Search

Objectives Gallium-68 (68Ga)-labeled somatostatin analog (SSA) PET imaging has been widely used in clinical practice. Compared with 68Ga, 18F has a great practical and economic advantage. The characteristics of 18F-AlF-NOTA-octreotide (18F-OC) have been even more rarely described. Herein, this retrospective study aimed to evaluate the efficacy of 18F-OC PET/CT in detecting NENs, as well as to compare it with 18F-FDG PET/CT and CT/MRI. Methods We retrospectively evaluated the data of 93 patients who had undergone 18F-OC PET/CT scans. Moreover, of 45 patients with suspected NENs, 42 patients underwent enhanced CT scans, 38 patients underwent MRI scans, and 5 patients underwent 18F-FDG PET/CT imaging. Of 48 NENs patients for detecting metastasis or recurrence, these patients had enhanced CT (n = 36), MRI (n = 30) and 18F-FDG PET/CT scans (n = 14). A total of 276 suspected NENs lesions were found in these 93 patients. Histopathologic (n = 198) or radiographic follow-up (n = 78) served as the reference standard for the final diagnosis. Results Forty-five patients with suspected NENs were confirmed by histopathological examination via resection or biopsy. 18F-OC PET/CT showed high radiotracer uptake in the lesions of G1-G3 NENs. 18F-OC PET/CT showed superior performance, with 96.3% sensitivity, 77.8% specificity and 88.9% accuracy in diagnosing NENs compared to CT/MRI. When a standardized uptake value (SUVmax) of 8.3, target-to-background ratio (TBR) of 3.1 and SUVmax of hypophysis (SUVhypophysis) of 15.4 were cutoff points for differentiating NENs from non-NENs lesions, 18F-OC PET/CT had the best equilibrium between sensitivity and specificity. For a total of 276 suspected NENs lesions, the sensitivity, specificity, and accuracy of 18F-OC were 90.5%, 82.1% and 88.8%, respectively, in the diagnosis of NENs and were higher than those of 18F-FDG PET/CT and CT/MRI. Furthermore, the TBR of 18F-OC PET was higher than that of 18F-FDG PET (P = 0.0118), especially in pancreas (P = 0.0024), liver (P max and TBR of 18F-OC PET/CT showed a significant correlation with the degree of CT enhancement in G2 but not in G1 or G3. Moreover, there was a higher blood supply and lower 18F-OC TBR in G1 and G2 NENs than in G3. Conclusions 18F-OC PET/CT is a promising imaging modality for initial diagnosis and detecting metastasis or postoperative recurrence in NENs.

Macrophages have crucial roles in the pathogenesis of rheumatoid arthritis (RA). We aimed to elucidate the temporal profile of macrophage infiltration in synovitis in RA rat models using PET (positron emission tomography) imaging based a new generation of TSPO (Translocator protein, 18 kDa)-PET ligand

The overexpression of HIF-1α in solid tumors due to hypoxia is closely related to drug resistance and consequent treatment failure. Herein, we constructed a hypoxia-activated prodrug named as YC-Dox. This prodrug could be activated under hypoxic conditions and undergo self-immolation to release doxorubicin (Dox) and YC-1 hemisuccinate (YCH-1), which could execute chemotherapy and result in HIF-1α downregulation, respectively. This prodrug is capable of specifically releasing Dox and YCH-1 in response to hypoxia, leading to a substantial synergistic potency and a remarkable cytotoxic selectivity (>8-fold) for hypoxic cancer cells over normoxic healthy cells. The in vivo experiments reveal that this prodrug can selectively aim at hypoxic cancer cells and avoid undesired targeting of normal cells, leading to elevated therapeutic efficacy for tumor treatment and minimized adverse effects on normal tissues.

