DWI – Leibniz Institute for Interactive Materials

Chimeric antigen receptor (CAR) technology represents a groundbreaking advancement in gene therapy. While CAR-T cells are approved for specific types of leukemia, the therapeutic potential of CAR-macrophages remains largely unexplored. Additionally, potentially synergistic effects between CAR-T cells and CAR-macrophages in cancer cell clearance are still elusive. This study aimed to investigate the efficiency and mechanisms of human CAR-T cells and CAR-macrophages for clearing cancer cells using co-culture experiments. We encapsulated a second generation CD19 CAR mRNA or enhanced green fluorescent protein (Egfp) encoding control mRNA into lipid nanoparticles (LNP) using different methods. We transfected human primary T cells or macrophages with these LNP and studied their CAR expression using flow cytometry or confocal microscopy. Killing and phagocytosis assays were conducted to evaluate the impact of CAR-T cells and CAR-macrophages on CD19+ NALM6 leukemia and CD19- control cells. Motility analyses of macrophages, T cells, and cancer cells were done using live-cell imaging. Activated T cells upregulated the low-density lipoprotein receptor (LDLR), resulting in higher CAR surface expression post-transfection than in non-activated T cells. CAR-T cells efficiently induced death of lymphoma cells. CAR-macrophages cleared cancer cells mainly via phagocytosis and CAR mRNA altered the expression of both M1 and M2-associated genes. Interestingly, CAR macrophages also upregulated the Signal regulatory protein alpha (SIRPA), a receptor of the CD47 ligand expressed by cancer cells, and knockdown of SIRPA by siRNA efficiently counteracted this phenomenon. We noted a decrease in the motility of macrophages, T cells, and cancer cells in co-cultures containing CAR-transfected effector cells. Co-culturing CAR-T cells with CAR-macrophages synergistically enhanced tumor cell eradication. Our findings underscore the superior cancer cell-killing capability of CAR-T cells. Additionally, CAR-macrophages play a crucial role in clearing cancer cells through phagocytosis, thereby synergistically supporting the activity of CAR-T cells.

Mammalian cardiac development and homeostasis rely on tightly coordinated transcriptional programs driven by core cardiogenic transcription factors. Among these, GATA binding protein 4 (GATA4) plays a pivotal role-not only in orchestrating embryonic heart formation, but also in modulating cardiac adaptation to physiological and pathological stress. To fulfil its canonical functions, emerging evidence reveals that GATA4 activity is shaped by a multilayered regulatory network involving chromatin dynamics, transcriptional and post-transcriptional inputs, and diverse post-translational modifications. In this review, we provide an integrated overview of the roles of GATA4 across developmental stages, postnatal physiology, and disease contexts. We further examine how chromatin occupancy and regulatory mechanisms fine-tune GATA4 function and evaluate current strategies that leverage GATA4 modulation for cardiac repair and regeneration. By highlighting both established and underexplored facets of GATA4 biology, this review establishes GATA4 as a central regulator of cardiac identity and plasticity, with broad implications for developmental biology, cardiac physiology, and therapeutic innovation.

The development of efficient methods for nitrile syntheses is a challenge due to the current reliance on toxic cyanide sources, metal catalysts and their associated waste products, and harsh conditions that limit functional group compatibility. Here, we show a metal‐ and complex reagent‐free strategy for the conversion of aldehydes to nitriles through carbamoylaldoxime intermediates. Therefore, we synthesize aldoximes from several aldehydes using hydroxylamine, which in turn are reacted with dimethylcarbamoyl chloride (DMCC) to afford N,N‐dimethylcarbamoyloximes. Subsequent heating cleanly produces the desired nitriles as well as volatile CO2 and HNMe2 through a pericyclic syn elimination. This approach relies on widely available commercial chemicals, proceeds with broad functional group tolerance, and minimizes the need for extensive purification of the nitrile product.

Abstract The development of NIR photosensitizers (PSs) based on Ru complexes with Type‐I process holds substantial promise for photodynamic therapy (PDT) of cancer, though this breakthrough remains unrealized to date. Herein, a pair of cyclometalated Ru enantiomers, [Λ/Δ‐Ru‐dqpy‐TPABP]Cl (dqpy: 2,6‐di(quinolin‐2‐yl)pyridine; TPABP: 4‐(4‐(pyridine‐2‐yl)‐2,1,3‐benzothiadiazol‐7‐yl)triphenylamine) (Λ/Δ‐Ru‐TPABP), were synthesized and evaluated. These complexes exhibit strong Ru(d) and TPABP(π) → dqpy(π*) charge transfer ((metal and ligand)–ligand charge transfer; ML–LCT) absorption at ∼640 nm, with an extended absorption tail reaching up to 800 nm. Moreover, the TPABP ligand, with its strong electron‐rich capacity, contributes to T1 formation, which increases the electron transfer possibility in the triplet state and promotes Type‐I PDT, making it highly effective for killing cancer cells under hypoxic conditions. Further encapsulating Λ/Δ‐Ru‐TPABP into polymeric nanoparticles results in high tumor inhibition efficiency (>85%) and causes a strong tumoricidal effect and inhibits lung metastasis of breast tumors under 700 nm light irradiation, thus offering a new strategy for developing NIR Ru complexes for anticancer treatment through the design of cyclometalating ligand.

