Institut Químic de Sarrià

The emergence of light‐based technologies is revolutionizing modern medicine and healthcare by enabling precise disease diagnosis and treatment through various luminescent agents and imaging techniques. Despite challenges like biocompatibility, spectral tuning, and synthesis complexity, the primary issue is the aggregation‐caused quenching of emission on high concentrations or physiological conditions. In light of these problems, Clustering‐Triggered Emission (CTE), which involves the formation of atomic clusters to induce light absorption and the luminescence of unconventional chromophores, represents an all‐in‐one solution to the challenges identified. Given the potential for CTE materials to behave in ways previously only associated with conventional chromophores, it seems reasonable that highly oxidative reactive oxygen species can be formed from CTE excited states. The results demonstrate that it is possible to transfer the excess energy from the CTE long‐lived excited states to molecular oxygen, thereby producing singlet oxygen. It is also noteworthy that over 99.9% of Staphylococcus aureus cells can be eradicated using fluences comparable to those used in traditional systems under violet light irradiation. Uncovering these photophysical properties of CTE opens the door to a revolutionary breakthrough that can disrupt conventional photodynamic therapy and usher in a new era of CTE‐based photosensitizers.

Optical matter, a transient arrangement formed by the interaction of light with micro/nanoscale objects, provides responsive and highly tunable materials that allow for controlling and manipulating light and/or matter. A combined experimental and theoretical exploration of optical matter is essential to advance our understanding of the phenomenon and potentially design applications. Most studies have focused on nanoparticles composed of a single material (either metallic or dielectric), representing two extreme regimes, one where the gradient force (dielectric) and one where the scattering force (metallic) dominates. To understand their role, it is important to investigate hybrid materials with different metallic-to-dielectric ratios. Here, we combine numerical calculations and experiments on hybrid metal–dielectric core–shell particles (200 nm gold spheres coated with silica shells with thicknesses ranging from 0 to 100 nm). We reveal how silica shell thickness critically influences the essential properties of optical binding, such as interparticle distance, reducing it below the anticipated optical binding length. Notably, for silica shells thicker than 50 nm, we observed a transition from a linear arrangement perpendicular to polarization to a hexagonal arrangement accompanied by a circular motion. Further, the dynamic swarming assembly changes from the conventional dumbbell-shaped to lobe-like morphologies. These phenomena, confirmed by both experimental observations and dynamic numerical calculations, demonstrate the complex dynamics of optical matter and underscore the potential for tuning its properties for applications.

This study investigates strategies to enhance game form recognition within economic experiments, particularly focusing on the Becker DeGroot Marshak (BDM) method. The BDM method aims to elicit individuals’ subjective valuations of objects, yet challenges arise in participants’ comprehension and optimal decision-making. Drawing on cognitive load theory, this research proposes integrating output tables to facilitate participants’ understanding and decision-making in BDM experiments. A randomized controlled experiment was conducted with 129 participants from diverse academic backgrounds. Results reveal that participants exposed to output tables exhibited improved game form recognition and higher rates of optimal bidding. Gender and specialization analyses provided further insights into participant performance. These findings contribute to refining economic experimental methodologies and understanding cognitive influences on decision-making, aligning with principles of modality and divided attention in organizational behavior research.

The self-organization of colloidal nanoparticles into complex structures, both in equilibrium and out-of-equilibrium, is a critical area in colloidal science with potential applications in creating new functional materials. While equilibrium assemblies yield thermodynamically stable and periodic structures, non-equilibrium (or active) assemblies exhibit dynamic, reconfigurable behavior in response to external stimuli. As a consequence, understanding the structure-function relationships in these assemblies remain challenging due to their transient, highly dynamic nature and the limitations of current characterization methods. In this work, we present a novel methodology for Fixation and Resolution of Colloidal Active Matter Ensembles (FRAME). FRAME combines UV photopolymerization to immobilize non-equilibrium (active) colloidal assembly with high-resolution imaging techniques, such as 3D confocal microscopy and SEM, for subsequent structural characterization. We demonstrate this method on Optical Matter (OM) structure formed by an optical trap at glass/water interface where it enables the preservation and detailed analysis of OM structures, using colloidal nanoparticles ranging from 200 nm to 1 μm. We demonstrate the method's efficacy by validating that the immobilization process does not alter the structural properties, allowing for accurate structural analysis. Additionally, this approach enables the capture of dynamic snapshots of the assembly during its formation, providing critical insights into its transient behavior. FRAME offers a new avenue for investigating non-equilibrium colloidal assemblies, paving the way for their rational design and application across a broad range of colloidal systems.