Objectives: Non-tuberculous mycobacterial (NTM) infection is a growing public health concern. Due to atypical clinical symptoms and poorly defined radiological findings, NTM is often misdiagnosed, resulting in treatment delay. The aim of the present study was to analyze the findings of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scan imaging in patients with NTM infection in order to improve the diagnosis and treatment of NTM disease.Methods: A total of 23 patients with confirmed NTM infection who underwent 18F-FDG PET/CT scan imaging were retrospectively analyzed. The data on clinical and 18F-FDG PET/CT imaging characteristics were reviewed. The 18F-FDG PET/CT images were analyzed both qualitatively and quantitatively using maximum standardized uptake value (SUVmax), SUVMax (the most FDG-avid lesion in the whole body), SURLiver and SURBlood (SUVMax ratio of lesion-to-liver and lesion-to-blood pool). The optimal cut-off of 8F-FDG was determined using receiver operating characteristic curve (ROC).Results: Subgroup analysis showed significant differences in metabolic parameters of 18F-FDG-avid lesions, including SURLiver, SURBlood, and SUVMax among the three groups with different immunological states (p = 0.007, 0.012, and 0.010, respectively). The cut-off point of 3.8 for SURLiver showed the best equilibrium between sensitivity and specificity (52.9% and 83.3%). In terms of the NTM lesion distribution, there were significant differences in SURLiver, SURBlood, and SUVMax between the localized and disseminated groups (p = 0.003, 0.009, and 0.005, respectively). The cut-off point of 3.3 for the SUVBlood had high specificity (87.5%) and sensitivity (71.4%). Furthermore, in terms of NTM lesion severity, SUVmax of lung lesions (SUVI-lung), SUVmax of marrow (SUVMarrow), and platelet count significantly differed between severe and non-severe groups (p = 0.036, 0.006, and 0.007, respectively). When the cut-off values of SUVMarrow and SUVI-lung were set at 3.1 and 4.6, the sensitivity was 76.9% and 76.9%, respectively, while the specificity was 88.9% and, 55.9%, respectively.Conclusion: In patients with NTM infection, 18F-FDG PET/CT is a unique and powerful tool in the diagnosis and evaluation of disease activity, immunological state, and extent of lesion involvement and it can help determine the appropriate treatment for NTM infection.

Cerenkov radiation (CR) from radionuclides and megavoltage X-ray radiation can act as an

Blood-brain barrier (BBB) is frequently disrupted in patients with diabetes mellitus (DM) and/or neurosyphilis (NS). Clinical cases reflect a trend that non-neurosyphilis (non-NS) patients with impaired glucose tolerance (IGT) are likely to develop NS and/or DM.To investigate whether IGT promotes BBB disruption in patients with non-NS.A total of 21 subjects were enrolled, including six with IGT, nine with non-NS, and six with both IGT and non-NS. BBB permeability was evaluated by dynamic contrast-enhanced (DCE) MRI and the secretion of biomarkers from cerebrospinal fluid (CSF) were measured by colorimetric method, immune turbidimetric method, and enzyme-linked immunosorbent assay (ELISA) method.The non-NS patients with IGT have higher BBB permeability at cortex superior frontal gyrus, white matter, and thalamus than non-NS patients without IGT or IGT patients without non-NS. The CSF-serum albumin-quotient (Qalb) levels and CSF secretion are highest in non-NS patients with IGT, including matrix metalloproteinase 9 (MMP9), soluble intercellular cell adhesion molecule-1 (sICAM-1), and soluble vascular cell adhesion molecule-1 (sVCAM-1).Significant correlations between CSF biomarkers and BBB permeability were found.

Approaches that could enable precise photodynamic therapy (PDT) are of therapeutic potential. We herein report a trifunctional probe (Glu-RdEB) that could be activated to generate fluorescent rhodamine species to pinpoint tumor foci. The probe contains a γ-glutaminyl moiety cleavable to γ-glutamyl transpeptidase (GGT) overexpressed in multiple tumors, an entity of an ENBS photosensitizer for PDT, and an entity of rhodamine fluorescently quenched by ENBS. Upon activation by tumor-associated GGT, the probe releases highly fluorescent rhodamine that is selectively confined in tumors whereby light irradiation leads to effective tumor regression in mice. These results indicate the feasibility of a fluorescently quenched dye-photosensitizer pair to yield tumor-activatable fluorescence to direct PDT.

