Novel Mn3 [Co(CN)6]2@SiO2@Ag Core-Shell Nanocube: Enhanced Two-Photon Fluorescence and Magnetic Resonance Dual-Modal Imaging-Guided Photothermal and Chemo-therapy.

The versatile Mn3[Co(CN)6]2@SiO2@Ag core-shell NCs are prepared by a simple coprecipitation method. Ag nanoparticles with an average diameter of 12 nm deposited on the surface of Mn3[Co(CN)6]2@SiO2 through S-Ag bonding are fabricated in ethanol solution by reducing silver nitrate (AgNO3 ) with NaBH4 . The NCs possess T1 -T2 dual-modal magnetic resonance imaging ability. The inner Prussian blue analogs (PBAs) Mn3[Co(CN)6]2 exhibit bright two-photon fluorescence (TPF) imaging when excited at 730 nm. Moreover, the TPF imaging intensity displays 1.85-fold enhancement after loading of Ag nanoparticles. Besides, the sample also has multicolor fluorescence imaging ability under 403, 488, and 543 nm single photon excitation. The as-synthesized Mn3[Co(CN)6]2@SiO2@Ag NCs show a DOX loading capacity of 600 mg g(-1) and exhibit an excellent ability of near-infrared (NIR)-responsive drug release and photothermal therapy (PTT) which is induced from the relative high absorbance in NIR region. The combined chemotherapy and PTT against cancer cells in vitro test shows high therapeutic efficiency. The multimodal treatment and imaging could lead to this material a potential multifunctional system for biomedical diagnosis and therapy.

Ultra-small Albumin Templated Gd/Ru Composite Nanodots for In Vivo Dual modal MR/Thermal Imaging Guided Photothermal Therapy.

Multifunctional theranostic nanoagents which realize precise diagnosis and treatment of tumors are attracting increasing interests in recent years. However, efficient and controlled synthesis of ultra-small noble metal nanoagents remains a challenge. Here, monodisperse Gd/Ru@BSA nanodots (GRBNDs) are successfully fabricated via a totally "green", "one-pot" protocol for in situ reduction of Ru(III) and biomineralization of Gd(III) in the presence of albumin. The as-prepared nanoagent possesses the features of being ultra small in size (≈6.7 nm), having strong colloidal stability, and thermal stability as well as high photothermal conversion efficiency (η = 50.7%). As expected, the GRBNDs achieve a significant efficacy of anticancer therapy under LASER activation both in vitro and in vivo. It also exhibits superior T1 -weighted magnetic resonance (MR) imaging ability due to its high longitudinal relaxivity value (r1 = 10.98 × 10-3 m-1 s-1 ). Moreover, it is demonstrated to be renal clearable with negligible systemic toxicity. This work highlights a straightforward and repeatable approach for synthesizing highly effective and multifunctional noble metal nanoagent of great clinical promising for cancer theranostics.

Bimetallic Zeolitic Imidazolate Framework as an Intrinsic Two-Photon Fluorescence and pH-Responsive MR Imaging Agent.

Zeolitic imidazolate framework-8 (ZIF-8) has received wide attention in recent years as a potential drug vehicle for the treatment of cancer due to its acid-responsiveness and moderate biocompatibility. However, its congenital deficiency of intrinsic imaging capability limits its wider applications; therefore, a postsynthetic exchange approach was utilized to introduce paramagnetic manganese(II) ions into the ZIF-8 matrix. As a result, bimetallic zeolitic imidazolate frameworks (Mn-Zn-ZIF) were thus fabricated and exhibited pH-responsive T1-weighted magnetic resonance imaging (MRI) contrast effect. Remarkably, we also found its own fluorescence derived from 2-methylimidazole, which is the first report of the intrinsic two-photon fluorescence imaging of ZIFs to our knowledge. Mn-Zn-ZIF still preserves the original properties of ZIF-8 of high surface areas, microporosity, and acid sensitivity. After further PEGylation of Mn-Zn-ZIF, the nanoparticles showed no obvious toxicity and its MRI contrast effect has also been enhanced. Our work highlights the promise of modified zeolitic imidazolate frameworks as potential cancer theranostic platforms.

