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Tumor hypoxia is correlated with increased resistance to chemotherapy and poor overall prognoses across a number of cancer types. We present here a cancer cell-selective and hypoxia-responsive probe (fol-BODIPY) designed on the basis of density functional theory (DFT)-optimized quantum chemical calculations. The fol-BODIPY probe was found to provide a rapid fluorescence "off-on" response to hypoxia relative to controls, which lack the folate or nitro-benzyl moieties. In vitro confocal microscopy and flow cytometry analyses, as well as in vivo near-infrared optical imaging of CT26 solid tumor-bearing mice, provided support for the contention that fol-BODIPY is more readily accepted by folate receptor-positive CT26 cancer cells and provides a superior fluorescence "off-on" signal under hypoxic conditions than the controls. Based on the findings of this study, we propose that fol-BODIPY may serve as a tumor-targeting, hypoxia-activatable probe that allows for direct cancer monitoring both in vitro and in vivo.

Huntington’s disease (HD) is a dominantly inherited neurodegenerative disorder caused by abnormally expanded CAG repeats in the huntingtin gene. The huntingtin gene mutation leads to the progressive degeneration of striatal GABAergic medium spiny neurons (MSN) and reduces the level of brain-derived neurotrophic factor (BDNF) in HD patient’s brain. BDNF is an essential neurotrophic factor for the cortico-striatal synaptic activity and the survival of GABAergic neurons. In this study, we transplanted BDNF-overexpressing human neural stem cells (HB1.F3.BDNF) into the contra-lateral side of unilateral quinolinic acid (QA)-lesioned striatum of HD rat model. The results of in vivo transplantation were monitored using various behavioral tests, 4.7 T animal magnetic resonance imaging (MRI) and immunohistochemical staining. We observed that the QA-lesioned rats receiving HB1.F3.BDNF cells exhibited significant behavioral improvements in the stepping, rotarod and apomorphine-induced rotation tests. Interestingly, contralaterally transplanted cells were migrated to the QA-lesioned striatum and the size of lateral ventricle was reduced. Histological analyses further revealed that the transplanted cells, which had migrated to the QA lesion site, were differentiated into the cells of GABAergic, MSN-type neurons expressing DARPP-32, and neural networks were established between the transplanted cells and the host brain, as revealed by retrograde tracing. Finally, there was a significant reduction of inflammatory response in HB1.F3.BDNF-transplanted HD animal model, compared with vehicle-transplanted group. Taken together, these results suggest that HB1.F3.BDNF can be an effective therapeutic strategy to treat HD patients in the future.

A theranostic, small-molecule-based prodrug, designed to be activated programmatically against hypoxic tumors, was successfully developed. The prodrug was stimulated to release the active chemotherapeutic drug in concurrent with a rhodol fluorophore in artificial hypoxia mimic conditions or an

Background Protein-based Cas9 in vivo gene editing therapeutics have practical limitations owing to their instability and low efficacy. To overcome these obstacles and improve stability, we designed a nanocarrier primarily consisting of lecithin that can efficiently target liver disease and encapsulate complexes of Cas9 with a single-stranded guide RNA (sgRNA) ribonucleoprotein (Cas9-RNP) through polymer fusion self-assembly. Results In this study, we optimized an sgRNA sequence specifically for dipeptidyl peptidase-4 gene (DPP-4) to modulate the function of glucagon-like peptide 1. We then injected our nanocarrier Cas9-RNP complexes directly into type 2 diabetes mellitus (T2DM) db/db mice, which disrupted the expression of DPP-4 gene in T2DM mice with remarkable efficacy. The decline in DPP-4 enzyme activity was also accompanied by normalized blood glucose levels, insulin response, and reduced liver and kidney damage. These outcomes were found to be similar to those of sitagliptin, the current chemical DPP-4 inhibition therapy drug which requires recurrent doses. Conclusions Our results demonstrate that a nano-liposomal carrier system with therapeutic Cas9-RNP has great potential as a platform to improve genomic editing therapies for human liver diseases. Electronic supplementary material The online version of this article (10.1186/s12951-019-0452-8) contains supplementary material, which is available to authorized users.

Abnormal anaerobic metabolism leads to a lowering of the pH of many tumours, both within specific intracellular organelles and in the surrounding extracellular regions. Information relating to pH-fluctuations in cells and tissues could aid in the identification of neoplastic lesions and in understanding the determinants of carcinogenesis. Here we report an amphiphilic fluorescent pH probe (CS-1) that, as a result of its temporal motion, provides pH-related information in cancer cell membranes and selected intracellular organelles without the need for specific tumour targeting. Time-dependent cell imaging studies reveal that CS-1 localizes within the cancer cell-membrane about 20 min post-incubation. This is followed by migration to the lysosomes at 30 min before being taken up in the mitochondria after about 60 min. Probe CS-1 can selectively label cancer cells and 3D cancer spheroids and be readily observed using the green fluorescence channel (λem = 532 nm). In contrast, CS-1 only labels normal cells marginally, with relatively low Pearson's correlation coefficients being found when co-incubated with standard intracellular organelle probes. Both in vivo and ex vivo experiments provide support for the suggestion that CS-1 acts as a fluorescent label for the periphery of tumours, an effect ascribed to proton-induced aggregation. A much lower response is seen for muscle and liver. Based on the present results, we propose that sensors such as CS-1 may have a role to play in the clinical and pathological detection of tumour tissues or serve as guiding aids for surgery., A self-assembled amphiphilic fluorescent probe allows pH-fluctuations within cancer cells and tumour tissues to be readily detected.

