Modulation of blood-tumor barrier transcriptional programs improves intra-tumoral drug delivery and potentiates chemotherapy in GBM.

Glioblastoma (GBM) is the most common malignant primary brain tumor. GBM has an extremely poor prognosis and new treatments are badly needed. Efficient drug delivery to GBM is a major obstacle as the blood-brain barrier (BBB) prevents passage of the majority of cancer drugs into the brain. It is also recognized that the blood-brain tumor barrier (BTB) in the growing tumor represents a challenge. The BTB is heterogeneous and poorly characterized, but similar to the BBB it can prevent therapeutics from reaching effective intra-tumoral doses, dramatically hindering their potential. Here, we identified a 12-gene signature associated with the BTB, with functions related to vasculature development, morphogenesis and cell migration. We identified CDH5 as a core molecule in this set and confirmed its over-expression in GBM vasculature using spatial transcriptomics of GBM patient specimens. We found that the indirubin-derivative, 6-bromoindirubin acetoxime (BIA), could downregulate CDH5 and other BTB signature genes, causing endothelial barrier disruption in endothelial monolayers and BBB 3D spheroids in vitro. Treatment of tumor-bearing mice with BIA enabled increased intra-tumoral accumulation of the BBB non-penetrant chemotherapeutic drug cisplatin and potentiated cisplatin-mediated DNA damage by targeting DNA repair pathways. Finally, using an injectable BIA nanoparticle formulation, PPRX-1701, we significantly improved the efficacy of cisplatin in patient-derived GBM xenograms and prolonged their survival. Overall, our work reveals potential targets at the BTB for improved chemotherapy delivery and the bifunctional properties of BIA as a BTB modulator and potentiator of chemotherapy, supporting its further development.

Has the COVID-19 pandemic changed existing patterns of non-COVID-19 health care utilization? A retrospective analysis of six regions in Europe.

BACKGROUND: Resilience of national health systems in Europe remains a major concern in times of multiple crises and as more evidence is emerging relating to the indirect effects of the COVID-19 pandemic on health care utilization (HCU), resulting from de-prioritization of regular, non-pandemic healthcare services. Most extant studies focus on regional, disease specific or early pandemic HCU creating difficulties in comparing across multiple countries. We provide a comparatively broad definition of HCU across multiple countries, with potential to expand across regions and timeframes. METHODS: Using a cross-country federated research infrastructure (FRI), we examined HCU for acute cardiovascular events, elective surgeries and serious trauma. Aggregated data were used in forecast modelling to identify changes from predicted European age-standardized counts via fitted regressions (2017-19), compared against post-pandemic data. RESULTS: We found that elective surgeries were most affected, universally falling below predicted levels in 2020. For cardiovascular HCU, we found lower-than-expected cases in every region for heart attacks and displayed large sex differences. Serious trauma was the least impacted by the COVID-19 pandemic. CONCLUSION: The strength of this study comes from the use of the European Population Health Information Research Infrastructure's (PHIRI) FRI, allowing for rapid analysis of regional differences to assess indirect impacts of events such as pandemics. There are marked differences in the capacity of services to return to normal in terms of elective surgery; additionally, we found considerable differences between men and women which requires further research on potential sex or gender patterns of HCU during crises.

Stepwise conversion of the Cys6[4Fe-3S] to a Cys4[4Fe-4S] cluster and its impact on the oxygen tolerance of [NiFe]-hydrogenase.

The membrane-bound [NiFe]-hydrogenase of Cupriavidus necator is a rare example of a truly O2-tolerant hydrogenase. It catalyzes the oxidation of H2 into 2e- and 2H+ in the presence of high O2 concentrations. This characteristic trait is intimately linked to the unique Cys6[4Fe-3S] cluster located in the proximal position to the catalytic center and coordinated by six cysteine residues. Two of these cysteines play an essential role in redox-dependent cluster plasticity, which bestows the cofactor with the capacity to mediate two redox transitions at physiological potentials. Here, we investigated the individual roles of the two additional cysteines by replacing them individually as well as simultaneously with glycine. The crystal structures of the corresponding MBH variants revealed the presence of Cys5[4Fe-4S] or Cys4[4Fe-4S] clusters of different architecture. The protein X-ray crystallography results were correlated with accompanying biochemical, spectroscopic and electrochemical data. The exchanges resulted in a diminished O2 tolerance of all MBH variants, which was attributed to the fact that the modified proximal clusters mediated only one redox transition. The previously proposed O2 protection mechanism that detoxifies O2 to H2O using four protons and four electrons supplied by the cofactor infrastructure, is extended by our results, which suggest efficient shutdown of enzyme function by formation of a hydroxy ligand in the active site that protects the enzyme from O2 binding under electron-deficient conditions.

