Direct protein quantification in complex sample solutions by surface-engineered nanorod probes

Detecting biomarkers from complex sample solutions is the key objective of molecular diagnostics. Being able to do so in a simple approach that does not require laborious sample preparation, sophisticated equipment and trained staff is vital for point-of-care applications. Here, we report on the specific detection of the breast cancer biomarker sHER2 directly from serum and saliva samples by a nanorod-based homogeneous biosensing approach, which is easy to operate as it only requires mixing of the samples with the nanorod probes. By careful nanorod surface engineering and homogeneous assay design, we demonstrate that the formation of a protein corona around the nanoparticles does not limit the applicability of our detection method, but on the contrary enables us to conduct in-situ reference measurements, thus further strengthening the point-of-care applicability of our method. Making use of sandwich assays on top of the nanorods, we obtain a limit of detection of 110 pM and 470 pM in 10-fold diluted spiked saliva and serum samples, respectively. In conclusion, our results open up numerous applications in direct protein biomarker quantification, specifically in point-of-care settings where resources are limited and ease-of-use is of essenceThis research was supported by the European Commission FP7 NAMDIATREAM project (EU NMP4-LA-2010–246479), and the German Research Foundation (DFG grant PA 794/25-1)S

Homogeneous Biosensing Based on Magnetic Particle Labels

The growing availability of biomarker panels for molecular diagnostics is leading to an increasing need for fast and sensitive biosensing technologies that are applicable to point-of-care testing. In that regard, homogeneous measurement principles are especially relevant as they usually do not require extensive sample preparation procedures, thus reducing the total analysis time and maximizing ease-of-use. In this review, we focus on homogeneous biosensors for the in vitro detection of biomarkers. Within this broad range of biosensors, we concentrate on methods that apply magnetic particle labels. The advantage of such methods lies in the added possibility to manipulate the particle labels by applied magnetic fields, which can be exploited, for example, to decrease incubation times or to enhance the signal-to-noise-ratio of the measurement signal by applying frequency-selective detection. In our review, we discriminate the corresponding methods based on the nature of the acquired measurement signal, which can either be based on magnetic or optical detection. The underlying measurement principles of the different techniques are discussed, and biosensing examples for all techniques are reported, thereby demonstrating the broad applicability of homogeneous in vitro biosensing based on magnetic particle label actuation

Roadmap Umwelttechnologien 2020 - State-of-the-Art-Report (Kurzfassung)

Globale Umweltprobleme wie der Klimawandel, die Verknappung des Süßwasserdargebots, der Verlust an Biodiversität oder der rasant steigende Verbrauch nicht erneuerbarer Rohstoffe werden den Handlungsdruck im Umweltbereich in den nächsten Jahrzehnten deutlich erhöhen. Obwohl viele der heutigen Umweltprobleme direkt oder indirekt durch Technik verursacht sind, beinhalten moderne Umwelttechnologien gleichzeitig das Potential zu ihrer Bewältigung. Vor diesem Hintergrund untersucht das BMBF-Projekt „Roadmap Umwelttechnologien 2020“ welche Beiträge Forschung und Technik für künftige Umweltinnovationen leisten können. Ziel des Projekts ist es, strategische Handlungsoptionen für die Forschungsförderung und die Unterstützung des Wissenstransfers in die Praxis aufzuzeigen. Als erstes Ergebnis des Projekts wurden in einem umfassenden State-of-the-Art-Report, Umweltprobleme und zugehörige technische Lösungsansätze entlang von sieben Umwelthandlungsfeldern dargestellt. Diese sind: Klimaschutz, Luftreinhaltung, Wasserschutz, Bodenschutz, Schonung endlicher Ressourcen, Abfallwirtschaft, Erhalt von Natur und Biodiversität. Der Report gibt einen umfassenden Überblick über reife Technologien und ihr Marktumfeld, neue Technologien und ihre Potentiale sowie mögliche Hemmnisse, die der Weiterentwicklung und Marktdurchdringung im Weg stehen. In der hier vorgelegten Kurzfassung des State-of-the-Art-Reports sind wesentliche Ergebnisse aus den sieben Handlungsfeldern zusammengefasst. Jedem Handlungsfeld ist ein so genannter „Kompass“ zugeordnet, der das Beziehungsgeflecht von Problemen, Lösungsansätzen und Technologien grafisch darstellt

