Purpose

Urinary Tract InfectionAQ1 (UTI) affects over 400 million people annually and globally and is a major reason for empiric antibiotic prescription by general practitioners (GPs).

Background

A problem related to microbiological UTI diagnosis is the current lack of point of care (POC) diagnostics. In addition, remote settings, including low and middle income countries (LMIC), are hard to service. Compliance with requirements posed by the In Vitro Diagnostic Regulation (IVDR) and adherence to guidelines as defined by professional user groups are mandatory to pursue. In addition, the World Health Organisation (WHO) promotes optimization of antimicrobial use and more adequate microbiological diagnostics to cure UTI and combat antimicrobial resistance (AMR).

Methods

Miniaturised chromogenic bacterial cultivation including rapid antimicrobial susceptibility testing (RAST) at the POC can be successfully used for the diagnosis of UTI. Using small and cost-effective dipsticks containing chromogenic cultivation media, UTI-causing bacteria can be detected, quantified and identified with good sensitivity and specificity.

Conclusion

Access to such trustworthy, easy-to-use and cost-efficient diagnostic tools at the POC would offer more timely results for optimised antibiotic treatment. This will improve UTI therapy and prevent AMR.

Biofilms constitute one of the most common forms of living matter, playing an increasingly important role in technology, health, and ecology. While it is well established that biofilm growth and morphology are highly dependent on the external flow environment, the precise role of fluid friction has remained elusive. We grew Bacillus subtilis biofilms on flat surfaces of a channel in a laminar flow at wall shear stresses spanning one order of magnitude (τw = 0.068 Pa to τw = 0.67 Pa). By monitoring the three-dimensional distribution of biofilm over seven days, we found that the biofilms consist of smaller microcolonies, shaped like leaning pillars, many of which feature a streamer in the form of a thin filament that originates near the tip of the pillar. While the shape, size, and distribution of these microcolonies depend on the imposed shear stress, the same structural features appear consistently for all shear stress values. The formation of streamers occurs after the development of a base structure, suggesting that the latter induces a secondary flow that triggers streamer formation. Moreover, we observed that the biofilm volume grows approximately linearly over seven days for all shear stress values, with a growth rate inversely proportional to the wall shear stress. We develop a scaling model, providing insight into the mechanisms by which friction limits biofilm growth.

Hybridizing biological cells with man-made sensors enable the detection of a wide range of weak physiological responses with high specificity. The anterior chamber of the eye (ACE) is an ideal transplantation site due to its ocular immune privilege and optical transparency, which enable superior non-invasive longitudinal analyses of cells and microtissues. Engraftment of biohybrid microstructures in the ACE might, however, be affected by the pupillary response and dynamics. Here, sutureless transplantation of biohybrid microstructures, 3D printed in IP-Visio photoresin, containing a precisely localized pancreatic islet to the ACE of mice is presented. The biohybrid microstructures allow mechanical fixation in the ACE, independent of iris dynamics. After transplantation, islets in the microstructures successfully sustain their functionality for over 20 weeks and become vascularized despite physical separation from the vessel source (iris) and immersion in a low-viscous liquid (aqueous humor) with continuous circulation and clearance. This approach opens new perspectives in biohybrid microtissue transplantation in the ACE, advancing monitoring of microtissue-host interactions, disease modeling, treatment outcomes, and vascularization in engineered tissues.

Aims: Current endoscopic ultrasound (EUS) is suboptimal in the assessment of pancreatic cystic lesions (PCLs). We developed a new through-the needle loop device, to improve the cellular yield, and thereby sensitivity, of EUS fine needle aspiration (EUS-FNA) of pancreatic cysts.

In this in-vivo animal randomized controlled trial (RCT), we aim to test the cell yield and safety profile of this through the needle loop device using artificial cysts, comparing it with the standard procedure, EUS-FNA.

Methods: This was an in-vivo randomized controlled trial in pigs using artificial cysts. In one group, the new device was deployed through a 22G EUS-FNA needle into the cysts. In the control group, cystic punction was performed with standard EUS-FNA. New devices were visually inspected post-procedure. Cytological assessment, cell counting, and hemoglobin analysis were performed in samples from both groups.

Results: Artificial cysts (n=114) were punctured in six pigs, 57 in each group. Neither adverse events nor significant device malfunction occurred during brushing with the new loop device. Samples collected with the loop had non-detectable concentrations of hemoglobin in 72% (41/57) of cases, and 26% (16/57) had less than 0.6 g/dL, with no significant difference to the controls (p=0.32). There was significantly increased cell counts with the new device (11.7×median difference, p<.0001). Cytological smears were diagnostic in 77% of cases in the device group, while 54% in the control group (p=0.01, Fisher’s exact test; p=0.006, Chi-square test).

