Targeted delivery of immune-stimulating bispecific RNA, inducing apoptosis and anti-tumor immunity in cancer cells

Double-stranded RNAs (dsRNA)-based strategies appeared as promising therapies to induce an inflammation in the tumor microenvironment. However, currently described systems generally lack active targeting of tissues, and their clinical translation is thus limited to intratumoral injection. Herein, we developed an antibody-siRNA-5'triphosphate conjugate with multiple modes of action, combining cell surface EphA2-specific internalization, leading to a simultaneous gene silencing and activation of the receptor retinoic acid-inducible gene I (RIG-I). Recognition of cytosolic siRNA-5'triphosphate by RIG-I triggers the expression of interferons and pro-inflammatory cytokines, inducing an inflammation of the tumor environment and activating neighboring immune cells. In addition, these RIG-I-specific effects synergized with siRNA-mediated PLK1 silencing to promote cancer cell death by apoptosis. Altogether, such immune-stimulating antibody-RNA conjugate opens a novel modality to overcome some limitations encountered by dsRNA molecules currently in clinical trials.

Site-Selective Protein Conjugation by a Multicomponent Ugi Reaction

The chemical bioconjugation of proteins has seen tremendous applications in the past decades, with the booming of antibody-drug conjugates and their use in oncology. While genetic engineering has permitted to produce bespoke proteins featuring key (un-)natural amino acid residues poised for site-selective modifications, the conjugation of native proteins is riddled with selectivity issues. Chemoselective strategies are plentiful and enable the precise modification of virtually any residue with a reactive side-chain; site-selective methods are less common and usually most effective on small and medium-sized proteins. In this context, we studied the application of the Ugi multicomponent reaction for the site-selective conjugation of amine and carboxylate groups on proteins, and antibodies in particular. Through an in-depth mechanistic methodology work supported by peptide mapping studies, we managed to develop a set of conditions allowing the highly selective modification of antibodies bearing N-terminal glutamate and aspartate residues. We demonstrated that this strategy did not alter their affinity toward their target antigen and produced an antibody-drug conjugate with subnanomolar potency. Excitingly, we showed that the high site selectivity of our strategy was maintained on other protein formats, especially on anticalins, for which directed mutagenesis helped to highlight the key importance of a single lysine residue.

Drug upgrade: A complete methodology from old drug to new chemical entities using Nematic Protein Organization Technique

Drug repurposing is used to propose new therapeutic perspectives. Here, we introduce "Drug Upgrade", that is, characterizing the mode of action of an old drug to generate new chemical entities and new therapeutics. We proposed a novel methodology covering target identification to pharmacology validation. As an old drug, we chose hydroxychloroquine (HCQ) for its well-documented clinical efficacy in lupus and its side effect, retinal toxicity. Using the Nematic Protein Organization Technique (NPOT®) followed by liquid chromatography-tandem mass spectrometry analyses, we identified myeloperoxidase (MPO) and alpha-crystallin β chain (CRYAB) as primary and secondary targets to HCQ from lupus patients' peripheral blood mononuclear cells (PBMCs) and isolated human retinas. Surface plasmon resonance (SPR) and enzymatic assays confirmed the interaction of HCQ with MPO and CRYAB. We synthesized INS-072 a novel analog of HCQ that increased affinity for MPO and decreased binding to CRYAB compared to HCQ. INS-072 delayed cutaneous eruption significantly compared to HCQ in the murine MRL/lpr model of spontaneous lupus and prevents immune complex vasculitis in mice. In addition, long-term HCQ treatment caused retinal toxicity in mice, unlike INS-072. Our study illustrates a method of drug development, where new applications or improvements can be explored by fully characterizing the drug's mode of action.

Effect of annealing temperature on the structure and optical properties of ZnO thin films

The effect of annealing temperature on the microstructure, defects and optical properties of ZnO thin films are investigated using sol-gel based spin coating method for a range of annealing temperatures from 200∘C to 500∘C. The correlation among the microstructure, defects, impurity content and the optical band gap of films of thickness about 10-12 nm is elucidated. The particle size increases and the optical band gap reduces with the annealing temperature. At 200∘C, amorphous films were formed with particle size less than 10 nm with an optical band gap of about 3.41 eV. As the temperature increases the grain size increases and the defect, impurity content as well as the optical band gap reduces. This could be due to the reduction in the lattice strain. For an average grain size of about 35 nm and above, the band gap asymptotically approaches the theoretical value of ZnO (3.37 eV). The photoluminescence (PL) spectra show a systematic red-shift in the excitonic levels corresponding to the variation in the optical band-gap. The defect emission from Zn-vacancies is observed in the PL spectra and are further supported by the positron annihilation measurements.

Safety, feasibility, and short-term-outcome of anal endoscopic submucosal dissection for anal intraepithelial neoplasia: an option for focal lesions?

BACKGROUND

Anal intraepithelial neoplasia (AIN) appears in three different stages. AIN 1 and AIN 2 (p16 negative) are defined as low risk and unlikely to progress to invasive anal cancer. AIN 2 (p16 positive) and AIN 3 are of high risk and should be treated because progression rates to anal cancer are around 10% and treatment significantly reduces this risk. The correct treatment is still a matter of debate. Human papilloma virus (HPV) plays a role in the development of AIN. Our aim was to assess anal endoscopic dissection (aESD) as an intervention for AIN3.

METHODS

We retrospectively evaluated patients who underwent aESD for AIN 3 between December 2017 and March 2023. The interventional technique itself (duration, complications, size of specimen) and patient outcomes (recurrence, progression to anal cancer, re-intervention) were analyzed.

