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Nanotheranostics 2019High metastatic rate and recurrence of tumor because of tumor circulating cells are seriously hinders for clinical tumor therapy. Herein, we develop a novel,...
High metastatic rate and recurrence of tumor because of tumor circulating cells are seriously hinders for clinical tumor therapy. Herein, we develop a novel, activetargeting nanotherapeutic by simultaneously loading doxorubicin (DOX) and transferrin (Tf) onto bacterial magnetosomes (Tf-BMs-DOX) and investigate its antitumor efficacy and . Drug release profiles indicated that Tf-BMs/BMs loaded with DOX were capable of sustained drug release, suggesting that reduce drugs required frequency of administration and enhance their therapeutic effect. The results of cellular uptake revealed that Tf-BMs-DOX recognized hepatocellular carcinoma HepG2 cells more specifically compared to HL-7702 normal hepatocytes because of high expression of transferrin receptor (TfR) on the surface of HepG2 cells. Tf-BMs-DOX increased tumor cytotoxicity and apoptosis more significantly than free DOX or BMs-DOX by regulating the expression of tumorrelated and apoptosisrelated genes. Following intravenous injection in HepG2 cellbearing mice, Tf-BMs-DOX displayed tumor suppression rate of 56.78%, significantly higher than that of the BMs-DOX (41.53%) and free DOX (31.26%) groups. These results suggest that Tf-BMs-DOX have the potential to actively target to tumor sites, as well as the ability to kill circulating tumor cells via intravenous injection. Our findings provide a promising candidate for the clinical treatment of metastatic cancer.
Topics: Animals; Antineoplastic Agents; Carcinoma, Hepatocellular; Cell Death; Cell Line, Tumor; Cell Membrane; Doxorubicin; Endocytosis; Humans; Iron; Liver Neoplasms; Magnetosomes; Male; Mice, Inbred BALB C; Mice, Nude; Molecular Targeted Therapy; Receptors, Transferrin; Transferrin
PubMed: 31423412
DOI: 10.7150/ntno.34601 -
Life (Basel, Switzerland) Mar 2013Magnetotactic bacteria (MTB) represent a diverse collection of motile prokaryotes that biomineralize intracellular, membrane-bounded, tens-of-nanometer-sized crystals of... (Review)
Review
Magnetotactic bacteria (MTB) represent a diverse collection of motile prokaryotes that biomineralize intracellular, membrane-bounded, tens-of-nanometer-sized crystals of a magnetic mineral called magnetosomes. Magnetosome minerals consist of either magnetite (Fe3O4) or greigite (Fe3S4) and cause cells to align along the Earth's geomagnetic field lines as they swim, a trait called magnetotaxis. MTB are known to mainly inhabit the oxic-anoxic interface (OAI) in water columns or sediments of aquatic habitats and it is currently thought that magnetosomes function as a means of making chemotaxis more efficient in locating and maintaining an optimal position for growth and survival at the OAI. Known cultured and uncultured MTB are phylogenetically associated with the Alpha-, Gamma- and Deltaproteobacteria classes of the phylum Proteobacteria, the Nitrospirae phylum and the candidate division OP3, part of the Planctomycetes-Verrucomicrobia-Chlamydiae (PVC) bacterial superphylum. MTB are generally thought to be ubiquitous in aquatic environments as they are cosmopolitan in distribution and have been found in every continent although for years MTB were thought to be restricted to habitats with pH values near neutral and at ambient temperature. Recently, however, moderate thermophilic and alkaliphilic MTB have been described including: an uncultured, moderately thermophilic magnetotactic bacterium present in hot springs in northern Nevada with a probable upper growth limit of about 63 °C; and several strains of obligately alkaliphilic MTB isolated in pure culture from different aquatic habitats in California, including the hypersaline, extremely alkaline Mono Lake, with an optimal growth pH of >9.0.
PubMed: 25369742
DOI: 10.3390/life3020295 -
The Journal of Physical Chemistry. B Apr 2022Defining chemical properties of intracellular organelles is necessary to determine their function(s) as well as understand and mimic the reactions they host. However,...
