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Non-toxic and long-term fluorescent probes for tumor imaging are in urgent need for non-invasively obtaining information about tumor genesis and metastasis in vivo. Here, we present a biocompatible near-infrared fluorescent probe for in vivo long-term imaging of tumor by modifying glucose (Glc), which experiences high uptake in cancer cells, on the surface of near-infrared Ag2Se quantum dots (NIR Ag2Se QDs). The fluorescence of glucose-functionalized Ag2Se QDs (Glc-Ag2Se QDs) from the targeted tumor can be observed in vivo for at least 7 days. In addition, this probe could be excreted through kidneys and the renal excretion ability is favorable for in vivo imaging applications. Moreover, Glc-Ag2Se QDs could be used for tumor targeted imaging of not only human breast cancer cells (MCF-7), but also SW1990 pancreatic cancer cells since glucose is highly taken up in almost all kinds of tumors. Glc-Ag2Se QDs could be a promising general tool for in vivo long-term observation of tumor evolution. [ABSTRACT FROM AUTHOR]

Magnetic iron oxide nanoparticles have been used for various applications such as in the treatment of iron deficiency, as theranostic agents, and as drug carriers. The effective delivery of magnetic iron oxide nanoparticles into the lesion and iron quantification are vital for in vivo theranostic application. To determine the feasibility of using T1 contrast to non-invasively quantify and monitor the IONPs in vivo, monodispersed Gd-doped iron oxide nanoparticles (GdIONPs) with 4 nm core size were fabricated and were used as T1-weighted contrast agents to quantify iron contents based on MRI longitudinal relaxation times (T1). Signal enhancement in positive T1 contrast caused by GdIONPs was observed in this work. The in vivo T1 relaxivity of GdIONPs in a tumor matched well with both in vitro T1 relaxivity and ICP-MS results, demonstrating that the concentration of iron at the tumor site can be directly read from real-time in vivo MRI T1 relaxivity. Hence, by using this strategy, the Fe content in the lesion can be accurately monitored based on MRI longitudinal relaxation times, and this may shed light on effective magnetic hyperthermia cancer therapy in future. [ABSTRACT FROM AUTHOR]

The charge-reversal strategy is usually employed in gene delivery to facilitate the endosomal escape of gene carriers and the release of the payload into cytoplasm. However, most of the charge-reversal materials are far from perfect biocompatible materials due to the cytotoxicity of themselves or their hydrolyzed products. In this study, an excellent charge-reversal material named modified bovine serum albumin (mBSA) was prepared. The charge reversal of biocompatible mBSA is a physical process and can instantly occur, which was confirmed by zeta potential, size detection and morphological studies. The introduction of mBSA can not only reduce the zeta potential of binary complexes (pDNA–PEI) but also increase the nuclease resistance ability of the pDNA–PEI binary complexes. In addition, cell viabilities tested by MTT assay and gene transfection assay demonstrated that mBSA can reduce the cytotoxicity of pDNA–PEI polyplexes and improve their gene transfection efficiency (serum free and 10% FBS medium) both in 293T and HepG2 cells at the same time. The experimental results of cell internalization and intracellular distribution of pDNA–PEI–mBSA ternary complexes confirmed that the improvement of transfection efficiency originated from the enhancement of endosomal escape of polyplexes. Therefore, mBSA has been proven to be a perfect charge-reversal platform to simultaneously improve the transfection efficiency and biocompatibility of polyplexes. [ABSTRACT FROM AUTHOR]

Gold nanorods (Au NRs) have been receiving extensive attention owing to their extremely attractive properties which make them suitable for various biomedical applications. Au NRs could induce nano-toxicity, but this problem could be turned into therapeutic potential through tuning autophagy. However, the autophagy-inducing activity and mechanism of Au NRs is still unclear. Here we showed that surface chemical modification can tune the autophagy-inducing activity of Au NRs in human lung adenocarcinoma A549 cells. CTAB-coated Au NRs induce remarkable levels of autophagy activity as evidenced by LC3-II conversion and p62 degradation, while PSS- and PDDAC-coated Au NRs barely induce autophagy. More importantly, we also demonstrated that the AKT-mTOR signaling pathway was responsible for CTAB-coated Au NRs-induced autophagy. We further showed that CTAB-coated Au NRs also induce autophagy in human fetal lung fibroblast MRC-5 cells in a time-dependent manner. This study unveils a previously unknown function for Au NRs in autophagy induction, and provides a new insight for designing surface modifications of Au NRs for biomedical applications. [ABSTRACT FROM AUTHOR]

