Functionalized magnetic nanoparticles remove donor-specific antibodies (DSA) from patient blood in a first ex vivo proof of principle study.

The presence of donor-specific antibodies (DSA) such as antibodies directed against donor class I human leucocyte antigen (e.g., HLA-A) is a major barrier to kidney transplant success. As a proof of concept, functionalized magnetic nanoparticles have been designed to eliminate DSA from saline, blood and plasma of healthy donors and sensitized patients. Specific HLA-A1 protein was covalently bound to functionalized cobalt nanoparticles (fNP), human serum albumin (HSA) as control. fNP were added to anti-HLA class I-spiked saline, spiked volunteers' whole blood, and to whole blood and plasma of sensitized patients ex vivo. Anti-HLA-A1 antibody levels were determined with Luminex technology. Antibodies' median fluorescent intensity (MFI) was defined as the primary outcome. Furthermore, the impact of fNP treatment on blood coagulation and cellular uptake was determined. Treatment with fNP reduced MFI by 97 ± 2% and by 94 ± 4% (p < 0.001 and p = 0.001) in spiked saline and whole blood, respectively. In six known sensitized anti-HLA-A1 positive patients, a reduction of 65 ± 26% (p = 0.002) in plasma and 65 ± 33% (p = 0.012) in whole blood was achieved. No impact on coagulation was observed. A minimal number of nanoparticles was detected in peripheral mononuclear blood cells. The study demonstrates-in a first step-the feasibility of anti-HLA antibody removal using fNP. These pilot data might pave the way for a new personalized DSA removal technology in the future.

Correction: Development and evaluation of PlasmoPod: A cartridge-based nucleic acid amplification test for rapid malaria diagnosis and surveillance.

[This corrects the article DOI: 10.1371/journal.pgph.0001516.].

Murine iPSC-Loaded Scaffold Grafts Improve Bone Regeneration in Critical-Size Bone Defects.

In certain situations, bones do not heal completely after fracturing. One of these situations is a critical-size bone defect where the bone cannot heal spontaneously. In such a case, complex fracture treatment over a long period of time is required, which carries a relevant risk of complications. The common methods used, such as autologous and allogeneic grafts, do not always lead to successful treatment results. Current approaches to increasing bone formation to bridge the gap include the application of stem cells on the fracture side. While most studies investigated the use of mesenchymal stromal cells, less evidence exists about induced pluripotent stem cells (iPSC). In this study, we investigated the potential of mouse iPSC-loaded scaffolds and decellularized scaffolds containing extracellular matrix from iPSCs for treating critical-size bone defects in a mouse model. In vitro differentiation followed by Alizarin Red staining and quantitative reverse transcription polymerase chain reaction confirmed the osteogenic differentiation potential of the iPSCs lines. Subsequently, an in vivo trial using a mouse model (n = 12) for critical-size bone defect was conducted, in which a PLGA/aCaP osteoconductive scaffold was transplanted into the bone defect for 9 weeks. Three groups (each n = 4) were defined as (1) osteoconductive scaffold only (control), (2) iPSC-derived extracellular matrix seeded on a scaffold and (3) iPSC seeded on a scaffold. Micro-CT and histological analysis show that iPSCs grafted onto an osteoconductive scaffold followed by induction of osteogenic differentiation resulted in significantly higher bone volume 9 weeks after implantation than an osteoconductive scaffold alone. Transplantation of iPSC-seeded PLGA/aCaP scaffolds may improve bone regeneration in critical-size bone defects in mice.

The environmental sustainability of digital content consumption.

Internet access has reached 60% of the global population, with the average user spending over 40% of their waking life on the Internet, yet the environmental implications remain poorly understood. Here, we assess the environmental impacts of digital content consumption in relation to the Earth's carrying capacity, finding that currently the global average consumption of web surfing, social media, video and music streaming, and video conferencing could account for approximately 40% of the per capita carbon budget consistent with limiting global warming to 1.5 °C, as well as around 55% of the per capita carrying capacity for mineral and metal resources use and over 10% for five other impact categories. Decarbonising electricity would substantially mitigate the climate impacts linked to Internet consumption, while the use of mineral and metal resources would remain of concern. A synergistic combination of rapid decarbonisation and additional measures aimed at reducing the use of fresh raw materials in electronic devices (e.g., lifetime extension) is paramount to prevent the growing Internet demand from exacerbating the pressure on the finite Earth's carrying capacity.