Abstract The global demand for in vitro respiratory airway models has surged due to the coronavirus disease 2019 (COVID-19) pandemic. Current state-of-the-art models use polymer membranes to separate epithelial cells from other cell types, creating a nonphysiological barrier. In this study, we applied three-dimensional (3D) printing and bioprinting to develop an in vitro model where endothelial and epithelial cells were in direct contact, mimicking their natural arrangement. This proof-of-concept model includes a culture chamber, with an endothelial bioink printed and perfused through an epithelial channel. In silico simulations of the air velocity within the channel revealed shear stress values ranging from 0.13 to 0.39 Pa, aligning with the desired in vivo shear stress observed in the bronchi regions (0.1–0.4 Pa). Biomechanical movements during resting breathing were mimicked by incorporating a textile mesh positioned away from the cell–cell interface. The epithelial channel demonstrated a capacity for compression and expansion of up to −14.7% and +6.4%, respectively. Microscopic images showed that the epithelial cells formed a uniform monolayer within the lumen of the channel close to the bioprinted endothelial cells. Our novel model offers a valuable tool for future research into respiratory diseases and potential treatments under conditions closely mimicking those in the lung.

The flow-induced activation of mechanophores embedded in linear polymers by ultrasound (US) suffers from slow mechanochemical conversions at the commonly used frequency of 20 kHz and in many cases remains ineffective with higher MHz frequencies. Here, we present polymeric microbubbles (PMBs) as a platform that accelerates the mechanochemical activation of several mechanophores under both 20 kHz and MHz irradiation. MHz irradiation generated by biocompatible high-intensity focused US (HIFU). Through their pressure-sensitive gas core, PMBs act as acousto-mechanical transducers for the transformation of sound energy into stretching and compression forces as well as fracturing the polymer shell by the volume oscillation of PMB. We investigate three different mechanophores among which one flex-activation derivative was unexpectedly activated by US. Through a combination of experiments and computation, we find that PMBs likely exert compressive force onto the copolymerized mechanophores rather than the typical elongational forces solvated chain fragments experience in flow. We thereby underscore the mechanochemical properties of the PMB platform and its versatility for accelerated mechanochemical transformations with a perspective on biomedical applications.

This study investigates water transport behavior through polyelectrolyte membranes under varying pressure gradients using non-equilibrium molecular dynamics (NEMD) simulations. While net water transport is achieved under a pressure gradient, there is also a significant back-diffusion component, challenging the assumption of unidirectional pore flow in such systems. The auto-correlation function of water molecules reveals that water associations are transient and only occur for short periods compared to the overall residence time within the membrane. The correlation of water associations and the water dynamics inside the membrane are not affected by varying pressure differences, which also favors the assumption of a diffusive transport mechanism rather than pore flow. Furthermore, our NEMD simulations provide a detailed analysis of the diffusion-related time lag, revealing an initial transient water transport response and a constant diffusive time lag for all pressure differences. These findings enhance our understanding of water transport mechanisms in membrane systems, underlining the validity of the solution-diffusion model for dense polymeric membranes. The methodology described can be applied to shed light on the discrimination between pore flow and solution-diffusion phenomena. • Water transport under pressure gradient shows net transport but also back-diffusion. • Water clusters are short-lived as compared to their residence time in the membrane. • Water associations and dynamics inside the membrane are unaffected by pressure. • MD simulations allow extraction of diffusion-related time lag.

In order to bring electrochemical CO 2 reduction (eCO 2 R) to economical feasibility on an industrial scale, the conventional oxygen evolution reaction (OER) can be replaced with a value added reaction. In this work, we replace OER with chlorine evolution reaction (CER) in a paired synthesis with CO from CO 2 . Hereby, the reaction system is assessed at industrial relevant current densities with respect to electrolyte species & concentration and stability of up to 24 h. We report constant anodic FEs to Cl 2 of > 97 % for up to 400 mA / cm 2 with concurrent FEs to CO of 90 % at 100 mA / cm 2 and 74 % at 200 mA / cm 2 over 4.5 h, significantly exceeding previous studies for comparable systems. The FE for CER did not show any decline over 24 h of operation. KCl showed superior results over NaCl and CsCl in terms of cathodic FE and cell potential. CER is affected by educt limitation with FE dropping below 95 % at an electrolyte concentration of 0.8 mol/L at 400 mA / cm 2 . By successfully pairing eCO 2 R and CER with stable and high FEs at industrially relevant current densities, this work marks an important step towards an industrial application. • Paired electrochemical synthesis of Cl 2 from alkali chloride and CO from CO 2 . • Concurrent FE of > 97 % to Cl 2 and 75 % to CO at 200 mA / cm 2 . • Online analytics of anodic chlorine evolution with Faraday efficiency (FE) > 97 % at 400 mA / cm 2 . • KCl superior over NaCl and CsCl in terms of cathodic FE to CO and cell potential. • Anodic FE drops below 95 % as anolyte concentration falls below 0.8 mol/L at 400 mA / cm 2 .