Development of finely tuned liposome nanoplatform for macrophage depletion.

BACKGROUND: Immunotherapy with clodronate-encapsulated liposomes, which induce macrophage depletion, has been studied extensively. However, previously reported liposomal formulation-based drugs (Clodrosome® and m-Clodrosome®) are limited by their inconsistent size and therapeutic efficacy. Thus, we aimed to achieve consistent therapeutic effects by effectively depleting macrophages with uniform-sized liposomes. RESULTS: We developed four types of click chemistry-based liposome nanoplatforms that were uniformly sized and encapsulated with clodronate, for effective macrophage depletion, followed by conjugation with Man-N3 and radiolabeling. Functionalization with Man-N3 improves the specific targeting of M2 macrophages, and radioisotope labeling enables in vivo imaging of the liposome nanoplatforms. The functionalized liposome nanoplatforms are stable under physiological conditions. The difference in the biodistribution of the four liposome nanoplatforms in vivo were recorded using positron emission tomography imaging. Among the four platforms, the clodronate-encapsulated mannosylated liposome effectively depleted M2 macrophages in the normal liver and tumor microenvironment ex vivo compared to that by Clodrosome® and m-Clodrosome®. CONCLUSION: The newly-developed liposome nanoplatform, with finely tuned size control, high in vivo stability, and excellent ex vivo M2 macrophage targeting and depletion effects, is a promising macrophage-depleting agent.

Circulation Time-Optimized Albumin Nanoplatform for Quantitative Visualization of Lung Metastasis via Targeting of Macrophages.

The development of molecular imaging probes to identify key cellular changes within lung metastases may lead to noninvasive detection of metastatic lesions in the lung. In this study, we constructed a macrophage-targeted clickable albumin nanoplatform (CAN) decorated with mannose as the targeting ligand using a click reaction to maintain the intrinsic properties of albumin in vivo. We also modified the number of mannose molecules on the CAN and found that mannosylated serum albumin (MSA) harboring six molecules of mannose displayed favorable pharmacokinetics that allowed high-contrast imaging of the lung, rendering it suitable for in vivo visualization of lung metastases. Due to the optimized control of functionalization and surface modification, MSA enhanced blood circulation time and active/passive targeting abilities and was specifically incorporated by mannose receptor (CD206)-expressing macrophages in the metastatic lung. Moreover, extensive in vivo imaging studies using single-photon emission computed tomography (SPECT)/CT and positron emission tomography (PET) revealed that blood circulation of time-optimized MSA can be used to discern metastatic lesions, with a strong correlation between its signal and metastatic burden in the lung.

KSNM60: The History of Radiopharmaceutical Sciences in Korea.

A number of researchers in Korea have tried to set-up the production of radionuclides and develop new radiopharmaceuticals for several decades. Thanks to their 60-year endeavor to advance the field of radiopharmaceutical sciences, now we have a lot of research units and facilities in Korea. Still, there are huge number of issues to be solved in radiopharmaceutical sciences; however, our efforts will be continued to develop new radiopharmaceuticals and to apply the new radiopharmaceuticals into nuclear medicine field.

Selective Detection of Nitrogen-Containing Compound Gases.

N-containing gaseous compounds, such as trimethylamine (TMA), triethylamine (TEA), ammonia (NH3), nitrogen monoxide (NO), and nitrogen dioxide (NO2) exude irritating odors and are harmful to the human respiratory system at high concentrations. In this study, we investigated the sensing responses of five sensor materials-Al-doped ZnO (AZO) nanoparticles (NPs), Pt-loaded AZO NPs, a Pt-loaded WO3 (Pt-WO3) thin film, an Au-loaded WO3 (Au-WO3) thin film, and N-doped graphene-to the five aforementioned gases at a concentration of 10 parts per million (ppm). The ZnO- and WO3-based materials exhibited n-type semiconducting behavior, and their responses to tertiary amines were significantly higher than those of nitric oxides. The N-doped graphene exhibited p-type semiconducting behavior and responded only to nitric oxides. The Au- and Pt-WO3 thin films exhibited extremely high responses of approximately 100,000 for 10 ppm of triethylamine (TEA) and approximately -2700 for 10 ppm of NO2, respectively. These sensing responses are superior to those of previously reported sensors based on semiconducting metal oxides. On the basis of the sensing response results, we drew radar plots, which indicated that selective pattern recognition could be achieved by using the five sensing materials together. Thus, we demonstrated the possibility to distinguish each type of gas by applying the patterns to recognition techniques.

Radioprotective effect of newly synthesized toll-like receptor 5 agonist, KMRC011, in mice exposed to total-body irradiation.