Low-nuclearity CuZn ensembles on ZnZrOx catalyze methanol synthesis from CO2.

Metal promotion could unlock high performance in zinc-zirconium catalysts, ZnZrOx, for CO2 hydrogenation to methanol. Still, with most efforts devoted to costly palladium, the optimal metal choice and necessary atomic-level architecture remain unclear. Herein, we investigate the promotion of ZnZrOx catalysts with small amounts (0.5 mol%) of diverse hydrogenation metals (Re, Co, Au, Ni, Rh, Ag, Ir, Ru, Pt, Pd, and Cu) prepared via a standardized flame spray pyrolysis approach. Cu emerges as the most effective promoter, doubling methanol productivity. Operando X-ray absorption, infrared, and electron paramagnetic resonance spectroscopic analyses and density functional theory simulations reveal that Cu0 species form Zn-rich low-nuclearity CuZn clusters on the ZrO2 surface during reaction, which correlates with the generation of oxygen vacancies in their vicinity. Mechanistic studies demonstrate that this catalytic ensemble promotes the rapid hydrogenation of intermediate formate into methanol while effectively suppressing CO production, showcasing the potential of low-nuclearity metal ensembles in CO2-based methanol synthesis.

Chemical unclonable functions based on operable random DNA pools.

Physical unclonable functions (PUFs) based on unique tokens generated by random manufacturing processes have been proposed as an alternative to mathematical one-way algorithms. However, these tokens are not distributable, which is a disadvantage for decentralized applications. Finding unclonable, yet distributable functions would help bridge this gap and expand the applications of object-bound cryptography. Here we show that large random DNA pools with a segmented structure of alternating constant and randomly generated portions are able to calculate distinct outputs from millions of inputs in a specific and reproducible manner, in analogy to physical unclonable functions. Our experimental data with pools comprising up to >1010 unique sequences and encompassing >750 comparisons of resulting outputs demonstrate that the proposed chemical unclonable function (CUF) system is robust, distributable, and scalable. Based on this proof of concept, CUF-based anti-counterfeiting systems, non-fungible objects and decentralized multi-user authentication are conceivable.

Pro-angiogenic and antibacterial copper containing nanoparticles in PLGA/amorphous calcium phosphate bone nanocomposites.

Large bone defects after trauma demand for adequate bone substitutes. Bone void fillers should be antibacterial and pro-angiogenic. One viable option is the use of composite materials like the combination of PLGA and amorphous calcium phosphate (aCaP). Copper stimulates angiogenesis and has antibacterial qualities. Either copper oxide (CuO) nanoparticles (NPs) were therefore added to PLGA/aCaP/CuO in different concentrations (1, 5 and 10 w/w %) or copper-doped tricalcium phosphate NPs (TCP with 2% of copper) were electrospun into PLGA/CuTCP nanocomposites. Bi-layered nanocomposites of PLGA/aCaP with different copper NPs (CuO or TCP) and a second layer of pristine PLGA were fabricated. Two clinical bacterial isolates (Staphylococcus aureus and Staphylococcus epidermidis) were used to assess antibacterial properties of the copper-containing materials. For angiogenesis, the chorioallantoic membrane (CAM) assay of the chicken embryo was performed. The higher the CuO content, the higher were the antibacterial properties, with 10 % CuO reducing bacterial adhesion most effectively. Vessel and cell densities were highest in the 5 % CuO containing scaffolds, while tissue integration was more pronounced at lower CuO content. The PLGA/aCaP/CuO (1 % CuO) behaved similar like PLGA/CuTCP in all angiogenic and antibacterial readouts, based on the same copper fraction. We conclude that CuO NPs or CuTCP NPs are useful components to increase angiogenic properties of nanocomposites and at the same time exhibiting antibacterial characteristics.

A digital twin for DNA data storage based on comprehensive quantification of errors and biases.