We have synthesized new magnetic resonance imaging (MRI) T1 contrast agents (CA1 and CA2) that permit the activatable recognition of the cellular vicinal thiol motifs of the protein thioredoxin. The contrast agents showed MR relaxivities typical of gadolinium complexes with a single water molecule coordinated to a Gd3+ center (i.e., ~4.54 mM−1s−1) for both CA1 and CA2 at 60 MHz. The contrast agent CA1 showed a ~140% relaxivity enhancement in the presence of thioredoxin, a finding attributed to a reduction in the flexibility of the molecule after binding to thioredoxin. Support for this rationale, as opposed to one based on preferential binding, came from 1H-15N-HSQC NMR spectral studies, these revealed that the binding affinities toward thioredoxin were almost the same for both CA1 and CA2. In the case of CA1, T1-weighted phantom images of cancer cells (MCF-7, A549) could be generated based on the expression of thioredoxin. We further confirmed thioredoxin expression-dependent changes in the T1-weighted contrast via knockdown of the expression of the thioredoxin using siRNA-transfected MCF-7 cells. The nontoxic nature of CA1, coupled with its relaxivity features, leads us to suggest that it constitutes a first-in-class MRI T1 contrast agent that allows for the facile and noninvasive monitoring of vicinal thiol protein motif expression in live cells.

Described here is the development of gadolinium(III) texaphyrin-platinum(IV) conjugates capable of overcoming platinum resistance by 1) localizing to solid tumors, 2) promoting enhanced cancer cell uptake, and 3) reactivating p53 in platinum-resistant models. Side by side comparative studies of these Pt(IV) conjugates to clinically approved platinum(II) agents and previously reported platinum(II)-texaphyrin conjugates demonstrate that the present Pt(IV) conjugates are more stable against hydrolysis and nucleophilic attack. Moreover, they display high potent antiproliferative activity in vitro against human and mouse cell cancer lines. Relative to the current platinum clinical standard of care (SOC), a lead Gd(III) texaphyrin-Pt(IV) prodrug conjugate emerging from this development effort was found to be more efficacious in subcutaneous (s.c.) mouse models involving both cell-derived xenografts and platinum-resistant patient-derived xenografts. Comparative pathology studies in mice treated with equimolar doses of the lead Gd texaphyrin-Pt(IV) conjugate or the US Food and Drug Administration (FDA)-approved agent oxaliplatin revealed that the conjugate was better tolerated. Specifically, the lead could be dosed at more than three times (i.e., 70 mg/kg per dose) the tolerable dose of oxaliplatin (i.e., 4 to 6 mg/kg per dose depending on the animal model) with little to no observable adverse effects. A combination of tumor localization, redox cycling, and reversible protein binding is invoked to explain the relatively increased tolerability and enhanced anticancer activity seen in vivo. On the basis of the present studies, we conclude that metallotexaphyrin-Pt conjugates may have substantial clinical potential as antitumor agents.

Rho GTPases control a wide range of cellular processes, and their deregulation is associated with promotion of an aggressive and metastatic tumor phenotype in human cancers. Rho guanine nucleotide dissociation inhibitor 1 (RhoGDI1) plays a key role in regulating the activity of Rho GTPases. However, the underlying mechanisms are still unclear. In this study, we show that protein phosphatase 1B (PPM1B) interacts with RhoGDI1 and functions as its phosphatase. Ectopic expression of PPM1B results in dephosphorylation of RhoGDI1 and, thereby, abates the activation of RhoA, Rac1 and CDC42 by epidermal growth factor (EGF). PPM1B overexpression in Hs578T and SKBR3 human breast cancer cells decreases their motility and invasiveness in vitro and cancer metastasis in vivo. In contrast, knockdown of PPM1B in MCF-7 and MDA-MB-468 human breast cancer cells that express endogenous PPM1B enhances EGF-induced RhoGDI1 phosphorylation, activation of Rho GTPases, and cancer cell migration and invasion. Knockdown of RhoA or Rac1 by siRNA reverses the enhanced cell migration seen after PP1MB depletion. Collectively, these results indicate that PPM1B negatively regulates cancer cell motility and invasiveness through dephosphorylating RhoGDI1.

Sun-Hee Cho,1,* Ahreum Kim,1,* Woojung Shin,2 Min Beom Heo,1 Hyun Jong Noh,1 Kwan Soo Hong,3,4 Jee-Hyun Cho,3,4 Yong Taik Lim1,2 1SKKU Advanced Institute of Nanotechnology (SAINT), 2School of Chemical Engineering, Sungkyunkwan University, Suwon, 3Bioimaging Research Team, Korea Basic Science Institute, Cheongju, 4Immunotherapy Convergence Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea *These authors contributed equally to this work Abstract: Injectable and stimuli-responsive hydrogels have attracted attention in molecular imaging and drug delivery because encapsulated diagnostic or therapeutic components in the hydrogel can be used to image or change the microenvironment of the injection site by controlling various stimuli such as enzymes, temperature, pH, and photonic energy. In this study, we developed a novel injectable and photoresponsive composite hydrogel composed of anticancer drugs, imaging contrast agents, bio-derived collagen, and multifaceted anionic polypeptide, poly (γ-glutamic acid) (γ-PGA). By the introduction of γ-PGA, the intrinsic temperature-dependent phase transition behavior of collagen was modified to a low viscous sol state at room temperature and nonflowing gel state around body temperature. The modified temperature-dependent phase transition behavior of collagen/γ-PGA hydrogels was also evaluated after loading of near-infrared (NIR) fluorophore, indocyanine green (ICG), which could transform absorbed NIR photonic energy into thermal energy. By taking advantage of the abundant carboxylate groups in γ-PGA, cationic-charged doxorubicin (Dox) and hydrophobic MnFe2O4 magnetic nanoparticles were also incorporated successfully into the collagen/γ-PGA hydrogels. By illumination of NIR light on the collagen/γ-PGA/Dox/ICG/MnFe2O4 hydrogels, the release kinetics of Dox and magnetic relaxation of MnFe2O4 nanoparticles could be modulated. The experimental results suggest that the novel injectable and NIR-responsive collagen/γ-PGA hydrogels developed in this study can be used as a theranostic platform after loading of various molecular imaging probes and therapeutic components. Keywords: hydrogel, photothermal, near-infrared, drug delivery, magnetic nanoparticles