Early diagnosis and therapy are crucial to control disease progression optimally and achieve a good prognosis in rheumatoid arthritis (RA). Previous study showed that a technetium-99m (99mTc)-labeled TSPO ligand (99mTc-CB256 [2-(8-(2-(bis(pyridin-2-yl)methyl)amino)acetamido)-2-(4-chlorophenyl)H-imidazo[1,2-a]pyridin-3-yl)-N,N-dipropylacetamide] composed of a translocator protein (TSPO) ligand CB86 [[2-(4-chlorophenyl)-8-amino-imidazo[1,2-a]-pyridin-3-yl]-N,N-di-n-propylacetamide] and di-(2-picolyl)amine, a bifunctional chelate agent, was used to image a TSPO-rich cancer cell in vitro; however, few 99mTc-CB256 in vivo evaluation has been reported so far probably due to the cytotoxicity of CB256 (ca. 75 times more than analogous CB86). Herein, we describe a novel TSPO targeting radiopharmaceutical consisting of CB86 and diethylenetriaminepentaacetic acid (DTPA), a conventional bifunctional chelating ligand in clinical trials used to prepare 99mTc-labeled CB86, and its evaluation as a 99mTc-single-photon emission computed tomography (SPECT) probe. The radiosynthesis and characterization of 99mTc-DPTA-CB86 including hydrophilicity and stability tests were determined. Additionally, the binding affinity and specificity of 99mTc-DTPA-CB86 to TSPO were evaluated using RAW264.7 macrophage cells. Biodistribution and 99mTc-SPECT studies were conducted on rheumatoid arthritis (RA) rat models after the injection of 99mTc-DTPA-CB86 with or without co-injection of unlabeled DTPA-CB86. The radiosynthesis of 99mTc-DTPA-CB86 was completed successfully with the labeling yields and radiochemical purity of 95.86 ± 2.45 and 97.45 ± 0.69%, respectively. The probe displayed good stability in vitro and binding specificity to RAW264.7 macrophage cells. In the biodistribution studies, 99mTc-DTPA-CB86 exhibited rapid inflammatory ankle accumulation. At 180 min after administration, 99mTc-DTPA-CB86 uptakes of the left inflammatory ankle were 2.35 ± 0.10 percentage of the injected radioactivity per gram of tissue (% ID/g), significantly higher than those of the normal tissues. 99mTc-SPECT imaging studies revealed that 99mTc-DTPA-CB86 could clearly identify the left inflammatory ankle with good contrast at 30–180 min after injection. Therefore, 99mTc-DTPA-CB86 may be a promising probe for arthritis 99mTc-SPECT imaging.

It is vital to distinguish between inflammatory and malignant lymphadenopathy in human immunodeficiency virus (HIV) infected individuals. The purpose of our study was to differentiate the variations in the clinical characteristics of HIV patients, and applyThis retrospective cross-sectional study included 59 consecutive HIV-infected patients who underwent whole-bodyConsidering the clinical records, the Karnofsky Performance Status (KPS) scores in patients with inflammatory lymphadenopathy were obviously higher than those in patients with malignant lymphoma (P = 0.015), whereas lymphocyte counts and lactate dehydrogenase (LDH) were obviously lower (P = 0.014 and 0.010, respectively). For theOur study identified the distinctive characteristics of the clinical manifestations, the SUR

Photodynamic therapy (PDT) necessitates approaches capable of increasing antitumor effects while decreasing nonspecific photodamage. We herein report an activatable probe (Glu-PyEB) comprising two distinct photosensitizers with mutually suppressed photodynamics. Activation by tumor-associated γ-glutamyltranspeptidase gives rise to a generator of superoxide radical (O