The demand for novel tissue grafting and regenerative wound care biomaterials is growing as traditional options often fall short in biocompatibility, functional integration with human tissue, associated cost(s), and sustainability. Salmon aquaculture generates significant volumes of waste, offering a sustainable opportunity for biomaterial production, particularly in osteo-conduction/-induction, and de novo clinical/surgical bone regeneration. Henceforth, this study explores re-purposing salmon waste through a standardized pre-treatment process that minimizes the biological waste content, followed by a treatment stage to remove proteins, lipids, and other compounds, resulting in a mineral-rich substrate. Herein, we examined various methods—alkaline hydrolysis, calcination, and NaOH hydrolysis—to better identify and determine the most efficient and effective process for producing bio-functional nano-sized hydroxyapatite. Through comprehensive chemical, physical, and biological assessments, including Raman spectroscopy and X-ray diffraction, we also optimized the extraction process. Our modified and innovative alkaline hydrolysis–calcination method yielded salmon-derived hydroxyapatite with a highly crystalline structure, an optimal Ca/P ratio, and excellent biocompatibility. The attractive nano-scale cellular/tissular properties and favorable molecular characteristics, particularly well-suited for bone repair, are comparable to or even surpass those of synthetic, human, bovine, and porcine hydroxyapatite, positioning it as a promising candidate for use in tissue engineering, wound healing, and regenerative medicine indications.

Analyzing changes in gene expression within specific brain regions of individuals with Type 2 Diabetes (T2DM) who do not exhibit significant cognitive deficits can yield valuable insights into the mechanisms underlying the progression towards a more severe phenotype. In this study, transcriptomic analysis of the cortex and hippocampus of mice with long-term T2DM revealed alterations in the expression of 28 genes in the cerebral cortex and 15 genes in the hippocampus. Among these genes, six displayed consistent changes in both the cortex and hippocampus: Interferon regulatory factor 7 (Irf7), Hypoxia-inducible factor 3 alpha (Hif-3α), period circadian clock 2 (Per2), xanthine dehydrogenase (Xdh), and Transforming growth factor β-stimulated clone 22/TSC22 (Tsc22d3) were upregulated, while Claudin-5 (Cldn5) was downregulated. Confirmation of these changes was achieved through RT-qPCR. At the protein level, CLDN5 and IRF7 exhibited similar alterations, with CLDN5 being downregulated and IRF7 being upregulated. In addition, the hippocampus and cortex of the T2DM mice showed decreased levels of IκBα, implying the involvement of NF-κB pathways as well. Taken together, these results suggest that the weakening of the blood-brain barrier and an abnormal inflammatory response via the Interferon 1 and NF-κB pathways underlie cognitive impairment in individuals with long-standing T2DM

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in social interaction and communication, anxiety, hyperactivity, and interest restricted to specific subjects. In addition to the genetic factors, multiple environmental factors have been related to the development of ASD. Animal models can serve as crucial tools for understanding the complexity of ASD. In this study, a chemical model of ASD has been developed in zebrafish by exposing embryos to valproic acid (VPA) from 4 to 48 h post-fertilization, rearing them to the adult stage in fish water. For the first time, an integrative approach combining behavioral analysis and neurotransmitters profile has been used for determining the effects of early-life exposure to VPA both in the larval and adult stages. Larvae from VPA-treated embryos showed hyperactivity and decreased visual and vibrational escape responses, as well as an altered neurotransmitters profile, with increased glutamate and decreased acetylcholine and norepinephrine levels. Adults from VPA-treated embryos exhibited impaired social behavior characterized by larger shoal sizes and a decreased interest for their conspecifics. A neurotransmitter analysis revealed a significant decrease in dopamine and GABA levels in the brain. These results support the potential predictive validity of this model for ASD research.