We have synthesized and characterized photophysical properties of a novel contrast agent based on switchable near-infrared (NIR) fluorescent nanoprobes that enables optical imaging with a higher sensitivity than conventional contrast agents allow. The high sensitivity was a result not only of the intrinsically high signal-to-background ratio that could be obtained in the NIR spectral region, but also from the increased signal intensity that was provided by using activatable nanoprobes. The NIR fluorescent nanoprobes were synthesized by encapsulating indocyanine green (ICG) into pH-responsive polymer nanoparticles. The intensity of the NIR fluorescence signal from the nanoparticles increased about 11-fold in acidic solution, due to the release of ICG molecules from the nanoparticles. The efficacy of fluorescence recovery from the quenched state to the de-quenched state could be modulated by controlling the relative concentrations between pH-responsive polymer and ICG. The fluorescence recovery properties of switchable NIR nanoprobes were also evaluated by cellular uptake experiments. Our experimental results support the use of pH-responsive nanoparticles with incorporated contrast agents as activatable molecular imaging nanoprobes.

Identification of a vulnerable atherosclerotic plaque before rupture is an unmet clinical need. Integrating nanomedicine with multimodal imaging has the potential to precisely detect biological processes in atherosclerosis. We synthesized silica-coated iron oxide nanoparticles (SIONs) coated with rhodamine B isothiocyanate and polyethylene glycol and investigated their feasibility in the detection of macrophages in inflamed atherosclerotic plaques of apolipoprotein E-deficient (ApoE−/−) mice via magnetic resonance (MR) and fluorescence reflectance (FR) imaging. In vitro cellular uptake of SIONs was assessed in macrophages using confocal laser scanning microscopy (CLSM). In vivo MR imaging was performed 24 h after SION injection via the tail vein in 26-week-old ApoE−/− mice fed a high-cholesterol diet (HCD). We also performed FR imaging of the extracted aortas from four different mice: two normal-diet-fed C57BL/6 mice injected with saline or 10 mg/kg SIONs and two HCD-fed ApoE−/− mice injected with 5 or 10 mg/kg SIONs. The harvested aortas were cryosectioned and stained with immunohistochemical staining. The CLSM images at 24 h after incubation showed efficient uptake of SIONs by macrophages, with no evidence of cytotoxicity. The in vivo and ex vivo MR and FR images demonstrated SION deposition in the atheroma. Upon immunohistochemical staining of the aorta, CLSM images revealed colocalization of macrophages and SIONs in the atherosclerotic plaque. These results demonstrate that polyethylene glycosylated SIONs could be a highly effective method to identify macrophage activity in atherosclerotic plaques as a multimodal imaging agent.

A novel dual imaging probe for in vivo magnetic resonance imaging (MRI) and optical imaging was developed by combining gadolinium (Gd)-chelating MR probe and a near-infrared (NIR) fluorophore, aza-BODIPY (AB; BODIPY = boron-dipyrromethene). This aza-BODIPY-based bimodal contrast agent (AB-BCA) showed a significant fluorescence emission around the NIR range and an enhanced longitudinal relaxivity in MR modality. The probe was easily delivered to phagocytic cells of the innate immune system, together with macrophages and dendritic cells (DCs), and presented high-performance fluorescence and MR imaging without obvious cytotoxicity. For in vivo visualization of AB-BCA using MRI and optical imaging, bone marrow-derived DCs were labeled and injected into the footpad of mice, and labeled DCs were tracked in vivo. We observed the migration of AB-BCA-labeled DCs into the lymph nodes via lymphatic vessels using NIR fluorescence and T1-weighted MR images. This dual-modality imaging probe was used for noninvasive monitoring of DC migration into lymph nodes and could be useful for investigating advanced cellular immunotherapy.

The hydrazone-based Gd(3+)-texaphyrin doxorubicin conjugate 1, releases active doxorubicin at acidic pH values, allowing its components to be followed by two complementary imaging methods, namely Off-On fluorescence enhancement and MR imaging. It thus acts as a promising theranostic agent.

