Supramolecular thermoplastic with 0.5 Pa·s melt viscosity.

Design of materials with polymer-like properties at service temperature but able to flow like simple liquids when heated remains one of the important challenges of supramolecular chemistry. Combining these antagonistic properties is highly desirable to provide durability, processability, and recyclability of materials. Here, we explore a new strategy based on polycondensation reactions to design supramolecular polymer materials with stress at break above 10 MPa and melt viscosity lower than 1 Pa·s. We report the synthesis and rheological and mechanical properties (uniaxial tensile tests) of supramolecular polymers based on a multiblock polyamide architecture. The flexibility of polycondensation reactions made it possible to control the molecular size distribution, the strength of hydrogen bonds, and the crystallization of middle and end groups and to achieve targeted properties.

Suppression of mesoscopic order by complementary interactions in supramolecular polymers.

We show here that complementary interactions can suppress mesoscopic order and thus lead to a counterintuitive change in material properties. We present results for telechelic supramolecular polymers based on poly(propylene oxide) (PPO), thymine (Thy), and diaminotriazine (DAT). The self-complementary systems based on Thy exhibit lamellar order and 2D crystallization of Thy in the bulk. We show that the microphase segregation is inhibited by addition of DAT: the strong complementary Thy-DAT interaction inhibits crystallization of thymine in microdomains and lamellar structuration. As a result, the supramolecular polymer with only weakly self-complementary stickers is a solid, whereas the supramolecular polymer with strongly complementary stickers is a liquid.

Prognostic Value of Metabolic, Volumetric and Textural Parameters of Baseline [18F]FDG PET/CT in Early Triple-Negative Breast Cancer.

(1) Background: triple-negative breast cancer (TNBC) remains a clinical and therapeutic challenge primarily affecting young women with poor prognosis. TNBC is currently treated as a single entity but presents a very diverse profile in terms of prognosis and response to treatment. Positron emission tomography/computed tomography (PET/CT) with 18F-fluorodeoxyglucose ([18F]FDG) is gaining importance for the staging of breast cancers. TNBCs often show high [18F]FDG uptake and some studies have suggested a prognostic value for metabolic and volumetric parameters, but no study to our knowledge has examined textural features in TNBC. The objective of this study was to evaluate the association between metabolic, volumetric and textural parameters measured at the initial [18F]FDG PET/CT and disease-free survival (DFS) and overall survival (OS) in patients with nonmetastatic TBNC. (2) Methods: all consecutive nonmetastatic TNBC patients who underwent a [18F]FDG PET/CT examination upon diagnosis between 2012 and 2018 were retrospectively included. The metabolic and volumetric parameters (SUVmax, SUVmean, SUVpeak, MTV, and TLG) and the textural features (entropy, homogeneity, SRE, LRE, LGZE, and HGZE) of the primary tumor were collected. (3) Results: 111 patients were enrolled (median follow-up: 53.6 months). In the univariate analysis, high TLG, MTV and entropy values of the primary tumor were associated with lower DFS (p = 0.008, p = 0.006 and p = 0.025, respectively) and lower OS (p = 0.002, p = 0.001 and p = 0.046, respectively). The discriminating thresholds for two-year DFS were calculated as 7.5 for MTV, 55.8 for TLG and 2.6 for entropy. The discriminating thresholds for two-year OS were calculated as 9.3 for MTV, 57.4 for TLG and 2.67 for entropy. In the multivariate analysis, lymph node involvement in PET/CT was associated with lower DFS (p = 0.036), and the high MTV of the primary tumor was correlated with lower OS (p = 0.014). (4) Conclusions: textural features associated with metabolic and volumetric parameters of baseline [18F]FDG PET/CT have a prognostic value for identifying high-relapse-risk groups in early TNBC patients.

Order-disorder transition in supramolecular polymers.

In supramolecular polymers, directional interactions control the constituting units connectivity, but dispersion forces may conspire to make complex organizations. Here we report on the long-range order and order-disorder transition (ODT) of main-chain supramolecular polymers based on poly(propylene oxide) (PPO) spacers functionalized on both ends with thymine. Below the ODT temperature (T(ODT)), these compounds are semicrystalline with a lamellar structure, showing nanophase separation between crystallized thymine planes and amorphous PPO layers. Above T(ODT), they are amorphous and homogeneous even though their X-ray scattering spectrum reveals a peak. This peak is due to correlation hole effect resulting from contrast between end-functional groups and spacer. Macroscopically, the transition is accompanied by dramatic flow and mechanical properties changes.

Structural and Barrier Properties of Compatibilized PE/PA6 Multinanolayer Films.

