Tissue-engineered vascular grafts (TEVGs) represent a promising alternative for coronary artery bypass grafting (CABG). However, replicating the mechanical and biological complexity of native vessels remains a major challenge. Compliance mismatch, local hemodynamics, and insufficient endothelialization are recognized as key contributors to maladaptive remodeling and graft failure. These limitations highlight the urgent need for advanced experimental platforms and standardized physical stimulation procedures to investigate these underlying biomechanisms and support the development of more effective TEVGs. In this work, we present an automated, modular platform designed to quantitatively characterize graft compliance and replicate coronary hemodynamics. The system integrates automated experimental procedures within a modular, incubator-compatible design, enabling an intuitive setup and real-time monitoring of physical parameters. Its modular architecture and dedicated control algorithms provide high adaptability, enabling its application across a broad range of experimental conditions. Bench testing demonstrates that the platform can automatically reproduce the pressure regimes defined by ISO standard and generate coronary-like flow-induced stimuli. These results confirm the innovative capability of the system to provide controlled and physiologically relevant conditions suitable for the investigation of key phenomena involved in CABG failure. In perspective, the platform offers a valuable tool for advanced mechanobiological studies in vascular tissue engineering.

Bicompartmental in vitro cultures are performed using culture inserts in multi-well plates. The main challenge of these systems is sample retrieval, which potentially impacts the experimental outcomes. To overcome this challenge, we developed a novel cartridge-based device called true-tissue-on-platform (TTOP). Our device offers the same handling than multi-well inserts with a key difference: the cartridge can be easily retrieved and reused without compromising sample morphology. The functionality of TTOP is demonstrated by building gut and vascular barrier in-vitro models. Barrier tightness is assessed by measuring trans epithelial/endothelial electrical resistance (TEER) and permeability by Lucifer Yellow assay (LY). Geometry-related effects on TEER are evaluated using a finite element model, comparing TTOP to conventional inserts, which showed an improvement in data robustness and accuracy. Moreover, the device enabled the detection of inflammation-related changes by comparing untreated versus Tumor-Necrosis-Factor-alpha-treated cell barriers, revealing significant differences both with TEER and LY assays. Preliminary data on coupled gut/vascular barriers in the two compartments supported the feasibility of mimicking the gut-vascular barrier in vitro. This new cartridge-based concept may provide a simple and modular device, accessible to any biological laboratory, enabling controlled handling of the biological samples during and after the experiment.

Short, bio-inspired peptides hold promise for creating functional materials with unique structural and biochemical properties, yet their generally limited tunability of mechanical properties often restricts their utility. Inspired by Nature's strategic use of halogenation to strengthen biomaterials, here, a novel electrospun scaffold is reported in which a brominated resilin-derived peptide SDSY(3,5Br)GAP (BR peptide), endowed with self-assembling properties, serves as the principal building block, supported by a gelatin matrix. The BR peptide transitions to beta-turn-rich assemblies upon electrospinning, resulting in the hybrid scaffolds with a twofold increase in modulus beyond approximate to 50% strain and good recovery properties, thereby mimicking the strain-stiffening behaviour of natural elastomers. Notably, such features are completely absent in the nonbrominated peptide (WR peptide) scaffolds, emphasizing the crucial structural role given by bromine atoms. Additionally, BR peptide-based systems exhibited superior proteolytic stability and notable antioxidant activity together with proven noncytotoxic effects, underscoring their potential for applications spacing from soft tissue engineering to adaptive textiles and wearable soft actuators. Collectively, this unique combination of mechanical resilience, proteolytic stability, antioxidant functionality, and biocompatibility highlights halogenation as an effective strategy for tuning the performance of peptide-based materials, ultimately bridging the gap between synthetic polymers and Nature's most resilient protein materials.

