A simple one step synthesis of magnetic-optical dual functional ZIF-8 in a sodalite phase for magnetically guided targeting bioimaging and drug delivery.

Functionalized metal-organic frameworks (MOFs) that integrate targeted tumor imaging and drug delivery are expected to significantly enhance the therapeutic efficacy of cancer. However, the complicated synthesis process has greatly limited their utilization in clinical application. Herein, a one-step simple method was used to construct novel multifunctional MOFs by co-loading doxorubicin (DOX) and Fe3O4 into the ZIF-8 with sodalite topology. DOX serves as a fluorescence imaging reagent and an anticancer drug and Fe3O4 is used as a magnetic resonance imaging and magnetic targeting anticancer reagent. The fabricated DOX/Fe3O4@ZIF-8 nanocomposite showed excellent fluorescence and magnetic resonance imaging performances in tumors. Moreover, DOX/Fe3O4@ZIF-8 can be accumulated in tumors via a magnetic targeting effect and tumor growth could be inhibited in vivo due to the release of DOX. Additionally, the apoptosis process of DOX/Fe3O4@ZIF-8 on HepG2 cells is well investigated. Overall, DOX/Fe3O4@ZIF-8 synthesized in simple one step can be used for simultaneous targeted bioimaging and cancer therapy.

Postsynthetic Metalation Metal-Organic Framework as a Fluorescent Probe for the Ultrasensitive and Reversible Detection of PO43- Ions.

The self-assembly of a zinc salt with the novel ligand 4,4',4″-[(1,3,5-triazine-2,4,6-triyl)tris(sulfanediyl)]tribenzoic acid generated 3D microporous metal-organic frameworks (MOFs), namely, {[Zn4(L3-)2(O2-)(H2O)2]·4EtOH} n. The frameworks with multiple Lewis basic sites exhibit easily sensitized properties. After encapsulation of the Tb3+ cation in this Zn-MOF, the as-obtained fluorescent-functionalized Tb@Zn-MOFs not only maintain distinguished chemical stabilities but also exhibit strong characteristic emissions of trivalent terbium ions. Interestingly, Tb@Zn-MOF has been chosen to be a potential highly selective and sensitive luminescent platform for the reversible detection of PO43- ions in aqueous and living cell buffer solutions with a fast response time of 10 s and a low detection limit (0.1 ppm). Strikingly, this work presents the first example of a fluorescent sensor that can quantitate PO43- in simulated biological fluids and monitor these ions in the water system in a wide range of concentrations from 10-6 to 10-3 M.

Synthesis and Characterization of α-ZrP@CHI Drug Deliver System.

This paper described the controlled synthesis and release properties of a new kind of multifunctional drug-release system which was prepared by encapsulation of zirconium bis-(monohydrogen orthophosphate) monohydrate (α-ZrP) with chitosan (CHI). As obtained the α-ZrP@CHI nanocomposites were found to possess the structural features of both α-ZrP and CHI. The release properties of the α-ZrP@CHI nanocomposites were evaluated using Gentamicin sulfate as the model drug. And α-ZrP@CHI composites showed a prolonged drug release time compared with α-ZrP, which can be attributed to the unique lamellar structure and the encapsulation with CHI. The controlled synthesis of α-ZrP@CHI nanocomposite thus provided a new opportunity for future development of delivery vehicles.

Hollow structural metal-organic frameworks exhibit high drug loading capacity, targeted delivery and magnetic resonance/optical multimodal imaging.

Metal-organic frameworks (MOFs) are attractive in designing drug delivery systems for the treatment of cancer because of their unique porous properties. However, the search for multifunctional MOFs with high drug loading and magnetic resonance/fluorescence imaging capacities is still a challenge and they have rarely been reported. In this article, using the intrinsic advantages of MOFs, hollow Fe-MOFs with biomolecular grafting were fabricated and shown to be capable of loading much more drugs and exhibiting targeted drug delivery, pH-controlled drug release and magnetic resonance/fluorescence imaging. Benefiting from their hollow structures, the drug loading capacity is as high as 35%. Due to post-modification with folic acid (FA) and the fluorescent reagent (5-FAM) and the existence of Fe(iii), in vitro experiments indicate that Fe-MOF-5-NH2-FA-5-FAM/5-FU can target cancer cells HepG-2 and display excellent magnetic resonance/fluorescence imaging. Furthermore, in vivo biodistribution indicates that Fe-MOF-5-NH2-FA-5-FAM/5-FU can accumulate in the tumor. Taken together, our work integrates high drug loading and bioimaging into a single MOF successfully and reveals the enormous potential of the functionalized MOF for drug delivery and bioimaging.