Exposure to ionizing radiation leads to severe damages in radiosensitive organs and induces acute radiation syndrome, including effects on the hematopoietic system and gastrointestinal system. In this study, the radioprotective ability of KMRC011, a novel toll-like receptor 5 (TLR5) agonist, was investigated in C57BL6/N mice exposed to lethal total-body gamma-irradiation. In a 30-day survival study, KMRC011-treated mice had a significantly improved survival rate compared with control after 11 Gy total-body irradiation (TBI), and it was found that the radioprotective activity of KMRC011 depended on its dosage and repeated treatment. In a 5-day short-term study, we demonstrated that KMRC011 treatment stimulated cell proliferation and had an anti-apoptotic effect. Furthermore, KMRC011 increased the expressions of genes related to DNA repair, such as Rad21, Gadd45b, Sod2 and Irg1, in the small intestine of lethally irradiated mice. Interestingly, downregulation of NF-κB p65 in the mouse intestine by KMRC011 treatment was observed. This data indicated that KMRC011 exerted a radioprotective activity partially by regulating NF-κB signaling. Finally, peak expression levels of G-CSF, IL-6, IFN-γ, TNF-α and IP-10 induced by KMRC011 treatment were different depending on the route of administration and type of cytokine. These cytokines could be used as candidate biomarkers for the evaluation of KMRC011 clinical efficacy. Our data indicated that KMRC011 has radioprotective activity in lethally irradiated mice and may be developed as a therapeutic agent for radioprotection.

Macrophage cell tracking PET imaging using mesoporous silica nanoparticles via in vivo bioorthogonal F-18 labeling.

We introduce an efficient cell tracking imaging protocol using positron emission tomography (PET). Since macrophages are known to home and accumulate in tumor tissues and atherosclerotic plaque, we design a PET imaging protocol for macrophage cell tracking using aza-dibenzocyclooctyne-tethered PEGylated mesoporous silica nanoparticles (DBCO-MSNs) with the short half-life F-18-labeled azide-radiotracer via an in vivo strain-promoted alkyne azide cycloaddition (SPAAC) covalent labeling reaction inside macrophage cells in vivo. This PET imaging protocol for in vivo cell tracking successfully visualizes the migration of macrophage cells into the tumor site by the bioorthogonal SPAAC reaction of DBCO-MSNs with [18F]fluoropentaethylene glycolic azide ([18F]2) to form 18F-labeled aza-dibenzocycloocta-triazolic MSNs (18F-DBCOT-MSNs) inside RAW 264.7 cells. The tissue radioactivity distribution results were consistent with PET imaging findings. In addition, PET images of atherosclerosis in ApoE-/- mice fed a western diet for 30 weeks were obtained using the devised macrophage cell-tracking protocol.

Sensing Properties of ZnO Nanoparticles for Detection of 2-Chloroethyl Ethyl Sulfide as a Mustard Simulant.

In this work, we present the fabrication and characterization of a 2-chloroethyl ethyl sulfide (2-CEES) gas sensor based on ZnO nanoparticles (NPs) synthesized by a hydrothermal method. We confirmed that synthesized ZnO NPs adopt a polycrystalline phase. Partially aggregated ZnO-NPs revealed spherical or ellipsoidal nanocrystalline particles in a size range of 30-50 nm, as observed by field-emission scanning electron microscopy (FE-SEM). The maximum response of the ZnO NPs was 15 at 1 ppm 2-CEES concentration, and a low detection limit of 0.4 ppm was observed at an optimal operating temperature of 250 °C. The lowest response time was 6 s in 20 ppm at 250 °C. The linearity response with correlation coefficient (R2) was 0.9887 at 2-CEE concentrations of 0.4-1 ppm at the operating temperature of 250 °C. The enhanced sensing performance and a decrease in the operating temperature were attributed to a high specific surface area and more active sites in the ZnO NPs after exposure to 2-CEES.

Thin PEGylated Carbon Nitrides: Water-Dispersible Organic Nanodots as Bioimaging Probes.

Fluorescent materials are being used for the optical/fluorescence imaging of living cells and animal models. As such, the development of heavy-metal-free, water-dispersible, and biocompatible imaging probes is still important. Carbon nitride (C3 N4 ) is used as a bioimaging probe due to its suitable optical properties, thus enhancing its biocompatibility and dispersibility in aqueous media is required. In this study, we incorporated short-chain polyethylene glycol (PEG) groups onto a carbon nitride network by the simple N-alkylation of hexaethylene glycolic mesylate with nucleophilic nitrogen atoms on oxidized carbon nitride (OCN). The PEGylated OCN (PEG-OCN) was well dispersed in water as nanodots with a lateral dimension of approximately 30 nm and a thickness of 0.5-1.2 nm and showed strong photoluminescence in the visible region. Cell-viability testing confirmed that these "heavy-metal-free" organic nanodots were highly biocompatible and noncytotoxic. In particular, the developed nanodots could provide clear confocal images of RAW 264.7 cells without weakening cell activity and displaying any aggregation in a range of concentrations (25-100 µg mL-1 ) with bright-green emission in the cytoplasm.

