Project description

Ischemic stroke is one of the major causes of death or long-term disabilities worldwide; thus, prevention and treatment of neurodegenerative diseases and stroke-related brain damage, being still largely unresolved problems of contemporary medicine, require new technologies for diagnostics and therapeutics. One of the major limitations to current neurodegenerative disease treatment is the inefficient delivery of neuroprotective drugs to the affected part of the brain due to the blood-brain barrier (BBB) that is permeable only by small, lipophilic molecules. Additionally, some of the orally delivered neuroprotective drugs may influence the whole organism, thus causing peripheral toxicity and numerous adverse reactions. Therefore, despite the progress in understanding molecular mechanisms of neuronal injury and preventing them, only a few neuroprotective substances are used in the clinic, and their efficiency in the treatment of stroke and neurodegenerations is still not satisfactory. The targeted and monitored delivery of neuroprotectants with the right dosage is a crucial issue in the treatment of central nervous system disorders.

The main project objective is to develop a new strategy for the delivery of selected neuroprotectants by theranostic nanocarriers that can cross the blood-brain barrier without imposing side effects on its normal function. We will concentrate on developing a methodology of encapsulation of neuroprotectants and fluorescent or MRI contrast agents in nanocarriers with a size below 150 nm and surfaces functionalized for targeted delivery. Immunosuppressant drugs such as cyclosporine A (CsA) and FK506 are neuroprotective in animal models of brain ischemia. CsA inhibits the opening of the mitochondrial permeability transition pore, thereby maintaining mitochondrial homeostasis following brain ischemia by inhibiting calcium influx and preserving mitochondrial membrane potential. However, high systemic doses of these drugs result in undesired effects and toxicity. Thus, we expect that nanocarriers could be useful for the efficient delivery of CsA or other neuroprotective drugs to cerebral ischemic tissue.

The proven technique of formation of core-shell nanocarriers by sequential adsorption of nanoobjects will be applied for the encapsulation of neuroprotectants and contrast agents. The hydrophobic drugs will be placed in the nanoemulsion or biocompatible polymer core. The MRI contrast agents’ superparamagnetic iron oxide nanoparticles (SPION) or Gadolinium complexes will be mainly located in the carrier shell. The effects of the most promising neuroprotectants in the theranostic formulations on the viability of neuronal cells exposed to toxic agents and oxygen-glucose deprivation will be first examined in SH-SY5Y cell line, primary cortical neurons, and organotypic hippocampal slice culture. Then, the efficiency of the transfer of nanocarriers in the “in vitro” and ex-vivo” model of BBB will be investigated. In-vivo experiments will be performed to determine the biodistribution of nanocarriers and the efficiency of transport to the brain. At the final stage of the project, the effect of the nanocarriers containing neuroprotectants will be tested in the middle cerebral artery occlusion (MCAO) stroke model, followed by 48 h reperfusion in rats. Our approach is universal and can be used for the simultaneous encapsulation of therapeutics for other diseases (e.g., cancer) and MRI contrast agents for concurrent therapy and monitoring its efficiency. The ultimate outcome of the project will be the application of the developed concepts of neuroprotectants delivery in therapies for neurodegenerative diseases to ensure an improvement in the health condition of society.

Prevention and treatment of neurodegenerative diseases and stroke-related brain damage are major and unresolved problems of contemporary medicine. Despite the progress in understanding of molecular mechanisms of neuronal injury and preventing them, only few neuroprotective substances are used in the clinic and their efficiency in the treatment of stroke and neurodegenerations is not satisfactory. One of the major limitations to current neurodegenerative disease treatment is an inefficient delivery of neuroprotective drugs to the affected part of the brain and difficulties in the diagnosis if the drug is well addressed, i.e., if it reaches the targeted organ. Theranostics is a new branch of medicine based on joining of therapeutic and diagnostic function in one entity. Application of nanotechnology in theranostics will allow engineering of drug carriers simultaneously delivering therapeutic components and possessing a diagnostic function.

The main objective of the project Theranostic nanocarriers for drug delivery in central nervous system disorders – TheraforNerv was to develop a new strategy for the delivery of drugs with neuroprotective effects using nanocarriers that are able to cross the blood-brain barrier, have no negative impact on its normal functioning, and whose presence in a given organ can be detected by nuclear resonance imaging (MRI). During the course of the project, we used various methodologies to encapsulate selected active substances with neuroprotective effects together with contrast markers for imaging by fluorescence and MRI methods. The developed multilayer nanocarriers, with sizes not exceeding 150 nm, were characterized by lack of toxicity, exhibited neuroprotective properties in various in-vitro models, penetrated the model blood-brain barrier and were well tolerated in in-vivo experiments. The addition of a medically approved gadolinium complex enabled their MRI detection. We also developed methods to synthesize cerium oxide nanoparticles with antioxidant properties as well as silica based nanocarriers. These nanoparticles were also synthesized with gadolinium for MRI detection capabilities. We have started preliminary tests on animal models, and the positive results obtained have indicated the direction of further research. The ultimate goal of the project, and the anticipated continuation of the research conducted therein, is to develop new drug delivery systems that may find future application in the treatment of stroke and neurodegenerative diseases. Furthermore, in addition to treating cerebral ischemic disorders, the proposed methodology enables the synthesis of multipurpose nanostructures for the delivery of both therapeutic agents and MRI contrast agents, potentially useful for various targeted therapies.