RESULTS

Fifteen patients with a median age of 52 years (23-78) underwent aESD for AIN 3. All tested specimens were positive for HPV. Median duration of intervention was 56.1 min, one delayed postinterventional bleeding occurred, and specimen size was 12.05 cm2. Median follow-up was 11.17 months. Three recurrences (20%) appeared: one was resected via biopsy and two were again treated with aESD. There was no progression to invasive anal cancer in the follow-up period.

CONCLUSIONS

Anal endoscopic submucosal dissection seems to be a safe and feasible treatment for AIN. Recurrences are seldom and can be treated again with the same method. Nevertheless, indications for resection in comparison to radiofrequency ablation, pharmacological therapy, and watch-and-wait strategy are still unclear.

TRIAL REGISTRATION

Ethics commission of Salzburg, Austria, EK-Nr. 1056/2023. Keywords: Endoscopic submucosal dissection, anal intraepithelial neoplasia, anal cancer.

Weight loss induced alleviation of sleep-disordered breathing is associated with improvement of non-alcoholic fatty liver disease

INTRODUCTION

Sleep-disordered breathing (SDB) and non-alcoholic fatty liver disease (NAFLD) are both common comorbidities in obese patients. Structured weight loss programs are effective and can reduce the incidence and severity of obesity-related comorbidities. The objective of the present analysis is to test whether weight loss induced alleviation of SDB is a predictor for improvement of NAFLD.

METHODS

Obese participants underwent a standardized non-surgical 3 months weight reduction program (800 kilocalories per day with low carbohydrate and fat content). Abdominal sonography for NAFLD (grade 0 to 3) and monitoring for SDB (defined as apnea-hypopnea index [AHI] ≥ 15/h) were performed at baseline and after 3 months. Alleviation of SDB was defined as a shift from AHI≥ 15/h to <15/h.

RESULTS

48 patients (48% female, age 42 ± 12 years, body-mass index 40.3 ± 8.1 kg/m2, AHI 14 ± 17/h, 85% NAFLD grade ≥1) participated in the weight loss program. In contrast to the no SDB group, in patients with SDB weight loss of 27.1 ±0 .9 kg (8.4 ± 2.8 kg/m2) after three months was paralleled by a reduction in AHI (-22 ± 17/h), prevalence of SDB (from 31% to 13%), and oxidized low-density lipoprotein (-13 ± 11 U/l). In individuals with preexisting SDB NAFLD grade improved more (2 versus 1, p<0.001) and was at a lower degree at 3 months than in those without SDB (0 versus 1, p = 0.015). In multivariable analysis models, SDB at baseline was associated with improvement of NAFLD grade (B 0.908; 95% CI 0.125, 1.691; p = 0.024), independently of age, sex, and BMI (each p>0.05, respectively). Decreasing BMI (B 0.16 [95%-CI 0.08; 0.23], p<0.001) and alleviation of SDB (B 0.90 [95%-CI 0.21; 1.58], p = 0.012) were independently associated with improvement of NAFLD grade.

CONCLUSION

Preexisting SDB and weight loss induced alleviation of SDB are predictors for improvement in NAFLD grade, independent of the extent of weight loss. SDB may contribute to the pathogenesis of NAFLD via SDB-induced oxidative stress and inflammation, but the causal mechanism remains unclear.

Evolution of point defects in pulsed-laser-melted Ge1-xSnxprobed by positron annihilation lifetime spectroscopy

Direct-band-gap Germanium-Tin alloys (Ge1-xSnx) with high carrier mobilities are promising materials for nano- and optoelectronics. The concentration of open volume defects in the alloy, such as Sn and Ge vacancies, influences the final device performance. In this article, we present an evaluation of the point defects in molecular-beam-epitaxy grown Ge1-xSnxfilms treated by post-growth nanosecond-range pulsed laser melting (PLM). Doppler broadening - variable energy positron annihilation spectroscopy and variable energy positron annihilation lifetime spectroscopy are used to investigate the defect nanostructure in the Ge1-xSnxfilms exposed to increasing laser energy density. The experimental results, supported with ATomic SUPerposition calculations, evidence that after PLM, the average size of the open volume defects increases, which represents a raise in concentration of vacancy agglomerations, but the overall defect density is reduced as a function of the PLM fluence. At the same time, the positron annihilation spectroscopy analysis provides information about dislocations and Ge vacancies decorated by Sn atoms. Moreover, it is shown that the PLM reduces the strain in the layer, while dislocations are responsible for trapping of Sn and formation of small Sn-rich-clusters.

Anti-HEV seroprevalence and rate of viremia in a German cohort of dogs, cats, and horses

Hepatitis E virus (HEV) genotype 3 infections in Germany are mainly transmitted zoonotically through the consumption of swine meat. Furthermore, there is evidence that pets might come into contact with HEV, but the relevance of companion animals as possible sources of HEV transmission in Germany still needs to be defined. A monitoring study was therefore carried out on dogs, cats, and horses from Germany. In total 365 serum samples from pets (124 dogs, 119 cats, and 122 horses) were tested for HEV by PCR and for anti-HEV antibodies by a commercial ELISA. The HEV seroprevalence determined by the sero-assay varied significantly between dogs (10%), cats (6%), and horses (2%). Liver injury-related enzymes, alanine transaminase (ALT), and aspartate transaminase (AST) showed no differences between HEV-positive or negative animals. None of the pet serum samples tested positive for PCR. This serological study suggests that dogs and cats are significantly exposed to HEV in Germany, while horses are of minor relevance.