Adoptive transfer of natural killer (NK) cells is becoming one of the most important parts of cancer immunotherapy. However, recent accomplishments have focused on the improvement of the targeting effects based on the engineering of chimeric antigen receptors (CARs) on cell surfaces. Despite the large quantity of therapeutic cells required for clinical applications, the technology for ex vivo expansion is not well developed. Herein, a three-dimensional (3D) engineered hyaluronic acid-based niche for cell expansion (3D-ENHANCE) is introduced. Compared with the conventional two-dimensional (2D) method, NK-92 cell lines and human EGFR-specific (CAR)–NK cells cultured in 3D-ENHANCE yield favorable mRNA expressions, elevated cytokine release, upregulated proliferative and tumor-lytic abilities, and result in enhanced antitumor efficacy. Furthermore, controllable degradation rates can be realized by tuning the formulation of 3D-ENHANCE so that it can be applied as an implantable cell reservoir at surgical sites. In vivo results with the incompletely resected MDA-MB-231 model confirm that the peri-operative implantation of 3D-ENHANCE prevents the relapse and metastases after surgery. Overall, 3D-ENHANCE presents an effective cytokine-free niche for ex vivo expansion and postsurgical treatment that enhances the low-therapeutic efficacy of human NK cells.

There is increasing interest in the coffee grade or quality with the rise of coffee consumption, but a classical, chemical analysis-based understanding of the coffee bean grade is still limited. We therefore report the identification of green coffee bean metabolites related to coffee bean quality using a 1 H NMR-based metabolomic analysis of well-established specialty-grade green coffee beans, in particular, of a single species ( Coffea arabica ). The higher levels of sucrose and the lower levels of γ-aminobutyric acid (GABA), quinic acid, choline, acetic acid and fatty acids observed in specialty or high-grade green coffee beans, compared to commercial-grade beans, were suggestive to be multiple markers for characterizing specialty green coffee bean. In particular, variations in sucrose and GABA levels between specialty and commercial coffees could be a consequence of different environmental conditions, for example, biotic or abiotc stresses, at growing regions. These results highlight an alternative method of metabolomic approach for grading green coffee bean.

Background Multimodal nanomaterials are useful for providing enhanced diagnostic information simultaneously for a variety of in vivo imaging methods. According to our research findings, these multimodal nanomaterials offer promising applications for cancer therapy. Results Melanin nanoparticles can be used as a platform imaging material and they can be simply produced by complexation with various imaging active ions. They are capable of specifically targeting epidermal growth factor receptor (EGFR)-expressing cancer cells by being anchored with a specific antibody. Ion-doped melanin nanoparticles were found to have high bioavailability with long-term stability in solution, without any cytotoxicity in both in vitro and in vivo systems. Conclusion By combining different imaging modalities with melanin particles, we can use the complexes to obtain faster diagnoses by computed tomography deep-body imaging and greater detailed pathological diagnostic information by magnetic resonance imaging. The ion-doped melanin nanoparticles also have applications for radio-diagnostic treatment and radio imaging-guided surgery, warranting further proof of concept experimental. Electronic supplementary material The online version of this article (doi:10.1186/s12951-017-0304-3) contains supplementary material, which is available to authorized users.

Nanoprobes used for biomedical applications usually require surface modifications with amphiphilic surfactants or inorganic coating materials to enhance their biocompatibility. We proposed a facile synthetic approach for the phase transfer of hydrophobic magnetic nanoparticles by the direct adherence of fluorescent probes, without any chemical modifications, for use as a magnetic resonance (MR)/near-infrared (NIR) fluorescence bimodal imaging contrast agent. Indocyanine green (ICG) was used not only as an optical component for NIR imaging, but also as a surfactant for phase transfer with no superfluous moiety: we therefore called the process “ICGylation”. Cell labeling and tracking in vivo with ICGylated magnetic nanoparticles were successfully performed by MR/NIR dual-mode imaging for three days, which showed remarkable biostability without any additional surface functionalization. We expect that this novel MR/NIR contrast agent demonstrating sensitive detection and simultaneous imaging capability can be used in diverse fields, such as the imaging and tracking of immune cells to confirm immunotherapeutic efficacy. The approach used could also be applied to other kinds of nanoparticles, and it would promote the development of advanced functional multimodal nanobioprobes.

Metastatic cancers have historically been difficult to treat. However, metastatic tumors have been found to have high levels of reactive oxygen species such as hydrogen peroxide (H2O2), supporting the hypothesis that a prodrug could be activated by intracellular H2O2 and lead to a potential antimetastatic therapy. In this study, prodrug 7 was designed to be activated by H2O2-mediated boronate oxidation, resulting in activation of the fluorophore for detection and release of the therapeutic agent, SN-38. Drug release from prodrug 7 was investigated by monitoring fluorescence after addition of H2O2 to the cancer cells. Prodrug 7 activated by H2O2, selectively inhibited tumor cell growth. Furthermore, intratracheally administered prodrug 7 showed effective antitumor activity in a mouse model of metastatic lung disease. Thus, this H2O2-responsive prodrug has therapeutic potential as a novel treatment for metastatic cancer via cellular imaging with fluorescence as well as selective release of the anticancer drug, SN-38.

A new theranostic strategy is described. It is based on the use of an “all in one” prodrug, namely the biotinylated piperazine-rhodol conjugate 4 a. This conjugate, which incorporates the anticancer drug SN-38, undergoes self-immolative cleavage when exposed to biological thiols. This leads to the tumor-targeted release of the active SN-38 payload along with fluorophore 1 a. This release is made selective as the result of the biotin functionality. Fluorophore 1 a is 32-fold more fluorescent than prodrug 4 a. It permits the delivery and release of the SN-38 payload to be monitored easily in vitro and in vivo, as inferred from cell studies and ex vivo analyses of mice xenografts derived from HeLa cells, respectively. Prodrug 4 a also displays anticancer activity in the HeLa cell murine xenograft tumor model. On the basis of these findings we suggest that the present strategy, which combines within a single agent the key functions of targeting, release, imaging, and treatment, may have a role to play in cancer diagnosis and therapy.