Non-Hydrolysable Analogues of Cyclic and Branched Condensed Phosphates: Chemistry and Chemical Proteomics.

Studies into the biology of condensed phosphates almost exclusively cover linear polyphosphates. However, there is evidence for the presence of cyclic polyphosphates (metaphosphates) in organisms and for enzymatic digestion of branched phosphates (ultraphosphates) with alkaline phosphatase. Further research of non-linear condensed phosphates in biology would profit from interactome data of such molecules, however, their stability in biological media is limited. Here we present syntheses of modified, non-hydrolysable analogues of cyclic and branched condensed phosphates, called meta- and ultraphosphonates, and their application in a chemical proteomics approach using yeast cell extracts. We identify putative interactors with overlapping hits for structurally related capture compounds underlining the quality of our results. The datasets serve as starting point to study the biological relevance and functions of meta- and ultraphosphates. In addition, we examine the reactivity of meta- and ultraphosphonates with implications for their "hydrolysable" analogues: Efforts to increase the ring-sizes of meta- or cyclic ultraphosphonates revealed a strong preference to form trimetaphosphate-analogue structures by cyclization and/or ring-contraction. Using carbodiimides for condensation, the so far inaccessible dianhydro product of ultraphosphonate, corresponding to P4 O11 2- , was selectively obtained and then ring-opened by different nucleophiles yielding modified cyclic ultraphosphonates.

Structure of the actively translating plant 80S ribosome at 2.2 Å resolution.

In plant cells, translation occurs in three compartments: the cytosol, the plastids and the mitochondria. While the structures of the (prokaryotic-type) ribosomes in plastids and mitochondria are well characterized, high-resolution structures of the eukaryotic 80S ribosomes in the cytosol have been lacking. Here the structure of translating tobacco (Nicotiana tabacum) 80S ribosomes was solved by cryo-electron microscopy with a global resolution of 2.2 Å. The ribosome structure includes two tRNAs, decoded mRNA and the nascent peptide chain, thus providing insights into the molecular underpinnings of the cytosolic translation process in plants. The map displays conserved and plant-specific rRNA modifications and the positions of numerous ionic cofactors, and it uncovers the role of monovalent ions in the decoding centre. The model of the plant 80S ribosome enables broad phylogenetic comparisons that reveal commonalities and differences in the ribosomes of plants and those of other eukaryotes, thus putting our knowledge about eukaryotic translation on a firmer footing.

Do patients with pathological health anxiety fear COVID-19? A time-course analysis of 12 single cases during the "first wave" of the COVID-19 pandemic in Germany.

OBJECTIVE: Pre-existing health anxiety is associated with an intensified affective response to the novel COVID-19 pandemic in the general population. Still, results on the reaction of people with a diagnosis of pathological health anxiety (i.e., hypochondriasis) are scarce. METHODS: In the present study, we investigated the course of (health) anxiety related to SARS-CoV-2/COVID-19 in comparison to (health) anxiety related to other severe diseases (e.g., cancer) in a sample of 12 patients with the diagnosis of pathological health anxiety during the "first wave" of the COVID-19 pandemic in Germany. Both SARS-CoV-2 related anxiety and anxiety related to other severe diseases were assessed weekly over 16 measurement points (30.03.-19.07.2020) and primarily analyzed with fixed effects regression analyses. RESULTS: Unexpectedly, SARS-CoV-2 related anxiety was on average significantly lower than anxiety related to other severe diseases (d = -0.54, p < .001) and not significantly associated with anxiety related to other severe diseases or pre-COVID-19 health anxiety. CONCLUSION: It therefore appears premature to assume that SARS-CoV-2 related anxiety and other health worries are necessarily strongly interrelated and comparably high in people with pathological health anxiety.

Engineered red blood cells as an off-the-shelf allogeneic anti-tumor therapeutic.