Reinvestigation of the Automated Synthesis of Stoichiometrically Conjugated Antibodies to Access High Molecular Weight Payloads and Multiplexed Conjugation via an In-Solution Trans-Tagging Process

Protein conjugates have found applications in a wide variety of fields, ranging from therapeutics to imaging and detection. However, robust control over the parameters of the conjugation process (such as sites and degree of conjugation) remains challenging. Previously, our group introduced Equimolar NAtive Chemical Tagging (ENACT), a method which allows for the monofunctionalization of proteins by combining an iterative low-conversion bioconjugation, an automated process, and a bioorthogonal trans-tagging reaction. However, while the automated ENACT was dimensioned to achieve monoconjugation at the mg scale, in early stage research, because of the rarity and cost of the starting materials, it is often necessary to prepare conjugates at the lower, μg, scale. Here, we introduce modified ENACT protocols, as well as a new ENACT conjugation reagent, which allow for the monofunctionalization of proteins on the micrograms scale, using minimal quantities of payload.

Microfluidic Droplet Stabilization via SPAAC Promoted Antibody Conjugation at the Water/Oil Interface

Droplet-based microfluidics is leading the development of miniaturized, rapid, and sensitive version of enzyme-linked immunosorbent assays (ELISAs), a central method for protein detection. These assays involve the use of a functionalized surface able to selectively capture the desired analyte. Using the droplet's oil water interface as a capture surface requires designing custom-perfluorinated fluorosurfactants bearing azide-containing polar groups, which spontaneously react when forming the droplet with strain-alkyne-functionalized antibodies solubilized in the aqueous phase. In this article, we present our research on the influence of the structure of surfactant's hydrophilic heads on the efficiency of SPAAC functionalization and on the effect of this antibody grafting process on droplet stability. We have shown that while short linkers lead to high grafting efficiency, long linkers lead to high stability, and that an intermediate size is required to balance both parameters. In the described family of surfactants, the optimal structure proved to be a PEG4 linker connecting a polar di-azide head and a per-fluoropolyether tail (Krytox). We also found that grafting an increasing amount of antibody, thus increasing interface coverage, increases droplet stability. It thus appears that such a bi-partite system with a reactive fluoro-surfactant in the oil phase and reactive antibody counterpart in the aqueous phase gives access in situ to novel surfactant construct providing unexplored interface structures and droplet functionality.

Targeted Anticancer Agent with Original Mode of Action Prepared by Supramolecular Assembly of Antibody Oligonucleotide Conjugates and Cationic Nanoparticles

Despite their clinical success, Antibody-Drug Conjugates (ADCs) are still limited to the delivery of a handful of cytotoxic small-molecule payloads. Adaptation of this successful format to the delivery of alternative types of cytotoxic payloads is of high interest in the search for novel anticancer treatments. Herein, we considered that the inherent toxicity of cationic nanoparticles (cNP), which limits their use as oligonucleotide delivery systems, could be turned into an opportunity to access a new family of toxic payloads. We complexed anti-HER2 antibody-oligonucleotide conjugates (AOC) with cytotoxic cationic polydiacetylenic micelles to obtain Antibody-Toxic-Nanoparticles Conjugates (ATNPs) and studied their physicochemical properties, as well as their bioactivity in both in vitro and in vivo HER2 models. After optimising their AOC/cNP ratio, the small (73 nm) HER2-targeting ATNPs were found to selectively kill antigen-positive SKBR-2 cells over antigen-negative MDA-MB-231 cells in serum-containing medium. Further in vivo anti-cancer activity was demonstrated in an SKBR-3 tumour xenograft model in BALB/c mice in which stable 60% tumour regression could be observed just after two injections of 45 pmol of ATNP. These results open interesting prospects in the use of such cationic nanoparticles as payloads for ADC-like strategies.

Droplet Surface Immunoassay by Relocation (D-SIRe) for High-Throughput Analysis of Cytosolic Proteins at the Single-Cell Level

Enzyme-linked immunosorbent assay (ELISA) is a central analytic method in biological science for the detection of proteins. Introduction of droplet-based microfluidics allowed the development of miniaturized, less-consuming, and more sensitive ELISA assays by coencapsulating the biological sample and antibody-functionalized particles. We report herein an alternative in-droplet immunoassay format, which avoids the use of particles. It exploits the oil/aqueous-phase interface as a protein capture and detection surface. This is achieved using tailored perfluorinated surfactants bearing azide-functionalized PEG-based polar headgroups, which spontaneously react when meeting at the droplet formation site, with strained alkyne-functionalized antibodies solubilized in the water phase. The resulting antibody-functionalized inner surface can then be used to capture a target protein. This surface capture process leads to concomitant relocation at the surface of a labeled detection antibody and in turn to a drastic change in the shape of the fluorescence signal from a convex shape (not captured) to a characteristic concave shape (captured). This novel droplet surface immunoassay by fluorescence relocation (D-SIRe) proved to be fast and sensitive at 2.3 attomoles of analyte per droplet. It was further demonstrated to allow detection of cytosolic proteins at the single bacteria level.

P05.01.B Distribution of the staining agent sodium-fluorescein in cerebral neoplasia - a comparison between intraoperative confocal laser endomicroscopy and in vitro fluorescence microscopy

Background

While conventional frozen sections and other ex vivo microscopy always come along with artefacts, in vivo confocal laser endomicroscopy (CLE) offers less invasive, less manipulated imaging of living tissues. Understanding the distribution of the staining agent sodium-fluorescein (NaFl) plays a key role in establishing in vivo CLE as a new opportunity for real-time transmitted, in vivo imaging.