[18F]FET PET is a useful tool for treatment evaluation and prognosis prediction of anti-angiogenic drug in an orthotopic glioblastoma mouse model.

O-2-18F-fluoroethyl-l-tyrosine ([18F]FET) has been widely used for glioblastomas (GBM) in clinical practice, although evaluation of its applicability in non-clinical research is still lacking. The objective of this study was to examine the value of [18F]FET for treatment evaluation and prognosis prediction of anti-angiogenic drug in an orthotopic mouse model of GBM. Human U87MG cells were implanted into nude mice and then bevacizumab, a representative anti-angiogenic drug, was administered. We monitored the effect of anti-angiogenic agents using multiple imaging modalities, including bioluminescence imaging (BLI), magnetic resonance imaging (MRI), and positron emission tomography-computed tomography (PET/CT). Among these imaging methods analyzed, only [18F]FET uptake showed a statistically significant decrease in the treatment group compared to the control group (P=0.02 and P=0.03 at 5 and 20 mg/kg, respectively). This indicates that [18F]FET PET is a sensitive method to monitor the response of GBM bearing mice to anti-angiogenic drug. Moreover, [18F]FET uptake was confirmed to be a significant parameter for predicting the prognosis of anti-angiogenic drug (P=0.041 and P=0.007, on Days 7 and 12, respectively, on Pearson's correlation; P=0.048 and P=0.030, on Days 7 and 12, respectively, on Cox regression analysis). However, results of BLI or MRI were not significantly associated with survival time. In conclusion, this study suggests that [18F]FET PET imaging is a pertinent imaging modality for sensitive monitoring and accurate prediction of treatment response to anti-angiogenic agents in an orthotopic model of GBM.

Complete genome analysis of a novel umbravirus-polerovirus combination isolated from Ixeridium dentatum.

Two novel viruses, isolated in Bonghwa, Republic of Korea, from an Ixeridium dentatum plant with yellowing mottle symptoms, have been provisionally named Ixeridium yellow mottle-associated virus 1 (IxYMaV-1) and Ixeridium yellow mottle-associated virus 2 (IxYMaV-2). IxYMaV-1 has a genome of 6,017 nucleotides sharing a 56.4% sequence identity with that of cucurbit aphid-borne yellows virus (genus Polerovirus). The IxYMaV-2 genome of 4,196 nucleotides has a sequence identity of less than 48.3% with e other species classified within the genus Umbravirus. Genome properties and phylogenetic analysis suggested that IxYMaV-1 and -2 are representative isolates of new species classifiable within the genus Polerovirus and Umbravirus, respectively.

Magnetically separable sulfur-doped SnFe2O4/graphene nanohybrids for effective photocatalytic purification of wastewater under visible light.

In this report, magnetically recoverable sulfur-doped SnFe2O4/graphene (S-SFO/GR) nanohybrids have been successfully developed via a facile solvothermal method. The characterizations on the structural, morphology, and optical properties of the nanohybrids indicate that S-SFO particles are successfully embedded on the GR nanosheets. The photocatalytic activity has been evaluated by photocatalytic degradation of chlorotetracycline under visible light irradiation. Among the composites with various mass ratios, the quasi-first-order rate constant of the nanohybrids formed with 9wt% S in SFO and 15wt% GR (9S-SFO/GR-15) can reach as high as 1.83min-1, which is much higher than that of SFO (0.68min-1) and SFO/GR (0.91min-1), confirming the important role of S and GR for the photocatalytic process. The combination of the three components of S, SFO, and GR has enhanced the visible light absorption capability and inhibited the recombination of photogenerated electron-hole. The 9S-SFO/GR-15 nanohybrids can be recovered easily by a magnet and reused for five times with remained photocatalytic efficiency about 70%. A possible catalytic mechanism explaining the efficient photocatalytic performances of the prepared nanohybrids has been proposed.

Monitoring of macrophage accumulation in statin-treated atherosclerotic mouse model using sodium iodide symporter imaging system.