The aim of this study is to develop a 1-(2-(2-(2-(1,2,3-triazol)ethoxy)ethoxy)ethyl)-5-[125/131 I]iodo-1,2,3-triazole-diestradiol ([125/131 I]ITE2), for estrogen receptor (ER)-expressing breast cancer imaging with single-photon emission computed tomography (SPECT). [125/131 I]ITE2 was prepared in good radiochemical yield (94.4 ± 0.4%) with high radiochemical purity (> 99%). [125/131 I]ITE2 had good stability in vitro and moderate molar activity (0.3 ± 0.2 GBq/µmol). Higher uptake in ER-positive MCF-7 cells than that of ER-negative MDA-MB-231 cells was observed at all time points. Rats biodistribution showed that [131 I]ITE2 had high uptake in ER-abundant uterine and ovarian (5.7 ± 0.4 and 10.1 ± 1.4 %ID/g at 1 h post-injection) and could be blocked by co-injection of estradiol (2.7 ± 0.1 and 5.5 ± 0.4 %ID/g) obviously. In the SPECT/CT imaging study, [125 I]ITE2 showed significant higher uptake in MCF-7 tumor (3.1 ± 0.4 %ID/g) than that of MDA-MB-231 (0.9 ± 0.1 %ID/g). Furthermore, the specific uptake of [125 I]ITE2 in ER-positive MCF-7 tumor could be blocked effectively by pre-administration of fulvestrant (1.2 ± 0.4 %ID/g). A novel radioiodinated dimeric estrogen was designed and synthesized with promising ER targeting ability and specificity. It is worthy of further investigation to validate the advantages of the dimer in ER-positive breast cancer diagnosis.

Current tumor imaging agents are often limited by their liability to dissipate from tumor tissues. As cell sugar sorting enables exogenous sugars to be delivered into predetermined subcellular locations, we synthesized sialic acid (Sia) derivatives with rhodamine-X conjugated at C-9 (ROXSia), which hitchhikes cell sialic acid sorting to target tumor cell lysosomes, exhibiting pH-independent long-term probe retention in lysosomes. ROXSia gives selective, bright, and endured fluorescence signals in subcutaneous tumors and orthotopic tumors in mice models. These results indicate the potential of ROXSia as a lysosome-targeted optical agent for fluorescence-guided tumor resection.

Objective Accurate evaluation of tumor programmed death ligand 1 (PD-L1) expression can assist in predicting whether a patient will respond to anti-PD-L1 therapy. In this study, we aimed to develop stable radioiodinated PD-L1 antibodies that can be used for PD-L1 targeted SPECT/PET imaging. Methods Radioiodination was accomplished via a prosthetic group ([131I]SIB or [124I]SIB) to give radioiodinated anti-human PD-L1 and anti-mouse PD-L1 antibody (anti-PD-L1 and anti-PD-L1M). MicroSPECT/PET imaging and biodistribution of radioiodinated antibodies were studied in two immune-competent murine models (B16F10 and 4T1 syngeneic tumor models) and patient-derived xenograft (PDX) model of lung adenocarcinoma to evaluate the feasibility of identifying tumor PD-L1 expression. Results Radioiodinated PD-L1 antibodies had high radiochemical purity (>99%) and favorable stability in vivo. There was high uptake of [131I]SIB-anti-PD-L1M in both 4T1 and B16F10 syngeneic tumors when injected with 5.5 MBq radiotracers containing 200 μg anti-mouse-PD-L1. The presence of excess unlabeled anti-PD-L1 antibody increased [131I]SIB-anti-PD-L1M uptake in tumors. The highly specific PD-L1-positive tumor uptake detected by SPECT imaging indicated that radioiodinated antibody could be used for PD-L1 expression imaging. In addition, PET imaging of the PDX model was performed with [124I]SIB-anti-PD-L1, which showed high signal intensity in tumors and optimal contrast between tumor and muscle (tumor-to-muscle ratios at 6 h p.i. and 24 h p.i. were 2.5 and 5.3, respectively). Conclusions This study provides an efficient strategy for synthesizing stable radioiodinated PD-L1 antibodies with excellent pharmacokinetics to identify PD-L1 expression in tumors.