By comparing the distribution of NaFl in in vivo and ex vivo CLE to conventional fluorescence microscopy of NaFl incubated tumor cell cultures we gain a better understanding of the staining mechanism.

Material and Methods

Sodium-fluorescein is the water-soluble sodium salt of fluorescein and is used as a fluorescent tracer in neurosurgery. The staining agent was applied intravenously at the beginning of the surgical procedure. In vivo CLE of the lesion was performed 30 to 50 minutes later and compared to ex vivo CLE imaging and conventional fluorescence microscopy. In addition, different tumor cell lines derived from malignant gliomas and carcinomas, respectively, were incubated with NaFl in vitro and the uptake of the fluorescent dye was monitored over time.

Results

From initial results, the intraoperative images showed specific fluorescein distribution depending on the architecture of the tumor entity. In most cases, glial tumors demonstrated higher accumulation of the staining agent in the extracellular tumor matrix, whereas the cells of carcinoma metastases appeared to take up NaFl intracellularly. These results were corroborated by NaFl uptake in cell culture experiments.

Compared to ex vivo CLE, in vivo imaging offered a faster assessment of the tissue, brighter images and higher staining levels. Due to movement artefacts and the narrow intraoperative imaging time frame, in vivo CLE images were sometimes impaired by lower image quality.

Conclusion

The specific distribution of the fluorescent agent NaFl allowed for a discrimination between the different neoplastic entities. Images from in vivo and ex vivo confocal laser endomicroscopy showed NaFl uptake in concordance with the results of NaFl incubated cell cultures.

Intraoperative, in vivo confocal laser endomicroscopy shows promising first results in the understanding of brain tumor histomorphology in situ. Being faster and less manipulated by artefacts than ex vivo investigations, it opens up wider opportunities for research and intraoperative diagnostics.

OP0243 OSTEOPOROSIS CASE-FINDING IN PEOPLE UNDERGOING ROUTINE DIAGNOSTIC CT SCANS ALMOST TRIPLED THE RATE OF OSTEOPOROSIS TREATMENT AT 12 MONTHS. A RANDOMISED, MULTI-CENTRE FEASIBILITY STUDY USING WAITING ROOM FRAX, OPPORTUNISTIC CT BONE DENSITY AND VERTEBRAL FRACTURE ASSESSMENT VERSUS USUAL CARE

Background

Up to 40% of all diagnostic computed tomography (CT) scans include views of the spine or hips. Among older people, osteoporosis or vertebral fractures have been found in 30% of such CT scans. Our ‘PHOENIX’ intervention repurposes CT scans taken for other reasons to identify fractures and measure bone density as an ‘added extra’. Early detection and treatment of osteoporosis in CT-attending patients could improve health outcomes.

Objectives

To determine the feasibility and efficacy of PHOENIX versus usual care in a multi-centre, randomised, pragmatic study conducted in Eastern England involving our Cambridge Specialist Hospital ‘hub’ and four regional General Hospital ‘spokes’.

Methods

Women ≥65 and men ≥75 years attending for routine diagnostic CT scans were invited to participate via a novel consent form incorporating FRAX Fracture Risk Assessment questions. After calculating their FRAX 10-year risk score, higher risk patients were block randomised (1:1:1) to Group 1) PHOENIX intervention, 2) Active Control, where the GP was sent the patients’ FRAX answers only, or 3) Usual Care where data were only analysed after 13 months had elapsed. The CT scans of high FRAX risk patients in Group 1 were retrieved by the Cambridge team using NHS Connecting for Health (Burnbank, UK). The team performed vertebral fracture assessment and measured bone density using QCT Pro (Mindways, USA). They added patient-specific treatment and investigation management advice from ‘drop down’ menus before results were reviewed by a physician, authorised and sent to general practitioners (GPs). Baseline CT scans from groups 2 and 3 were assessed in the same way after 13 months to ensure no patient with osteoporosis/fractures was neglected long term. Assuming 25% attrition, the study was powered to find a superior osteoporosis treatment rate in Group 1 (estimated 20%) versus 16% (Active Control) and 5% (Usual Care). Co-primary feasibility endpoints were the ability to a) randomise 375 patients within 10 months and b) retain 75% of survivors able to complete a 1-year bone health outcome questionnaire. Secondary outcomes included osteoporosis/vertebral fracture identification rates and osteoporosis treatment rates. Stakeholder acceptability and economic aspects will be reported separately.

Results

From 1828 invites, 595 participants consented to participate of whom 213 were excluded due to ‘low’ FRAX score. Mortality at 12 months was 20%. Both feasibility objectives were achieved: 1) 382 people were randomised within 10 months; 2) 84.4% of survivors at 1 year (95%CI: 80.5, 88.3) were successfully followed-up. Groups were well matched at baseline. The average age of 375 patients (334 female, 41 male) was 75.2 years (74.6, 75.9). Osteoporosis of the hip/spine was present in 41% of 362 analysable CT scans. From the 264 spines that were suitable for VFA, 20% (n=53) were found to have vertebral fractures, with 8.3% having multiple vertebral fractures (n=22). Osteoporosis treatment was reported in 8.5% of Usual Care group (2.9, 14.2) and 24.2% (15.4, 33.0) of PHOENIX group participants, while in the Active Control group (FRAX only) it was 18.8% (10.9, 26.6 p=0.021). In the PHOENIX group, a recommendation to treat was sent to 50 patients’ GPs at baseline. Only 18 of the 50 patients (36%) were found to be taking osteoporosis treatment 12 months after this advice was sent.