Defining chemical properties of intracellular organelles is necessary to determine their function(s) as well as understand and mimic the reactions they host. However, the small size of bacterial and archaeal microorganisms often prevents defining local intracellular chemical conditions in a similar way to what has been established for eukaryotic organelles. This work proposes to use magnetite (FeO) nanocrystals contained in magnetosome organelles of magnetotactic bacteria as reporters of elemental composition, pH, and redox potential of a hypothetical environment at the site of formation of intracellular magnetite. This methodology requires combining recent single-cell mass spectrometry measurements together with elemental composition of magnetite in trace and minor elements. It enables a quantitative characterization of chemical disequilibria of 30 chemical elements between the intracellular and external media of magnetotactic bacteria, revealing strong transfers of elements with active influx or efflux processes that translate into elemental accumulation (Mo, Se, and Sn) or depletion (Sr and Bi) in the bacterial internal medium of up to seven orders of magnitude relative to the extracellular medium. Using this concept, we show that chemical conditions in magnetosomes are compatible with a pH of 7.5-9.5 and a redox potential of -0.25 to -0.6 V.
Topics: Bacteria; Ferrosoferric Oxide; Gram-Negative Bacteria; Magnetosomes; Magnetospirillum
PubMed: 35362974
DOI: 10.1021/acs.jpcb.2c00752 -
Materials (Basel, Switzerland) Dec 2023Liquid marbles are widely known for their potential biomedical applications, especially due to their versatility and ease of preparation. In the present work, we...
Liquid marbles are widely known for their potential biomedical applications, especially due to their versatility and ease of preparation. In the present work, we prepared liquid marbles with various cores composed of water, agar-based hydrogels, magnetic fluids, or non-aqueous substances. As a coating material, we used biocompatible particles of plant origin, such as turmeric grains and pollen. Additionally, we provided marbles with magnetic properties by incorporating either magnetosomes or iron oxide nanoparticles as a powder or by injecting another magnetic fluid. Structures obtained in this way were stable and susceptible to manipulation by an external magnetic field. The properties of the magnetic components of our marbles were verified using electron paramagnetic resonance (EPR) spectroscopy and vibrating sample magnetometry (VSM). Our approach to encapsulation of active substances such as antibiotics within a protective hydrogel core opens up new perspectives for the delivery of hydrophobic payloads to the inherently hydrophilic biological environment. Additionally, hydrogel marbles enriched with magnetic materials showed promise as biocompatible heating agents under alternating magnetic fields. A significant innovation of our research was also the fabrication of composite structures in which the gel-like core was surrounded without mixing by a magnetic fluid covered on the outside by the particle shell. Our liquid marbles, especially those with a hydrogel core and magnetic content, due to the ease of preparation and favorable properties, have great potential for biomedical use. The fact that we were able to simultaneously produce, functionalize (by filling with predefined cargo), and manipulate (by means of an external magnetic field) several marbles also seems to be important from an application point of view.
PubMed: 38203953
DOI: 10.3390/ma17010099 -
International Journal of Molecular... Jul 2021Metabolic syndrome (MetS) is a set of complex, chronic inflammatory conditions that are characterized by central obesity and associated with an increased risk of... (Review)
Review
Metabolic syndrome (MetS) is a set of complex, chronic inflammatory conditions that are characterized by central obesity and associated with an increased risk of cardiovascular diseases. In recent years, microRNAs (miRNAs) have become an important type of endocrine factors, which play crucial roles in maintaining energy balance and metabolic homeostasis. However, its unfavorable properties such as easy degradation in blood and off-target effect are still a barrier for clinical application. Nanosystem based delivery possess strong protection, high bioavailability and control release rate, which is beneficial for success of gene therapy. This review first describes the current progress and advances on miRNAs associated with MetS, then provides a summary of the therapeutic potential and targets of miRNAs in metabolic organs. Next, it discusses recent advances in the functionalized development of classic delivery systems (exosomes, liposomes and polymers), including their structures, properties, functions and applications. Furthermore, this work briefly discusses the intelligent strategies used in emerging novel delivery systems (selenium nanoparticles, DNA origami, microneedles and magnetosomes). Finally, challenges and future directions in this field are discussed provide a comprehensive overview of the future development of targeted miRNAs delivery for MetS treatment. With these contributions, it is expected to address and accelerate the development of effective NA delivery systems for the treatment of MetS.
