Nanocapsules for uptake, release and sensing in cells
Mainz: Univ. 2020 150 S.
Erscheinungsjahr: 2020
Publikationstyp: Buch (Dissertation)
Sprache: Englisch
Doi/URN: urn:nbn:de:hebis:77-diss-1000034867
Geprüft | Bibliothek |
Inhaltszusammenfassung
Nanotechnology has emerged as a powerful tool for many biomedical applications including diagnostics, therapy, imaging, and sensing. Among them, nanocapsules are some of the most interesting nanostructures and known to be commonly used for loading therapeutic agents or fluorescent dyes in order to have curing effects or tracking the capsule, respectively. The main function of the nanocapsule is to protect and transport cargo to target cells. It can also be created to enable release of a funct...Nanotechnology has emerged as a powerful tool for many biomedical applications including diagnostics, therapy, imaging, and sensing. Among them, nanocapsules are some of the most interesting nanostructures and known to be commonly used for loading therapeutic agents or fluorescent dyes in order to have curing effects or tracking the capsule, respectively. The main function of the nanocapsule is to protect and transport cargo to target cells. It can also be created to enable release of a functional payload according to the stimuli used for a controlled release platform. Furthermore, responsive stimuli can be used for triggering the sensing unit and then emitting the signal as a reporter in the sensor system. Therefore, critical cytotoxicity must be determined before applying the loaded nanocapsules to the cells. Internalization of the capsule inside the cells must subsequently be investigated by flow cytometry and confirmed by confocal laser scanning microscopy. Finally, the specific functions/properties of the nanocapsules are verified. With the aim of utilizing silica nanocapsules (SiNCs) to carry siRNA to CD8 T-cell, an immune cell destroying virus-infected cells and cancer, a novel silica core-shell NC with various physicochemical properties including sizes, core hydrophilicities, surface charges, and surface functionalizations as well as serum concentrations in a culture medium were systematically examined for their effect on toxicity and uptake. It was found that different physicochemical characteristics of the SiNCs, especially sizes, and serum concentrations had a strong impact on cytotoxicity and cellular uptake. These findings can be used for the suitable design of nanocarriers and adjustments in culture conditions to avoid toxicity and promote the uptake of nanocarriers for T-cell immunotherapy. Subsequently, the SiNCs loaded with siRNA specific to Pd-l1 mRNA, which translates to a crucial immune checkpoint protein PD-L1 inactivating T-cell, were applied to the CD8 T-cell. The results suggest that these siRNA loaded nanocarriers exhibit the potential for use in the delivery of siRNA into T-cells, enhancement of T-cell survival and functions by decreasing the expression of inhibitory protein PD-L1, increasing cell proliferation and specific T-cell activation biomarkers CD25 and CD71, and can be applied in adoptive T-cell immunotherapy for the treatment of cancer. Stimuli-responsive nanocarriers are of great interest for achieving the controlled release of functional payloads at a target site. Near infrared (NIR) light was used to trigger the enzyme inhibitor releasing platform. The system consisted of the upconversion nanoparticles (UCNP) and the ruthenium (Ru)-Cathepsin K enzyme inhibitor complex, which was loaded inside mesoporous silica nanocapsules. NIR light activated UCNP resulted in the emission of blue light, which can cleave the light sensitive bond of Ru complex, then releasing the inhibitor and finally inhibiting the enzyme activity in vitro. In another system, red light was used instead of NIR light to trigger the Ru complex and showed deep penetration through thick tissue, which was still able to cleave the light sensitive bond, uncage the toxic product and finally kill HeLa cancer cells. With the significant potential of a red-light sensitive Ru complex releasing system, a micelles-containing Ru complex conjugated anti-cancer drug chlorambucil was developed. After red light stimulation, the anti-cancer product was cleaved and effectively killed HeLa cells, even under hypoxia simulated in vitro conditions and in tumor-bearing mouse in vivo. Due to the non-invasive method and spatiotemporal control, the light-responsive controlled release system provides a promising strategy for cancer therapy. Temperature at the cellular level can be used to determine the metabolic state of cells such as anti-cancer drug metabolism. It could also be used to distinguish between cancer cells and normal cells. To measure intracellular temperature, light activated-polymeric upconversion nanocapsules (UCNCs) based on the temperature dependence of triplet-triplet annihilation upconversion (TTA-UC) phenomenon were developed. A cellular temperature measurement in the range of 22 to 40 C was successfully obtained after red light activation. The novel nanothermometer exhibited the potential for use in treatment and diagnostics in the medical field. These studies demonstrate the advantages of recently-developed nanocarrier systems, which can be used for cellular uptake, controlled release and intracellular sensing in living cells. The proof of concept systems reveals the critical factors involved in cytotoxicity and cellular uptake, ideas for innovatively and carefully designing the delivery or sensing systems and new strategies for cancer therapy that can be applied in various bio-applications.» weiterlesen» einklappen
Autoren
Klassifikation
DDC Sachgruppe:
Biowissenschaften, Biologie