Conclusion

Osteoporosis treatment rates were almost tripled by screening patients attending for routine diagnostic CT scans with waiting room FRAX, CT-bone densitometry and vertebral fracture analysis.

Acknowledgements

This project is funded by the National Institute for Health Research (NIHR) under its Research for Patient Benefit (RfPB) Programme (Grant Reference Number PB-PG-0816-20027) and by the Cambridge NIHR Biomedical Research Centre (BRC-1215-20014). The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care. Funding is in place to 31.03.2022. Three individuals, Mr Jeremy Dearling, Mrs Tessa Plume and Dr Ann Frost joined our trial group as PPI representatives; they were specifically involved in patient documentation design (particularly the PHOENIX pack, informed consent form which facilitated consent without having a researcher present) and contributed to suggestions for increasing patient recruitment and follow up.

Disclosure of Interests

None declared

Manipulating magnetic and magnetoresistive properties by oxygen vacancy complexes in GCMO thin films

The effect ofin situannealing is investigated in Gd_0.1Ca_0.9MnO₃(GCMO) thin films in oxygen and vacuum atmospheres. We show that the reduction of oxygen content in GCMO lattice by vacuum annealing induced more oxygen complex vacancies in both subsurface and interface regions and larger grain domains when compared with the pristine one. Consequently, the double exchange interaction is suppressed and the metallic-ferromagnetic state below Curie temperature turned into spin-glass insulating state. In contrast, the magnetic and resistivity measurements show that the oxygen treatment increases ferromagnetic phase volume, resulting in greater magnetization (M_S) and improved magnetoresistivity properties below Curie temperature by improving the double exchange interaction. The threshold field to observe the training effect is decreased in oxygen treated film. In addition, the positron annihilation spectroscopy analysis exhibits fewer open volume defects in the subsurface region for oxygen treated film when compared with the pristine sample. These results unambiguously demonstrate that the oxygen treated film with significant spin memory and greater magnetoresistance can be a potential candidate for the future memristor applications.

[Comparison of catheter-associated quality of life in external urinary diversion: nephrostomy vs. suprapubic catheter]

Einleitung

Die katheterbezogene Lebensqualität (LQ) bei Nephrostomieträgern wurde bisher noch nie systematisch untersucht. Dies sollte nun erstmalig vergleichend mit einer ebenfalls externen Urinableitung, dem suprapubischen Katheter, geschehen.

Methodik

Das die katheterbezogene LQ untersuchende Assessment nach Mary Wilde wurde bei Patienten mit perkutaner Nephrostomie (PCN) in lebenslanger Intention und minimaler Liegedauer von 3 Monaten vorgelegt.

Ergebnisse

Es zeigte sich insgesamt bei 66 Patienten (davon 42 mit unilateraler PCN) mit einem Punktwert von median 4,0 auf einer Skala von 0–5 eine nur moderat eingeschränkte katheterbezogene LQ. Diese wurde insgesamt und in allen Domänen schlechter als bei Patienten mit suprapubischem Katheter (SPK) bewertet, bei denen sich ein Score von 4,3 im Median fand. Signifikant waren die Unterschiede in den Einzelitems „Gefühl der Erniedrigung“, „Konflikte mit ärztlichem oder pflegerischem Personal“, „Angst vor schmerzhaften Katheterwechseln“, „Gefühl als kranke Person“, „Behinderungen in Aktivitäten des täglichen Lebens“ und „Besorgnis, nicht alles tun zu können, was ich mag“. Ebenso ergaben sich bei PCN-Trägern signifikant häufiger Angst vor Katheterlecks und Uringeruch. Die Anzahl der einliegenden PCN und die Grunderkrankung spielten für die Beurteilung der LQ keine Rolle.

Schlussfolgerung

Erstmals wurde die katheterassoziierte LQ, die sich bei PCN-Trägern nur moderat eingeschränkt fand, mit einem validierten Assessment quantitativ eingeordnet. Die Angabe der Betroffenen, sich als „krank“ und in der Ausübung von Aktivitäten des täglichen Lebens „behindert“ zu fühlen und die Angst vor Urinleckagen und schmerzhaften Wechseln sollten Ansporn für eine sorgfältige Indikationsstellung und technisch korrekte Katheterwechsel sein.

[Guidelines for consultations regarding incontinence care products]

An investigation of the German consumer organisation "Stiftung Warentest" in 2017 confirmed significant deficiencies in the information, advice and supply of incontinence care products received by urinary incontinence patients. The German Society of Urology (DGU) thereupon drafted and later published guidelines concerning the consultation of patients in the context of incontinence care. Important aspects of the consultation process include the determination of the type of incontinence as well as its severity, clinical examination, and advice regarding possible curative treatments. However, the advice appointment takes centre stage and should ideally be conducted by a qualified person in a separate room granting sufficient privacy and time. Furthermore, repeated supply of a selection of samples for differing degrees and types of incontinence, accommodating the patient's individual preferences and anatomical features, is crucial in order to ensure optimal incontinence care. In the case of commercial health care service providers, transparency relating to the financial implications of e.g. expensive products is key, which is what has been intended by German health insurance providers. The new guidelines concerning urinary incontinence care consultation constitute a step towards the improvement and structuring of processes in the consultation regarding, and the supply of, incontinence care products.