Objective. We undertook this study to investigate the discriminant metabolites in urine from patients with established rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and from healthy individuals. Methods. Urine samples were collected from 148 RA patients, 41 SLE patients and 104 healthy participants. The urinary metabolomic profiles were assessed using 1H nuclear magnetic resonance spectroscopy. The relationships between discriminant metabolites and clinical variables were assessed. Collagen-induced arthritis was induced in mice to determine if a choline-rich diet reduces arthritis progression. Results. The urinary metabolic fingerprint of patients with established RA differs from that of healthy controls and SLE patients. Markers of altered gut microbiota (trimethylamine-N-oxide, TMAO), and oxidative stress (dimethylamine) were upregulated in patients with RA. In contrast, markers of mitochondrial dysfunction (citrate and succinate) and metabolic waste products (p-cresol sulfate, p-CS) were downregulated in patients with RA. TMAO and dimethylamine were negatively associated with serum inflammatory markers in RA patients. In particular, patients with lower p-CS levels exhibited a more rapid radiographic progression over two years than did those with higher p-CS levels. The in vivo functional study demonstrated that mice fed with 1% choline, a source of TMAO experienced a less severe form of collagen-induced arthritis than did those fed a control diet. Conclusion. Patients with RA showed a distinct urinary metabolomics pattern. Urinary metabolites can reflect a pattern indicative of inflammation and accelerated radiographic progression of RA. A choline-rich diet reduces experimentally-induced arthritis. This finding suggests that the interaction between diet and the intestinal microbiota contributes to the RA phenotype. (J Rheum Dis 2019;26:46-56)

Virus-like theranostic nanoparticles: virus-like poly(amino acid) nanoparticles are synthesized that can be internalized via receptor-mediated endocytosis, resulting in encapsulated pH-activatable fluorescence probes that can be turned on in acidic environments but otherwise remain undetectable. The encapsulated anticancer drugs are also released into cytosol by endosome disruption.

A series of heptamethine cyanine (1-3) derivatives bearing a carbamate ethyl disulfide group and gemcitabine, an anticancer drug, have been newly synthesized. Their disulfide bonds are readily cleaved by various thiols including glutathione, to result in a subsequent decomposition of the carbamate into amine followed by release of the active gemcitabine, which can be monitored by the fluorescence changes. In the biological experiment, prodrug 1 is preferentially up-taken by folate-positive KB cells over folate-negative A549 cells via receptor-mediated endocytosis to release gemcitabine causing cell death and to emit fluorescence in endoplasmic reticulum. Moreover, it is selectively accumulated in the KB cells which were treated to mice by dorsal subcutaneous injection. This drug delivery system is a new theranostic agent, wherein both therapeutic effect and drug uptake can be easily monitored at the subcellular level, by in vivo and in vitro fluorescence imaging.

Purpose We determined whether poly(lactic-co-glycolic acid) nanoparticles would be a useful reagent for the successful monitoring of isolated islets by magnetic resonance imaging and optical imaging systems, without clinically relevant toxicity in vitro or in vivo. Methods We used iron oxide for MR imaging and a cyanide dye approved by the Food and Drug Administration (indocyanine green) for optical imaging and estimated the in vivo detection of transplanted pancreatic islets. Results The poly(lactic-co-glycolic acid) nanoparticles were associated with the islets in vitro and were successfully detected by 4.7 T (MR) and optical imaging, without other toxic effects. When labeled islets were transplanted under the mouse kidney capsule, in vivo T2/ -weighted scans with 4.7 T MR detected as few as 300 labeled islets by 4 weeks. Optical in vivo imaging revealed indocyanine green fluorescence by 2 and 4 days after transplantation of islets containing 250 and 500 µg/mL poly(lactic-co-glycolic acid) nanoparticles, respectively. These results were further supported by the immunohistochemical results for insulin and iron in the recipient mouse kidney and pancreas. Conclusions Taken together, these data indicate that poly(lactic-co-glycolic acid) nanoparticles may be used to label transplanted islets and may be imaged with in vivo MR and optical imaging systems. Magn Reson Med 71:1054–1063, 2014. © 2013 Wiley Periodicals, Inc.

Magnetic nanoparticles (MNPs) are considered promising for biomedical applications such as hyperthermia treatment and disease diagnosis owing to their distinctive thermal properties. For these applications, it is essential to screen the temperature distribution in the targeted disease site. This study aimed to investigate and observe the thermal properties of a small amount of MNPs used as highly sensitive biomarkers for disease diagnosis by microthermography. Toward this end, we used polyacrylamide and agarose phantoms containing a small amount of MNPs (30 mg Fe−1). In phantoms, the increasing temperature was observed using lock-in thermography for a small amount of MNPs distributed around the lesion. This suggests that the proposed microthermography technique can be used for diagnosis and screening in the early stage of a disease.