The barrier performance and structural lightening of organic materials are increasingly desired and constitute a major challenge for manufacturers, particularly for transport and packaging. A promising technique which tends to emerge in recent years is that of multinanolayer coextrusion. The advantage is that it can produce multilayers made of thousands of very thin layers, leading to new properties due to crystalline morphology changes induced by confinement. This paper is focusing on the study of multinanolayered films with alternated polyethylene (PE), compatibilizer (PEgMA) and polyamide 6 (PA6) layers and made by a forced assembly coextrusion process equipped with layer multiplying elements (LME). PE/PA6 multilayer films consisting of 5 to 2049 layers (respectively 0 to 9 LME) were successfully obtained with well-organized multilayered structure. The evolution of the morphology and the microstructure of these two semi-crystalline polymers, when the thickness of each polymer layer decreases from micro-scale to nano-scale, was correlated to the water and gas transport properties of the PE/PA multilayers. The expected improvement of barrier properties was limited due to the on-edge orientation of crystals in very thin PE and PA6 layers. Despite this change of crystalline morphology, a slight improvement of the gas barrier properties was shown by comparing experimental results with permeabilities predicted on the basis of a serial model developed by considering a PE/PA6 interphase. This interphase observed by TEM images and the on-edge crystal orientation in multilayers were evidenced from mechanical properties showing an increase of the stiffness and the strength.

Prognostic Impact of Pretherapeutic FDG-PET in Localized Anal Cancer.

Due to the heterogeneity of tumour mass segmentation methods and lack of consensus, our study evaluated the prognostic value of pretherapeutic positron emission tomography with fluorodeoxyglucose (FDG-PET) metabolic parameters using different segmentation methods in patients with localized anal squamous cell carcinoma (SCC). Eighty-one patients with FDG-PET before radiochemotherapy were retrospectively analyzed. Semiquantitative data were measured with three fixed thresholds (35%, 41% and 50% of Maximum Standardized Uptake Value (SUVmax)) and four segmentation methods based on iterative approaches (Black, Adaptive, Nestle and Fitting). Metabolic volumes of primary anal tumour (P-MTV) and total tumour load (T-MTV: P-MTV+ lymph node MTV) were calculated. The primary endpoint was event-free survival (EFS). Seven multivariate models were created to compare FDG-PET tumour volumes prognostic impact. For all segmentation thresholds, PET metabolic volume parameters were independent prognostic factor and T-MTV variable was consistently better associated with EFS than P-MTV. Patient's sex was an independent variable and significantly correlated with EFS. With fixed threshold segmentation methods, 35% of SUVmax threshold seemed better correlated with EFS and the best cut-off for discrimination between a low and high risk of event occurrence was 40 cm3. Determination of T-MTV by FDG-PET using fixed threshold segmentation is useful for predicting EFS for primary anal SCC. If these data are confirmed in larger studies, FDG-PET could contribute to individualized patient therapies.

Spin Coating and Micro-Patterning Optimization of Composite Thin Films Based on PVDF.

We optimize the elaboration of very thin film of poly(vinylidene fluoride) (PVDF) polymer presenting a well-controlled thickness, roughness, and nano-inclusions amount. We focused our effort on the spin coating elaboration technique which is easy to transfer to an industrial process. We show that it is possible to obtain continuous and smooth thin films with mean thicknesses of 90 nm by properly adjusting the concentration and the viscosity of the PVDF solution as well as the spin rate and the substrate temperature of the elaboration process. The electro-active phase content versus the magnetic and structural properties of the composite films is reported and fully discussed. Last but not least, micro-patterning optical lithography combined with plasma etching has been used to obtain well-defined one-dimensional micro-stripes as well as squared-rings, demonstrating the easy-to-transfer silicon technology to polymer-based devices.

Dual time point [18F]FLT-PET for differentiating proliferating tissues vs non-proliferating tissues.