Novel Metal Polyphenol Framework for MR Imaging-Guided Photothermal Therapy.

Phothermal therapy has received increasing attention in recent years as a potentially effective way to treat cancer. In pursuit of a more biocompatible photothermal agent, we utilize biosafe materials including ellagic acid (EA), polyvinylpyrrolidone (PVP), and iron element as building blocks, and we successfully fabricate a homogeneous nanosized Fe-EA framework for the first time by a facile method. As expected, the novel nanoagent exhibits no obvious cytotoxicity and good hemocompatibility in vitro and in vivo. The microenvironment responsiveness to both pH and hydrogen peroxide makes the NPs biodegradable in tumor tissues, and the framework should be easily cleared by the body. Photothermal potentials of the nanoparticles are demonstrated with relevant features of strong NIR light absorption, moderately effective photothermal conversion efficiency, and good photothermal stability. The in vivo photothermal therapy also achieved effective tumor ablation with no apparent toxicity. On the other hand, it also exhibits T2 MR imaging ability originated from ferric ions. Our work highlights the promise of the Fe-EA framework for imaging-guided photothermal therapy.

Controllable synthesis of dual-MOFs nanostructures for pH-responsive artemisinin delivery, magnetic resonance and optical dual-model imaging-guided chemo/photothermal combinational cancer therapy.

Theranostic nanoagents which integrate diagnostic and therapeutic moieties into a single platform have attracted broad attention in cancer therapy, however the development of more effective and less toxic diagnostic and therapeutic interventions is still of great urgency. Herein, novel core-shell PB@MIL-100(Fe) dual metal-organic-frameworks (d-MOFs) nanoparticles are fabricated and their combined theranostic effects in vitro and in vivo are investigated. The d-MOFs nanoparticles can serve as a T1-T2 dual-modal magnetic resonance imaging (MRI) contrast and fluorescence optical imaging (FOI) agent due to the existence of inner PB MOFs and outer MIL-100(Fe) MOFs. The artemisinin (a traditional Chinese anticancer medicine) with a high loading content of 848.4 mg/g is released from the d-MOFs upon tumor cellular endocytosis due to the pH-responsive degradation of outer MOFs in low pH lysosomes of tumor cells. Furthermore, the inner PB MOFs can be utilized for photothermal therapy due to its strong absorbance in NIR region. Under the guidance by such dual-modal imaging, in vivo photothermal and chemotherapy is finally carried out, achieving effective tumor ablation in an animal tumor model. Furthermore, histological analysis revealed that the drug delivery system had no obvious effect on the major organs of mice due to the low toxicity of both d-MOFs and artemisinin. The distinctive multimodal imaging capability, excellent synergistic therapy effect through the combined chemo-photothermal therapy together with the low toxicity of both d-MOFs and artemisinin endow the theranostic nanoagent a promising next generation of nanomedicine for efficient and safe cancer therapy.

Universal strategy for homogeneously doping noble metals into cyano-bridged coordination polymers.

Coordination polymers with large surface areas and uniform but tunable cavities have attracted extensive attention because of their unique properties and potential applications in numerous fields. The introduction of noble metal into coordination polymers, which may enhance or display new behaviors beyond their parent counterparts, presents great challenges in maintaining the fragile coordination structures and meeting the compatibility. Here, cyano-bridged coordination polymers are robust and show very nice compatibilities with a series of noble metals, such as Pd, Pt, Au, Ag. Those noble elements partially take the place of the transition metal ions under room temperature (for Au and Ag) or a mild hydrothermal environment (for Pd and Pt) without damaging the framework. By using this universal simple synthetic procedure, we prepared a series of noble metal containing metal hexacyanoferrate (MHCF) with various morphologies and structures, including Pd/Pt/Ag/Au-MnHCF, Pd/Pt/Ag/Au-CoHCF, and Pd/Pt/Ag/Au-NiHCF. Among them, Pd-MnHCF demonstrates the control of morphologies by adjusting operational details, and notably, it shows very unique, enhanced catalytic performance, reflecting the superiority of cyano-connected positive-valent Pd as a single-atom catalyst.