Checkpoint inhibitors and T-cell therapies have highlighted the critical role of T cells in anti-cancer immunity. However, limitations associated with these treatments drive the need for alternative approaches. Here, we engineer red blood cells into artificial antigen-presenting cells (aAPCs) presenting a peptide bound to the major histocompatibility complex I, the costimulatory ligand 4-1BBL, and interleukin (IL)-12. This leads to robust, antigen-specific T-cell expansion, memory formation, additional immune activation, tumor control, and antigen spreading in tumor models in vivo. The presence of 4-1BBL and IL-12 induces minimal toxicities due to restriction to the vasculature and spleen. The allogeneic aAPC, RTX-321, comprised of human leukocyte antigen-A*02:01 presenting the human papilloma virus (HPV) peptide HPV16 E711-19, 4-1BBL, and IL-12 on the surface, activates HPV-specific T cells and promotes effector function in vitro. Thus, RTX-321 is a potential 'off-the-shelf' in vivo cellular immunotherapy for treating HPV + cancers, including cervical and head/neck cancers.

Reappraisal of a 2-Cm Cut-off Size for the Management of Cystic Pancreatic Neuroendocrine Neoplasms: A Multicenter International Study.

OBJECTIVE: The aim of this study was to characterize an international cohort of resected cystic pancreatic neuroendocrine neoplasms (cPanNENs) and identify preoperative predictors of aggressive behavior. BACKGROUND: The characteristics of cPanNENs are unknown and their clinical management remains unclear. An observational strategy for asymptomatic cPanNENs ≤2 cm has been proposed by recent guidelines, but evidence is scarce and limited to single-institutional series. METHODS: Resected cPanNENs (1995-2017) from 16 institutions worldwide were included. Solid lesions (>50% solid component), functional tumors, and MEN-1 patients were excluded. Aggressiveness was defined as lymph node (LN) involvement, G3 grading, distant metastases, and/or recurrence. RESULTS: Overall, 263 resected cPanNENs were included, among which 177 (63.5%) were >2 cm preoperatively. A preoperative diagnosis of cPanNEN was established in 162 cases (61.6%) and was more frequent when patients underwent endoscopic ultrasound [EUS, odds ratio (OR) 2.69, 95% confidence interval (CI) 1.52-4.77] and somatostatin-receptor imaging (OR 3.681, 95% CI 1.809-7.490), and for those managed in specialized institutions (OR 3.12, 95% CI 1.57-6.21). Forty-one cPanNENs (15.6%) were considered aggressive. In the whole cohort, LN involvement on imaging, age >65 years, preoperative size >2 cm, and pancreatic duct dilation were independently associated with aggressive behavior. In asymptomatic patients, older age and a preoperative size >2 cm remained independently associated with aggressiveness. Only 1 of 61 asymptomatic cPanNENs ≤2 cm displayed an aggressive behavior. CONCLUSIONS: The diagnostic accuracy of cPanNENs is increased by the use of EUS and somatostatin-receptor imaging and is higher in specialized institutions. Preoperative size >2 cm is independently associated with aggressive behavior. Consequently, a watch-and-wait policy for sporadic asymptomatic cPanNENs ≤2 cm seems justified and safe for most patients.

Syk-dependent glycolytic reprogramming in dendritic cells regulates IL-1ß production to ß-glucan ligands in a TLR-independent manner.

Dendritic cells (DCs) activated via TLR ligation experience metabolic reprogramming, in which the cells are heavily dependent on glucose and glycolysis for the synthesis of molecular building blocks essential for maturation, cytokine production, and the ability to stimulate T cells. Although the TLR-driven metabolic reprogramming events are well documented, fungal-mediated metabolic regulation via C-type lectin receptors such as Dectin-1 and Dectin-2 is not clearly understood. Here, we show that activation of DCs with fungal-associated ß-glucan ligands induces acute glycolytic reprogramming that supports the production of IL-1ß and its secretion subsequent to NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome activation. This acute glycolytic induction in response to ß-glucan ligands requires spleen tyrosine kinase signaling in a TLR-independent manner, suggesting now that different classes of innate immune receptors functionally induce conserved metabolic responses to support immune cell activation. These studies provide new insight into the complexities of metabolic regulation of DCs immune effector function regarding cellular activation associated with protection against fungal microbes.

Benchmarking of a checklist for the identification of familial risk for breast and ovarian cancers in a prospective cohort.

The detection of deleterious germline mutations in BRCA1 and BRCA2 considerably influences the clinical management of healthy and diseased carriers. Therefore, the identification of persons at risk who could uptake genetic counseling and testing is pivotal. We developed a checklist with validated criteria to improve the identification, and prospectively evaluate the incidence, of familial cancer history in 5091 breast cancer patients. The rate of 30.4% of patients at high genetic risk underpins the demand for care in risk identification and counseling. The easy-to-use instrument promotes the implementation and dissemination of risk counseling by physicians.

Austria: Health System Review.

