MATERIALS AND METHODS: PMNPs were produced using cetyltrimethyl ammonium bromide template and then coated by a polyethylene glycol layer with molecular weight of 1500 Da (PEG1500) and phase transition temperature of 48 ± 2 °C to endow a thermosensitive behavior. The profile of drug release from the nanostructure was studied at various hyperthermia conditions generated by waterbath, magnetic resonance-guided focused ultrasound (MRgFUS), and alternating magnetic field (AMF). The in vitro cytotoxicity and hyperthermia efficacy of the doxorubicin-loaded nanoparticles (DOX-PEG1500-PMNPs) were assessed using human lung adenocarcinoma (A549) cells.
RESULTS: Heat treatment of DOX-PEG1500-PMNPs containing 235 ± 26 mg·g-1 DOX at 48 °C by waterbath, MRgFUS, and AMF, respectively led to 71 ± 4%, 48 ± 3%, and 74 ± 5% drug release. Hyperthermia treatment of the A549 cells using DOX-PEG1500-PMNPs led to 77% decrease in the cell viability due to the synergistic effects of magnetic hyperthermia and chemotherapy.
CONCLUSION: The large pores generated in the PMNPs structure could provide a sufficient space for encapsulation of the chemotherapeutics as well as fast drug encapsulation and release kinetics, which together with thermosensitive characteristics of the PEG1500 shell, make DOX-PEG1500-PMNPs promising adjuvants to the magnetic hyperthermia modality.
METHODS: Relevant published studies, literature and reports were searched from accessible electronic databases and related institutional databases. We used keywords, viz; microbiome, microbiota, microbiome drug delivery and respiratory disease. Selected articles were carefully read through, clustered, segregated into subtopics and reviewed.
FINDINGS: The traditional belief of sterile lungs was challenged by the emergence of culture-independent molecular techniques and the recently introduced invasive broncho-alveolar lavage (BAL) sampling method. The constitution of a lung microbiome mainly depends on three main ecological factors, which include; firstly, the immigration of microbes into airways, secondly, the removal of microbes from airways and lastly, the regional growth conditions. In healthy conditions, the microbial communities that co-exist in our lungs can build significant pulmonary immunity and could act as a barrier against diseases, whereas, in an adverse way, microbiomes may interact with other pathogenic bacteriomes and viromes, acting as a cofactor in inflammation and host immune responses, which may lead to the progression of a disease. Thus, the use of microbiota as a target, and as a drug delivery system in the possible modification of a disease state, has started to gain massive attention in recent years. Microbiota, owing to its unique characteristics, could serve as a potential drug delivery system, that could be bioengineered to suit the interest. The engineered microbiome-derived therapeutics can be delivered through BC, bacteriophage, bacteria-derived lipid vesicles and microbe-derived extracellular vesicles. This review highlights the relationships between microbiota and different types of respiratory diseases, the importance of microbiota towards human health and diseases, including the role of novel microbiome drug delivery systems in targeting various respiratory diseases.