Topics: Drug Delivery Systems; Exosomes; Genetic Therapy; Humans; Liposomes; Metabolic Syndrome; MicroRNAs; Nanostructures
PubMed: 34360621
DOI: 10.3390/ijms22157855 -
Scientific Reports Apr 2020Magnetosomes are intracellular magnetic nanocrystals composed of magnetite (FeO) or greigite (FeS), enveloped by a lipid bilayer membrane, produced by...
Magnetosomes are intracellular magnetic nanocrystals composed of magnetite (FeO) or greigite (FeS), enveloped by a lipid bilayer membrane, produced by magnetotactic bacteria. Because of the stability of these structures in certain environments after cell death and lysis, magnetosome magnetite crystals contribute to the magnetization of sediments as well as providing a fossil record of ancient microbial ecosystems. The persistence or changes of the chemical and magnetic features of magnetosomes under certain conditions in different environments are important factors in biotechnology and paleomagnetism. Here we evaluated the thermal stability of magnetosomes in a temperature range between 150 and 500 °C subjected to oxidizing conditions by using in situ scanning transmission electron microscopy. Results showed that magnetosomes are stable and structurally and chemically unaffected at temperatures up to 300 °C. Interestingly, the membrane of magnetosomes was still observable after heating the samples to 300 °C. When heated between 300 °C and 500 °C cavity formation in the crystals was observed most probably associated to the partial transformation of magnetite into maghemite due to the Kirkendall effect at the nanoscale. This study provides some insight into the stability of magnetosomes in specific environments over geological periods and offers novel tools to investigate biogenic nanomaterials.
PubMed: 32317676
DOI: 10.1038/s41598-020-63531-5 -
Probing the Nanostructure and Arrangement of Bacterial Magnetosomes by Small-Angle X-Ray Scattering.Applied and Environmental Microbiology Dec 2019Magnetosomes are membrane-enveloped single-domain ferromagnetic nanoparticles enabling the navigation of magnetotactic bacteria along magnetic field lines. Strict...
Magnetosomes are membrane-enveloped single-domain ferromagnetic nanoparticles enabling the navigation of magnetotactic bacteria along magnetic field lines. Strict control over each step of biomineralization generates particles of high crystallinity, strong magnetization, and remarkable uniformity in size and shape, which is particularly interesting for many biomedical and biotechnological applications. However, to understand the physicochemical processes involved in magnetite biomineralization, close and precise monitoring of particle production is required. Commonly used techniques, such as transmission electron microscopy (TEM) or Fe measurements, allow only for semiquantitative assessment of the magnetosome formation without routinely revealing quantitative structural information. In this study, lab-based small-angle X-ray scattering (SAXS) is explored as a means to monitor the different stages of magnetosome biogenesis in the model organism SAXS is evaluated as a quantitative stand-alone technique to analyze the size, shape, and arrangement of magnetosomes in cells cultivated under different growth conditions. By applying a simple and robust fitting procedure based on spheres aligned in linear chains, it is demonstrated that the SAXS data sets contain information on both the diameter of the inorganic crystal and the protein-rich magnetosome membrane. The analyses corroborate a narrow particle size distribution with an overall magnetosome radius of 19 nm in Furthermore, the averaged distance between individual magnetosomes is determined, revealing a chain-like particle arrangement with a center-to-center distance of 53 nm. Overall, these data demonstrate that SAXS can be used as a novel stand-alone technique allowing for the at-line monitoring of magnetosome biosynthesis, thereby providing accurate information on the particle nanostructure. This study explores lab-based small-angle X-ray scattering (SAXS) as a novel quantitative stand-alone technique to monitor the size, shape, and arrangement of magnetosomes during different stages of particle biogenesis in the model organism The SAXS data sets contain volume-averaged, statistically accurate information on both the diameter of the inorganic nanocrystal and the enveloping protein-rich magnetosome membrane. As a robust and nondestructive technique, SAXS can provide new insights into the physicochemical steps involved in the biosynthesis of magnetosome nanoparticles as well as their assembly into well-ordered chains. The proposed fit model can easily be adapted to account for different particle shapes and arrangements produced by other strains of magnetotactic bacteria, thus rendering SAXS a highly versatile method.