This analysis of the Austrian health system reviews recent developments in organization and governance, health financing, health care provision, health reforms and health system performance. Two major reforms implemented in 2013 and 2017 are among the main issues today. The central aim of the reforms that put in place a new governance system was to strengthen coordination and cooperation between different levels of government and self-governing bodies by promoting joint planning, decision-making and financing. Yet despite these efforts, the Austrian health system remains complex and fragmented in its organizational and financial structure. The Austrian population has a good level of health. Life expectancy at birth is above the EU average and low amenable mortality rates indicate that health care is more effective than in most EU countries. Yet, the number of people dying from cardiovascular diseases and cancer is high compared to the EU-28 average. Tobacco and alcohol represent the major health risk factors. Tobacco consumption has not declined over the last decade like in most other EU countries and lies well above the EU-28 average. In terms of performance, the Austrian health system provides good access to health care services. Austrias residents report the lowest levels of unmet needs for medical care across the EU. Virtually all the population is covered by social health insurances and enjoys a broad benefit basket. Yet, rising imbalances between the numbers of contracted and non-contracted physicians may contribute to social and regional inequalities in accessing care. The Austrian health system is relatively costly. It has a strong focus on inpatient care as characterized by high hospital utilization and imbalances in resource allocation between the hospital and ambulatory care sector. The ongoing reforms therefore aim to bring down publicly financed health expenditure growth with a global budget cap and reduce overutilization of hospital care. Efficiency of inpatient care has improved over the reform period but the fragmented financing between the inpatient and ambulatory sector remain a challenge. Current reforms to strengthen primary health care are an important step to further shift activities out of the large and costly hospital sector and improve skill mix within the health workforce.

Crystal structure and functional characterization of selenocysteine-containing glutathione peroxidase 4 suggests an alternative mechanism of peroxide reduction.

Glutathione peroxidases (GPX) are anti-oxidative enzymes that reduce organic and inorganic hydroperoxides to the corresponding alcohols at the expense of reduced glutathione. The human genome involves eight GPX genes and five of them encode for selenocysteine-containing enzymes. Among the human GPX-isoforms, GPX4 is unique since it is capable of reducing complex hydroperoxy ester lipids such as hydroperoxy phospholipids and hydroperoxy cholesterolesters. Using a number of genetically modified mouse strains the biological role of GPX4 has comprehensively characterized but the molecular enzymology is less well explored. This lack of knowledge is partly related to the fact that mammalian selenoproteins are not high-level expressed in conventional overexpression systems. To explore the structural and functional properties of human GPX4 we expressed this selenoprotein in a cysteine-auxotrophic E. coli strain using a semi-chemical expression strategy. The recombinant enzyme was purified in mg amounts from the bacterial lysate to electrophoretic homogeneity and characterized with respect to its protein-chemical and enzymatic properties. Its crystal structure was solved at 1.3 Šresolution and the X-ray data indicated a monomeric protein, which contains the catalytic selenium at the redox level of the seleninic acid. These data suggest an alternative reaction mechanism involving three different redox states (selenol, selenenic acid, seleninic acid) of the catalytically active selenocysteine.

Metformin Decreases the Incidence of Pancreatic Ductal Adenocarcinoma Promoted by Diet-induced Obesity in the Conditional KrasG12D Mouse Model.

Pancreatic ductal adenocarcinoma (PDAC) is a particularly deadly disease. Chronic conditions, including obesity and type-2 diabetes are risk factors, thus making PDAC amenable to preventive strategies. We aimed to characterize the chemo-preventive effects of metformin, a widely used anti-diabetic drug, on PDAC development using the KrasG12D mouse model subjected to a diet high in fats and calories (HFCD). LSL-KrasG12D/+;p48-Cre (KC) mice were given control diet (CD), HFCD, or HFCD with 5 mg/ml metformin in drinking water for 3 or 9 months. After 3 months, metformin prevented HFCD-induced weight gain, hepatic steatosis, depletion of intact acini, formation of advanced PanIN lesions, and stimulation of ERK and mTORC1 in pancreas. In addition to reversing hepatic and pancreatic histopathology, metformin normalized HFCD-induced hyperinsulinemia and hyperleptinemia among the 9-month cohort. Importantly, the HFCD-increased PDAC incidence was completely abrogated by metformin (p < 0.01). The obesogenic diet also induced a marked increase in the expression of TAZ in pancreas, an effect abrogated by metformin. In conclusion, administration of metformin improved the metabolic profile and eliminated the promoting effects of diet-induced obesity on PDAC formation in KC mice. Given the established safety profile of metformin, our findings have a strong translational potential for novel chemo-preventive strategies for PDAC.