Archiving data in synthetic DNA offers unprecedented storage density and longevity. Handling and storage introduce errors and biases into DNA-based storage systems, necessitating the use of Error Correction Coding (ECC) which comes at the cost of added redundancy. However, insufficient data on these errors and biases, as well as a lack of modeling tools, limit data-driven ECC development and experimental design. In this study, we present a comprehensive characterisation of the error sources and biases present in the most common DNA data storage workflows, including commercial DNA synthesis, PCR, decay by accelerated aging, and sequencing-by-synthesis. Using the data from 40 sequencing experiments, we build a digital twin of the DNA data storage process, capable of simulating state-of-the-art workflows and reproducing their experimental results. We showcase the digital twin's ability to replace experiments and rationalize the design of redundancy in two case studies, highlighting opportunities for tangible cost savings and data-driven ECC development.

Development and evaluation of PlasmoPod: A cartridge-based nucleic acid amplification test for rapid malaria diagnosis and surveillance.

Malaria surveillance is hampered by the widespread use of diagnostic tests with low sensitivity. Adequate molecular malaria diagnostics are often only available in centralized laboratories. PlasmoPod is a novel cartridge-based nucleic acid amplification test for rapid, sensitive, and quantitative detection of malaria parasites. PlasmoPod is based on reverse-transcription quantitative polymerase chain reaction (RT-qPCR) of the highly abundant Plasmodium spp. 18S ribosomal RNA/DNA biomarker and is run on a portable qPCR instrument which allows diagnosis in less than 30 minutes. Our analytical performance evaluation indicates that a limit-of-detection as low as 0.02 parasites/µL can be achieved and no cross-reactivity with other pathogens common in malaria endemic regions was observed. In a cohort of 102 asymptomatic individuals from Bioko Island with low malaria parasite densities, PlasmoPod accurately detected 83 cases, resulting in an overall detection rate of 81.4%. Notably, there was a strong correlation between the Cq values obtained from the reference RT-qPCR assay and those obtained from PlasmoPod. In an independent cohort, using dried blood spots from malaria symptomatic children living in the Central African Republic, we demonstrated that PlasmoPod outperforms malaria rapid diagnostic tests based on the PfHRP2 and panLDH antigens as well as thick blood smear microscopy. Our data suggest that this 30-minute sample-to-result RT-qPCR procedure is likely to achieve a diagnostic performance comparable to a standard laboratory-based RT-qPCR setup. We believe that the PlasmoPod rapid NAAT could enable widespread accessibility of high-quality and cost-effective molecular malaria surveillance data through decentralization of testing and surveillance activities, especially in elimination settings.

Knowledge Transfer in Support of the Development of Oxygen Concentrators in Emergency Settings During the COVID-19 Pandemic.

The COVID-19 pandemic simultaneously disrupted supply chains and generated an urgent demand in medical infrastructure. Among personal protective equipment and ventilators, there was also an urgent demand for chemical oxygen. As devices to purify oxygen could not be manufactured and shipped rapidly enough, a simple and accessible oxygen concentrator based on pressure swing adsorption was developed at ETH Zurich in spring 2020. Instead of building devices locally and shipping them, it was decided to educate others in need of oxygen. The implementation encompassed education on process chemistry, material choice, and assembly and optimization of the concentrator and was realized using synchronous teaching tools, such as video call, and asynchronous ones, such as a website and video streaming. The project gained traction and interaction with engineering teams from universities and non-Governmental Organizations (Red Cross and the UN Development Program) in developing countries and emerging market economies, including Ecuador, Mexico, Somalia, and Peru. At the end of the project, the teams were surveyed regarding their experience in the educative knowledge transfer. It was reported that the learning experience prepared these groups well to build the device and to teach others as well. Major challenges were accessing some parts of the device and optimizing its performance. While synchronous communication is expected to be a very effective teaching method, the survey results showed that explanations via a website and video streaming have contributed the most to the implementation of the oxygen concentrator and thereby provide autonomous and sustainable education tools.

Role and dynamics of transition metal carbides in methane coupling.

