Functional polymeric micro- and nano-containers for drug delivery: image reconstruction from coherent X-ray diffraction, encapsulation of bioactive compounds and multicompound targeted delivery

Drug delivery is a promising field, directed for a transfer of desirable chemical or therapeutic substances to a certain point. For this case different systems can be used, for example, capsules synthesized by layer-by-layer technique. These capsules can be synthesized using different polymers for the shell formation and different templates, where this shell will be formed. It is quite important to study the structure of these objects. Moreover, it is necessary to study the capsules in their natural surroundings, in a liquid one. For the first time these types of objects were studied in a liquid medium by Coherent X-ray Diffraction imaging. There is a significant difference in images that were obtained for dried and liquid samples. When capsules are synthesized, they can be used for the encapsulation. In this work the capsules were loaded with such biologically active compounds as aquacobalamin (Vitamin B12) and dimeglumine chlorin E6. These compounds were encapsulated for the first time into this type of microcontainers. For a better and more precise delivery the shell of the capsules can be functionalized. For this reason, magnetite nanoparticles were incorporated into the shell. This allows to use external magnetic field for targeted delivery. Moreover, this incorporation of magnetite nanoparticles made it possible to bring two types of capsules, loaded by different substances, in one zone. After the targeted delivery, pores of capsules were opened in the zone and different substances inside the capsules were released and performed a reaction between each other.