Size and surface controllable metal-organic frameworks (MOFs) for fluorescence imaging and cancer therapy.

Benefiting from their porous structures, metal-organic frameworks (MOFs) have attracted intensive attention for use in drug release. However, the controllable synthesis of MOFs with proper particle sizes is still very challenging, which largely limits its applications. Here, UIO-66-NH2 with controlled particle sizes in the range of 20-200 nm has been achieved successfully. The amine on UIO-66-NH2 is demonstrated for the feasible post-modifying of UIO-66-NH2 to obtain multifunctional MOFs, overcoming the limitations of functional simplicity and broadening the range of applications. After covalent grafting the targeting reagent folic acid (FA) and the fluorescence imaging agent 5-carboxyfluorescein (5-FAM), UIO-66-NH2-FA-5-FAM/5-FU can target the cancer cells HePG-2 and display excellent fluorescence imaging in vitro. Moreover, the in vivo biodistribution and antitumor assays indicate that UIO-66-NH2-FA-5-FAM/5-FU can accumulate in the tumor and display stronger antitumor efficiency due to the long-time drug release. Taken together, this study integrates the imaging section and the treated section in a single platform successfully and the present approach can be a good use of therapeutic MOFs to achieve the desired objective, a better treatment.

In situ growth of metal-organic frameworks (MOFs) on the surface of other MOFs: a new strategy for constructing magnetic resonance/optical dual mode imaging materials.

This work presents for the first time the synthesis of a novel nanoscale Fe-MOFs/Eu-MOFs heterostructure, in which spherical Fe-MOFs with a large surface area were introduced as a matrix for the well-dispersed growth of rodlike Eu-MOFs. The obtained Fe-MOFs/Eu-MOFs materials exhibit excellent magnetic resonance/optical imaging capacity and satisfactory drug delivery behavior.

Controllable Synthesis of a Smart Multifunctional Nanoscale Metal-Organic Framework for Magnetic Resonance/Optical Imaging and Targeted Drug Delivery.

As a result of their extraordinarily large surfaces and well-defined pores, the design of a multifunctional metal-organic framework (MOF) is crucial for drug delivery but has rarely been reported. In this paper, a novel drug delivery system (DDS) based on nanoscale MOF was developed for use in cancer diagnosis and therapy. This MOF-based tumor targeting DDS was fabricated by a simple postsynthetic surface modification process. First, magnetic mesoporous nanomaterial Fe-MIL-53-NH2 was used for encapsulating the drug and served as a magnetic resonance contrast agent. Moreover, the Fe-MIL-53-NH2 nanomaterial exhibited a high loading capacity for the model anticancer drug 5-fluorouracil (5-FU). Subsequently, the fluorescence imaging agent 5-carboxyfluorescein (5-FAM) and the targeting reagent folic acid (FA) were conjugated to the 5-FU-loaded Fe-MIL-53-NH2, resulting in the advanced DDS Fe-MIL-53-NH2-FA-5-FAM/5-FU. Owing to the multifunctional surface modification, the obtained DDS Fe-MIL-53-NH2-FA-5-FAM/5-FU shows good biocompatibility, tumor enhanced cellular uptake, strong cancer cell growth inhibitory effect, excellent fluorescence imaging, and outstanding magnetic resonance imaging capability. Taken together, this study integrates diagnostic and treatment aspects into a single platform by a simple and efficient strategy, aiming for facilitating new possibilities for MOF use for multifunctional drug delivery.

Fabrication of functional hollow microspheres constructed from MOF shells: Promising drug delivery systems with high loading capacity and targeted transport.