INTRODUCTION: Macrophages play a key role in atherosclerotic plaque formation in atherosclerosis, but its detailed understanding has poorly investigated until now. Thus, we sought to demonstrate a noninvasive technique for macrophage tracking to atherosclerotic lesions in apolipoprotein E-/-(ApoE-/-) mice with an imaging system based on sodium iodide symporter (NIS) gene coupled with 99mTc-single-photon emission computed tomography (SPECT). METHODS AND RESULTS: Macrophage cells (RAW264.7) were stably transduced with retrovirus expressing NIS gene (RAW-NIS). In RAW-NIS cells, uptake of 125I was higher than the parental cells. [18F]FDG signals in the aorta at 30weeks on an ApoE-/- mice with high cholesterol diet were higher (1.7±0.12% injected dose (ID)) than those in control group (0.84±0.06% ID). Through 99mTc-SPECT/computed tomography (CT), in the RAW-NIS cell injected group, the 99mTc-pertechnetate uptake in aorta was higher than control groups. However, according to atorvastatin treatment, RAW-NIS cell recruitment reduced to the aorta. Area of 99mTc-pertechnetate uptake was positively correlated with immunostaining results against macrophage antigen (CD68). Cholesterol and low-density lipoprotein levels of atorvastatin-treated group showed lower than those of atorvastatin-untreated group, but did not reach statistical difference. CONCLUSIONS: This novel approach to tracking macrophages to atherosclerotic plaques in vivo can be applied for studies of arterosclerotic vascular disease.

Accuracy of four different digital intraoral scanners: effects of the presence of orthodontic brackets and wire.

OBJECTIVE: The objective of this study was to compare the accuracy of four different digital intraoral scanners and the effects of buccal brackets and orthodontic wire. METHODS: For this study, three sets of models (Control model, BKT model with buccal bracket, and WBKT model with buccal bracket and orthodontic wire) were scanned using four different types of intraoral scanners: E4D dentist, iTero, Trios, and Zfx IntraScan. The mesiodistal width of the teeth, intercanine width, and intermolar width measured by four scanners were compared. Three-dimensional (3D) images of the brackets were taken using the four scanners. Data were analyzed with one-way ANOVA, independent t test, and post-hoc Tukey test at a significance level of P < 0.05. RESULTS: When comparing the 3D images with manual measurements using a traditional caliper, iTero and Trios showed the highest accuracy in horizontal measurements.iTero had the lowest values in Devmax-min of maxillary intermolar and intercanine widths (0.16 mm and 0.20 mm, respectively), whereas Trios had the lowest values in Devmax-min of mandibular intermolar and intercanine widths (0.36 mm and 0.14 mm, respectively). The horizontal variables were barely affected by the presence of buccal brackets and orthodontic wire. Comparison of 3D bracket images scanned by the four scanners showed differences in image distortion among the scanners. Bracket characteristics did not affect the 3D bracket images. CONCLUSIONS: The four intraoral scanners used in this study differed in accuracy. However, the results acquired by iTero and Trios were more reliable. Effects of buccal brackets and orthodontic wire on the 3D images taken by intraoral scanners were not clinically significant.

Establishment of a mouse model of 70% lethal dose by total-body irradiation.

Whereas increasing concerns about radiation exposure to nuclear disasters or side effects of anticancer radiotherapy, relatively little research for radiation damages or remedy has been done. The purpose of this study was to establish level of LD70/30 (a lethal dose for 70% of mice within 30 days) by total-body γ irradiation (TBI) in a mouse model. For this purpose, at first, 8-week-old male ICR and C57BL/6N mice from A and B companies were received high dose (10, 11, 12 Gy) TBI. After irradiation, the body weight and survival rate were monitored for 30 days consecutively. In next experiment, 5-week-old male ICR and C57BL/6N mice from B company were received same dose irradiation. Results showed that survival rate and body weight change rate in inbred C57BL/6N mice were similar between A and B company. In ICR mice, however, survival rate and body weight change rate were completely different among the companies. Significant difference of survival rate both ICR and C57BL6N mice was not observed in between 5-week-old and 8-week-old groups receiving 10 or 12 Gy TBI. Our results indicate that the strain and age of mice, and even purchasing company (especially outbred), should be matched over experimental groups in TBI experiment. Based on our results, 8-week-old male ICR mice from B company subjected to 12 Gy of TBI showed LD70/30 and suitable as a mouse model for further development of new drug using the ideal total-body irradiation model.

Evaluation of [(89)Zr]-Oxalate as a PET Tracer in Inflammation, Tumor, and Rheumatoid Arthritis Models.

