Репозиторий Университета

© 2020 Microcapsules are ideal cargo platform for variety of applications such as drug delivery, sensing and imaging due to the combination of a simplicity fabrication and flexibility in the design. We developed remotely collapsing polymer capsules to response to external microwave treatment. The multilayer structure of the capsules was designed to create a polyfunctional system intercalating with nanodiamonds (NDs) and upconversion nanoparticles (UCNPs) into the polyelectrolyte shell. NDs empower local overheating to the microcapsules, while UCNPs provide opportunity to luminescent thermal sensing. UCNPs consist of inorganic crystalline host matrix - hexagonal β-phase NaYF4, doped with pairs of trivalent lanthanide ions, which play role of sensitizer (Yb3+) and activator (Er3+). The microwave triggering followed by the capsule heating results in the controlled destruction of the polyelectrolyte shell with subsequent cargo release. UCNPs luminescence was utilized to determine the local temperature of the capsule shell at nanoscale under GHz ultrasonic treatment. Our novel approach provides on demand microcapsule system destruction, which can be used in the development of nanotheranostic platform for the unification of diagnosis and treatment of various diseases.

© 2019 Nanodiamonds (ND) are one of the most attractive carbon materials for nanotechnology. The impregnation of NDs into the polymer capsule shell in the form of the single nanoparticles insures the control over the thermal conductivity of the capsule shell and increases their sensitivity to the external microwave irradiation. The polymer shell of the polyelectrolyte capsules was modified with NDs by electrostatic adsorption technique. The sensitivity of the capsules with embedded NDs to the external microwave irradiation was demonstrated by scanning electron microscopy leading to the shell rupture and release of the encapsulated agents.