An advanced multifunctional, hollow metal-organic framework (MOF) drug delivery system with a high drug loading level and targeted delivery was designed and fabricated for the first time and applied to inhibit tumour cell growth. This hollow MOF targeting drug delivery system was prepared via a simple post-synthetic surface modification procedure, starting from hollow ZIF-8 successfully obtained for the first time via a mild phase transformation under solvothermal conditions. As a result, the hollow ZIF-8 exhibits a higher loading capacity for the model anticancer drug 5-fluorouracil (5-FU). Subsequently, 5-FU-loaded ZIF-8 was encapsulated into polymer layers (FA-CHI-5-FAM) with three components: a chitosan (CHI) backbone, the imaging agent 5-carboxyfluorescein (5-FAM), and the targeting reagent folic acid (FA). Thus, an advanced drug delivery system, ZIF-8/5-FU@FA-CHI-5-FAM, was fabricated. A cell imaging assay demonstrated that ZIF-8/5-FU@FA-CHI-5-FAM could target and be taken up by MGC-803 cells. Furthermore, the as-prepared ZIF-8/5-FU@FA-CHI-5-FAM exhibited stronger cell growth inhibitory effects on MGC-803 cells because of the release of 5-FU, as confirmed by a cell viability assay. In addition, a drug release experiment in vitro indicated that ZIF-8/5-FU@FA-CHI-5-FAM exhibited high loading capacity (51%) and a sustained drug release behaviour. Therefore, ZIF-8/5-FU@FA-CHI-5-FAM could provide targeted drug transportation, imaging tracking and localized sustained release.

Decorated TiO2 Nanoparticles with La and Ag Elements to Improve Photocatalytic Activity Under Visible Light for the Degradation of MO.

Visible-light photocatalyst of TiO2/La/Ag nanocomposites were successfully synthesized via the conventional sol-gel method and reducing agent of Ag+. The photocatalytic activities were evaluated by methyl orange (MO) degradation. They have remarkable photocatalytic activities compared to TiO2-Anatase, which is thanks to the separation of electron-hole pairs by Ag nanoparticles and lanthanum. The products were characterized by a series of techniques such as X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and Uv-vis. The results show that spherical nanocomposites have been prepared with the size 300 nm and Ag nanoparticles (~10 nm) are dispersed uniformly onto the surface of TiO2/La, which forms TiO2/La/Ag nanocomposites. TiO2/La/Ag nanocomposites have good absorption in the visible region (700 nm > λ > 400 nm). The reasons are as follows: (1) the efficient separation of photogenerated electrons and holes of the photocatalysts on the surface of TiO2/La/Ag nanocomposites and (2) a wide visible-light photoabsorption range (700 nm > λ > 400 nm). Therefore, this study may provide some new idea for the rational design and the facile synthesis of composite catalysts with a green, efficient pathway.

Synthesis and Characteristic of the NaYF4/Fe3O4@SiO2@Tb(DBM)3 . 2H2O/SiO2 Luminomagnetic Microspheres with Core-Shell Structure.

The structure and properties of the multifunctional nanoparticles were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Photoluminescence spectra and Vibrating sample magnetometer (VSM). The experimental results show that the microsphere has the magnetic core and silica shell bonded with terbium complex. These multifunctional nanoparticles exhibit strong visible emission and up-conversion emission, which is based on the use of up-converting nanoparticles (UCNPs) of the NaYF4:Yb3+, Er3+/Tm3+ type that can be excited with 980 nm laser light to give a green and red luminescence, moreover, nanoparticles possess magnetism with a saturation magnetization of 18.48 emu/g and paramagnetism at room temperature.

Inorganic nanovehicle for potential targeted drug delivery to tumor cells, tumor optical imaging.

In this work, an inorganic multifunctional nanovehicle was tailored as a carrier to deliver anticancer drug for tumor optical imaging and therapy. The nanovehicle could be used as a dually targeted drug nanovehicle by bonded magnetical (passive) and folic acid (active) targeting capabilities. In addition, it was developed using rhodamine 6G (R6G) as a fluorescence reagent, and an α-zirconium phosphate nanoplatform (Zr(HPO4)2·H2O, abbreviated as α-ZrP) as the anticancer drug nanovehicle. The novel drug-release system was designed and fabricated by intercalation of α-ZrP with magnetic Fe3O4 nanoparticles and anticancer drug 5-fluorouracil (5-FU), followed by reacting with a folate acid-chitosan-rhodamine6G (FA-CHI-R6G) complex, and then α-ZrP intercalated with Fe3O4 nanoparticles and 5-fluorouracil (5-FU) was successfully encapsulated into chitosan (CHI). The resultant multifunctional drug delivery system was characterized by scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray analysis, photoluminescence spectra, magnetometry, fluorescence microscopy imaging studies and other characterization methods. Simultaneously, the drug release in vitro on the obtained nanocomposites that exhibited a sustained release behavior was carried out in buffer solution at 37 °C, which demonstrated clearly that the nanocomposites shown a sustained release behavior. Meanwhile, cell culture experiments also indicated that the drug-release system had the potential to be used as an dually targeted drug nanovehicle into the tumor cells.