Topics: Bacterial Proteins; Evaluation Studies as Topic; Ferrosoferric Oxide; Magnetosomes; Magnetospirillum; Membrane Proteins; Microscopy, Electron; Nanostructures; Scattering, Small Angle; X-Ray Diffraction
PubMed: 31604767
DOI: 10.1128/AEM.01513-19 -
Nanomaterials (Basel, Switzerland) Jul 2020Nanoparticles, specifically magnetosomes, synthesized in nature by magnetotactic bacteria, are very promising to be usedin magnetic hyperthermia in cancer treatment. In...
Nanoparticles, specifically magnetosomes, synthesized in nature by magnetotactic bacteria, are very promising to be usedin magnetic hyperthermia in cancer treatment. In this work, using the solution of the stochastic Landau-Lifshitz equation, we calculate the specific absorption rate (SAR) in an alternating (AC) magnetic field of assemblies of magnetosome chains depending on the particle size , the distance between particles in a chain , and the angle of the applied magnetic field with respect to the chain axis. The dependence of SAR on the / ratio is shown to have a bell-shaped form with a pronounced maximum. For a dilute oriented chain assembly with optimally chosen /ratio,a strong magneto-dipole interaction between the chain particles leads to an almost rectangular hysteresis loop, and to large SARvaluesin the order of 400-450 W/g at moderate frequencies = 300 kHz and small magnetic field amplitudes = 50-100 Oe. The maximum SAR value only weakly depends on the diameter of the nanoparticles and the length of the chain. However, a significant decrease in SAR occurs in a dense chain assembly due to the strong magneto-dipole interaction of nanoparticles of different chains.
PubMed: 32635626
DOI: 10.3390/nano10071320 -
International Microbiology : the... Dec 2002Magnetotactic bacteria (MTB) are major constituents of natural microbial communities in sediments and chemically stratified water columns. The ability of MTB to migrate... (Review)
Review
Magnetotactic bacteria (MTB) are major constituents of natural microbial communities in sediments and chemically stratified water columns. The ability of MTB to migrate along magnetic field lines is based on specific intracellular structures, the magnetosomes, which, in most MTB, are nanometer-sized, membrane-bound magnetic particles consisting of the iron mineral magnetite (Fe(3)O(4)). A broad diversity of morphological forms has been found in various MTB. The unique characteristics of bacterial magnetosomes have attracted a broad interdisciplinary research interest. The magnetosome membrane (MM) in Magnetospirillum gryphiswaldense contains a number of specific Mam proteins. Several mam genes were analyzed and assigned to different genomic regions. Many of the Mam proteins are highly conserved in other MTB but display low sequence similarity to any proteins from nonmagnetic organisms.
Topics: Bacterial Proteins; Crystallization; Ecology; Ferrosoferric Oxide; Genome, Bacterial; Iron; Magnetics; Models, Biological; Models, Genetic; Organelles; Oxides; Rhodospirillaceae
PubMed: 12497187
DOI: 10.1007/s10123-002-0086-8 -
Biosensors Sep 2022Magnetic nanocarriers have attracted attention in translational oncology due to their ability to be employed both for tumor diagnostics and therapy. This review... (Review)
Review
Magnetic nanocarriers have attracted attention in translational oncology due to their ability to be employed both for tumor diagnostics and therapy. This review summarizes data on applications of synthetic and biogenic magnetic nanoparticles (MNPs) in oncological theranostics and related areas. The basics of both types of MNPs including synthesis approaches, structure, and physicochemical properties are discussed. The properties of synthetic MNPs and biogenic MNPs are compared with regard to their antitumor therapeutic efficiency, diagnostic potential, biocompatibility, and cellular toxicity. The comparative analysis demonstrates that both synthetic and biogenic MNPs could be efficiently used for cancer theranostics, including biosensorics and drug delivery. At the same time, reduced toxicity of biogenic particles was noted, which makes them advantageous for in vivo applications, such as drug delivery, or MRI imaging of tumors. Adaptability to surface modification based on natural biochemical processes is also noted, as well as good compatibility with tumor cells and proliferation in them. Advances in the bionanotechnology field should lead to the implementation of MNPs in clinical trials.
Topics: Humans; Magnetite Nanoparticles; Drug Delivery Systems; Magnetics; Nanoparticles; Biosensing Techniques; Magnetic Resonance Imaging; Neoplasms
PubMed: 36290927
DOI: 10.3390/bios12100789