A hybrid soft solar cell based on the mycobacterial porin MspA linked to a sensitizer-viologen diad

A prototype of a nano solar cell containing the mycobacterial channel protein MspA has been successfully designed. MspA, an octameric transmembrane channel protein from Mycobacterium smegmatis, is one of the most stable proteins known to date. Eight Ruthenium(II) aminophenanthroline-viologen maleimide Diads (Ru-Diads) have been successfully bound to the MspA mutant MspAA96C via cysteine-maleimide bonds. MspA is known to form double layers in which it acts as nanoscopic surfactant. The nanostructured layer that is formed by (Ru-Diad)(8)MspA at the TiO2 electrode is photochemically active. The resulting "protein nano solar cell" features an incident photon conversion efficiency of 1% at 400 nm. This can be regarded as a proof-of-principle that stable proteins can be successfully integrated into the design of solar cells

Cell Based Drug Delivery: Micrococcus luteus Loaded Neutrophils as Chlorhexidine Delivery Vehicles in a Mouse Model of Liver Abscesses in Cattle

Citation: Wendel, S. O., Menon, S., Alshetaiwi, H., Shrestha, T. B., Chlebanowski, L., Hsu, W. W., . . . Troyer, D. L. (2015). Cell Based Drug Delivery: Micrococcus luteus Loaded Neutrophils as Chlorhexidine Delivery Vehicles in a Mouse Model of Liver Abscesses in Cattle. Plos One, 10(5), 13. doi:10.1371/journal.pone.0128144The recent WHO report on antibiotic resistances shows a dramatic increase of microbial resistance against antibiotics. With only a few new antibiotics in the pipeline, a different drug delivery approach is urgently needed. We have obtained evidence demonstrating the effectiveness of a cell based drug delivery system that utilizes the innate immune system as targeting carrier for antibacterial drugs. In this study we show the efficient loading of neutrophil granulocytes with chlorhexidine and the complete killing of E. coli as well as Fusobacterium necrophorum in in-vitro studies. Fusobacterium necrophorum causes hepatic abscesses in cattle fed high grain diets. We also show in a mouse model that this delivery system targets infections of F. necrophorum in the liver and reduces the bacterial burden by an order of magnitude from approximately 2.10(6) to 1.10(5)

Early breast cancer screening using iron/iron oxide-based nanoplatforms with sub-femtomolar limits of detection

Citation: Udukala, D. N., Wang, H. W., Wendel, S. O., Malalasekera, A. P., Samarakoon, T. N., Yapa, A. S., . . . Bossmann, S. H. (2016). Early breast cancer screening using iron/iron oxide-based nanoplatforms with sub-femtomolar limits of detection. Beilstein Journal of Nanotechnology, 7, 364-373. doi:10.3762/bjnano.7.33Additional Authors: Ortega, R.;Toledo, Y.;Bossmann, L.;Robinson, C.;Janik, K. E.;Koper, O. B.;Motamedi, M.;Zhu, G. H.Proteases, including matrix metalloproteinases (MMPs), tissue serine proteases, and cathepsins (CTS) exhibit numerous functions in tumor biology. Solid tumors are characterized by changes in protease expression levels by tumor and surrounding tissue. Therefore, monitoring protease levels in tissue samples and liquid biopsies is a vital strategy for early cancer detection. Water-dispersable Fe/Fe3O4-core/shell based nanoplatforms for protease detection are capable of detecting protease activity down to sub-femtomolar limits of detection. They feature one dye (tetrakis(carboxyphenyl) porphyrin (TCPP)) that is tethered to the central nanoparticle by means of a protease-cleavable consensus sequence and a second dye (Cy 5.5) that is directly linked. Based on the protease activities of urokinase plasminogen activator (uPA), MMPs 1, 2, 3, 7, 9, and 13, as well as CTS B and L, human breast cancer can be detected at stage I by means of a simple serum test. By monitoring CTS B and L stage 0 detection may be achieved. This initial study, comprised of 46 breast cancer patients and 20 apparently healthy human subjects, demonstrates the feasibility of protease-activity-based liquid biopsies for early cancer diagnosis

The METIS model review

An integral part of the model quality control and quality assurance at the European Commission is a scientific peer-review of models, including those developed by external contractors. The present reports details the outcome of the review of the METIS, which was carried out by an external scientific Review Panel closely following ‘Guidelines for the review of models used in support of EU policies’. The review aimed at verifying and consolidating the scientific credibility of METIS and identifying most promising/relevant areas for a future model development. The report includes also a first reaction from the METIS team, detailing among others how Review Panel’s suggestions will be addressed.JRC.I.2-Foresight, Modelling, Behavioural Insights & Design for Polic

Adaptation of Mycobacterium smegmatis to an industrial scale medium and isolation of the mycobacterial porinMspA

The adaptation of the organism to a simple and cost-effective growth medium is mandatory in developing a process for large scale production of the octamericporinMspA, which is isolated from Mycobacterium smegmatis. A fermentation optimization with the minimal nutrients required for growth has been performed. During the fermentation, the iron- and ammonium chloride concentrations in the medium were varied to determine their impact on the observed growth rates and cell mass yields. Common antibiotics to control contamination were eliminated in favor of copper sulfate to reduce costs. MspA has been successfully isolated from the harvested M. smegmatisusing aqueous nOPOE (noctyloligooxyethylene) at 65°C. Because of the extraordinary stability of MspA, it is possible to denature and precipitate virtually all other proteins and contaminants by following this approach. To further purify the product, acetone is used for precipitation. Gel electrophoresis confirmed the presence and purity of MspA. A maximum of 840µg (via Bradford assay) of pure MspA per liter of the optimized simple growth medium has been obtained. This is a 40% increase with respect to the previously reported culture medium for MspA