Non-toxic and long-term fluorescent probes for tumor imaging are in urgent need for non-invasively obtaining information about tumor genesis and metastasis in vivo. Here, we present a biocompatible near-infrared fluorescent probe for in vivo long-term imaging of tumor by modifying glucose (Glc), which experiences high uptake in cancer cells, on the surface of near-infrared Ag 2 Se quantum dots (NIR Ag 2 Se QDs). The fluorescence of glucose-functionalized Ag 2 Se QDs (Glc-Ag 2 Se QDs) from the targeted tumor can be observed in vivo for at least 7 days. In addition, this probe could be excreted through kidneys and the renal excretion ability is favorable for in vivo imaging applications. Moreover, Glc-Ag 2 Se QDs could be used for tumor targeted imaging of not only human breast cancer cells (MCF-7), but also SW1990 pancreatic cancer cells since glucose is highly taken up in almost all kinds of tumors. Glc-Ag 2 Se QDs could be a promising general tool for in vivo long-term observation of tumor evolution.

Magnetic iron oxide nanoparticles have been used for various applications such as in the treatment of iron deficiency, as theranostic agents, and as drug carriers. The effective delivery of magnetic iron oxide nanoparticles into the lesion and iron quantification are vital for in vivo theranostic application. To determine the feasibility of using T 1 contrast to non-invasively quantify and monitor the IONPs in vivo, monodispersed Gd-doped iron oxide nanoparticles (GdIONPs) with 4 nm core size were fabricated and were used as T 1 -weighted contrast agents to quantify iron contents based on MRI longitudinal relaxation times (T 1 ). Signal enhancement in positive T 1 contrast caused by GdIONPs was observed in this work. The in vivo T 1 relaxivity of GdIONPs in a tumor matched well with both in vitro T 1 relaxivity and ICP-MS results, demonstrating that the concentration of iron at the tumor site can be directly read from real-time in vivo MRI T 1 relaxivity. Hence, by using this strategy, the Fe content in the lesion can be accurately monitored based on MRI longitudinal relaxation times, and this may shed light on effective magnetic hyperthermia cancer therapy in future.

We report on a novel type of shaped hydrogel microparticles which undergo large, rapid, and reversible volume changes in response to solution pH. The cubic hydrogels are produced as interconnected poly(methacrylic acid) (PMAA) network replicas of mesoporous manganese oxide templates by sequential infiltration of (PMAA) and poly(N-vinylpyrrolidone) (PVPON), followed by cross-linking of PMAA and template dissolution. The integrated advantages of the porous cubic sacrificial templates and responsive PMAA matrix enable synthesis of monodisperse and pH-sensitive hydrogel cubes in a rapid, facile, and reproducible manner. These hydrogel cubes display a reversible 2-fold change in size while maintaining their shape in response to pH variations. The swelling behavior of cubic and spherical hydrogel particles is controlled by the network structure which is regulated by the PMAA molecular weight. These networks maintain their three-dimensional shapes in the dry state. No cytotoxicity is found for cubic and spherical hydrogels upon their interactions with human cancer cells for various time intervals. Finally, pH-triggered loading and release of doxorubicin to and from the cubic hydrogels is shown and their anticancer effect is demonstrated. The viability of A549 and HeLa cancer cells was significantly decreased upon interaction with doxorubicin-loaded cubic hydrogels. The approach presented here provides a new platform of multi-functional particles with highly-controlled geometry, size, composition, and responsive properties to be potentially used in targeted drug delivery for cancer therapy.