To obtain an additional pharmacological agent for the diagnosis of inflammation, we investigated the medical use of (89)Zr-oxalate as a positron emission tomography (PET) probe for the in vivo imaging of inflammation and compared its efficacy to that of 2-deoxy-2-[(18)F]fluoro-d-glucose ([(18)F]FDG) and sodium [(18)F]fluoride. (89)Zr-oxalate exhibited observable higher uptake in a macrophage cell line than in tumor cells. The inflammatory lesions and tumors were clearly visualized by PET imaging and autoradiography using (89)Zr-oxalate. Compared to [(18)F]FDG and sodium [(18)F]fluoride, (89)Zr-oxalate demonstrated a high selectivity index to the tumor at an early time point after injection and to inflammation at a delayed time point after injection (24 h). Through histological examination, large numbers of macrophages and neutrophils were observed in the tumor lesions with the highest (89)Zr-oxalate uptake. In a rheumatoid arthritis (RA) mouse model, (89)Zr-oxalate demonstrated a high level of accumulation in inflammatory lesions. (89)Zr-oxalate is a new strategic tool for tumor imaging and inflammatory processes.

The complete genomic sequence of a tentative new polerovirus identified in barley in South Korea.

The complete nucleotide sequence of a new barley polerovirus, tentatively named barley virus G (BVG), which was isolated in Gimje, South Korea, has been determined using an RNA sequencing technique combined with polymerase chain reaction methods. The viral genomic RNA of BVG is 5,620 nucleotides long and contains six typical open reading frames commonly observed in other poleroviruses. Sequence comparisons revealed that BVG is most closely related to maize yellow dwarf virus-RMV, with the highest amino acid identities being less than 90 % for all of the corresponding proteins. These results suggested that BVG is a member of a new species in the genus Polerovirus.

Development of tobacco ringspot virus-based vectors for foreign gene expression and virus-induced gene silencing in a variety of plants.

We report here the development of tobacco ringspot virus (TRSV)-based vectors for the transient expression of foreign genes and for the analysis of endogenous gene function in plants using virus-induced gene silencing. The jellyfish green fluorescent protein (GFP) gene was inserted between the TRSV movement protein (MP) and coat protein (CP) regions, resulting in high in-frame expression of the RNA2-encoded viral polyprotein. GFP was released from the polyprotein via an N-terminal homologous MP-CP cleavage site and a C-terminal foot-and-mouth disease virus (FMDV) 2 A catalytic peptide in Nicotiana benthamiana. The VIGS target gene was introduced in the sense and antisense orientations into a SnaBI site, which was created by mutating the sequence following the CP stop codon. VIGS of phytoene desaturase (PDS) in N. benthamiana, Arabidopsis ecotype Col-0, cucurbits and legumes led to obvious photo-bleaching phenotypes. A significant reduction in PDS mRNA levels in silenced plants was confirmed by semi-quantitative RT-PCR.

Complete Genome Sequence of Rehmannia Mosaic Virus Infecting Rehmannia glutinosa in South Korea.

The complete genome sequence of a South Korean isolate of Rehmannia mosaic virus (ReMV) infecting Rehmannia glutinosa was determined through next-generation sequencing and Sanger sequencing. To our knowledge, this is the first report of a natural infection of R. glutinosa by ReMV in South Korea.

Complete Genome Sequences of Grapevine Yellow Speckle Viroid 1 and Hop Stunt Viroid Assembled from the Transcriptome of Ixeridium dentatum Plants.

Here, we report complete genome sequences of grapevine yellow speckle viroid 1 (GYSVd1) and hop stunt viroid (HSVd), members of the family Pospiviroidae, assembled from the transcriptome data generated from Ixeridium dentatum plants. To our knowledge, this is the first report of GYSVd1 and HSVd in I. dentatum.

Complete genome sequence of a novel endornavirus isolated from hot pepper.

The complete genome of a putative new endornavirus infecting hot peppers (Capsicum annuum) was determined to be 14,729 nt in size, including 12 cytosines at the 3' end. The hot pepper-infecting virus has the highest nucleotide sequence similarity (94% query cover and 72% identity) to bell pepper endornavirus (BPEV) isolated from the cultivar Yolo Wonder in the USA (GenBank accession no. JN019858). The putative single, large open reading frame encodes a 4,884-amino-acid-long polyprotein that contains four putative functional domains: a viral methyltransferase, a viral RNA helicase, a glycosyltransferase, and an RNA-dependent RNA polymerase. A phylogenetic tree based on whole polyprotein sequences confirmed the close evolutionary relationship of the studied endornavirus to BPEV. The hot pepper-infecting virus also has a nick at nt position 975. Taken together, these results suggest that this virus belongs to a new species in the genus Endornavirus (family Endornaviridae), for which the name hot pepper endornavirus (HPEV) is proposed.