Transition metal carbides have numerous applications and are known to excel in terms of hardness, thermal stability and conductivity. In particular, the Pt-like behavior of Mo and W carbides has led to the popularization of metal carbides in catalysis, ranging from electrochemically-driven reactions to thermal methane coupling. Herein, we show the active participation of carbidic carbon in the formation of C2 products during methane coupling at high temperature that is associated with the dynamics of Mo and W carbides. A detailed mechanistic study reveals that the catalyst performance of these metal carbides can be traced back to its carbon diffusivity and exchange capability upon interaction with methane (gas phase carbon). A stable C2 selectivity over time on stream for Mo carbide (Mo2C) can be rationalized by fast carbon diffusion dynamics, while W carbide (WC) shows loss of selectivity due to slow diffusion leading to surface carbon depletion. This finding showcases that the bulk carbidic carbon of the catalyst plays a crucial role and that the metal carbide is not only responsible for methyl radical formation. Overall, this study evidences the presence of a carbon equivalent to the Mars-Van Krevelen type mechanism for non-oxidative coupling of methane.

Targeted Large-Volume Lymphocyte Removal Using Magnetic Nanoparticles in Blood Samples of Patients with Chronic Lymphocytic Leukemia: A Proof-of-Concept Study.

In the past, our research group was able to successfully remove circulating tumor cells with magnetic nanoparticles. While these cancer cells are typically present in low numbers, we hypothesized that magnetic nanoparticles, besides catching single cells, are also capable of eliminating a large number of tumor cells from the blood ex vivo. This approach was tested in a small pilot study in blood samples of patients suffering from chronic lymphocytic leukemia (CLL), a mature B-cell neoplasm. Cluster of differentiation (CD) 52 is a ubiquitously expressed surface antigen on mature lymphocytes. Alemtuzumab (MabCampath®) is a humanized, IgG1κ, monoclonal antibody directed against CD52, which was formerly clinically approved for treating chronic lymphocytic leukemia (CLL) and therefore regarded as an ideal candidate for further tests to develop new treatment options. Alemtuzumab was bound onto carbon-coated cobalt nanoparticles. The particles were added to blood samples of CLL patients and finally removed, ideally with bound B lymphocytes, using a magnetic column. Flow cytometry quantified lymphocyte counts before, after the first, and after the second flow across the column. A mixed effects analysis was performed to evaluate removal efficiency. p < 0.05 was defined as significant. In the first patient cohort (n = 10), using a fixed nanoparticle concentration, CD19-positive B lymphocytes were reduced by 38% and by 53% after the first and the second purification steps (p = 0.002 and p = 0.005), respectively. In a second patient cohort (n = 11), the nanoparticle concentration was increased, and CD19-positive B lymphocytes were reduced by 44% (p < 0.001) with no further removal after the second purification step. In patients with a high lymphocyte count (>20 G/L), an improved efficiency of approximately 20% was observed using higher nanoparticle concentrations. A 40 to 50% reduction of B lymphocyte count using alemtuzumab-coupled carbon-coated cobalt nanoparticles is feasible, also in patients with a high lymphocyte count. A second purification step did not further increase removal. This proof-of-concept study demonstrates that such particles allow for the targeted extraction of larger amounts of cellular blood components and might offer new treatment options in the far future.

Synthetic Microbial Surrogates Consisting of Lipid Nanoparticles Encapsulating DNA for the Validation of Surface Disinfection Procedures.

Effective cleaning and disinfection procedures are an integral part of good manufacturing practice and in maintaining hygiene standards in health-care facilities. In this study, a method to validate such cleaning and disinfection procedures of surfaces was established employing lipid nanoparticles (LNPs) encapsulating DNA. It was possible to determine and distinguish between the physical cleaning effect (dilution) and the chemical cleaning effect (disintegration) on the LNPs during the cleaning and disinfection procedure (wiping). After treatment with 70 v % ethanol as a disinfectant and SDS solution as a cleaning agent, LNPs showed log10 reductions of 4.5 and 4.0, respectively. These values are similar to the log10 reductions exhibited by common bacteria, such as Escherichia coli and Serratia marcescens. Therefore, LNPs pose as useful tools for cleaning validation with advantages over the already existing tools and enable a separate detection of dilution and chemical disinfectant action.

SAXS imaging reveals optimized osseointegration properties of bioengineered oriented 3D-PLGA/aCaP scaffolds in a critical size bone defect model.