Background Bypass surgery using saphenous vein (SV) grafts is commonly performed to revascularize the ischemic heart and lower limbs. These interventions have limited success due to adverse remodeling caused by overproliferation of smooth muscle cells in the intima layer, leading to progressive bypass stenosis. We previously showed that cyclic strain deriving from exposure to coronary flow induces the expression of the matricellular protein thrombospondin‐1 in the human SV, promoting activation of progenitor cells normally residing in the adventitia. Methods We analyzed the data of an RNA‐sequencing profiling of human SV progenitors subjected to uniaxial strain we previously performed by. Experiments in cell culture, ex vivo, and in vivo vein arterialization models were performed to substantiate findings with particular reference to the role of mechanically activated transcription factors. Validation was performed in vitro and in ex vivo/in vivo models of vein graft disease. Results Results of bioinformatic assessment of the RNA‐sequencing data indicated Yes‐associated protein (YAP) as a possible mechanically regulated effector in pathologic evolution of SV progenitors. Inhibition of YAP by verteprofin—a drug that abolishes the interaction of YAP with Tea Domain DNA–binding proteins—reduced the expression of pathologic markers in vitro and reduced intima hyperplasia in vivo. Conclusions Our results reveal that desensitizing the SV‐resident cells to mechanoactivation of YAP is feasible to reduce the graft disease progression.

Abstract Funding Acknowledgements None. Background Luminal arterial endothelial cells are mainly aligned along the blood flow direction, whereas the in vitro endothelial cells (EC) showed heterogeneous distribution. In atherosclerosis the altered blood flow, acting on mechano-transduction, contributes to endothelial dysfunction and barrier disorganization. A low wall shear stress (WSS) has a pro-atherosclerotic effect, whilst elevated WSS is atheroprotective. Purposes Aim of this work is to study the primary human aortic EC cells (HAOEC) capability to acquire a distribution reminiscent of the luminal alignment under atheroprotective WSS using a prototypal new generation bioreactor. Methods We have developed a novel device compatible with culture inside standard sterile incubator, allowing to apply complex WSS patterns in controlled conditions. The bioreactor includes a sample housing and a parallel plate flow chamber and is controlled by a custom electronic interface actuating motor and pump. The cells were settled over PMMA supports and coating conditions were setup. Atheroprotective WSS patterns were tested. We compared HAOEC submitted to high flow (1.2 Pa for 24h) vs. ramps with different slopes (3h, 8h, 24h) followed by steady-state flow (1.2Pa for 24h, 48h). Viability and distribution of Acridine Orange-labelled HAOEC were assessed over bioreactor supports at both beginning and end of the experiments using fluorescence microscope. Hematoxylin/Eosin and Coomassie Blue staining were tested after the experiment to evaluate the shape and cell orientation (directionality FiJi plugin). Confocal microscopy on HAOEC labelled with Phalloidin–TRITC, anti-CD31/PECAM1-AlexaFluor488 and DAPI displayed the flow-related changes. Results HAOEC settled over naked sterile PMMA supports mainly detached under WSS, independently from the cell number. Coating with extracellular matrix components (i.e., human laminin, bovine fibronectin, chicken collagen type II, human collagen type I) showed the superiority of collagen type I to obtain homogeneously distributed, flow-resistant cell monolayers. In static condition, HAOEC on coated supports demonstrated ≥50% detachment within 24h, those submitted to a direct atheroprotective WSS of 1.2Pa almost completely detached. Consistently, to ramps with high slope (range 0.2-1,2Pa in 3h or 8h) followed by1.2Pa WSS corresponded 60%-90% cell detachment. Conversely, a 24h ramp (range 0.2-1,2Pa) followed by 24h or 48h of 1.2Pa WSS preserved the HAOEC monolayer adherence, and aligned cells were found. Microscopy comparative analysis of selected areas before/after WSS showed a partial spatial reorganization, with changes in the F-actin cytoskeleton and CD31 distribution. Conclusion We have optimized a protocol for studying HAOEC under atheroprotective WSS. In perspective further increasing the duration of the stimulus under constant WSS will achieve full alignment and provide a pseudo-physiologic model for multidirectional atherogenic WSS studies.

