Heart failure with preserved ejection fraction (HFpEF) is a complex and heterogeneous syndrome characterized by delayed diagnosis and limited therapeutic options, contributing to poor clinical outcomes. In the present study, we investigated the applicability of Raman micro-spectroscopy (RmS) as a label-free, rapid, and cost-effective approach for identifying molecular signatures associated with HFpEF and enabling reliable disease classification. RmS was applied to evaluate disease-related biochemical alterations in cardiac and renal tissues obtained from a clinically relevant HFpEF model (ZSF1 rat). Furthermore, the effects of three pharmacological interventions were analyzed and classified (five experimental groups-36 animals in total), highlighting organ-specific therapeutic responses. We developed a spectroscopic data analysis strategy in which second-derivative Raman spectral features serve as quantitative inputs to a supervised classification model, enabling micro-spectroscopic discrimination of HFpEF versus control tissues and achieving a classification accuracy of 92% (sensitivity 93% and specificity 91%) based on the protein-to-tryptophan ratio in cardiac tissue, while minimizing the need for extensive data preprocessing. The spectroscopic markers used in this study were derived from prior multivariate discovery analyses and are evaluated here within a validation and translational classification framework. Collectively, these findings support the integration of RmS into molecular and translational research settings and suggest its potential utility for improving HFpEF diagnosis and treatment monitoring.

Cardiorenal syndrome (CRS) involves complex and spatially heterogeneous remodeling in both cardiac and renal tissues. Conventional histological and biochemical assays rely on labeling or lack direct molecular specificity, limiting their ability to capture compartment-specific remodeling. Analytical approaches that resolve localized biochemical alterations are essential to advance mechanistic insight into heart-kidney interactions. Here, Fourier-transform infrared (FTIR) micro-imaging was applied to left ventricular and renal tissues from a rat model of heart-kidney interaction, in which unilateral nephrectomy induced renal stress prior to cardiac ischemia-reperfusion injury. To address tissue heterogeneity, an analytical workflow was implemented in which unsupervised hierarchical clustering segmented spectrally homogeneous regions, followed by principal component analysis, to identify spectral markers associated of disease-related biochemical alterations. This strategy enabled identification of spatially localized spectral variations associated with disease progression. Distinct spectral signatures of tissue remodeling were identified in both organs. Cardiac perivascular regions exhibited pronounced alterations in bands at 1040, 1202, and 1232 cm-1, while renal medullary compartments displayed disease-associated variations at 1313 and 1396 cm-1 following nephrectomy. Several spectral features correlated with independent biological measures, including histologically quantified fibrosis, urinary protein excretion, and left ventricular mass. Treatment-associated spectral modulation was also observed, with animals receiving Sacubitril/Valsartan exhibited spectral intensities below pathological thresholds for the main cardiac markers, indicating partial normalization of disease-associated spectral alterations. These findings demonstrate that spatially resolved FTIR spectroscopic imaging can identify compartment-specific spectral signatures of disease progression and treatment response in experimental heart-kidney interaction.

Preservation of spermatogonial cells is of critical importance for male patients undergoing gonadotoxic therapies. Testicular organoids generated by 3D polymeric scaffolds filled with decellularized extracellular matrix (dECM) have the potential to promote stem cell growth. We propose a protocol to produce dECM from porcine prepubertal tunica albuginea for use in polymeric scaffolds. Spectroscopic analysis, molecular biology techniques, and histo-morphological assessment were used to evaluate the morphology and mechano-chemistry of the dECM at each phase of the process. The results obtained from this study demonstrate that the protocol can produce a high-purity product without causing significant alterations to protein conformation. The dECM obtained was then employed in the creation of a 3D scaffold for the cultivation of testis organoids. This was achieved by utilizing a mixture of alginate (A) and chitosan (C), which are natural polymers with a high degree of biocompatibility, that have extensive application in the field of biomedicine. Scaffold characterization demonstrated that the presence of dECM affects the scaffold's mechanical properties by tuning structural reorganization and reducing hygroscopicity. The cell viability assay demonstrates that the A/C scaffolds are non-cytotoxic after a pre-phase of immersion in the medium.

