Synthesis and characterisation of aerosolised MIF inhitibitors for the treatment of respiratory disease
Citation:DOROUDIAN, MOHAMMAD, Synthesis and characterisation of aerosolised MIF inhitibitors for the treatment of respiratory disease, Trinity College Dublin.School of Medicine, 2019
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The main focus of this PhD thesis was to investigate the synthesis and characterisation of an aerosolised poly lactic-co-glycolic acid (PLGA) nanodrug delivery system for MIF enzyme inhibitors to modulate the physiological activity of macrophage migration inhibitory factor (MIF) in pulmonary diseases, particularly lung cancer. MIF is a proinflammatory mediator of the immune system that plays a substantial role in the overall inflammatory cascade, tumour growth, angiogenesis, and cancer progression. Recently, we have identified a novel drug candidate, SCD19, which showed convincing results in both in vitro and in vivo studies of lung cancer. Herein we report our work to maximise local delivery of MIF therapeutics directly to the lungs through the development of an aerosolised delivery system utilising state of the art nanoparticle-based drug delivery systems. Aerosolised nanoparticle delivery systems to the lung represent a novel future therapeutic strategy for cancer and in particular lung cancer. The use of aerosolised PLGA nanodrug delivery systems has increased markedly due to numerous advantages of this biodegradable, nontoxic and FDA approved nanodrug delivery system. Initially, we encapsulated SCD19 into PLGA nanospheres by employing single emulsion-solvent evaporation technique. Transmission electron microscopy (TEM) and scanning electron microscope (SEM) images of PLGA-SCD19 nanoparticles showed a uniform spherical shape with smooth surfaces. The average hydrodynamic size of the PLGA-SCD19 nanoparticles, as measured by using nanoparticle tracking analysis (NTA) was 200 nm without aggregation. The drug loading efficiency, yield efficiency, and the drug content were 63%, 66%, and 5.7%, respectively, which were within the acceptable range. The nanoparticles were found to be stable in both artificial lung fluid and artificial lysosomal fluid. For the internalisation study of the nanoparticles, we co-encapsulated iron oxide nanoparticles (magnetic nanoparticles (MNPs)) and SCD19 into PLGA nanoparticles to make PLGA-MNP-SCD19. Then, we carried out different methods to investigate the cellular uptake of the PLGA-MNP-SCD19, in all of which significant accumulations of nanoparticles occurred in the cells after overnight incubation. Biocompatibility and toxicity of the nanoformulation were evaluated with high content analysis and LDH assay. There was no attributable toxicity associated with the nanoparticles and they showed a high degree of biocompatibility in human A549, murine RAW 264.7, and LLC cell lines. In this study, we established a collaboration with Aerogen Ltd, a company specialising in the production of aerosol drug delivery devices. Initially, we optimised our nanoformulation for Aerogen?s vibrating mesh nebuliser to achieve maximum drug delivery within acceptable nebulisation times. The vibrating mesh nebuliser did not affect the size nor the volume of PLGA-SCD19 nanoparticles. Also, laser diffraction method showed that the nebulised nanoparticles had an acceptable volume mean diameter (VMD) with an optimal particle size distribution for deep lung deposition. This leads to improve treatment efficiency by allowing aerosols to access the small airways with minimum waste. Moreover, in our study, the regional deposition of the aerosol nanoparticles in a mechanical human respiratory tract model, resulted in high deposition (more than 70%) in the alveolar region of the lung model with very low deposition in upper respiratory tract. Further investigation was conducted to define drug delivery efficiency. In this study we achieved 23% and 14% drug delivery efficiency from the mechanical ventilator and the breathing simulator, respectively. However, previous studies of other compounds had shown a wide range of drug delivery efficiency (from 1% to 16%). Finally, we examined the ability of our aerosolised PLGA-SCD19 nanoparticles to reduce cell proliferation in a MIF-Induced cell growth in vitro model which resulted in a significant reduction of cell proliferation (***p 0.001) in the selected cancer cells. This study has demonstrated that the developed aerosolised nanodrug delivery system may provide a novel adjunctive agent for use with anticancer drugs in the treatment of patients with lung cancer and the data obtained from characterisation studies may contribute to future drug delivery research.
Author: DOROUDIAN, MOHAMMAD
Publisher:Trinity College Dublin. School of Medicine. Discipline of Clinical Medicine
Type of material:Thesis
Availability:Full text available