Inositol Pyrophosphate Specificity of the SPX-Dependent Polyphosphate Polymerase VTC.

The free energy of nucleotide hydrolysis depends on phosphate concentration. Cells regulate cytosolic phosphate levels by orchestrating phosphate acquisition and storage through inositol pyrophosphates (PP-InsP) and SPX domains. Here, we report the synthesis of the novel 5-PPP-InsP5 containing a triphosphate subunit. Using this and a series of synthetic PP-InsP, we examined the ligand specificity of the SPX domain in the PP-InsP-controlled yeast polyphosphate polymerase VTC. SPX decodes the relative positioning of the phosphoric anhydrides, their structure (diphosphate vs triphosphate), and the presence of other phosphates on the inositol ring. Despite the higher potency of 1,5-(PP)2-InsP4, 5-PP-InsP5 is the primary activator of VTC in cells, indicating that its higher concentration compensates for its lower potency. 1,5-(PP)2-InsP4 levels rise and could become relevant under stress conditions. Thus, SPX domains may integrate PP-InsP dependent signaling to adapt cytosolic phosphate concentrations to different metabolic situations.

Direct growth-inhibitory effects of prostaglandin E2 in pancreatic cancer cells in vitro through an EP4/PKA-mediated mechanism.

BACKGROUND: There is strong evidence linking inflammation and the development of pancreatic ductal adenocarcinoma. Cyclooxygenase-2 (COX-2) and COX-2-derived PGE2 are overexpressed in human and murine pancreatic ductal adenocarcinoma. Several studies have demonstrated an important role of COX-2-derived PGE2 in tumor-stroma interactions; however, the direct growth effects of prostaglandin E2 (PGE2) on pancreatic ductal adenocarcinoma cells is less well defined. Our aim was to investigate the effects of PGE2 on pancreatic ductal adenocarcinoma cell growth and to characterize the underlying mechanisms. METHODS: Human pancreatic ductal adenocarcinoma cell lines, Panc-1 and MIA PaCa-2, were treated with PGE2 in varying doses (0-10 µM). Effects on the phosphorylation of ERK1/2 were evaluated by Western blot. Colony formation was observed for cells treated with PGE2 for 11 days. DNA synthesis was determined by (3H)-thymidine incorporation assay. Gene expression of E-type prostaglandin (EP)2/EP4 receptors and their correlation with survival in patients with pancreatic ductal adenocarcinoma were assessed using the RNA-Seq data set from The Cancer Genome Atlas Research Network. RESULTS: PGE2 decreased the size and number of colonies in Panc-1 but not MIA PaCa-2 cells. In the Panc-1 cells, PGE2 activated PKA/CREB and decreased phosphorylation of ERK1/2, which was reversed by an EP4 receptor antagonist, while an EP2 receptor antagonist had no effect. In contrast, in MIA PaCa-2 cells, PGE2 had no effect on ERK1/2 phosphorylation. Treatment of both Panc-1 and MIA PaCa-2 cells with forskolin/IBMX decreased ERK1/2 phosphorylation. Finally, PGE2 decreased DNA synthesis only in Panc-1 cells, which was reversed by an EP4 receptor antagonist. In human pancreatic ductal adenocarcinoma, high EP2 and low EP4 gene expression was correlated to worse median overall survival (15.6 vs 20.8 months, log-rank P = .017). CONCLUSION: Our study provides evidence that PGE2 can inhibit directly pancreatic ductal adenocarcinoma cell growth through an EP4-mediated mechanism. Together with our gene expression and survival analysis, this observation suggests a protective role of EP4 receptors in human pancreatic ductal adenocarcinoma that expresses E-type prostaglandin receptors.

Distant metastasis detected by routine staging in breast cancer patients participating in the national German screening programme: consequences for clinical practice.

PURPOSE: To determine frequency of routine radiological staging of breast cancer patients diagnosed in a German Breast Cancer Screening Center from 2007 to 2014, the incidence and consequences of distant metastases detected and the resulting implications for clinical routine. METHODS: Records of 896 patients with primary breast cancer diagnosed in the Screening Centre and treated in five participating hospitals were analyzed retrospectively. Evaluation included frequency and type of staging procedures and results with respect to distant metastasis and their consequences on clinical management. RESULTS: 894/896 Patients (99.8 %) received staging for distant metastases by bone scintigraphy, chest X-ray and liver sonography and/or CT/MRT diagnostics. Distant metastasis was suggested In 6/894 patients but excluded in 3 by further diagnostics or clinical course. Thus, 3 (0.3 %) were clinically verified to have metastatic disease in bone (n = 2; both pT2) or in bone and lung (n = 1; cT4, cN3). CONCLUSION: Due to the low incidence of verified metastatic disease, the high false positive rate of staging procedures and the unfavorable cost/benefit ratio routine radiological staging should be completely omitted in asymptomatic breast cancer patients diagnosed in a breast cancer screening programme.