The thermal noise of mirror coatings for gravitational-wave detectors critically depends on the elastic properties of the constituent materials. Data analyses and theoretical models typically assume each material is homogeneous and isotropic, but isotropy has never been explicitly verified. Using Brillouin light scattering (BLS), we demonstrate that ion-beam-sputtered SiO_{2}—a material still viable for future mirror coatings—exhibits cylindrical elastic symmetry, with in-plane isotropy but a notable 6% compressive anisotropy along the film normal. This anisotropy remains unchanged after the postdeposition heat treatment currently used in ground-based detectors (500 °C, 10 h) but is nearly eliminated at 900 °C. Infrared reflectivity experiments support these findings by directly revealing heterogeneities in the distribution of bridging and nonbridging oxygen structures along the growth axis. While BLS measures the real part of the elastic constants at gigahertz frequencies, the data reveal negligible contributions from mechanical relaxations in the kilohertz to gigahertz range, making BLS a valid substitute for low-frequency properties obtained from standard anisotropy-insensitive techniques. Our results highlight that restoring isotropy through heat treatment—by softening the material, enabling more than 7% out-of-plane expansion, and smoothing out structural heterogeneities—may play a key role in reducing thermal noise. This proof-of-concept study extends beyond silica, providing critical insights for the design of future coatings.

Hypothesis Chondroitin sulphate (CS) is a linear polysaccharide typically found on the surface of cells and contributing to the structure of the extracellular matrix. Because of its proximity to the plasma membrane, the outermost cellular barrier, CS can interact with the phospholipids forming the structural scaffold of this cellular membrane. We hypothesise that the lipid composition of the plasma membrane, and specifically the exposure of phosphatidylserine (PS) lipids (an event that is detected in cancer cells and also associated to apoptosis and inflammation), affects the structural conformation of CS at the cell surface. Experiments We combined experimental data obtained with different techniques, i.e., quartz crystal microbalance with dissipation monitoring, neutron reflectometry and infrared spectroscopy, with molecular dynamics (MD) simulations to investigate the adsorption of CS at the surface of lipid bilayers prepared with either phosphatidylcholine (PC) lipids or a mixture of PC and PS lipids. Experiments were designed to identify the molecular groups that are involved in the CS-lipid interaction. Findings Our results indicate that CS adsorbs and remains stably attached to the lipid bilayer without PS lipids, due to stabilising interactions between the negatively charged sulphate groups on CS and positively charged choline groups within PC. The addition of POPS strongly reduces the CS-bilayer association: detecting experimentally CS chains attached to the bilayer was challenging, and the MD simulations suggest a weaker binding of CS to a PC-PS membrane.

Concomitant cardiac and renal dysfunction represent a clinically relevant condition with limited therapeutic options. This study examined the effects of the linear ANP fragment proANP31-67 in a preclinical model combining unilateral nephrectomy (UNX) and cardiac ischemia/reperfusion (I/R) injury. Wistar rats underwent UNX followed by I/R and were randomized to receive proANP31-67 or vehicle for 4 wk. Cardiac structure and function were evaluated by echocardiography and isolated cardiomyocyte analyses. Fourier-transform infrared (FTIR) spectroscopy was used to assess biochemical composition in cardiac and renal tissue, as well as urine. Chronic UNX induced diastolic impairment with preserved systolic function, which was further aggravated by I/R. ProANP31-67 prevented systolic deterioration, reduced myocardial fibrosis, attenuated cardiomyocyte hypertrophy, and improved Ca2+ handling, independent of blood pressure. FTIR imaging identified distinct cardiac (amino acid-, collagen-, and carbohydrate-associated) and renal (free amino acid-, protein-, and lipid-associated) spectral features across experimental groups. Conventional renal indices, including albumin-to-creatinine ratio and 24 h protein excretion, remained unchanged; however, vibrational spectroscopy detected subtle biochemical alterations in renal tissue and urine that were modulated by proANP31-67. In this model of reduced nephron mass with superimposed cardiac injury, proANP31-67 exerted marked cardioprotective effects and was associated with coordinated changes in tissue biochemical signatures, supporting further investigation of its therapeutic potential.NEW & NOTEWORTHY In a model of reduced nephron mass combined with cardiac ischemia/reperfusion injury, proANP31-67 prevented adverse cardiac remodeling independent of blood pressure. Vibrational spectroscopy identified coordinated biochemical alterations in cardiac and renal tissues not detected by conventional assays, providing molecular-level insight into cardiorenal remodeling.