Purpose The authors point out that the existing research confuses the operational liabilities formed based on the “transaction” relationship with the financial liabilities formed based on the “investment” relationship, which not only exaggerates the value of leverage but also underestimates the level of protection that companies provide for creditors alone. That is, the confusion of concepts not only triggers the problem of leverage misestimate but also triggers the short-term financial risk misestimate. The performance of “nominal leverage” and “nominal short-term solvency” based on total assets calculation cannot reflect the real leverage level and the real short-term financial risk of enterprises. Design/methodology/approach To distinguish the concepts of “assets” and “capital” and rationalize the relationship between “transactions” and “investments”, authors systematically design the “real leverage” indicators and “real short-term solvency” indicators, and measure the degree of misestimate of leverage and short-term financial risk indicators by traditional research. On this basis, this paper describes and analyses the trends of leveraged misestimate and short-term financial risk misestimate of listed companies in China and analyses which companies have more serious leverage misestimate. And it helps readers to form an objective understanding of the leveraged misestimate and short-term financial risk misestimate of listed companies in China. Findings Firstly, the overall high level of leverage of listed companies in China in the traditional sense is largely because of the misestimate of indicators. And this kind of misestimate is more serious among firms that have advantages in trading, such as state-owned enterprises and firms with higher market shares. Secondly, for most firms with normal solvency, traditional research systematically overestimated the negative impact of “nominal leverage” on financial risk indicators (represented by short-term solvency). The overestimation is significant in firms with serious leverage misestimate. Thirdly, indicators’ misestimate of the traditional research makes the banks cannot make effective credit decisions according to the firm's “real leverage” and “real short-term solvency”. Originality/value Firstly, clarify the differences between the concepts of “assets” and “capital”, and clarify the level of “real leverage” of listed companies in China, which is conducive to the process of “de-leveraging”. Secondly, revise the problem of misestimate of related indicators, so that financial institutions can clearly identify the true profitability and real risk level of the entity domain, and thus improve the effectiveness of credit decisions.

Vulnerable atherosclerotic plaques are responsible for most cardiovascular diseases (CVDs). Folate receptor (FR) positive activated macrophages were thought to be a prominent component in the development of vulnerable plaque. The objective of this study is to develop folate conjugated two-dimensional (2D) Pd@Au nanomaterials (Pd@Au-PEG-FA) for targeted multimodal imaging of the FRs in advanced atherosclerotic plaques. Pharmacokinetic and imaging studies (single photon emission computed tomography (SPECT), computed tomography (CT) and photoacoustic (PA) imaging) were performed to confirm the prolonged blood half-life and enrichment of radioactivity in atherosclerotic plaques. Strong signals were detected in vivo with SPECT, CT and PA imaging in heavy atherosclerotic plaques, which were significantly higher than those of the normal aortas after injection of Pd@Au-PEG-FA. Blocking studies with preinjection of excess FA could effectively reduce the targeting ability of Pd@Au-PEG-FA in atherosclerotic plaques, further demonstrating the specific binding of Pd@Au-PEG-FA for plaque lesions. Histopathological characterization revealed that the signal of probe was in accordance with the high-risk plaques. In summary, the Pd@Au-PEG-FA has favorable pharmacokinetic properties and provides a valuable approach for detecting high-risk plaques in the presence of FRs in atherosclerotic plaques.

Nanoparticles with effective tumor accumulation and efficient renal clearance have attracted significant interests for clinical applications. We prepared 2.5 nm tyrosine based carbon dots (TCDs) with phenolic hydroxyl groups on the surface for directly 125I labeling. The 125I labeled polyethylene glycol (PEG) functionalized TCDs (125I-TCDPEGs) showed excellent radiochemical stability both in vitro and in vivo. Due to the enhanced permeability and retention effect, these 125I-TCDPEGs demonstrated a tumor accumulation around 4%–5% of the injected dose per gram (ID/g) for U87MG, 4T1, HepG2 and MCF7 tumor-bearing mice at 1 h post-injection. Meanwhile, the 125I-TCDPEGs also could be fast renally excreted, with less than 0.6% ID/g left in the liver and spleen within 24 h. These radioactive carbon dots not only can be used for cellular fluorescence imaging due to their intrinsic optical property, but are also effective single photon emission computed tomography (SPECT) imaging agents for tumor. Together with their excellent biocompatibility and stability, we anticipate these 125I-TCDPEGs of great potential for early tumor diagnosis in clinic. What’s more, our TCDPEGs are also proved to be feasible carriers for other iodine isotopes such as 127I and 131I for different biomedical application.

Fluorine-18-2-(3-{1-carboxy-5-[(6-We retrospectively evaluated the data of 56 SPCa patients who had undergoneAll the patients were confirmed by histopathological examination via prostatectomy or prostate biopsy. Fluorine-18-DCFPyL PET/CT showed higher radiotracer uptake in prostate cancer than that in non-prostate cancer. When SUVmax 5.0 and SULmax 4.0 were cut-off points for determining prostate cancer, the sensitivity ofFluorine-18-DCFPyL PET/CT is a promising imaging modality for initial diagnosis and preoperative N staging in SPCa.

