune system

The starting point is the Work of Ralph M. Steinman (Nobel prize 2011) and other researchers, which showed the Potential of dendritic cells. The Langerhans cells are, and are to trigger a immune response.

These findings were developed in order for the application in cancer therapy and it could be proved that an immune response is artificially introduced antigens can be achieved.

Later Work confirmed this and also showed that human Langerhans cells are able to activate the immune system, what is a vaccine development on the skin especially interesting.

Targeted delivery of immune-modulators of Langerhans cells would thus be desirable. This is however prevented by the complex environment of the skin, especially by competing phagocytes, the macrophages in this tissue is frequently difficult or even.

Thus, agents, which no longer reach the Langerhans cells can lead, by recording in adjacent cells to unwanted side effects.

Binding by synthetic sugar

Based on the findings for the detection of the natural sugar ligand of the Langerins has now been developed in the research group of Dr. Christoph Rademacher, an artificial Ligand, which is specific to the events changed to Langerhans cells binds.

This synthetic sugar has been produced in the laboratory, and their interactions with the Receptor by nuclear magnetic resonance spectroscopy are studied.

With this method, the researchers were able to determine which atoms of the ligand which shares of the receptor interact. This structure-based approach, they came to a compound, anchored to nanoparticles and testing.

When these particles are liposomes, which are used without the ligands for many years in the clinic as a carrier for various active ingredients.

The difference to existing systems is that the sugar-like Ligand enables a specific binding to Langerhans cells.

The studies on these immune cells were in co-operation with the research group of Assoz. Prof. Patrizia Stoitzner in Langerhans cell research laboratory at the Medical University of Innsbruck, carried out.

The cooperation of the two groups could show that the specific absorption of the liposomes even in the complex environment of human skin cells is maintained. The use of methods of flow cytometry and confocal microscopy were used.

These liposomal particles now may be a generally applicable platform, by means of which the researchers at the MPI for colloid and boundary surface research in the future development of novel vaccines can work. (ad)