Silk fibroin (SF), the primary protein component of Bombyx mori silkworm cocoons, undergoes liquid-liquid phase separation (LLPS), followed by coacervation into fibers, in the silkworm glands. The molecular mechanisms underlying LLPS remain to be revealed. Here, we show that phosphate buffer (PB), a less commonly utilized, but more biomimetic route towards triggering SF assembly, induces LLPS of water-soluble SF by increasing hydrophobic interactions between SF chains. We demonstrate the ability of phosphate anions to promote self-assembly of silk fibroin through LLPS, resulting in protein-rich droplets. Complementary computational modeling using a bead-spring representation of SF supports the experimental findings and confirms the mechanistic origin of the assembly transitions, as driven primarily by hydrophobic interactions. FTIR spectroscopy was used to investigate structural differences upon LLPS between the dense and light phases, which were shown to be comprised mainly of random coil. After evaporation of the solvent, SF agglomerates were incorporated within the continuous silk matrix. This spatial confinement of solid droplets was stabilized by treatment with ethanol solution, promoting β-sheet formation via protein backbone dehydration. The material formulation was, finally, tested in simulated biological fluids (e.g., gastro-intestinal tract, based on European Pharmacopeia 9.0), highlighting the pH-dependent swelling, and overall stability of the films.

HypothesisChondroitin sulfate (CS) is a linear polysaccharide typically found on the surface of cells and contributing to the structure of the extracellular matrix. Because of its proximity to the plasma membrane, the outermost cellular barrier, CS can interact with the phospholipids forming the structural scaffold of this cellular membrane. We hypothesize that the lipid composition of the plasma membrane, and specifically the exposure of phosphatidylserine (PS) lipids (an event that is detected in cancer cells and also associated to apoptosis and inflammation), affects the structural conformation of CS at the cell surface.ExperimentsWe combined experimental data obtained with different techniques, i.e., quartz crystal microbalance with dissipation monitoring, neutron reflectometry and infrared spectroscopy, with molecular dynamics (MD) simulations to determine the structural organizations of CS at the surface of lipid bilayers prepared with either phosphatidylcholine (PC) lipids or a mixture of PC and PS lipids. Experiments were designed to identify the molecular groups that are involved in the CS-lipid interaction.FindingsOur results indicate that CS adsorbs and remains stably attached to the lipid bilayer without PS lipids, due to stabilizing interactions between the negatively charged sulfate groups on CS and positively charged choline groups within PC. The addition of POPS strongly reduces the CS-bilayer association: detecting experimentally CS chains attached to the bilayer was challenging, and the MD simulations suggest a weaker binding of CS to a PC-PS membrane.

In this study, functional composites were developed by dispersing ZnO tetrapods (ZnO-T) in a solution of silk fibroin (SF) and formic acid (FA). Micro- and nanoparticles with different shapes were observed in the SF matrix after evaporation of the solvent, depending on ZnO-T filler content. The secondary structure of SF, as well as the shape (e.g., spherical, linear, or branched) and aspect ratio of the fillers, were investigated by FTIR spectroscopy, optical and scanning electron microscopy. While FTIR spectroscopy indicates that the secondary structure of SF is not affected by the size and shape of ZnO-T, the observed variation in effective elastic modulus measured for composites is correlated with different filler particle aspect ratios, predicting the formation of a stiff interface. We observed that branched tetrapodal fillers exhibit significant potential for optimization of composites' mechanical properties in comparison to their spherical and linear counterparts. By combining ZnO microparticles with SF, we fabricated a stretchable strain sensor that demonstrated an appreciable improvement in the fractional change of electrical resistivity and gauge factor with respect to neat SF films.