An overview of chemo- and site-selectivity aspects in the chemical conjugation of proteins

The bioconjugation of proteins-that is, the creation of a covalent link between a protein and any other molecule-has been studied for decades, partly because of the numerous applications of protein conjugates, but also due to the technical challenge it represents. Indeed, proteins possess inner physico-chemical properties-they are sensitive and polynucleophilic macromolecules-that make them complex substrates in conjugation reactions. This complexity arises from the mild conditions imposed by their sensitivity but also from selectivity issues, viz the precise control of the conjugation site on the protein. After decades of research, strategies and reagents have been developed to address two aspects of this selectivity: chemoselectivity-harnessing the reacting chemical functionality-and site-selectivity-controlling the reacting amino acid residue-most notably thanks to the participation of synthetic chemistry in this effort. This review offers an overview of these chemical bioconjugation strategies, insisting on those employing native proteins as substrates, and shows that the field is active and exciting, especially for synthetic chemists seeking new challenges.

Al2O3 co-doped with Cr3+ and Mn4+, a dual-emitter probe for multimodal non-contact luminescence thermometry

Luminescence probes that facilitate multimodal non-contact measurements of temperature are of particular interest due to the possibility of cross-referencing results across different readout techniques. This intrinsic referencing is an essential addition that enhances accuracy and reliability of the technique. A further enhancement of sensor performance can be achieved by using two luminescent ions acting as independent emitters, thereby adding in-built redundancy to non-contact temperature sensing, using a single readout technique. In this study we combine both approaches by engineering a material with two luminescent ions that can be independently probed through different readout modes of non-contact temperature sensing. The approach was tested using Al₂O₃ co-doped with Cr³⁺ and Mn⁴⁺, exhibiting sharp emission lines due to ²E → ⁴A₂ transitions. The temperature sensing performance was examined by measuring three characteristics: temperature-induced changes of the intensity ratio of the emission lines, their spectral position, and the luminescence decay time constant. The processes responsible for the changes with temperature of the measured luminescence characteristics are discussed in terms of relevant models. By comparing temperature resolutions achievable by different modes of temperature sensing it is established that in Al₂O₃-Cr,Mn spectroscopic methods provide the best measurement accuracy over a broad temperature range. A temperature resolution better than ±2.8 K can be achieved by monitoring the luminescence intensity ratio (40-145 K) and the spectral shift of the R-line of Mn⁴⁺ (145-300 K range).

[Quality of life for wearers of a suprapubic or transurethral bladder catheter as lifelong permanent care]

Hintergrund

Die Anlage eines transurethralen Dauerkatheters (DK) oder suprapubischen Harnblasenkatheters (SPK) in lebenslanger Indikation stellt einen Eingriff mit relevanten Komplikationen, Komorbiditäten und möglichen Auswirkungen auf die katheterassoziierte Lebensqualität des Betroffenen dar. Letztere wurde aber bisher noch nicht untersucht.

Methodik

Zur Anwendung kam ein validiertes Assessment zur katheterbezogenen Lebensqualität mit 25 Items in 5 Domänen. Befragt wurden im Rahmen eines Katheterwechsels Patienten mit einem DK oder SPK in lebenslanger Intention, die diesen mindestens 3 Monate trugen.

Ergebnisse

Fragebögen von 357 Patienten, davon 260 Männer und 97 Frauen, 193 mit SPK und 162 mit DK (2 ohne Angabe) lagen vor. Patienten mit DK waren mit 78,9 ± 11,1 Jahren signifikant älter als solche mit SPK mit 74,4 ± 12,6 Jahren (p < 0,001). Der mittlere Gesamtlebensqualitätsscore lag bei 4,1 ± 0,9 Punkten auf einer Skala von 1 (maximal beeinträchtigte Lebensqualität) bis 5 (keine Beeinträchtigung der Lebensqualität). Es zeigten sich u. a. mit niedrigeren Scores eine vermehrte Angst vor Katheterlecks, Angst vor Uringeruch und Harnwegsinfektionen und vor schmerzhaften Katheterwechseln. Diese Sorgen waren v. a. bei Frauen, solchen mit Harninkontinenz, Trägern eines Katheters ≥ 18 Ch und bei Patienten < 70 Jahren vorhanden. Frauen mit einem SPK wiesen eine schlechtere Bewertung ihrer Lebensqualität als Männer mit SPK auf.

Schlussfolgerung

Die gefundenen Ergebnisse sollten in die Aufklärung zu einer lebenslangen Katheterableitung einfließen bzw. im Kontext möglicher Alternativen wie z. B. einer operativen Desobstruktion oder einer Hilfsmittelversorgung mit dem Patienten bzw. Betreuungspersonen besprochen werden.

Zusatzmaterial online

Die Online-Version dieses Beitrags (10.1007/s00120-021-01642-1) enthält weitere Tabellen mit detaillierten Ergebnissen der Fragen der 5 abgefragten Domänen.

Abstract 691: Antibody conjugated to a bispecific RNA molecule targeting RIG-I and PLK1

Simultaneous access to several targets has become the subject of intense studies in immuno-oncology. In order to benefit from the synergies provided by the activation of different signaling pathways in immunology and the knockdown of proteins involved in cancer cell survival, we established a bispecific approach. The activation of the innate immune response by delivering agonists of pattern-recognition receptors (PRR) such as RIG-I (retinoic acid-inducible I) represents a promising strategy. RIG-I detects short double-stranded RNA molecules ended by a 5'-di/triphosphate moiety (5'ppp-dsRNA). RIG-I activation promotes type I IFN secretion and cancer-cell selective apoptosis. To obtain a bifunctional molecule, the 5'ppp-dsRNA sequence was designed to silence PLK1 (polo-like kinase 1). Suppressing PLK1 expression with small interfering RNAs (siRNA) leads to cell cycle arrest and retards cancer cell growth. This concept of bifunctional RNAs has been validated by using non-targeted systems.1

To enhance this synergy, we conjugated this 5'ppp-siPLK1 to an antibody for a specific delivery to cancerous cells that overexpress erythropoietin-producing hepatocellular receptor A2 (EphA2) at their surface. Upon binding to EphA2 receptor, the antibody is well internalized, thus making it a good vehicle to deliver the bispecific 5'ppp-siPLK1. After EphA2-positive cells treatment, we observed RIG-I specific activation as well as PLK1 depletion. Both effects were correlated with cellular apoptosis and the mode of action was further confirmed with mechanistic and kinetic studies. Finally, while non-modified unconjugated siRNA has a very short half-life in plasma, we observed an increase in stability for the antibody-5'ppp-siPLK1 conjugates. These data suggest that anti-EphA2 receptor antibody could be used to deliver a bispecific RNA molecule.