Idiopathic inflammatory myopathy (IIM) is a group of autoimmune diseases that frequently leads to unfavorable outcome. This study aimed at identifying the clinical value of PET/CT scan in predicting the outcome of adult IIM patients.Adult IIM patients who were admitted to the four divisions of the First Affiliated Hospital, Zhejiang University School of Medicine (FAHZJU), from January 1, 2017, to December 31, 2020, were retrospectively reviewed. PET/CT scan and other factors of IIM patients who met the inclusion and exclusion criteria were collected and analyzed.A total of 69 adult IIM patients were finally enrolled into this study. Thirty cases (43.5%) of all the patients enrolled died in follow-up, and the medium follow-up time was 11.90 (4.00, 23.80) months. In particular, 14 patients died within 3 months. The univariate Cox proportional hazards regression analyses revealed pulmonary bacterial infection (P 0.001), rapidly progressive interstitial lung disease (RP-ILD, P = 0.018), maximum standard uptake value of spleen (spleen SUVmax, P = 0.002), and positivity of anti-MDA5 antibody (P = 0.041) were significantly related to survival in follow-up. The following multivariate Cox proportional hazards regression analysis identified pulmonary bacterial infection (P = 0.003) and spleen SUVmax (P = 0.032) as factors significantly associated with survival of IIM-ILD patients. The subsequent receiver operating characteristic curve analysis showed SUVmax was comparably effective in predicting death within 3 months.Spleen SUVmax and complication of pulmonary bacterial infection were significantly associated with survival of IIM patients. In addition, elevated spleen SUVmax was efficient in predicting unfavorable outcome of adult IIM patients. Key Points • IIM is a group of autoimmune diseases that frequently leads to unfavorable outcome • Complications of splenic SUVmax and pulmonary bacterial infection were significantly associated with survival in IIM patients.

Diabetes mellitus (DM) and neurosyphilis (NS) may both damage the blood-brain barrier (BBB). It seems that non-neurosyphilis (non-NS) patients with high HbA1c levels are likely to develop into NS. However, the correlation of HbA1c level with BBB disruption in syphilis (non-NS) patients is unclear. In this study, we used dynamic contrast-enhanced (DCE) MRI to quantify regional BBB permeability in syphilis (non-NS) patients and detected several molecular biomarkers of cerebrospinal fluid (CSF). We found that BBB permeability values in the hippocampus, white matter, and cortex inferior temporal gyrus were correlated with albumin quotient (Qalb), CSF concentrations of interleukin IL-6 and IL-10. Moreover, BBB breakdown in white matter was correlated with CSF concentrations of sICAM-1 and sVCAM-1. In conclusion, our data suggest that BBB integrity may be liable to be disrupted in syphilis (non-NS) patients, patients with high HbA1c levels, as well as syphilis (non-NS) patients with high HbA1c levels, and it is particularly important to control blood glucose in these patients.

A novel 131 I-radiolabeled probe with aromatic boronate motif (131 I-EIPBA) was designed to target progesterone receptor (PR)-positive breast cancer with enhanced nucleus uptake. Acetylene progesterone was conjugated with pegylated phenylboronic acid via click reaction and radiolabeled with 131 I to afford 131 I-EIPBA. Meanwhile, 131 I-EIPB without boronate was prepared as control agent. After determination of the lipophilicity and stability of these tracers, in vitro cell uptake studies and in vivo biodistribution in rats were performed to verify the enhanced nucleus uptake and PR targeting ability of 131 I-EIPBA. 131 I-EIPBA was obtained with moderate radiochemical yield (40.35 ± 3.52%) and high radiochemical purity (>98%). As expected, the high binding affinity (39.58 nM) of 131 I-EIPBA for PR was determined by cell binding assay. The internalization ratio of 131 I-EIPBA was remarkably higher than that of 131 I-EIPB in PR-positive MCF-7 cells. Furthermore, the enhanced nucleus uptake of 131 I-EIPBA (0.59 ± 0.02%) was found to be significantly higher than that of 131 I-EIPB (0.13 ± 0.01%) in MCF-7 cells. A novel 131 I-EIPBA compound was developed for PR targeting with improved cellular nucleus uptake. Furthermore, the introduction of aromatic boronate motif provides a worthwhile strategy for enhancing the nuclear receptor targeting of tracers.