Self‐deploying bio‐based scaffolds able to lay out in programmable way according to a defined external stimulus are extremely useful for the treatment and regeneration of endoluminal tissues, since they combine biocompatibility with the ability to be brought into place in a minimally invasive way through, for instance, endoscopic or laparoscopic instruments. Here, four‐dimensional (4D) printing is exploited to design and fabricate, via extrusion‐based additive manufacturing on a rotating spindle, a self‐deploying scaffold for the minimally invasive treatment of gastrointestinal tissue. Starting from a tubular configuration, upon hydration, the scaffold automatically unfolds, forming a flat sheet able to cover a wider surface of the damaged tissue. The desired shape morphing is achieved thanks to a specific spatial arrangement of silk/gelatin‐based solution, featuring differential swelling behavior. The geometry of the scaffold is guided by finite element modeling. The silk/gelatin‐based solution is tested via Raman and Fourier‐transform infrared spectroscopy (FTIR) measurements, rheological tests and biological assays. The latter is performed on two colorectal cell lines, HT‐29 and Caco‐2, and proves the ability of the materials to support the growth of the seeded cells.

The fundamental principles behind the complexity of protein assembly, especially in mixed protein systems and crowded environments, remain elusive. This study provides molecular, structural, and viscoelastic insights into the aggregation and gelation processes in aqueous solutions of pure and mixed beta-lactoglobulin and albumin whey proteins. To better understand protein aggregation in complex systems, we used a multi-technique approach that spans from molecular to macroscopic length scales. Our results show that, under low pH and heat denaturation, beta-lactoglobulin tends to form ordered amyloid-type aggregates, while bovine serum albumin forms non-amyloid aggregates. In crowded environments, all protein solutions tested develop composite gel networks with distinct molecular origins. Here the ability to control the amyloid aggregate content, which has a substantial effect on the structural and viscoelastic properties of these composite gels, has been demonstrated. Gel structure and viscosity are crucial parameters to control for the food industry, as they play a key role in determining the softness and texture of food products.

The preservation of cultural heritage is a matter of global importance, necessitating the development of advanced diagnostic methodologies capable of delivering detailed insights into the composition, condition, and degradation processes of historical artifacts. Non-invasive chemical analysis-such as Raman spectroscopy, X-ray fluorescence, and Fourier-transform infrared spectroscopy-are widely employed to identify pigments, binders, and varnishes. Chromatographic methods, including gas chromatography-mass spectrometry and high-performance liquid chromatography, while requiring micro-sampling, remain indispensable for the characterization of organic compounds. Conversely, the mechanical characterization - critical for assessing structural integrity and deterioration phenomena such as cracking, delamination, and embrittlement - remains comparatively underdeveloped, primarily due to the scarcity of non-destructive tools suitable for delicate and heterogeneous materials. Within this framework, we propose Brillouin and Raman micro-spectroscopy (BRaMS) as a novel, non-invasive, non-destructive, and label-free technique capable of simultaneously assessing both chemical and mechanical properties of cultural heritage materials. BRaMS integrates Brillouin light scattering (BLS) and Raman spectroscopy into a single experimental configuration, enabling co-localized microscale mapping of compositional and viscoelastic parameters. This dual analytical capability offers a significant advancement in the study of complex, multi-material artifacts. Initially established within the biomedical sciences, BRaMS has demonstrated exceptional sensitivity to subtle chemical and mechanical variations across a wide range of biological systems. Recent applications to cultural heritage research-such as monitoring the polymerization of linseed oil binders and investigating the degradation of modern plastic objects-further underscore its diagnostic potential. As such, BRaMS represents a promising integrated approach for advancing the preservation and understanding of irreplaceable cultural assets.