PURPOSE: For differentiating tumor from inflammation and normal tissues, fluorodeoxyglucose ([18F]FDG) dual time point PET could be helpful. Albeit [18F]FLT is more specific for tumors than [18F]FDG; we explored the role of dual time point [18F]FLT-PET for discriminating benign from malignant tissues. METHODS: Before any treatment, 85 womens with de novo unifocal breast cancer underwent three PET acquisitions at 33.94 ± 8.01 min (PET30), 61.45 ± 8.30 min (PET60), and 81.06 ± 12.12 min (PET80) after [18F]FLT injection. Semiquantitative analyses of [18F]FLT uptake (SUV) were carried out on tumors, liver, bone marrow (4th thoracic vertebra (T4) and humeral head), descending thoracic aorta, muscle (deltoid), and contralateral normal breast. Repeated measures ANOVA tests and Tukey's posttests were used to compare SUVmax of each site at the three time points. RESULTS: There was a significant increase in SUVmax over time for breast lesions (5.58 ± 3.80; 5.97 ± 4.56; 6.19 ± 4.42; p < 0.0001) (m ± SD for PET30, PET60, and PET80, respectively), and bone marrow (for T4, 8.21 ± 3.17, 9.64 ± 3.66, 10.85 ± 3.63, p < 0.0001; for humeral head, 3.36 ± 1.79, 3.87 ± 1.89, 4.39 ± 2.00, p < 0.0001). A significant decrease in SUVmax over time was observed for liver (6.79 ± 2.03; 6.24 ± 1.99; 5.57 ± 1.74; p < 0.0001), muscle (0.95 ± 0.28; 0.93 ± 0.29; 0.86 ± 0.20; p < 0.027), and aorta (1.18 ± 0.34; 1.01 ± 0.32; 0.97 ± 0.30; p < 0.0001). No significant difference was observed for SUVmax in contralateral breast (0.8364 ± 0.40; 0.78 ± 0.38; 0.80 ± 0.35). CONCLUSION: [18F]FLT-SUVmax increased between 30 and 80 min only in proliferating tissues. This could be helpful for discriminating between residual tumor and scar tissue.

Uncommon breast tumor attenuation artifact on radionuclide ventriculography.

A 39-year-old woman with locally advanced left breast cancer (T4 N0 M0) underwent equilibrium radionuclide ventriculography for baseline assessment of left ventricular function before neoadjuvant chemotherapy. The left ventricular ejection fraction was 76% at 75 beats per minute, without localized wall motion abnormality. In the best septal left anterior oblique projection, a large photopenic "halo" surrounded the cardiac chambers, mimicking a pericardial effusion. In fact, this aspect resulted from an attenuation artifact by a large left breast tumor, as demonstrated by FDG-PET/CT imaging.

Chemotherapy of metastatic hepatoid adenocarcinoma: Literature review and two case reports with cisplatin etoposide.

Hepatoid adenocarcinoma (HAC) is a rare and aggressive cancer subtype with a poor prognosis under metastatic conditions. Currently, there is no specific chemotherapy treatment protocol for advanced stages of the disease. This review evaluates two cases of HAC of gastric cardia with synchronous liver metastasis, which were successfully treated by chemotherapy with cisplatin (25 mg/m2 each day) (day 1 to day 3) and etoposide (100 mg/m2) (day 1 to day 3), every three weeks. A structured literary evaluation and reviewed pertinent articles are additionally presented to analyse the different approaches for the treatment of metastatic HAC (mHAC). The two described case reports demonstrated good partial responses to treatment and one of the two patients exhibited a good prognosis after a 9-year follow-up. A total of 20 case reports concerning the use of chemotherapy in mHAC were presented in the literature, 11 of which were regarding gastric HACs. The two aforementioned cases result in a total of 22 reports, 11 of which exhibited objective responses to chemotherapy, 8 patients demonstrated a partial response and 3 a complete response. The cisplatin-based regimen concerned 55% (12/22) patients and enabled 9 (75%) to exhibit a partial or complete response. A total of three patients exhibited a good prognosis in the long-term follow-up, all of them treated with a cisplatin-based regimen. It was demonstrated that the usual digestive regimens were not efficient in the treatment of HAC. In the absence of prospective trials, it may be hypothesized that cisplatin-based chemotherapy may be the most efficient first-line treatment in mHAC, with a 75% patient response, in accordance with the literature and follow-up cases.

Initial FDG-PET/CT predicts survival in adults Ewing sarcoma family of tumors.

PURPOSE: The aim of this retrospective study was to determine, at baseline, the prognostic value of different FDG-PET/CT quantitative parameters in a homogenous Ewing Sarcoma Family of Tumors (ESFT) adult population, compared with clinically relevant prognostic factors. METHODS: Adult patients from 3 oncological centers, all with proved ESFT, were retrospectively included. Quantitative FDG-PET/CT parameters (SUV (maximum, peak and mean), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of the primary lesion of each patient were recorded before treatment, as well as usual clinical prognostic factors (stage of disease, location, tumor size, gender and age). Then, their relation with progression free survival (PFS) and overall survival (OS) was evaluated. RESULTS: 32 patients were included. Median age was 21 years (range, 15 to 61). Nineteen patients (59%) were initially metastatic. On multivariate analysis, high SUVmax remained independent predictor of worst OS (p=0.02) and PFS (p=0.019), metastatic disease of worst PFS (p=0.01) and high SUVpeak of worst OS (p=0.01). Optimal prognostic cut-off of SUVpeak was found at 12.5 in multivariate analyses for PFS and OS (p=0.0001). CONCLUSIONS: FDG-PET/CT, recommended at ESFT diagnosis for initial staging, can be a useful tool for predicting long-term adult patients outcome through semi-quantitative parameters.