Radioactive iodine labeled gold nanomaterials (Au NMs) have been widely used in biomedical application such as cell tracking and disease theranostics. The radiolabeling can be accomplished via simply mixing Na131I and Au NMs ([131I(−1)] Au NRs) due to the specific absorption between iodide ions and Au NMs. However, it is reported that the absorption strength is highly dependent on the incubation medium and the serious detachment of 131I from [131I(−1)] Au NRs-PEG in vivo inhibited their application. We found that adding a simple preoxidization treatment of Na131I could greatly improve their radiochemical stability both in vitro and in vivo. The [131I(0)] Au NRs-PEG we prepared barely showed iodine detachment in different media and demonstrated 6 times higher cellular internalization of radioactivity than that of [131I(−1)] Au NRs-PEG since the detached radioiodine of which could not enter the cells. The mechanism study pointed out that the preoxidized iodide could chemically react with Au NRs, mediating A...

A novel coumarin analogue, synthesized from 2-formylcinnamic acid and resorcinol via acid catalyzed condensation and intramolecular rearrangement, is used for pH-independent staining of lysosome in live cells via lysosomal esterase mediated fluorogenic deacetylation.

Endoscopic video sequences provide surgeons with much structural information (e.g., vessels and neurovascular bundles) that guides them to accurately manipulate various surgical tools and avoid surgical risks. Unfortunately, it is difficult for surgeons to intuitively perceive these small structures with tiny pulsation motion on endoscopic images. This work proposes a new endoscopic video motion magnification method to accurately generate the amplified pulsation motion that can be intuitively and easily visualized by surgeons. The proposed method explores a new temporal filtering for Eulerian motion magnification method to precisely magnify the tiny pulsation motion and simultaneously suppress noise and artifacts in endoscopic videos. We evaluate our approach on surgical endoscopic videos acquired in robotic prostatectomy. The experimental results demonstrate that our proposed temporal filtering method essentially outperforms other filters in current video motion magnification approaches, while it provides better visual quality and quantitative assessment than other methods.

Persistent luminescence nanoparticles (PLNPs) with rechargeable near-infrared afterglow properties attract much attention for tumor diagnosis in living animals since they can avoid tissue autofluorescence and greatly improve the signal-to-background ratio. Using UV, visible light, or X-ray as excitation sources to power up persistent luminescence (PL) faces the challenges such as limited tissue penetration, inefficient charging capability, or tissue damage caused by irradiation. Here, it is proved that radiopharmaceuticals can efficiently excite ZnGa2 O4 :Cr3+ nanoparticles (ZGCs) for both fluorescence and afterglow luminescence via Cerenkov resonance energy transfer as well as ionizing radiation. 18 F-FDG, a clinically approved tumor-imaging radiopharmaceutical with a short decay half-life around 110 min, is successfully used as the internal light source to in vivo excite intravenously injected ZGCs for tumor luminescence imaging over 3 h. The luminescence with similar decay time can be re-obtained for multiple times upon injection of 18 F-FDG at any time needed with no health concern. It is believed this strategy can not only provide tumor luminescence imaging with high sensitivity, high contrast, and long decay time at desired time, but also guarantee the patients much less radiation exposure, greatly benefiting image-guided surgery in the future.

Stressed organelles are often challenging to image with canonical organelle probes owing to their propensity to dissipate from stressed organelles. We herein report the imaging of stressed lysosomes with color-switchable glyco-probes that contain an entity of mannose-6-carboxylate or sialic acid for targeting to and long-term retention in stressed lysosomes, and a diad of fluorescein/rhodamine-X-lactam exhibiting dramatic red-to-green fluorescence shift upon pH elevation. Relative to acidotropic dyes prone to dissipate from pH-elevated lysosomes, both glyco-probes are stably trapped in lysosomes without resorting to lysosomal acidity. Importantly, these probes are red emissive in acidic lysosomes (pH 4.5-5.8), but switched to green fluorescence in lysosomes of pH 6.0-7.4, allowing dual color discrimination of lysosomal pH alterations in cell starvation. These results support the use of sugar-armed sensors to investigate stressed lysosomes in biology and disease.