References:1H. Poeck, R. Besch, C. Maihoefer, M. Renn, D. Tormo, S. S. Morskaya, S. Kirschnek, E. Gaffal, J. Landsberg, J. Hellmuth, A. Schmidt, D. Anz, M. Bscheider, T. Schwerd, C. Berking, C. Bourquin, U. Kalinke, E. Kremmer, H. Kato, S. Akira, R. Meyers, G. Häcker, M. Neuenhahn, D. Busch, J. Ruland, S. Rothenfusser, M. Prinz, V. Hornung, S. Endres, T. Tüting and G. Hartmann, 5′-triphosphate-siRNA: turning gene silencing and Rig-I activation against melanoma, Nat. Med., 2008, 14, 1256-1263.

Citation Format: Tony Rady, Stéphane Erb, Safia Deddouche-Grass, Renaud Morales, Hervé Bouchard, Guilhem Chaubet, Sarah Cianférani, Dmitri Wiederschain, Nicolas Basse, Alain Wagner. Antibody conjugated to a bispecific RNA molecule targeting RIG-I and PLK1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 691.

Plasma induced acceleration and selectivity in strain-promoted azide-alkyne cycloadditions

Strain-promoted azide-alkyne cycloaddition (SPAAC) is an important member of the bioorthogonal reaction family. Over the past decade, much work has been dedicated to the generation of new strained alkynes with improved reactivity. While kinetics studies of SPAAC are often conducted in organic solvents, buffered solutions or mixtures, these media do not reflect the complexity of in vivo systems. In this work, we show that performing SPAAC in human plasma leads to intriguing kinetics and selectivity effects. In particular, we observed that reactions in plasma could be accelerated up to 70-fold compared to those in methanol, and that selective couplings between a pair of reagents could be possible in competition experiments. These findings highlight the value of evaluating bioorthogonal reactions in such a complex medium, especially when in vivo applications are planned, as unsuspected behaviour can be observed, disrupting the usual rules governing the reactivity in simple solvent systems.

Tuned AFM-FM coupling by the formation of vacancy complex in Gd0.6Ca0.4MnO3thin film lattice

The effect ofin situoxygen and vacuum annealings on the low bandwidth manganite Gd_1-xCa_xMnO₃(GCMO) thin film withx= 0.4 was investigated. Based on the magnetic measurements, the AFM-FM coupling is suppressed by the vacuum annealing treatment via destroying the double exchange interaction and increasing the unit cell volume by converting the Mn⁴⁺to the Mn³⁺. Consequently, resistance increases significantly compared to pristine film. The results are explained by a model obtained from the positron annihilation studies, where the vacuum annealing increased the annihilation lifetime in A and B sites due to the formation of vacancy complexesV_A,B-V_O, which was not the case in the pristine sample. The positron annihilation analysis indicated that most of the open volume defects have been detected in the interface region rather than on the subsurface layer and this result is confirmed by detailed x-ray reflection analysis. On the other hand, the effect of oxygen annealing on the unit cell volume and magnetization was insignificant. This is in agreement with positron annihilation results which demonstrated that the introduction of oxygen does not change the number of cation vacancies significantly. This work demonstrates that the modification of oxygen vacancies and vacancy complexes can tune magnetic and electronic structure of the epitaxial thin films to provide new functionalities in future applications.

Non-specific interactions of antibody-oligonucleotide conjugates with living cells

Antibody-Oligonucleotide Conjugates (AOCs) represent an emerging class of functionalized antibodies that have already been used in a wide variety of applications. While the impact of dye and drug conjugation on antibodies' ability to bind their target has been extensively studied, little is known about the effect caused by the conjugation of hydrophilic and charged payloads such as oligonucleotides on the functions of an antibody. Previous observations of non-specific interactions of nucleic acids with untargeted cells prompted us to further investigate their impact on AOC binding abilities and cell selectivity. We synthesized a series of single- and double-stranded AOCs, as well as a human serum albumin-oligonucleotide conjugate, and studied their interactions with both targeted and non-targeted living cells using a time-resolved analysis of ligand binding assay. Our results indicate that conjugation of single strand oligonucleotides to proteins induce consistent non-specific interactions with cell surfaces while double strand oligonucleotides have little or no effect, depending on the preparation method.

An experimental investigation of light emission produced in the process of positronium formation in matter

The excess energy emitted during the positronium (Ps) formation in condensed matter may be released as light. Spectroscopic analysis of this light can be a new method of studying the electronic properties of materials. We report the first experimental attempt, according to our knowledge, to verify the existence of this emission process. As a result, the possibility of the emission of photons during Ps formation is within the experimental uncertainty in two different solids: an n-alkane and porous silica. However, it seems that the Ps formation on the alkane surface is not accompanied by the emission of photons with energy in the detection range of 1.6-3.8 eV. Various processes that can influence the energy of the photon emitted during the Ps formation are discussed to elucidate this issue. To aid future experiments, equations were developed to estimate the expected ratio of light emission events to annihilation events with the presence or absence of a photon during the Ps formation.

