Reliable and safe delivery
Chronic diseases often require long-term medication. For such cases, researchers from Northeastern University in Boston have developed a stable and controlled system capable of releasing the drug for a long time after administration.
Existing nano-suppliers can be programmed to migrate to their destination (to a tumor or a focus of chronic inflammation). This allows the use of higher concentrations of the drug without fear of systemic side effects. In addition, they are able to deliver water-insoluble drugs and compounds used for diagnostic purposes.
In practice, this delivery method is not without drawbacks. One of them is an inflammatory reaction at the injection site. To avoid inflammation, some researchers suggest injecting nanoparticles in parts by several injections or by intravenous transfusion.
Evan Scott and his group have developed a nanosystem that can be administered by a single injection and eventually obtain a controlled long-term release of the drug without the risk of local inflammation.
Another problem of modern nanomedicine is the use of polymer matrices, which remain in the body after the end of treatment and cause chronic inflammation. To solve this problem and avoid the use of a polymer network, Scott and his group developed a system of filamentous nanoparticles (filomycelles) with a drug that are capable of self-assembly. The threads are organized into a network after injection and turn into a gel.
Schematic structure of philomycella. In vitro, individual micelles are released under the action of photochemical oxidation, in vivo – in the presence of reactive oxygen species. Source: article in Nature Communication.
The gel formed immediately after administration gradually releases the nanodiverse with the drug into the blood. The process can last for several months. After performing their function, the nanocarriers return to the injection site and accumulate in a gel, which is then reorganized into nanoparticles and excreted from the body. Thus, all the material used does not circulate in the blood, does not cause an immune system reaction and does not lead to fibrosis.
The system can be used both for single drug delivery, for example, for vaccination, and for long-term treatment, for example, chemotherapy or hormone replacement therapy.
The effectiveness of the technique has been tested in in vitro and in vivo studies on animal models. In the latter case, after a single subcutaneous injection, the drug was delivered to the lymph nodes in a controlled mode for more than a month.
The next step of the authors of the development is to adapt it for the treatment of specific diseases. In particular, it is currently planned to study in detail the delivery of drugs for chemotherapy and vaccination.
Chemotherapy usually requires the simultaneous administration of several toxic drugs for a long time. A self-assembled nano-delivery system could deliver all these drugs through a single injection and reduce the intensity of systemic complications.
Vaccination with the help of nano-suppliers can be made more "targeted": activate certain types of immune cells for the required period of time.
Article by N. B. Karabin et al. Sustained micellar delivery via inducible transitions in nanostructure morphology is published in the journal Nature Communication.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru Based on materials from Northwestern University: Using Injectable Self-Assembled Nanomaterials for Sustained Delivery of Drugs.