Control of eukaryotic phosphate homeostasis by inositol polyphosphate sensor domains.

Phosphorus is a macronutrient taken up by cells as inorganic phosphate (P(i)). How cells sense cellular P(i) levels is poorly characterized. Here, we report that SPX domains--which are found in eukaryotic phosphate transporters, signaling proteins, and inorganic polyphosphate polymerases--provide a basic binding surface for inositol polyphosphate signaling molecules (InsPs), the concentrations of which change in response to P(i) availability. Substitutions of critical binding surface residues impair InsP binding in vitro, inorganic polyphosphate synthesis in yeast, and P(i) transport in Arabidopsis In plants, InsPs trigger the association of SPX proteins with transcription factors to regulate P(i) starvation responses. We propose that InsPs communicate cytosolic P(i) levels to SPX domains and enable them to interact with a multitude of proteins to regulate P(i) uptake, transport, and storage in fungi, plants, and animals.

Supramolecular exo-functionalized palladium cages: fluorescent properties and biological activity.

Metallosupramolecular systems are promising new tools for pharmaceutical applications. Thus, novel self-assembled Pd(ii) coordination cages were synthesized which were exo-functionalized with naphthalene or anthracene groups with the aim to image their fate in cells. The cages were also investigated for their anticancer properties in human lung and ovarian cancer cell lines in vitro. While the observed cytotoxic effects hold promise and the cages resulted to be more effective than cisplatin in both cell lines, fluorescence emission properties were scarce. Therefore, using TD-DFT calculations, fluorescence quenching observed in the naphthalene-based system could be ascribed to a lower probability of a HOMO-LUMO excitation and an emission wavelength outside the visible region. Overall, the reported Pd2L4 cages provide new insights into the chemical-physical properties of this family of supramolecular coordination complexes whose understanding is necessary to achieve their applications in various fields.

Krypton Derivatization of an O2 -Tolerant Membrane-Bound [NiFe] Hydrogenase Reveals a Hydrophobic Tunnel Network for Gas Transport.

[NiFe] hydrogenases are metalloenzymes catalyzing the reversible heterolytic cleavage of hydrogen into protons and electrons. Gas tunnels make the deeply buried active site accessible to substrates and inhibitors. Understanding the architecture and function of the tunnels is pivotal to modulating the feature of O2 tolerance in a subgroup of these [NiFe] hydrogenases, as they are interesting for developments in renewable energy technologies. Here we describe the crystal structure of the O2 -tolerant membrane-bound [NiFe] hydrogenase of Ralstonia eutropha (ReMBH), using krypton-pressurized crystals. The positions of the krypton atoms allow a comprehensive description of the tunnel network within the enzyme. A detailed overview of tunnel sizes, lengths, and routes is presented from tunnel calculations. A comparison of the ReMBH tunnel characteristics with crystal structures of other O2 -tolerant and O2 -sensitive [NiFe] hydrogenases revealed considerable differences in tunnel size and quantity between the two groups, which might be related to the striking feature of O2 tolerance.

Evaluation of New Palladium Cages as Potential Delivery Systems for the Anticancer Drug Cisplatin.

Self-assembled metallocages are very promising drug-delivery systems among supramolecular complexes. Thus, exo-functionalized Pd2 L4 (L=ligand) cages were synthesized and characterized, and the encapsulation of the anticancer drug cisplatin in their cavity has been documented. The antiproliferative effects of the metallocages and their combination with cisplatin were examined in vitro in cancer cell lines, while fluorescence microscopy was used to monitor their uptake. Notably, the hydroxymethyl-functionalized Pd(II) cage encapsulating cisplatin showed improved cytotoxic effect against human ovarian cancer cells compared to free cisplatin. The toxicity of Pd2 L4 cages was evaluated for the first time ex vivo in healthy rat-liver tissues using the precision cut-tissue slices technology, demonstrating in some cases scarce effects on liver viability. These results further highlight the potential of self-assembled Pd2 L4 cages for biological applications.