Sinteza votlih sferičnih magnetnih struktur : doktorska disertacija

slovenian

doktorska dela

2019

doxorubicin   hollow spheres   magnetism   mesoporous silica particles   nanomedicine   nanotechnology   targeted drug delivery

Univerza v Mariboru, Fakulteta za kemijo in kemijsko tehnologijo

Cancer is one of the most common causes of death in modern society. Studies in the field of improvement of anticancer drugs and new methods of treatment of this disease are on the rise, including the research based on nanotechnology.%Nanomedicine is one of the rapidly growing areas of nanotechnology due to the development of nanomaterials or nanotools, which can be advantageously used for the purposes of tissue engineering and for early detection and treatment of disease states. A rising field of nanomedicine is research of targeted drug delivery. The targeted drug delivery is a method of delivering medication to a patient in a manner that increases the concentration of the medication in some parts of the body relative to others. In other words, the targeted drug delivery seeks to concentrate the medication in the tissues of interest while reducing the relative concentration of the medication in the remaining tissues. This improves efficacy of the drug while reducing its side effects. Resarch in this field therefore increases the survival of patients.%This doctoral thesis presents the preparation of a targeted drug delivery system for the delivery of active substances on the basis of the hollow spherical magnetic structures or hollow magnetic spheres (HMSs). HMSs have the potential to be used in the fields of nanomedicine and sensing. We used mesoporous silica (SiO2) particles as the templates for the preparation of hollow spheres, which were synthesized via sol-gel process or by the hydrolysis and condensation of tetraethoxysilane (TEOS) precursor in an alcoholic base medium in the presence of a surfactant, which was used as a pore-forming agent. Various reaction parameters were changed, and their effect on the morphological properties of SiO2 particles studied. Porous silica particles were later coated by precipitation of iron salts. Iron salts had oxidized on the mesoporous surface as superparamagnetic maghemite envelopes or external shell. The process of the formation of the hollow interior was conducted simultaneously with the process of precipitation of the iron salts on the surface of mesoporous silica particles at room temperature with the use of phosphate buffers. In this way, we obtained hollow spheres in an environmentally friendly and affordable manner, without the use of high-temperature calcination processes or organic solvents. The described procedure was also patented. Chemotherapeutic active substance Doxorubicin (DOX) was successfully incorporated in such hollow spheres. DOX is used in the treatment of various diseases, such as acute lymphoblastic leukemia, breast cancer, ovarian cancer, colorectal cancer, kidney cancer, liver cancer, head and neck cancer, etc. Hollow spheres with an integrated active ingredient were successfully surface modified by the enzyme and the entire system was protected by biocompatible polymer envelope based on water-soluble polyvinyl alcohol. The system was charactarized and its applicability for targeted delivery evaluated.

07.08.2023