In vitro and in vivo MRI imaging and photothermal therapeutic properties of Hematite (α-Fe2O3) Nanorods.

Herein we report synthesis of hematite (α-Fe2O3) nanorods by calcinating hydrothermally synthesized goethite nanorods at 5000C. The structural, optical and MRI imaging guided cancer therapeutic properties of fabricated nanorods have been discussed in this manscript. FESEM and TEM imaging techniques were used to confirm the nanorod like morphology of as prepared materials. As we know that Fe2O3 nanorods with size in the range of 25-30 nm exhibit super magnetism. After coating with the PEG, the as prepared nanorods can be used as T2 MR imaging contrast agents. An excellent T2 MRI contrast of 38.763 mM-1s-1 achieved which is highest reported so far for α-Fe2O3. Besides the as prepared nanorods display an excellent photothermal conversion efficiency of 39.5% thus acts as an excellent photothermal therapeutic agent. Thus, we envision the idea of testing our nanorods for photothermal therapy and MR imaging application both in vitro and in vivo, achieving an excellent T2 MRI contrast and photothermal therapy effect with as prepared PEGylated nanorods.

X-ray-triggered NO-released Bi-SNO nanoparticles: all-in-one nano-radiosensitizer with photothermal/gas therapy for enhanced radiotherapy.

Hypoxia in tumor cells is regarded as the most crucial cause of clinical drug resistance and radio-resistance; thus, relieving hypoxia of tumor cells is the key to enhancing the efficacy of anticancer therapy. As a gas signal molecule of vasodilatation factors, nitric oxide (NO) can relieve the hypoxia status of tumor cells, thereby, enhancing the sensitivity of tumor cells to radiotherapy. However, considering complications of vascular activity, the level of NO required for radiotherapy sensitization cannot be obtained in vivo. In view of this, we design and fabricate a multifunctional bismuth-based nanotheranostic agent, which is functionalized with S-nitrosothiol and termed Bi-SNO NPs. X-rays break down the S-N bond and simultaneously trigger large amount of NO-releasing (over 60 µM). Moreover, the as-prepared Bi-SNO NPs not only possess the capability of absorbing and converting 808 nm NIR photons into heat for photothermal therapy, but also have the ability to increase X-ray absorption and CT imaging sensitivity. In addition, the collaborative radio-, photothermal-, and gas-therapy of Bi-SNO in vivo was further investigated and remarkable synergistic tumor inhibition was realized. Finally, no obvious toxicity of Bi-SNO NPs was observed in the treated mice within 14 days. Therefore, the Bi-SNO developed in this work is an effective nano-agent for cancer theranostics with well-controlled morphology and uniform size (36 nm), which could serve as a versatile CT imaging-guided combined radio-, photothermal- and gas-therapy nanocomposite with negligible side effects.

Redox-responsive UCNPs-DPA conjugated NGO-PEG-BPEI-DOX for imaging-guided PTT and chemotherapy for cancer treatment.

The disulfide bond (-S-S-) is an enormously valuable functional group in a variety of chemical and biological agents that display effective reactivity or biological activities (e.g., antitumor activities). The disulfide bonds prevalent in proteins are somewhat oxidizing in the extracellular space; however, such disulfide bonds can rarely be found inside cells because of disulfide cleavage reactions facilitated by abundant free cellular thiols, including glutathione (GSH), which is the most important common thiol-containing small molecule. Interestingly, intracellular GSH concentrations are considerably higher in cancer cells than in analogous normal cells; this feature may prove to be significant in the development of anticancer drug delivery systems (DDS). Moreover, upconversion nanoparticles (UCNPs) have been extensively investigated in multimodal imaging, photodynamic therapy (PDT) and photothermal therapy. UCNPs exploit near-infrared excitation instead of ultraviolet excitation and possess exclusive properties, which include greatly increased penetration depth in biological samples and reductions in background autofluorescence, photobleaching and photodamage to biological specimens. These fascinating optical features of UCNPs may broaden their prospects in the fields of imaging and therapy. Graphene has emerged as a flat monolayer of carbon atoms that are tightly embedded in a two-dimensional (2D) honeycomb lattice. Widespread research has been carried out on graphene in recent years owing to its exclusive shape and size, as well as innumerable fascinating physical and chemical properties. Owing to their high optical absorption in the near-infrared (NIR) region, graphene and GO have been extensively employed for photothermal therapy (PTT). In this study, we attempted to merge the properties of these compounds by conjugating UCNPs and NGO-PEG-BPEI-DOX into a single platform for chemotherapy and photothermal therapy.

Integration of IR-808 Sensitized Upconversion Nanostructure and MoS2 Nanosheet for 808 nm NIR Light Triggered Phototherapy and Bioimaging.

Near infrared (NIR) light triggered phototherapy including photothermal therapy (PTT) and photodynamic therapy (PDT) affords superior outcome in cancer treatment. However, the reactive oxygen species (ROS) generated by NIR-excited upconversion nanostructure is limited by the feeble upconverted light which cannot activate PDT agents efficiently. Here, an IR-808 dye sensitized upconversion nanoparticle (UCNP) with a chlorin e6 (Ce6)-functionalized silica layer is developed for PDT agent. The two booster effectors (dye-sensitization and core-shell enhancement) synergistically amplify the upconversion efficiency, therefore achieving superbright visible emission under low 808 nm light excitation. The markedly amplified red light subsequently triggers the photosensitizer (Ce6) to produce large amount of ROS for efficient PDT. After the silica is endowed with positive surface, these PDT nanoparticles can be easily grafted on MoS2 nanosheet. As the optimal laser wavelength of UCNPs is consistent with that of MoS2 nanosheet for PTT, the invented nanoplatform generates both abundant ROS and local hyperthermia upon a single 808 nm laser irradiation. Both the in vitro and in vivo assays validate that the innovated nanostructure presents excellent cancer cell inhibition effectiveness by taking advantages of the synergistic PTT and PDT, simultaneously, posing trimodal (upconversion luminescence/computed tomography (CT)/magnetic resonance imaging (MRI) imaging capability.

Y2O3:Yb,Er@mSiO2-Cu(x)S double-shelled hollow spheres for enhanced chemo-/photothermal anti-cancer therapy and dual-modal imaging.

Multifunctional composites have gained significant interest due to their unique properties which show potential in biological imaging and therapeutics. However, the design of an efficient combination of multiple diagnostic and therapeutic modes is still a challenge. In this contribution, Y2O3:Yb,Er@mSiO2 double-shelled hollow spheres (DSHSs) with up-conversion fluorescence have been successfully prepared through a facile integrated sacrifice template method, followed by a calcination process. It is found that the double-shelled structure with large specific surface area and uniform shape is composed of an inner shell of luminescent Y2O3:Yb,Er and an outer mesoporous silica shell. Ultra small Cu(x)S nanoparticles (about 2.5 nm) served as photothermal agents, and a chemotherapeutic agent (doxorubicin, DOX) was then attached onto the surface of mesoporous silica, forming a DOX-DSHS-Cu(x)S composite. The composite exhibits high anti-cancer efficacy due to the synergistic photothermal therapy (PTT) induced by the attached Cu(x)S nanoparticles and the enhanced chemotherapy promoted by the heat from the Cu(x)S-based PTT when irradiated by 980 nm near-infrared (NIR) light. Moreover, the composite shows excellent in vitro and in vivo X-ray computed tomography (CT) and up-conversion fluorescence (UCL) imaging properties owing to the doped rare earth ions, thus making it possible to achieve the target of imaging-guided synergistic therapy.