Fermentation optimization of Mycobacterium smegmatis using experimental design

The exceptionally stable mycobacterial protein porin A (MspA) from Mycobacterium smegmatis has potential applications in protein-based solar cells, and as a biotemplate for nano-wires and nano-dots. These applications would be enabled by an efficient and cost effective method to grow the host organism at high cell mass yields, and recover purified MspA. In this work, the cell mass yield was maximized and costs lowered by applying experimental design (varying nitrogen and iron contents according to a Doehlert matrix) based on a minimal fermentation medium that was reported earlier. Glucose use was minimized by adjusting glucose feed based on analyzing residual glucose after fermentation. The costs for extracted and purified MspA were lowered by 67% for the minimum medium and the optimized composition derived here compared to commercial medium (7H9 Middlebrook)

Early detection of non-small cell lung cancer in liquid biopsies by ultrasensitive protease activity analysis

Aim: A significant fraction of mortalities from non-small cell lung cancer could be prevented, if the cancer would be diagnosed earlier. Nanobiosensors for the ultrasensitive detection of active proteases in serum were designed to detect a significant protease activity signature of non-small cell lung cancer (stage I and higher).Methods: We determined the activity of nine protease biomarkers in the sera of non-small cell lung cancer patients and compared them with the protease activities of a control group of healthy human subjects using optical nanobiosensors. They consist of a central Fe/Fe3O4 core/shell nanoparticle with an attached Fluorescence resonance energy transfer-pair [tetrakis-carboxyphenyl porphyrin (TCPP) and cyanine 5.5]. TCPP is attached to the central nanoparticle via a protease-cleavable tether, whereas cyanine 5.5 is tethered permanently to the dopamine-layer surrounding the nanoparticle.Results: Based on the activity pattern of urokinase plasminogen activator, matrix metalloproteinases 1, 2, 3, 7, 9, and 13, and cathepsins B and L as well, non-small cell lung cancer could be detected at stage I by means of a liquid biopsy.Conclusion: This feasibility study, comprising 33 non-small cell lung cancer patients and 20 apparently healthy subjects, clearly demonstrated the feasibility of minimally invasive early diagnosis of non-small cell lung cancer, starting with stage I

Early breast cancer screening using iron/iron oxide-based nanoplatforms with sub-femtomolar limits of detection

Proteases, including matrix metalloproteinases (MMPs), tissue serine proteases, and cathepsins (CTS) exhibit numerous functions in tumor biology. Solid tumors are characterized by changes in protease expression levels by tumor and surrounding tissue. Therefore, monitoring protease levels in tissue samples and liquid biopsies is a vital strategy for early cancer detection. Water-dispersable Fe/Fe3O4-core/shell based nanoplatforms for protease detection are capable of detecting protease activity down to sub-femtomolar limits of detection. They feature one dye (tetrakis(carboxyphenyl)porphyrin (TCPP)) that is tethered to the central nanoparticle by means of a protease-cleavable consensus sequence and a second dye (Cy 5.5) that is directly linked. Based on the protease activities of urokinase plasminogen activator (uPA), MMPs 1, 2, 3, 7, 9, and 13, as well as CTS B and L, human breast cancer can be detected at stage I by means of a simple serum test. By monitoring CTS B and L stage 0 detection may be achieved. This initial study, comprised of 46 breast cancer patients and 20 apparently healthy human subjects, demonstrates the feasibility of protease-activity-based liquid biopsies for early cancer diagnosis

A Hybrid Soft Solar Cell Based on the Mycobacterial Porin MspA Linked to a Sensitizer–Viologen Diad

A prototype of a nano solar cell containing the mycobacterial channel protein MspA has been successfully designed. MspA, an octameric transmembrane channel protein from Mycobacterium smegmatis, is one of the most stable proteins known to date. Eight Ruthenium(II) aminophenanthroline–viologen maleimide Diads (Ru-Diads) have been successfully bound to the MspA mutant MspAA96C via cysteine–maleimide bonds. MspA is known to form double layers in which it acts as nanoscopic surfactant. The nanostructured layer that is formed by (Ru-Diad)₈MspA at the TiO₂ electrode is photochemically active. The resulting “protein nano solar cell” features an incident photon conversion efficiency of 1% at 400 nm. This can be regarded as a proof-of-principle that stable proteins can be successfully integrated into the design of solar cells

Early breast cancer screening using iron/iron oxide-based nanoplatforms with sub-femtomolar limits of detection

Proteases, including matrix metalloproteinases (MMPs), tissue serine proteases, and cathepsins (CTS) exhibit numerous functions in tumor biology. Solid tumors are characterized by changes in protease expression levels by tumor and surrounding tissue. Therefore, monitoring protease levels in tissue samples and liquid biopsies is a vital strategy for early cancer detection. Water-dispersable Fe/Fe3O4-core/shell based nanoplatforms for protease detection are capable of detecting protease activity down to sub-femtomolar limits of detection. They feature one dye (tetrakis(carboxyphenyl)porphyrin (TCPP)) that is tethered to the central nanoparticle by means of a protease-cleavable consensus sequence and a second dye (Cy 5.5) that is directly linked. Based on the protease activities of urokinase plasminogen activator (uPA), MMPs 1, 2, 3, 7, 9, and 13, as well as CTS B and L, human breast cancer can be detected at stage I by means of a simple serum test. By monitoring CTS B and L stage 0 detection may be achieved. This initial study, comprised of 46 breast cancer patients and 20 apparently healthy human subjects, demonstrates the feasibility of protease-activity-based liquid biopsies for early cancer diagnosis