bims-mricoa Biomed News
on MRI contrast agents
Issue of 2022‒01‒23
eight papers selected by
Merve Yavuz
Bilkent University

  1. Materials (Basel). 2022 Jan 10. pii: 503. [Epub ahead of print]15(2):
      Due to their good magnetic properties, excellent biocompatibility, and low price, magnetic iron oxide nanoparticles (IONPs) are the most commonly used magnetic nanomaterials and have been extensively explored in biomedical applications. Although magnetic IONPs can be used for a variety of applications in biomedicine, most practical applications require IONP-based platforms that can perform several tasks in parallel. Thus, appropriate engineering and integration of magnetic IONPs with different classes of organic and inorganic materials can produce multifunctional nanoplatforms that can perform several functions simultaneously, allowing their application in a broad spectrum of biomedical fields. This review article summarizes the fabrication of current composite nanoplatforms based on integration of magnetic IONPs with organic dyes, biomolecules (e.g., lipids, DNAs, aptamers, and antibodies), quantum dots, noble metal NPs, and stimuli-responsive polymers. We also highlight the recent technological advances achieved from such integrated multifunctional platforms and their potential use in biomedical applications, including dual-mode imaging for biomolecule detection, targeted drug delivery, photodynamic therapy, chemotherapy, and magnetic hyperthermia therapy.
    Keywords:  Fe3O4; antibacterial; bacterial detection; biomedical applications; biomolecules; cancer treatment; diagnosis; drug delivery; fluorescence imaging; magnetic nanoparticles; magnetic resonance imaging; metal nanoparticles; organic dyes; photodynamic therapy; photothermal ablation; quantum dots; stimuli-responsive polymers; surface functionalization; tumor targeting
  2. Pharmaceutics. 2022 Jan 16. pii: 204. [Epub ahead of print]14(1):
      The enormous development of nanomaterials technology and the immediate response of many areas of science, research, and practice to their possible application has led to the publication of thousands of scientific papers, books, and reports. This vast amount of information requires careful classification and order, especially for specifically targeted practical needs. Therefore, the present review aims to summarize to some extent the role of iron oxide nanoparticles in biomedical research. Summarizing the fundamental properties of the magnetic iron oxide nanoparticles, the review's next focus was to classify research studies related to applying these particles for cancer diagnostics and therapy (similar to photothermal therapy, hyperthermia), in nano theranostics, multimodal therapy. Special attention is paid to research studies dealing with the opportunities of combining different nanomaterials to achieve optimal systems for biomedical application. In this regard, original data about the synthesis and characterization of nanolipidic magnetic hybrid systems are included as an example. The last section of the review is dedicated to the capacities of magnetite-based magnetic nanoparticles for the management of oncological diseases.
    Keywords:  MRI; SPIONS; cancer; hyperthermia; magnetite; multimodal; multitherapy; theranostics
  3. J Colloid Interface Sci. 2022 Jan 12. pii: S0021-9797(22)00082-0. [Epub ahead of print]613 447-460
      Stimuli-responsive nanomaterials are very attractive for biomedical applications. They can be activated through external stimuli or by the physico-chemical conditions present in cells or tissues. Here, we describe the preparation of hybrid iron oxide-manganese oxide core-satellite shell nanostructures that change their contrast mode in magnetic resonance imaging (MRI) from T2 to T1, after being internalized by cells. This occurs by the dissolution of the MnO2 of the shell, preserving intact the iron oxide at the core. First, we study the seeded-growth synthesis of iron oxide-manganese oxide nanoparticles studying the effect of varying the core size of the magnetic seeds and the concentration of the surfactant. This allows tuning the size and shape of the final hybrid nanostructure. Then, we show that the shell can be removed by a redox reaction with glutathione, which is naturally present inside the cells at much higher concentrations than outside the cells. Finally, the dissolution of the MnO2 shell and the change in the contrast mode is confirmed in cell cultures. After this process, the iron oxide nanoparticles at the core remain intact and are still active as heating mediators when an alternating magnetic field is applied.
    Keywords:  Hybrid nanoparticles; Intracellular-responsive; MRI; Magnetic hyperthermia; Stimuli-responsive
  4. Nanomaterials (Basel). 2022 Jan 17. pii: 288. [Epub ahead of print]12(2):
      Currently, the design of nanomaterials for the treatment of different pathologies is presenting a major impact on biomedical research. Thanks to this, nanoparticles represent a successful strategy for the delivery of high amounts of drugs for the treatment of cancer. Different nanosystems have been designed to combat this pathology. However, the poor penetration of these nanomaterials into the tumor tissue prevents the drug from entering the inner regions of the tumor. Some bacterial strains have self-propulsion and guiding capacity thanks to their flagella. They also have a preference to accumulate in certain tumor regions due to the presence of different chemo-attractants factors. Bioconjugation reactions allow the binding of nanoparticles in living systems, such as cells or bacteria, in a simple way. Therefore, bacteria are being used as a transport vehicle for nanoparticles, facilitating their penetration and the subsequent release of the drug inside the tumor. This review would summarize the literature on the anchoring methods of diverse nanosystems in bacteria and, interestingly, their advantages and possible applications in cancer therapy.