We present the results of a search for gravitational-wave transients associated with core-collapse supernova SN 2023ixf, which was observed in the galaxy Messier 101 via optical emission on 2023 May 19, during the LIGO–Virgo–KAGRA 15th Engineering Run. We define a five-day on-source window during which an accompanying gravitational-wave signal may have occurred. No gravitational waves have been identified in data when at least two gravitational-wave observatories were operating, which covered ∼14% of this five-day window. We report the search detection efficiency for various possible gravitational-wave emission models. Considering the distance to M101 (6.7 Mpc), we derive constraints on the gravitational-wave emission mechanism of core-collapse supernovae across a broad frequency spectrum, ranging from 50 Hz to 2 kHz, where we assume the gravitational-wave emission occurred when coincident data are available in the on-source window. Considering an ellipsoid model for a rotating proto-neutron star, our search is sensitive to gravitational-wave energy 1 × 10 −4 M ⊙ c 2 and luminosity 2.6 × 10 −4 M ⊙ c 2 s −1 for a source emitting at 82 Hz. These constraints are around an order of magnitude more stringent than those obtained so far with gravitational-wave data. The constraint on the ellipticity of the proto-neutron star that is formed is as low as 1.08, at frequencies above 1200 Hz, surpassing past results.

Chemical recycling of plastics holds great promise but remains constrained by sustainability issues, with polyethylene terephthalate (PET) epitomizing this challenge. Herein, we introduce a conceptually novel strategy that overcomes PET's intrinsic hydrophobicity by physically re‐engineering the polymer's microstructure to enable ultrafast alkaline hydrolysis under exceptionally mild conditions. We leverage the ability of propylene carbonate (PC)—an inexpensive, commercial, green solvent—to selectively dissolve PET, to thermally induce phase separation, and subsequently act as a carrier for water insertion between polymer chains. Upon complete PC replacement, the water uptake exceeds twice the polymer mass, preventing chain re‐compaction and establishing an interfacial environment that facilitates hydroxyl ion diffusion to ester bonds and depolymerization with minimal alkali consumption. As a result, water‐swollen PET fully depolymerizes (96% TPA yield) at atmospheric pressure within 5 min at 90 or under 2 h at room temperature, vastly outperforming conventional hydrolysis methods. The process achieves a 20‐fold reduction in energy footprint versus direct PET hydrolysis. It performs robustly on challenging, real‐world feedstocks—including textiles and mixed plastic waste—enabling selective depolymerization unaffected by PET crystallinity. A techno‐economic analysis (TEA) confirms energy efficiency and strong economic feasibility, demonstrating overall competitiveness with existing engineered technologies. Beyond PET, the physical mechanism underpinning the strategy offers a scalable and sustainable platform for recycling a wide range of condensation polymers.

We present results from a search for X-ray/gamma-ray counterparts of gravitational-wave (GW) candidates from the third observing run (O3) of the LIGO-Virgo-KAGRA network using the Swift Burst Alert Telescope (Swift-BAT). The search includes 636 GW candidates received with low latency, 86 of which have been confirmed by the offline analysis and included in the third cumulative Gravitational-Wave Transient Catalogs (GWTC-3). Targeted searches were carried out on the entire GW sample using the maximum-likelihood Non-imaging Transient Reconstruction and Temporal Search pipeline on the BAT data made available via the GUANO infrastructure. We do not detect any significant electromagnetic emission that is temporally and spatially coincident with any of the GW candidates. We report flux upper limits in the 15-350 keV band as a function of sky position for all the catalog candidates. For GW candidates where the Swift-BAT false alarm rate is less than 10(-3) Hz, we compute the GW-BAT joint false alarm rate. Finally, the derived Swift-BAT upper limits are used to infer constraints on the putative electromagnetic emission associated with binary black hole mergers.