Reported here is a new theranostic agent, 1, which consists of a Gd3+-texaphyrin core conjugated to a doxorubicin prodrug via a disulfide bond. Conjugate 1 was designed to undergo cleavage in the presence of glutathione (GSH), a species typically upregulated in cancer cells. As prepared, conjugate 1 displays no appreciable fluorescence. However, when exposed to excess GSH an increase in the fluorescence intensity at 592 nm is observed that is ascribed to release of free doxorubicin. To improve the solubility and enhance the tumor targeting of 1, it was loaded into folate-receptor-targeted liposomes to produce FL-1 (for folate liposome loaded with 1). As inferred from both fluorescence turn on studies and independent HPLC analyses, FL-1 was found to undergo selective uptake and cleavage to release free Dox in the KB and CT26 cell lines, which express folate receptors on the cell surface, relative to the HepG2 and NIH3T3 cell lines, which show low expression of those receptors. FL-1 was found to produce a g...

Development of targeted, selective, and noninvasive fluorescent probes for in vivo visualization of tumor-associated overexpressed enzymes are highly anticipated for cancer diagnosis and therapy. Herein, we developed a noninvasive fluorescent probe (DCDHF-βgal) for the sensitive detection, and in vivo visualization of β-galactosidase in hepatocyte HepG2 cells and its xenograft model. As a model system for in vivo targeted imaging, DCDHF-βgal possessing galactose unit selectively target hepatocyte and monitor the β-galactosidase activity with deep tissue penetration, and low background interference. DCDHF-βgal was activated by intracellular β-galactosidases as the driving force for the release of NIR fluorophore, thereby exhibiting ratiometric optical response. Initial fluorescence emission measured at 615 nm was changed to fluorescence at 665 nm upon activation of DCDHF-βgal with β-galactosidase. Ratiometric fluorescence detection of β-galactosidase was also observed in hepatocellular carcinoma cells and tumor xenograft. The noninvasive in vivo optical imaging facilitated by targeted and enzyme-activated imaging agent would be useful in various biomedical and diagnostic applications.

The significance of lymphatic system has gathered great attention for immunotechnology related to cancer metastasis and immunotherapy. To develop innovative immunodiagnostics and immunotherapy in in vivo environments, it is very important to understand excretion pathways and clearance of injected cargoes. Herein, we employed Tm3+-doped upconverting nanoparticles (UCNPs) with versatile advantages suitable for long-term non-invasive in vivo optical imaging and tracking. Transport and retention of the UCNPs in the lymphatic system were evaluated with high-quality NIR-to-NIR upconversion luminescence (UCL) imaging. We obtained their kinetic luminescence profiles for the injection site and sentinel lymph node (SLN) and observed luminescence signals for one month; we also examined UCL images in SLN tissues, organs, and faeces at each time point. We speculate that the injected UCNPs in a footpad of a small mouse are transported rapidly from the lymphatic system to the blood system and then eventually result in an efficient excretion by the hepatobiliary route. These results will support development of novel techniques for SLN biopsy as well as immunotechnology.

Old chemistry for novel materials: Self-fluorescent high-relaxivity T(2)-weighted magnetic resonance imaging (MRI) contrast agents are produced. They are a novel type of MR/optical dual-modality in vivo imaging nanoprobe using glutaraldehyde crosslinking chemistry, and they are used to label and monitor therapeutic cells both in vitro and in vivo.

An easy but robust strategy for the synthesis of bioderived polyelectrolyte nanogels for protein antigen loading and vaccine adjuvant systems that can improve both humoral (Th2) and cellular immunity (Th1) is presented. The synthesized polyelectrolyte nanogels promote the uptake of antigens into antigen-presenting cells and strongly induce ovalbumin-specific INF-γ producing cells, cytotoxic T cell activity, and antibody production.

Magneto-fluorescent silica nanoparticles were conjugated with cetuximab for the targeting and imaging of colon cancer. In this study, cetuximab-conjugated magneto-fluorescent nanoparticles (MFSN-Ctx) could specifically target colon cancer cells that expressed EGFR on their cell membranes, and specific fluorescence was detected. MFSN-Ctx produced significant MRI signal changes in a human colon cancer xenograft mouse model. Intravenous injection of MFSN-Ctx resulted in faster uptake as compared to intraperitoneal injection, indicating that MFSN-Ctx had different kinetic properties in tumors based on the method of injection. The local concentration of MFSN-Ctx in a tumor was amplified by the use of an external magnetic field. These results demonstrate the potential application of MFSN-Ctx for the detection of EGFR-expressing colon cancer using in vivo imaging approaches.

The effects of lipid on magnetic resonance (MR) images and diffusion data in soaked rice were investigated using MR imaging and pulsed field gradient (PFG)-NMR spectroscopy, as well as water diffusion within rice. Lipid contributed to proton density-weighted MR image and found to be diffused by diffusion-ordered spectroscopy (DOSY). During diffusion experiments, two components for the self-diffusion coefficient ( D s1 and D s2 ) of water and one component for lipid ( D s3 ) were observed in soaking rice. It suggests that D s2 of water self-diffusion corresponds to water diffusion within starch granules of rice, resulting in a restricted diffusion. Based on the restricted diffusion, the average size ( a ) of the starch granules was estimated to be 4.6 μm. The permeability of water ( P ) of starch granule was increased from 1.77 × 10 −5 m/s to 2.49 × 10 −5 m/s as the soaking time increased from 3 to 6. This study demonstrates that lipids play a role in MR images contrast and diffusion data, and that physicochemical properties of the starch granule can be characterized in soaked seeds by PFG-NMR.