Conclusions: This novel loop device appears to be safe, causing neither significant bleeding nor device malfunction. Samples obtained with the loop brush were suitable for cytological analysis and showed significantly higher cell yield than controls. Further clinical studies are warranted.

Lubricated textured surfaces immersed in liquid flows offer tremendous potential for reducing fluid drag, enhancing heat and mass transfer, and preventing fouling. According to current design rules, the lubricant must chemically match the surface to remain robustly trapped within the texture. However, achieving such chemical compatibility poses a significant challenge for large-scale flow systems, as it demands advanced surface treatments or severely limits the range of viable lubricants. In addition, chemically tuned surfaces often degrade over time in harsh environments. Here, we demonstrate that a lubricant-infused surface (LIS) can resist drainage in the presence of external shear flow without requiring chemical compatibility. Surfaces featuring longitudinal grooves can retain up to 50% of partially wetting lubricants in fully developed turbulent flows. The retention relies on contact-angle hysteresis, where triple-phase contact lines are pinned to substrate heterogeneities, creating capillary resistance that prevents lubricant depletion. We develop an analytical model to predict the maximum length of pinned lubricant droplets in microgrooves. This model, validated through a combination of experiments and numerical simulations, can be used to design chemistry-free LISs for applications where the external environment is continuously flowing. Our findings open up new possibilities for using functional surfaces to control transport processes in large systems.

“Hot flow in the cold

changes shape in a dead world

comes matter to life”

Programmable matter that allows free shape transfiguration and locomotionon command promises ubiquitous access to objects or functions of interest.Current approaches for the autonomous reshaping of solid objects (smartmaterials, soft actuators, modular robotics) are limited in spatial resolution andshape. Solid-liquid phase change pumping as a mechanism for the contactlesstransfiguring and locomotion of solid objects is introduced. Thin objects aredeformed into any intended shape with sub-millimeter resolution and the abilityto freely change their topology is demonstrated, including adding or removingholes, splitting and merging. The unique locomotion of objects throughmillimeter-sized constrictions narrower than their body size is demonstrated,followed by restoring the original shape. This approach opens up avenues fordeveloping autonomous programmable matter with free shape transfiguration.

Cytobrushes are used for low-invasive sample collection and screening in multiple diseases, with a significant impact on early detection, prevention, and diagnosis. This study focuses on improving the safety of cell brushing in hard-to-reach locations by exploring brush construction from absorbable materials. We investigated the efficacy of loop brushes made of absorbable suture wires of Chirlac, Chirasorb, Monocryl, PDS II, Vicryl Rapid, Glycolon, and Catgut during their operation in conjunction with fine-needle aspiration in an artificial cyst model. PDS II brushes demonstrated the highest efficiency, while Monocryl and Catgut also provided a significant brushing effect. Efficient brushes portrayed higher flexural rigidity than their counterparts, and their efficiency was inversely proportional to their plastic deformation by the needle. Our results open avenues for safer cell biopsies in hard-to-reach locations by utilizing brushes composed of absorbable materials.

Stimuli-responsive materials with reversible supramolecular networks controlled by a change in temperature are of interest in medicine, biomedicine and analytical chemistry. For these materials to become more impactful, the development of greener synthetic practices with more sustainable solvents, lower energy consumption and a reduction in metallic catalysts is needed. In this work, we investigate the polymerisation of N-acryloyl glycinamide monomer by single-electron transfer reversible-deactivation radical polymerisation and its effect on the cloud point of the resulting PNAGA polymers. We accomplished 80% conversion within 5 min in water media using a copper wire catalyst. The material exhibited a sharp upper critical solution temperature (UCST) phase transition (10–80% transition within 6 K). These results indicate that UCST-exhibiting PNAGA can be synthesized at ambient temperatures and under non-inert conditions, eliminating the cost- and energy-consuming deoxygenation step. The choice of copper wire as the catalyst allows the possibility of catalyst recycling. Furthermore, we show that the reaction is feasible in a simple vial which would facilitate upscaling.

Separating bacteria from infected blood is an important step in preparing samples for downstream bacteria detection and analysis. However, the extremely low bacteria concentration and extremely high blood cell count make efficient separation challenging. In this study, we introduce a method for separating bacteria from blood in a single centrifugation step, which involves sedimentation velocity-based differentiation followed by size-based cross-flow filtration over an inclined filter. Starting from 1 mL spiked whole blood, we recovered 32 ± 4% of the bacteria (Escherichia coli, Klebsiella pneumonia, or Staphylococcus aureus) within one hour while removing 99.4 ± 0.1% of the red blood cells, 98.4 ± 1.4% of the white blood cells, and 90.0 ± 2.6% of the platelets. Changing the device material could further increase bacteria recovery to >50%. We demonstrated bacterial recovery from blood spiked with 10 CFU mL⁻¹. Our simple hands-off efficient separation of low-abundant bacteria approaches clinical expectations, making the new method a promising candidate for future clinical use.