The impact of (18)F-FDG-PET/CT on Merkel cell carcinoma management: a retrospective study of 66 scans from a single institution.

PURPOSE: Merkel cell carcinomas (MCC) are neuroendocrine skin tumours frequently responsible for lymph node recurrence and metastatic disease and for which optimal management remains to be defined. The objective of this study was to evaluate the impact of (18)F-fluorodeoxyglucose ((18)F-FDG)-PET/computed tomography (CT) on the staging and treatment of MCC patients. MATERIALS AND METHODS: Twenty-three patients with a histologic diagnosis of MCC explored by (18)F-FDG-PET/CT between 2004 and 2012 were retrospectively included in the study. The detection of new lesions and the change in tumour staging and treatment were evaluated. For each patient, the (18)F-FDG-PET/CT results were compared with histological, clinical and imaging data. RESULTS: Sixty-six (18)F-FDG-PET/CT scans were performed at initial presentation (n=18), during subsequent monitoring (n=34) or during evaluation of chemotherapy response (n=14). The sensitivity, specificity and positive and negative predictive values of the (18)F-FDG-PET/CT were 97, 89, 94 and 94%, respectively. Two false-positive results (lymphadenitis) and one false-negative result (regional metastatic lymph nodes) were accounted for. Lesions not detected clinically or by conventional imaging techniques were found in 44% of the 52 (18)F-FDG-PET/CTs performed at initial presentation and subsequent monitoring, with, respectively, 50 and 41% of scans identifying new lesions. At initial presentation, (18)F-FDG-PET/CT led to a change in tumour staging in 39% of patients. Patient management was modified by (18)F-FDG-PET/CT results in one-third of patients (33% of patients at initial presentation, 32% during subsequent monitoring and 36% during evaluation of chemotherapy response). F-FDG-PET/CT incidentally detected four additional histologically confirmed cancers. CONCLUSION: This retrospective study confirms the important impact of (18)F-FDG-PET/CT on the management of MCC patients.

Unusual uptake of 18FDG by a hepatic adenoma.

Hepatic adenoma is a rare, benign tumor (with potential for malignant degeneration) and its diagnosis is difficult because its presentation is highly variable in medical imaging, particularly with MRI. In such cases, the use of a hepatic biopsy is usually recommended. (18)FDG-PET/CT provides a very significant predictive value for malignant hepatic lesions. In addition, the occurrence of an (18)FDG-avid benign tumor is a rare event. We hereby present the case of a patient with advanced breast cancer for whom an (18)FDG-PET/CT showed a focal hepatic uptake. A subsequent biopsy provided a diagnosis of a hepatic adenoma.

Use of FDG-PET/CT for peritoneal carcinomatosis before hyperthermic intraperitoneal chemotherapy.

BACKGROUND: Peritoneal carcinomatosis (PC) is associated with a very poor prognosis. Complete cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy has been shown to improve survival rates of PC. However, this treatment is beneficial for patients if the complete cytoreductive surgery is macroscopically completed before implementing hyperthermic intraperitoneal chemotherapy. Even so, a strict selection of patients is of fundamental importance because of the invasive nature of the intervention. The aim of this study was to assess the performance of FDG-PET/CT examinations for the diagnosis and evaluation of the extent of PC. METHODS: A retrospective analysis was conducted on 28 consecutive patients with suspected PC, scheduled for a complete cytoreductive surgery and hyperthermic intraperitoneal chemotherapy, and who underwent an FDG-PET/CT examination. We compared the results of PET examinations with histological and intraoperative findings. The extent of PC was assessed precisely using a simplified 'peritoneal cancer index', within the three modalities (PET, surgery and histology). RESULTS: Of 28 patients, 23 had histological PC. The sensitivity and specificity of the PET examination for the diagnosis of PC were, respectively, 82 and 100%. Even if the extent of PC was underestimated by PET, there was a good correlation when compared with histology and intraoperative results. CONCLUSION: PET presented a good performance level in the diagnosis and evaluation of the extent of PC. PET/CT examinations could be useful to avoid unnecessary surgery.