Self-assembly of polyesters like PLLA and PDLA into stereocomplexes (SCs) is an interesting approach to tailor physical properties of polymeric nanoparticles without affecting their hydrophilicity. Here, we use the stereocomplexation of P(LLA-stat-EtGly) and P(DLA-stat-EtGly) (EtGly: 3-ethylglycolide) to tune the melting temperature (T m ) and degree of crystallinity (w c ) of the bulk polymer. Using time-dependent blending experiments and characterization techniques, such as dynamic light scattering, wide-angle X-ray spectroscopy, differential scanning calorimetry, and atomic force microscopy, we tested the hypothesis that the amount of SCs within the nanoparticles impacts their mechanical properties. Our results show that T m and w c can be adjusted via the EtGly content. Interestingly, mechanical properties of the nanoparticles depend on the EtGly content as well as the self-assembly time of SCs before nanoparticle formation. This offers a high potential for their application in drug delivery, where their tunable properties will allow to adjust degradation and drug release behavior.

Within this open observational study, repeated PCR ( n  > 4,700) and antibody screening ( n  > 1,600) tests were offered in three different working fields. The study identified 51 subjects with acute SARS-CoV-2 infection and 37 subjects reported to have had a positive PCR test taken externally.

For improved cost-effectiveness and temperaturestability, a ready to use lateral flow assay (LFA) is developed in this work for detecting inflammation/infection biomarker C-reactive protein (CRP) in human patient samples on the basis of aptamers. In prescreening investigations, an aptamer with CRP affinity was immobilized on microarray chips in forward and sandwich formats to optimize assay conditions. We suggest these microarray techniques as a resource-sparing and fast-screening instrument for evaluation of various conditions. The capability of the aptamer to detect CRP was shown. Optimized assay conditions were consequently transferred to the LFA-platform. Here we could demonstrate for the first time an aptamer-based LFA for the detection of CRP in human patient samples in pathologically relevant concentrations. The cutoff for CRP detection is set at 10 mg/L, providing a distinctive "yes" (≥10 mg/L CRP) or "no" (<10 mg/L CRP) answer for the patient. The resulting aptamer-based LFA is promising with regard to its application as point-of-care testing (POCT) for efficient monitoring, especially of patients affected by frequent infections or inflammations.

No abstract

Chronic antibody-mediated rejection (AMR) is a key limiting factor for the clinical outcome of a kidney transplantation (Ktx), where early diagnosis and therapeutic intervention is needed. This study describes the identification of the biomarker CXC-motif chemokine ligand (CXCL) 9 as an indicator for AMR and presents a new aptamer-antibody-hybrid lateral flow assay (hybrid-LFA) for detection in urine. Biomarker evaluation included two independent cohorts of kidney transplant recipients (KTRs) from a protocol biopsy program and used subgroup comparisons according to BANFF-classifications. Plasma, urine and biopsy lysate samples were analyzed with a Luminex-based multiplex assay. The CXCL9-specific hybrid-LFA was developed based upon a specific rat antibody immobilized on a nitrocellulose-membrane and the coupling of a CXCL9-binding aptamer to gold nanoparticles. LFA performance was assessed according to receiver operating characteristic (ROC) analysis. Among 15 high-scored biomarkers according to a neural network analysis, significantly higher levels of CXCL9 were found in plasma and urine and biopsy lysates of KTRs with biopsy-proven AMR. The newly developed hybrid-LFA reached a sensitivity and specificity of 71% and an AUC of 0.79 for CXCL9. This point-of-care-test (POCT) improves early diagnosis-making in AMR after Ktx, especially in KTRs with undetermined status of donor-specific HLA-antibodies.

Abstract. Due to climate change and growing urbanization, fatalities from landslides are rising worldwide, and thus solutions for people at risk are needed. This is especially the case for the Andean cities which are often expanding into the steep slopes surrounding them. In Medellín, Colombia, a combination of landslide-prone dunite rock and steep slopes in the east of the city creates a high-hazard scenario for about 87,000 residents, most of whom live in informal settlements. We developed a landslide early warning system (LEWS) which can be applied in such semi-urban situations. The LEWS consists mainly of a measurement system of horizontal and vertical sensor lines across the slope and autonomous point-sensors in between these lines. All parts of the LEWS, from hazard assessment to the monitoring system and the reaction capacity, are supported by extensive activities together with the local community to gain trust and create synergies. This also includes local authorities, agencies and NGO's. To test such a system, a prototype has been installed in a neighborhood in Medellín in 2020–2022. The experiences of this installation resulted in a framework for LEWS's of this kind which we have compiled on a wiki-page to facilitate replication by people in other parts of the world. Hopefully, this can stimulate a lively exchange between researchers and other stakeholders who want to use, modify and replicate our system.

In this work a novel point of care test to detect sIL-2R during acute kidney rejection with high specificity and sensitivity was developed.

Fatalities from landslides are rising worldwide, especially in cities in mountainous regions, which often expand into the steep slopes surrounding them. For residents, often those living in poor neighborhoods and informal settlements, integrated landslide early warning systems (LEWS) can be a viable solution, if they are affordable and easily replicable. We developed a LEWS in Medellín, Colombia, which can be applied in such semi-urban situations. All the components of the LEWS, from hazard and risk assessment, to the monitoring system and the reaction capacity, were developed with and supported by all local stakeholders, including local authorities, agencies, NGO’s, and especially the local community, in order to build trust. It was well integrated into the social structure of the neighborhood, while still delivering precise and dense deformation and trigger measurements. A prototype was built and installed in a neighborhood in Medellín in 2022, comprising a dense network of line and point measurements and gateways. The first data from the measurement system are now available and allow us to define initial thresholds, while more data are being collected to allow for automatic early warning in the future. All the newly developed knowledge, from sensor hardware and software to installation manuals, has been compiled on a wiki-page, to facilitate replication by people in other parts of the world. According to our experience of the installation, we give recommendations for the implementation of LEWSs in similar areas, which can hopefully stimulate a lively exchange between researchers and other stakeholders who want to use, modify, and replicate our system.