Bicyclo[6.1.0]nonyne carboxylic acid for the production of stable molecular probes

Bicyclo[6.1.0]non-4-yn-9-ylmethanol (BCN alcohol) is the most prominent strained-alkyne scaffold in chemical biology. Described herein is the synthesis of an oxidized analogue – BCN acid – whose facile functionalization via amide bond formation yields more stable derivatives than the classically encountered carbamates.

We report a novel strained alkyne, coined BCN acid. This compound participates efficiently in diverse bioorthogonal reactions and allows the facile production of amide probes, which showed superior in vitro stability compared to carbamate analogues.

Diagnosis and management of tropomyosin receptor kinase (TRK) fusion sarcomas: expert recommendations from the World Sarcoma Network

Sarcomas are a heterogeneous group of malignancies with mesenchymal lineage differentiation. The discovery of neurotrophic tyrosine receptor kinase (NTRK) gene fusions as tissue-agnostic oncogenic drivers has led to new personalized therapies for a subset of patients with sarcoma in the form of tropomyosin receptor kinase (TRK) inhibitors. NTRK gene rearrangements and fusion transcripts can be detected with different molecular pathology techniques, while TRK protein expression can be demonstrated with immunohistochemistry. The rarity and diagnostic complexity of NTRK gene fusions raise a number of questions and challenges for clinicians. To address these challenges, the World Sarcoma Network convened two meetings of expert adult oncologists and pathologists and subsequently developed this article to provide practical guidance on the management of patients with sarcoma harboring NTRK gene fusions. We propose a diagnostic strategy that considers disease stage and histologic and molecular subtypes to facilitate routine testing for TRK expression and subsequent testing for NTRK gene fusions.

Manniindole, an indole derivative from the roots of Anonidium mannii and combined antischistosomal and enzymatic activities

A new alkaloid, manniindole 1, together with four known compounds: aristolactam AII 2, aristolactam BII 3, piperolactam D 4 and polycarpol 5 were isolated from the crude extract EtOH-H₂O (8:2) of the roots of Anonidium mannii by chromatographic separation. The structure elucidation was performed on the basis of a spectroscopic analysis (IR, HRESI MS, 1D and 2D NMR) as well as a comparison of their spectral data with those reported in the literature. For the first time, the crude extract and those isolated compounds were evaluated for their anti-schistosomal activity against Schistosoma mansoni and for cytotoxicity activity against Huh7 and A549 cells. Furthermore, they were also tested in vitro on the recent characterized Schistosoma mansoni NAD⁺ catabolizing enzyme (SmNACE) for their impact on this enzyme which is localized on the outer surface of the adult parasite. Compound 2 displayed quite good worm killing capability, while 4 showed significant inhibition of SmNACE.

A new mechanism for void-cascade interaction from nondestructive depth-resolved atomic-scale measurements of ion irradiation-induced defects in Fe

The nondestructive investigation of single vacancies and vacancy clusters in ion-irradiated samples requires a depth-resolved probe with atomic sensitivity to defects. The recent development of short-pulsed positron beams provides such a probe. Here, we combine depth-resolved Doppler broadening and positron annihilation lifetime spectroscopies to identify vacancy clusters in ion-irradiated Fe and measure their density as a function of depth. Despite large concentrations of dislocations and voids in the pristine samples, positron annihilation measurements uncovered the structure of vacancy clusters and the change in their size and density with irradiation dose. When combined with transmission electron microscopy measurements, the study demonstrates an association between the increase in the density of small vacancy clusters with irradiation and a remarkable reduction in the size of large voids. This, previously unknown, mechanism for the interaction of cascade damage with voids in ion-irradiated materials is a consequence of the high porosity of the initial microstructure.

On the use of DNA as a linker in antibody-drug conjugates: synthesis, stability and in vitro potency

Here we present the synthesis and evaluation of antibody-drug conjugates (ADCs), for which antibody and drug are non-covalently connected using complementary DNA linkers. These ADCs are composed of trastuzumab, an antibody targeting HER2 receptors overexpressed on breast cancer cells, and monomethyl auristatin E (MMAE) as a drug payload. In this new ADC format, trastuzumab conjugated to a 37-mer oligonucleotide (ON) was prepared and hybridized with its complementary ON modified at 5-end with MMAE (cON-MMAE) in order to obtain trastuzumab-DNA-MMAE. As an advantage, the cON-MMAE was completely soluble in water, which decreases overall hydrophobicity of toxic payload, an important characteristic of ADCs. The stability in the human plasma of these non-engineered ON-based linkers was investigated and showed a satisfactory half-life of 5.8 days for the trastuzumab-DNA format. Finally, we investigated the in vitro cytotoxicity profile of both the DNA-linked ADC and the ON-drug conjugates and compared them with classical covalently linked ADC. Interestingly, we found increased cytotoxicity for MMAE compared to cON-MMAE and an EC50 in the nanomolar range for trastuzumab-DNA-MMAE on HER2-positive cells. Although this proved to be less potent than classically linked ADC with picomolar range EC50, the difference in cytotoxicity between naked payload and conjugated payload was significant when an ON linker was used. We also observed an interesting increase in cytotoxicity of trastuzumab-DNA-MMAE on HER2-negative cells. This was attributed to enhanced non-specific interaction triggered by the DNA strand as it could be confirmed using ligand tracer assay.