Significant artifacts occur from the overlapping signals of the water and lipids in relaxation time-weighted magnetic resonance (MR) images and should be compensated, in order to determine a precise water distribution in the soybean seeds. The chemical shift selective T1-, T2∗-, and T2-weighted MR images of water were compared to those with water or lipid suppression in soaked soybean seeds. In the absence of lipid suppression, the chemical shift artifacts were observed in the chemical shift selective T1- and T2-weighted MR images, due to the overlapping signals of the water and lipid protons. However, the MR images with lipid suppression had reduced artifacts. This study demonstrates that an appropriate MR imaging technique provides relatively uniform signal intensity and has importance in the investigation of true water distribution within food systems, such as to correlate a relationship between water distribution using MR imaging and water diffusion using pulsed field gradient (PFG) NMR.

Most imaging studies using intermolecular multiple-quantum coherences (iMQCs) have focused on the two-spin dipolar interactions — zero and double quantum coherences. Here, we report the results of various experimental studies to assess the feasibility of magnetic resonance microscopy with high-order iMQCs in model systems at 7 and 14 T. Experimental results demonstrated that the iMQC microscopic images with high coherence orders are readily observable at high field and have unique contrast depending on the sample microstructure and coherence order.

This study aimed to track the migration of primary macrophages labeled with near-infrared (NIR) fluorescent magnetic nanoparticles toward chemically induced acute inflammatory lesions in mice and to visualize the effect of anti-inflammatory drugs on macrophage migration using combined fluorescence and magnetic resonance imaging (FLI/MRI). Primary macrophages were labeled with NIR fluorescent magnetic nanoparticles, and labeled cells were injected into mice intravenously. One day later, inflammation was induced by subcutaneous injection of 1 % carrageenan (CG) solution to footpads of the right hind leg, and phosphate-buffered saline (PBS) as control treatment was subcutaneously injected to footpad of the left hind leg. To evaluate the effect of drug treatment on macrophage migration, a single dose of dexamethasone (DEX) was intraperitoneally administered to the mice immediately after the induction of inflammation and was followed by combined FLI/MRI at predetermined time points. No difference in cellular viability or phagocytic activity was observed between the labeled and parent macrophages. In vivo optical imaging revealed an increase in FLI signals in CG-injected footpads in a time-dependent manner, but not in PBS-treated footpads. DEX treatment inhibited the migration of the labeled macrophages to the CG-injected footpads, with relative decreases in FLI activity. In accordance with FLI, T2*-weighted MR images showed hypo-intense signals in the CG-injected footpads but not in the PBS-injected footpads. The DEX-treated mice did not show a dark signal loss zone on MR images in the CG-treated paw. We successfully tracked the migration of macrophages to inflammatory lesions using both FLI and MRI with NIR fluorescent magnetic nanoparticles and demonstrated the inhibitory effects of DEX on macrophage migration to inflammation sites.

We studied hydrogen adsorption onto the oxidized nano-palladium surface using 1H NMR. In the α phase, the incoming hydrogen molecules dissociate and form OHad. We confirm that the transformation occurs during the α–β phase transition by observing a decrease in OHad resonance intensity.

133Cs (I=7/2) nuclear magnetic resonance in a Cs2CuCl4 single crystal grown by using the slow evaporation method was measured in its three mutually perpendicular crystal planes. The 133Cs resonances of two different groups with two crystallographically inequivalent cesium nuclei, Cs(I) and Cs(II), in the unit cell were recorded. The transferred hyperfine fields for Cs(I) and Cs(II) calculated from the paramagnetic shift and the molecular susceptibility measurements could be expressed by the linear equation Hhf=AT+B. The angular dependence of the 133Cs nuclear magnetic resonance spectra showed that the Cs(I) and the Cs(II) nuclei had different values for the quadrupole coupling constant. The electric field gradient tensors of Cs(I) and Cs(II) were symmetric, and the orientations of their principal axes did not coincide. The Cs(I) ion surrounded by 11 chlorine ions had a small quadrupole parameter, a smaller charge distribution, and a small value for the transferred hyperfine field. However, the Cs(II) ion surrounded by nine chlorine ions had a larger quadrupole parameter, a larger charge distribution, and a larger value for the transferred hyperfine field.

The proton NMR line width and spin–lattice relaxation times for [N(CH3)4]2ZnCl4 single crystal were studied over a wide temperature range. Proton spin–lattice relaxation time measurements on [N(CH3)4]2ZnCl4 yielded a minimum, which were attributed to the effect of molecular tumbling. It seems obvious that the high-temperature minima of T1 is attributable to the tumbling motion of [N(CH3)4] ions, and that the T1 below 161 K is attributable to the same molecular motion which dominates at 210 K. Then, the T1 below 161 K undergoes a slow motion. The activation energies in phase VI and IV were determined to be 13.94 and 22.49 kJ/mol, respectively.

The proton NMR line width and spin–lattice relaxation rate in a [N(CH3)4]2CuCl4 single crystal have been investigated in the temperature range of 140–340 K. A large discontinuity in the curve of the spin–lattice relaxation rate shows near 200 K: this curve corresponds to a new phase transition. The activation energies were determined at each phase from the spin–lattice relaxation times. The large change in the activation energy at 200 K indicates that the N(CH3)4 groups are significantly affected during this transition.