Intercellular adhesion molecule-1(ICAM-1) is a potential molecular target and biomarker for triple negative breast cancer (TNBC) therapy and diagnosis. In this study, aICAM-1 was radioiodinated with 125I/131I in high radiochemical yield and the probes for TNBC tumor targeting and radioimmunotherapy were evaluated in tumor-bearing mice. High and specific accumulation of 125I-aICAM1 in TNBC MDA-MB-231 tumor was observed in SPECT imaging and the tumor grew was inhibited obviously by 131I-aICAM1. Thus, the radioiodinated aICAM1 could serve as potential agents for TNBC theranostics.

Background and Objective TSPO (translocator protein, 18 kDa) is up-regulated in activated macrophages, and serves as an attractive target for macrophages molecular imaging. Previous studies showed that TSPO radiotracer can visualize arthritis via positron emission tomography (PET). Compared with PET, single photon emission computed tomography (SPECT) has several advantages, such as lower cost and commercial availability. The aim of the present study is to develop the 99mTc-labeled TSPO ligand CB86 as a novel SPECT probe for imaging of rheumatoid arthritis and preliminary evaluating the effectiveness of steroid anti-inflammatory therapy. Methods A novel TSPO ligand CB86 was linked to DTPAA and then labeled with 99mTc to obtain 99mTc-DTPA-CB86. The labeling efficiency, radiochemical purity, and stability were determined in vitro. In vitro cellular uptake, efflux and binding affinity of 99mTc-DTPA-CB86 to TSPO were performed on RAW264.7 macrophage cells. The distribution and SPECT studies were conducted on Freund’s Adjuvant-Induced Left Arthritis in rats after the injection of 99mTc-DTPA-CB86 with or without co-injection of unlabeled DTPA-CB86. Result The radiosynthesis of 99mTc-DTPA-CB86 was completed successfully with the labeling yields and radiochemical purity of 95.86 ± 2.45 % and 97.45 ± 0.69 %, respectively. 99mTc-DTPA-CB86 displayed good stability, which the radiochemical purity was more than > 90%, in the saline or mouse serum at 4 h. It also exhibited high specific TSPO binging in RAW264.7 macrophage cells in vitro. The highest uptake ratio was (36.45 ± 2.18) % at 3 h after incubation, and decreased significantly after adding excessive unlabeled DTPA-CB86. 99mTc-DTPA-CB86 bound to TSPO with low nanomolar affinity (IC50 =0.49 nM) in RAW264.7 cells. The cell efflux study showed that 99mTc-DTPA-CB86 has good cell retention by RAW264.7 cells, with only about 13.99 % (decreased from (33.31 ± 2.34) % to (19.32 ± 2.01) % of total input radioactivity) of 99mTc-DTPA-CB86 efflux observed during 4.5 h to 8 h incubation. Biodistribution studies showed the left inflammatory ankle uptake was 2.35±0.10 %ID/g, and the inflammatory ankle to muscle ratio was 3.01 ± 0.09 at 180 min after injection. Small animal SPET imaging studies revealed that 99mTc-DTPA-CB86 could clearly identify left inflammatory ankle with good contrast at 30-180 min after injection. Uptake of 99mTc-DTPA-CB86 in the inflammatory ankles could be largely blocked by an excess of unlabled DTPA-CB86. Furthermore, 99mTc-DTPA-CB86 accumulation in the left inflammatory ankles significantly decreased in RA rats treated with dexamethasone. Conclusion 99mTc-DTPA-CB86 can be readily synthesized, clearly visualized arthritis with low background and monitor therapy response of anti-inflammatory therapy, suggesting its potential as a novel promising molecular probe targeting TSPO for arthritic SPECT imaging. Key words TSPO (translocator protein, 18 kDa); Technetium radioisotope; SPECT imaging; Rheumatoid arthritis; Macrophages; Glucocorticoids.