In this study, we analyzed the neuroprotective action of silk fibroin (SF) regenerated with calcium chloride (CaCl2), distinguishing the effects of CaCl2 and SF, and subsequently fabricating a neuroprotective hybrid material based on SF gelatin film. Cytotoxicity induced by 6-hydroxydopamine (6-OHDA) on the human neuroblastoma SH-SY5Y cell line showed that SF had a significant shielding power against 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in SH-SY5Y neuroblastoma cells, as assessed by the CCK-8 assay, cell imaging and cell cycle using flow cytometer. Specifically, the concurrent treatment with SF and 6-OHDA produced a marked neuroprotective effect. Circular dichroism analysis suggested the formation of silk III because of the interaction between the secondary structures of SF and 6-OHDA. Raman analysis was also employed to assess the impact of SF and CaCl2 on cellular metabolism, indicating the combined administration of fibroin and 6-OHDA as more effective than the use of CaCl2 alone. Subsequently, we synthesized a silk/gelatin-based film, demonstrated its ability to release SF, and confirmed its capacity to protect SH-SY5Y neuroblastoma cells.

Organic semiconducting nanoparticles (NPs) have been attracting increasing attention for their diverse applications in biotechnology, especially as photoactive materials for spatially controlled optical modulation of living-cell functions. Different approaches to optimize their efficacy and reliability have been recently attempted, including control of photophysical/-chemical properties, ad hoc tailoring of materials synthesis, and functionalization with biological moieties. Another promising strategy is offered by the realization of composite light-sensitive NPs, with a supramolecular architecture. This work reports on the fabrication and characterization of polymer NPs based on poly(3-hexylthiophene-2,5-diyl) (P3HT) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as prototypical examples of fully biocompatible, semiconducting and conducting materials, respectively. This peculiar NP architecture, with conducting islets distributed within the semiconducting phase, translates into optimization of charge dissociation and electron-transfer efficiency, as well as photocurrent generation increase by about an order of magnitude. As an example of relevant physiological interest, effective optical modulation of angiogenesis, driven by NPs, is demonstrated in primary human endothelial cells. The reported strategy is of general validity and broadens the tools available for spatiotemporally controlled, optical modulation of living-cell functions via engineering of the NP architecture and processes at the interface with living cells.

Silk proteins are versatile biopolymers well-suited to act as foundational components of a wide range of biomaterials. Rapidly gelling, self-assembling systems are especially valuable for drug delivery and biomedical applications. In this study, we present a way to induce the solid coaggregation of silk fibroin (SF) by adding the anionic surfactant sodium dodecylbenzene sulfonate (SDBS) into an SF solution prepared in formic acid (FA). SF films prepared by dissolving silk in CaCl2–FA and subsequently rinsing in water to remove CaCl2 were re-solubilized in FA with different content of SDBS. It was found that SF aggregation time is strongly modulated by the presence of SDBS. At increasing surfactant content, hydrophobic interactions between the SF chains and SDBS promote the formation of spherical coaggregates, whose size increases with surfactant concentration. FTIR analysis reveals that this process is accompanied by the formation of β-sheet structures, likely driven by hydrophobic interactions. This spontaneous liquid-to-solid phase transition promotes the formation of mechanically robust SF films with tunable electrical properties.

Saltwater stands as the most prevalent liquid on Earth. Consequently, substantial interest has been directed toward its characterization, both as an independent system and as a solvent for complex structures such as biomacromolecules. In the last few decades, special emphasis was placed on the investigation of the hydration properties of ions for the fundamental role they play in numerous chemical processes. In this study, we employed multi-wavelength Raman spectroscopy to examine the hydration shell surrounding bromide ions in solutions of simple electrolytes, specifically lithium bromide, potassium bromide, and cesium bromide, at two different concentrations. Cation-induced differences among electrolytes were observed in connection to their tendency to form ion pairs. An increased sensitivity to reveal the structure of the first hydration shell was evidenced when employing ultraviolet excitation in the 228-266 nm range, under resonance conditions with the charge transfer transition to the solvent peaked at about 200 nm. Other than a significant increase in the Raman cross-section for the OH stretching band when shifting from pure water to the solution, a larger enhancement for the Raman signal of the H-O-H bending mode over the stretching vibration was observed. Thus, the bending band plays a crucial role in monitoring the H-bond structure of water around the anions related to the charge distribution within the first hydration shell of anions, being an effective probe of hydration phenomena.