of the factors of biological origin suggested as an effectively stimulating agent involved in regeneration process.It is required for many cellular processes, it may promote cell migration, wound healing or neovascularization.Methods: Explaining the mechanism of regeneration in atherosclerosis we performed an aortic ring assay.Rat aorta rings were coated with Geltrex™ with stimulators (cholesterol, VEGF) in 24-well plate and incubated with medium for 14 days.Sprouting cells were observed and photographed daily.We conducted transcriptomic analysis using isolated RNA of HMEC-1 stimulated with cholesterol.Moreover, we examined angiogenesis in an in vivo model (rat).Subcutaneous implantation of PLA-based composite modified with cholesterol (0,15 and 0,015%) was fixed and dyed with hematoxylin and eosine after 7, 30 and 90 days.Results: In aortic ring assay cholesterol stimulated cells to sprout, even faster than VEGF.Transcriptomic analysis showed significant changes in up-and downregulation of genes involved in angiogenesis.Whereas histological analysis of implantations indicated that PLA-based composite modified with cholesterol (0,15%) stimulated angiogenesis which continued to progress over time.Conclusions: We conclude cholesterol stimulates regeneration of endothelium after its damage in atherosclerosis.These studies were performed within the project "Multifunctional composites biologically active for applications in regenerative medicine of bone system (POIR.04.04.00-00-16D7/18)" carried out within the TEAM NET programme of the Foundation for Polish Science co-

Self-assembling peptides are of huge interest for biological, medical and nanotechnological applications. The enormous chemical variety that is available from the 20 amino acids offers potentially unlimited peptide sequences, but it is currently an issue to predict their supramolecular behavior in a reliable and cheap way. Herein we report a computational method to screen and forecast the aqueous self-assembly propensity of amyloidogenic pentapeptides. This method was found also as an interesting tool to predict peptide crystallinity, which may be of interest for the development of peptide based drugs.

Mechanical stimuli from the extracellular environment affect cell morphology and functionality. Recently, we reported that mesenchymal stem cells (MSCs) grown in a custom-made 3D microscaffold, the Nichoid, are able to express higher levels of stemness markers. In fact, the Nichoid is an interesting device for autologous MSC expansion in clinical translation and would appear to regulate gene activity by altering intracellular force transmission. To corroborate this hypothesis, we investigated mechanotransduction-related nuclear mechanisms, and we also treated spread cells with a drug that destroys the actin cytoskeleton. We observed a roundish nuclear shape in MSCs cultured in the Nichoid and correlated the nuclear curvature with the import of transcription factors. We observed a more homogeneous euchromatin distribution in cells cultured in the Nichoid with respect to the Flat sample, corresponding to a standard glass coverslip. These results suggest a different gene regulation, which we confirmed by an RNA-seq analysis that revealed the dysregulation of 1843 genes. We also observed a low structured lamina mesh, which, according to the implemented molecular dynamic simulations, indicates reduced damping activity, thus supporting the hypothesis of low intracellular force transmission. Also, our investigations regarding lamin expression and spatial organization support the hypothesis that the gene dysregulation induced by the Nichoid is mainly related to a reduction in force transmission. In conclusion, our findings revealing the Nichoid's effects on MSC behavior is a step forward in the control of stem cells via mechanical manipulation, thus paving the way to new strategies for MSC translation to clinical applications.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

species, both in basal condition and in the presence of an oxidative stress inducer (menadione).On the other hand, 1mM IPA induced a significative reduction of the nitric oxide released by ATP-stimulated BAE-1 cells, suggesting a potential role of the molecule in altering the physiological vascular tone.Conclusions: This research is a starting point to understand the mechanisms underlying the relationship between IPA and endothelial function, which further supports recent findings relating gut microbiota to cardiometabolic health.

Bromination is herein exploited to promote the emergence of elastic behavior in a short peptide-SDSYGAP-derived from resilin, a rubber-like protein exerting its role in the jumping and flight systems of insects. Elastic and resilient hydrogels are obtained, which also show self-healing behavior, thanks to the promoted non-covalent interactions that limit deformations and contribute to the structural recovery of the peptide-based hydrogel. In particular, halogen bonds may stabilize the β-sheet organization working as non-covalent cross-links between nearby peptide strands. Importantly, the unmodified peptide (i.e., wild type) does not show such properties. Thus, SDSY(3,5-Br)GAP is a novel minimalist peptide elastomer.