Magnetic ferrite nanoparticles (MNPs) are nano-sized magnets that distort the local magnetic field and alter the T2 and T 2 ∗ of the water protons in the surrounding water molecules. This property renders MNPs a favorable negative MR contrast agent for biomedical applications. Silica coating and polyethylene glycolation confers additional stability and biocompatibility to the MNPs. Organic dyes incorporated into the silica shell enable the detection of MNP fluorescence by confocal laser scanning microscopy (CLSM). Mouse mesenchymal stem cells (mMSCs) in adult bone marrow can differentiate into cardiomyocytes. The mMSCs recruited in the region of myocardial infarction can express muscle-specific markers and increase the regional wall motion. Using MRI, we tracked the fate of MNP-labeled mMSCs injected into the infarcted myocardium. The mMSCs were effectively labeled with polyethylene-glycolated MNPs, as confirmed by CLSM. The MNP-labeled mMSCs were injected around and into the infarcted myocardium of C57/BL6 mice. Using MR, we successfully tracked the MNP-labeled mMSCs in the hearts of mice at 7 d after inducing myocardial infarction. The localization of MNPs in the myocardium was validated by the in vivo and ex vivo MR images.

The temperature dependence of the 7Li nuclear magnetic resonance in a LiKSO4 single crystal grown by the slow evaporation method was investigated by employing a Bruker FT NMR spectrometer. The 7Li NMR spectra demonstrates the occurrence of the first-order phase transition at 190 K which is connected with a lowering of the Li+ site symmetry and formation of three kinds of ferroelastic domains. Below and above 190 K, the quadrupole coupling constants and asymmetry parameters of Li in LiKSO4 decrease as the temperature increases. The temperature dependence of the quadrupole parameters in the temperature range of 130–400 K is explained by a single torsional frequency of the LiO ion by means of the simple Bayer theory.

Nuclear spin-lattice relaxations of Be9 and Al27 in an alexandrite (BeAl2−xCrxO4, x=0.02) single crystal have been investigated in the temperature range 140 K–400 K. The paramagnetic impurity effect on the relaxation is negligible for both nuclei. The relaxation of the Be9 nuclear spins is found single exponential in time when the whole resonance lines are uniformly excited. When only the central resonance line is excited for Al27, the relaxation is well fitted with a linear combination of three exponential functions given by Simmons et al. [Phys. Rev. 127, 1168 (1962)]. Since the spin-lattice relaxation rate is proportional to the square of temperature for both nuclei, the dominant relaxation mechanism in this temperature range can be inferred as the Raman process.

A water-soluble T1 magnetic resonance imaging contrast agent (1) has been synthesized. The bimodal contrast agent 1 responds to the Cu(2+) ion in living cells by enhancing the MRI modality signal whereas the optical signal gradually drops. This dual modality probe response depends on the cellular free copper ions in RAW 264.7 cells even at the micromolar level.

Purpose The purpose of this study was to evaluate the metabolomic changes in 3D-cultured human mesenchymal stem cells (hMSCs) in alginate beads, so as to identify biomarkers during chondrogenesis using 1H nuclear magnetic resonance (NMR) spectroscopy. Materials and Methods hMSCs (2×106 cells/mL) were seeded into alginate beads, and chondrogenesis was allowed to progress for 15 days. NMR spectra of the chondrogenic hMSCs were obtained at 4, 7, 11, and 15 days using a 14.1-T (600-MHz) NMR with the water suppression sequence, zgpr. Real-Time polymerase chain reaction (PCR) was performed to confirm that that the hMSCs differentiated into chondrocytes and to analyze the metabolomic changes indicated by the NMR spectra. Results During chondrogenesis, changes were detected in several metabolomes as hMSC chondrogenesis biomarkers, e.g., fatty acids, alanine, glutamate, and phosphocholine. The metabolomic changes were compared with the Real-Time PCR results, and significant differences were determined using statistical analysis. We found that changes in metabolomes were closely related to biological reactions that occurred during the chondrogenesis of hMSCs. Conclusions In this study, we confirm that metabolomic changes detected by 1H-NMR spectroscopy during chondrogenic differentiation of 3D-cultured hMSCs in alginate beads can be considered as biomarkers of stem cell differentiation.

Blends of thermotropic liquid crystalline polymer (TLCP) with poly (butylene terephthalate) (PBT) were prepared by coprecipitation from a common solvent. Their glass transition temperatures ( T g ) and melting transition temperatures ( T m ) of the blends were not affected depending on the LCP weight percent in the PBT matrix, respectively, while the isotropic temperatures ( T i ) decreased with increasing LCP composition. The measurements of the line-width and spin-lattice relaxation time for 1 H have been investigated on LCP/PBT blends at different LCP contents. The line-width monotonically decreased with increasing LCP content. The decrease of the line-width with increasing temperature is due to the motional narrowing effect. The inverse T 1 relaxation rate increases with increasing the temperature.

Nuclear magnetic resonance (NMR) spectra of the 9Be nucleus in an alexandrite (BeAl2-xCrxO4, x=0.02) single crystal, grown by the Czochralski method, have been investigated employing a Bruker FT NMR spectrometer. Two sets of NMR spectra for 9Be (I=3/2) were observed in the crystallographic planes. The principal X axis of the electric field gradient tensors for both is found to be along the crystallographic a axis. The principal Y and Z axes are located in the b-c plane at about 9 degrees from the crystallographic c and b axes, respectively. These results indicate that there are two magnetically inequivalent Be sites, but they are chemically equivalent. The temperature dependence of 9Be NMR spectra has been measured in the temperture range 120-440 K. e2qQ/h for 9Be is found to increase linearly whereas eta decreases with increasing temperature.