    Keywords:  bacteria; cancer; drug delivery; nanocarrier; nanoparticles
  5. Biosensors (Basel). 2022 Jan 12. pii: 38. [Epub ahead of print]12(1):
      Cancer is the top cause of death globally. Developing smart nanomedicines that are capable of diagnosis and therapy (theranostics) in one-nanoparticle systems are highly desirable for improving cancer treatment outcomes. The magnetic nanoplatforms are the ideal system for cancer theranostics, because of their diverse physiochemical properties and biological effects. In particular, a biocompatible iron oxide nanoparticle based magnetic nanoplatform can exhibit multiple magnetic-responsive behaviors under an external magnetic field and realize the integration of diagnosis (magnetic resonance imaging, ultrasonic imaging, photoacoustic imaging, etc.) and therapy (magnetic hyperthermia, photothermal therapy, controlled drug delivery and release, etc.) in vivo. Furthermore, due to considerable variation among tumors and individual patients, it is a requirement to design iron oxide nanoplatforms by the coordination of diverse functionalities for efficient and individualized theranostics. In this article, we will present an up-to-date overview on iron oxide nanoplatforms, including both iron oxide nanomaterials and those that can respond to an externally applied magnetic field, with an emphasis on their applications in cancer theranostics.
    Keywords:  cancer; iron oxide nanoparticles; magnetotheranostics
  6. Pharmaceutics. 2022 Jan 11. pii: 163. [Epub ahead of print]14(1):
      A crucial challenge to face in the treatment of biofilm-associated infection is the ability of bacteria to develop resistance to traditional antimicrobial therapies based on the administration of antibiotics alone. This study aims to apply magnetic hyperthermia together with controlled antibiotic delivery from a unique magnetic-responsive nanocarrier for a combination therapy against biofilm. The design of the nanosystem is based on antibiotic-loaded mesoporous silica nanoparticles (MSNs) externally functionalized with a thermo-responsive polymer capping layer, and decorated in the outermost surface with superparamagnetic iron oxide nanoparticles (SPIONs). The SPIONs are able to generate heat upon application of an alternating magnetic field (AMF), reaching the temperature needed to induce a change in the polymer conformation from linear to globular, therefore triggering pore uncapping and the antibiotic cargo release. The microbiological assays indicated that exposure of E. coli biofilms to 200 µg/mL of the nanosystem and the application of an AMF (202 kHz, 30 mT) decreased the number of viable bacteria by 4 log10 units compared with the control. The results of the present study show that combined hyperthermia and antibiotic treatment is a promising approach for the effective management of biofilm-associated infections.
    Keywords:  antibiotic delivery; bacterial biofilm; combined therapy; mesoporous silica nanoparticles; superparamagnetic iron oxide nanoparticles; thermo-responsive polymer coating
  7. Soft Matter. 2022 Jan 17.
      The paper addresses coupling of magnetic nanoparticles (MNPs) with the polymer matrix of temperature-sensitive microgels and their response to magnetic fields. Therefore, CoFe2O4@CA (CA = citric acid) NPs are embedded within N-isopropylacrylamid (NIPAM) based microgels. The volume phase transition (VPT) of the magnetic microgels and the respective pure microgels is studied by dynamic light scattering and electrophoretic mobility measurements. The interaction between MNPs and microgel network is studied via magnetometry and AC-susceptometry using a superconducting quantum interference device (SQUID). The data show a significant change of the magnetic properties by crossing the VPT temperature (VPTT). The change is related to the increased confinement of the MNP due to the shrinking of the microgels. Modifying the microgel with hydrophobic allyl mercaptan (AM) affects the swelling ability and the magnetic response, i.e. the coupling of MNPs with the polymer matrix. Modeling the AC-susceptibility data results in an effective size distribution. This distribution represents the varying degree of constraint in MNP rotation and motion by the microgel network. These findings help to understand the interaction between MNPs and the microgel matrix to design multi responsive systems with tunable particle matrix coupling strength for future applications.
  8. Appl Microbiol Biotechnol. 2022 Jan 21.
      Recombinant Escherichia coli (E. coli) strain that produces phytochelatin (PC) and/or metallothionein (MT) can synthesize various metal nanoparticles (NPs) by reducing metal ions. Here we report in vivo biosynthesis of iron oxide nanocomposites (NCs) using recombinant E. coli. We designed a strategy of biosynthesizing iron oxide NCs by first internalizing chemically synthesized iron oxide NPs, followed by the reduction of added metal ions on the surface of internalized NPs by PC and/or MT in E. coli. For this, chemically synthesized Fe3O4 NPs were internalized by recombinant E. coli, and then, Au and Ag ions were added for the biosynthesis of AuFe3O4 and AgFe3O4 NCs, respectively. The NCs synthesized were analyzed by transmission electron microscopy, UV-vis spectrophotometry, and X-ray diffractometry to characterize their shape, optical property, and crystallinity. The Fe3O4 NPs in the biosynthesized NCs allowed easy purification of the biosynthesized NCs by applying a magnetic field. The AuFe3O4 NCs were used for enzyme-linked immunosorbent assay to detect prostate-specific antigen protein, while AgFe3O4 NCs were utilized for the antimicrobial application with low minimum inhibitory concentration. As recombinant E. coli can uptake and reduce various NPs and metal ions, biosynthesis of a wide range of NCs as new nanomaterials will be possible for diverse applications. KEY POINTS: • AuFe3O4 and AgFe3O4 nanocomposites were synthesized by recombinant E. coli. • Escherichia coli synthesized different iron oxide NCs depending on the metal ions to be added. • Biosynthesized AuFe3O4 NC was used for ELISA and AgFe3O4 NC for antimicrobial tests.
    Keywords:  Antimicrobial activity; Biosensor; Biosynthesis; Nanocomposite; Recombinant Escherichia coli