Detection of a gammaretrovirus, XMRV, in the human population: Open questions and implications for xenotransplantation

XMRV (xenotropic murine leukaemia virus-related virus) is a gammaretrovirus that has been detected in human patients with prostate carcinoma, chronic fatigue syndrome (CFS) and also in a small percentage of clinically healthy individuals. It is not yet clear whether the distribution of this virus is primarily limited to the USA or whether it is causally associated with human disease. If future investigations confirm a broad distribution of XMRV and its association with disease, this would have an impact on xenotransplantation of porcine tissues and organs. Xenotransplantation is currently being developed to compensate for the increasing shortage of human material for the treatment of tissue and organ failure but could result in the transmission of porcine pathogens. Maintenance of pathogen-free donor animals will dramatically reduce this risk, but some of the porcine endogenous retroviruses (PERVs) found in the genome of all pigs, can produce infectious virus and infect cultured human cells. PERVs are closely related to XMRV so it is critical to develop tests that discriminate between them. Since recombination can occur between viruses, and recombinants can exhibit synergism, recipients should be tested for XMRV before xenotransplantation

Uncertainty analysis using Bayesian Model Averaging: a case study of input variables to energy models and inference to associated uncertainties of energy scenarios

Background Energy models are used to illustrate, calculate and evaluate energy futures under given assumptions. The results of energy models are energy scenarios representing uncertain energy futures. Methods The discussed approach for uncertainty quantification and evaluation is based on Bayesian Model Averaging for input variables to quantitative energy models. If the premise is accepted that the energy model results cannot be less uncertain than the input to energy models, the proposed approach provides a lower bound of associated uncertainty. The evaluation of model-based energy scenario uncertainty in terms of input variable uncertainty departing from a probabilistic assessment is discussed. Results The result is an explicit uncertainty quantification for input variables of energy models based on well-established measure and probability theory. The quantification of uncertainty helps assessing the predictive potential of energy scenarios used and allows an evaluation of possible consequences as promoted by energy scenarios in a highly uncertain economic, environmental, political and social target system. Conclusions If societal decisions are vested in computed model results, it is meaningful to accompany these with an uncertainty assessment. Bayesian Model Averaging (BMA) for input variables of energy models could add to the currently limited tools for uncertainty assessment of model-based energy scenarios

Reduced Skin Blistering in Experimental Epidermolysis Bullosa Acquisita After Anti-TNF Treatment

Epidermolysis bullosa acquisita (EBA) is a difficult-to-treat subepidermal autoimmune blistering skin disease (AIBD) with circulating and tissue-bound anti-type VII collagen antibodies. Different reports have indicated increased concentration of tumor necrosis factor a (TNF) in the serum and blister fluid of patients with subepidermal AIBD. Furthermore, successful anti-TNF treatment has been reported for individual patients with AIBD. Here we show that in mice, induction of experimental EBA by repeated injections of rabbit anti-mouse type VII collagen antibodies led to increased expression of TNF in skin, as determined by real-time polymerase chain reaction (PCR) and immunohistochemistry. To investigate whether the increased TNF expression is of functional relevance in experimental EBA, we inhibited TNF function using the soluble TNF receptor fusion protein etanercept (Enbrel) or a monoclonal antibody to murine TNF. Interestingly, mice that received either of these treatments showed significantly milder disease progression than controls. In addition, immunohistochemical staining demonstrated reduced numbers of macrophages in lesional skin in mice treated with TNF inhibitors compared with controls. Furthermore, etanercept treatment significantly reduced disease progression in immunization-induced EBA. In conclusion, increased expression of TNF in experimental EBA is of functional relevance, as both the prophylactic blockade of TNF and the therapeutic use of etanercept impaired induction and progression of experimental EBA. Thus, TNF is likely to serve as a new therapeutic target for EBA and AIBDs with a similar pathogenesis