Healing large bone defects remains challenging in orthopedic surgery and is often associated with poor outcomes and complications. A major issue with bioengineered constructs is achieving a continuous interface between host bone and graft to enhance biological processes and mechanical stability. In this study, we have developed a new bioengineering strategy to produce oriented biocompatible 3D PLGA/aCaP nanocomposites with enhanced osseointegration. Decellularized scaffolds -containing only extracellular matrix- or scaffolds seeded with adipose-derived mesenchymal stromal cells were tested in a mouse model for critical size bone defects. In parallel to micro-CT analysis, SAXS tensor tomography and 2D scanning SAXS were employed to determine the 3D arrangement and nanostructure within the critical-sized bone. Both newly developed scaffold types, seeded with cells or decellularized, showed high osseointegration, higher bone quality, increased alignment of collagen fibers and optimal alignment and size of hydroxyapatite minerals.

Information decay and enzymatic information recovery for DNA data storage.

Synthetic DNA has been proposed as a storage medium for digital information due to its high theoretical storage density and anticipated long storage horizons. However, under all ambient storage conditions, DNA undergoes a slow chemical decay process resulting in nicked (broken) DNA strands, and the information stored in these strands is no longer readable. In this work we design an enzymatic repair procedure, which is applicable to the DNA pool prior to readout and can partially reverse the damage. Through a chemical understanding of the decay process, an overhang at the 3' end of the damaged site is identified as obstructive to repair via the base excision-repair (BER) mechanism. The obstruction can be removed via the enzyme apurinic/apyrimidinic endonuclease I (APE1), thereby enabling repair of hydrolytically damaged DNA via Bst polymerase and Taq ligase. Simulations of damage and repair reveal the benefit of the enzymatic repair step for DNA data storage, especially when data is stored in DNA at high storage densities (=low physical redundancy) and for long time durations.

Flame-made ternary Pd-In2O3-ZrO2 catalyst with enhanced oxygen vacancy generation for CO2 hydrogenation to methanol.

Palladium promotion and deposition on monoclinic zirconia are effective strategies to boost the performance of bulk In2O3 in CO2-to-methanol and could unlock superior reactivity if well integrated into a single catalytic system. However, harnessing synergic effects of the individual components is crucial and very challenging as it requires precise control over their assembly. Herein, we present ternary Pd-In2O3-ZrO2 catalysts prepared by flame spray pyrolysis (FSP) with remarkable methanol productivity and improved metal utilization, surpassing their binary counterparts. Unlike established impregnation and co-precipitation methods, FSP produces materials combining low-nuclearity palladium species associated with In2O3 monolayers highly dispersed on the ZrO2 carrier, whose surface partially transforms from a tetragonal into a monoclinic-like structure upon reaction. A pioneering protocol developed to quantify oxygen vacancies using in situ electron paramagnetic resonance spectroscopy reveals their enhanced generation because of this unique catalyst architecture, thereby rationalizing its high and sustained methanol productivity.

Preserving DNA in Biodegradable Organosilica Encapsulates.

A core-shell strategy was developed to protect synthetic DNA in organosilica particles encompassing dithiol linkages allowing for a DNA loading of 1.1 wt %. DNA stability tests involving bleach as an oxidant showed that following the procedure DNA was sandwiched between core particles of ca. 450 nm size and a protective outer layer, separating the DNA from the environment. Rapid aging tests at 60 °C and 50% relative humidity revealed that the DNA protected within this material was significantly more stable than nonprotected DNA, with an expected ambient temperature half-life of over 60 years. Still, and due to the presence of the dithiol linkages in the backbone of the organosilica material, the particles degraded in the presence of reducing agents (TCEP and glutathione) and disintegrated within several days in a simulated compost environment, which was employed to test the biodegradability of the material. This is in contrast to DNA encapsulated following state of the art procedures in pure SiO2 particles, which do not biodegrade in the investigated timeframes and conditions. The results show that synthetic DNA protected within dithiol comprising organosilica particles presents a strategy to store digital data at a high storage capacity for long time frames in a fully biodegradable format.

Removal of Circulating Tumor Cells from Blood Samples of Cancer Patients Using Highly Magnetic Nanoparticles: A Translational Research Project.

The count of circulating tumor cells (CTCs) has been associated with a worse prognosis in different types of cancer. Perioperatively, CTCs detach due to mechanical forces. Diagnostic tools exist to detect and isolate CTCs, but no therapeutic technique is currently available to remove CTCs in vivo from unprocessed blood. The aim of this study was to design and test new magnetic nanoparticles to purify whole blood from CTCs. Novel magnetic carbon-coated cobalt (C/Co) nanoparticles conjugated with anti-epithelial cell adhesion molecule (EpCAM) antibodies were synthesized, and their antifouling and separation properties were determined. The newly developed C/Co nanoparticles showed excellent separation and antifouling properties. They efficiently removed tumor cells that were added to healthy subjects' blood samples, through an anti-EpCAM antibody interaction. The nanoparticles did not interact with other blood components, such as lymphocytes or the coagulation system. In blood samples of carcinoma patients suffering from metastatic disease, on average, ≥68% of CTCs were removed. These nanoparticles could prompt the development of a blood purification technology, such as a dialysis-like device, to perioperatively remove CTCs from the blood of cancer patients in vivo and potentially improve their prognosis.

Hybrid nanocomposite as a chest wall graft with improved vascularization by copper oxide nanoparticles.

Chest wall repair can be necessary after tumor resection or chest injury. In order to cover or replace chest wall defects, autologous tissue or different synthetic materials are commonly used, among them the semi-rigid gold standard Gore-Tex® and prolene meshes. Synthetic tissues include composite materials with an organic and an inorganic component. On the basis of previously reported hybrid nanocomposite poly-lactic-co-glycolic acid amorphous calcium phosphate nanocomposite (PLGA/aCaP), a CuO component was incorporated to yield (60%/35%/5%). This graft was tested in vitro by seeding with murine adipose-derived stem cells (ASCs) for cell attachment and migration. The graft was compared to PLGA/CaCO3 and PLGA/hydroxyapatite, each providing the inorganic phase as nanoparticles. Further characterization of the graft was performed using scanning electron microscopy. Furthermore, PLGA/aCaP/CuO was implanted as a chest wall graft in mice. After 4 weeks, total cell density, graft integration, extracellular matrix components such as fibronectin and collagen I, the cellular inflammatory response (macrophages, F4/80 and lymphocytes, CD3) as well as vascularization (CD31) were quantitatively assessed. The nanocomposite PLGA/aCaP/CuO showed a good cell attachment and cells migrated well into the pores of the electrospun meshes. Cell densities did not differ between PLGA/aCaP/CuO and PLGA/CaCO3 or PLGA/hydroxyapatite, respectively. When applied as a chest wall graft, adequate stability for suturing into the thoracic wall could be achieved. Four weeks post-implantation, there was an excellent tissue integration without relevant fibrotic changes and a predominating collagen I matrix deposition within the graft. Slightly increased inflammation, reflected by increased infiltration of macrophages could be observed. Vascularization of the graft was significantly enhanced when compared with PLGA/aCaP (no CuO). We conclude that the hybrid nanocomposite PLGA/aCaP/CuO is a viable option to be used as a chest wall graft. Surgical implantation of the material is feasible and provides stability and enough flexibility. Proper tissue integration and an excellent vascularization are characteristics of this biodegradable material.

Integrating DNA Encapsulates and Digital Microfluidics for Automated Data Storage in DNA.

Using DNA as a durable, high-density storage medium with eternal format relevance can address a future data storage deficiency. The proposed storage format incorporates dehydrated particle spots on glass, at a theoretical capacity of more than 20 TB per spot, which can be efficiently retrieved without significant loss of DNA. The authors measure the rapid decay of dried DNA at room temperature and present the synthesis of encapsulated DNA in silica nanoparticles as a possible solution. In this form, the protected DNA can be readily applied to digital microfluidics (DMF) used to handle retrieval operations amenable to full automation. A storage architecture is demonstrated, which can increase the storage capacity of today's archival storage systems by more than three orders of magnitude: A DNA library containing 7373 unique sequences is encapsulated and stored under accelerated aging conditions (4 days at 70 °C, 50% RH) corresponding to 116 years at room temperature and the stored information is successfully recovered.