Here we describe a complex enzymatic approach to the efficient transformation of abundant waste chitin, a byproduct of the food industry, into valuable chitooligomers with a degree of polymerization (DP) ranging from 6 to 11. This method involves a three-step process: initial hydrolysis of chitin using engineered variants of a novel fungal chitinase from Talaromyces flavus to generate low-DP chitooligomers, followed by an extension to the desired DP using the high-yielding Y445N variant of β-N-acetylhexosaminidase from Aspergillus oryzae, achieving yields of up to 57%. Subsequently, enzymatic deacetylation of chitooligomers with DP 6 and 7 was accomplished using peptidoglycan deacetylase from Bacillus subtilisBsPdaC. The innovative enzymatic procedure demonstrates a sustainable and feasible route for converting waste chitin into unavailable bioactive chitooligomers potentially applicable as natural pesticides in ecological and sustainable agriculture.

A new family of antifibrinolytic drugs has been recently discovered, combining a triazole moiety, an oxadiazolone, and a terminal amine. Two of the molecules of this family have shown activity that is greater than or similar to that of tranexamic acid (TXA), the current antifibrinolytic gold standard, which has been associated with several side effects and whose use is limited in patients with renal impairment. The aim of this work was to thoroughly examine the mechanism of action of the two ideal candidates of the 1,2,3-triazole family and compare them with TXA, to identify an antifibrinolytic alternative active at lower dosages. Specifically, the antifibrinolytic activity of the two compounds (1 and 5) and TXA was assessed in fibrinolytic isolated systems and in whole blood. Results revealed that despite having an activity pathway comparable to that of TXA, both compounds showed greater activity in blood. These differences could be attributed to a more stable ligand–target binding to the pocket of plasminogen for compounds 1 and 5, as suggested by molecular dynamic simulations. This work presents further evidence of the antifibrinolytic activity of the two best candidates of the 1,2,3-triazole family and paves the way for incorporating these molecules as new antifibrinolytic therapies.

The development of diverse types of biomaterials has significantly contributed to bringing new biomedical strategies to treat clinical conditions. Applications of these biomaterials can range from mechanical support and protection...

Nanomedicine is a field at the intersection of nanotechnology and medicine, promising due to its potential to revolutionize healthcare. Despite its long trajectory, there is still a long road ahead...

Modular supramolecular complexes, where different proteins are assembled to gather targeting capability and photofunctional properties within the same structures, are of special interest for bacterial photodynamic inactivation, given their inherent biocompatibility and flexibility. We have recently proposed one such structure, exploiting the tetrameric bacterial protein streptavidin as the main building block, to target S. aureus protein A. To expand the palette of targets, we have linked biotinylated Concanavalin A, a sugar-binding protein, to a methylene blue-labelled streptavidin. By applying a combination of spectroscopy and microscopy, we demonstrate the binding of Concanavalin A to the walls of Gram-positive S. aureus and Gram-negative E. coli. Photoinactivation is observed for both bacterial strains in the low micromolar range, although the moderate affinity for the molecular targets and the low singlet oxygen yields limit the overall efficiency. Finally, we apply a maximum entropy method to the analysis of autocorrelation traces, which proves particularly useful when interpreting signals measured for diffusing systems heterogeneous in size, such as fluorescent species bound to bacteria.

Immunotherapy has emerged as a promising approach to cancer treatment, offering improved survival rates and enhanced patients’ quality of life. However, realizing the full potential of immunotherapy in clinical practice remains a challenge, as there is still plenty of room for modulating the complexity of the human immune system in favor of an antitumor immunogenicity. Nanotechnology, with its unique properties, holds promise in augmenting the efficacy of cancer immunotherapies in biotherapeutic protection and site- and time-controlled delivery of the immune modulator biologicals. Polymeric nanoparticles are promising biomaterials among different nanocarriers thanks to their robustness, versatility, and cost-efficient design and production. This perspective paper overviews critical concepts in nanometric advanced delivery systems applied to cancer immunotherapy. We focus on a detailed exploration of the current state of the art and trends in using poly(beta-aminoester) (pBAE) polymers for nucleic acid-based antitumor immunotherapies. Through different examples of the use of pBAE polymers reported in the literature, we revise the main advantages these polymers offer and some challenges to overcome. Finally, the paper provides insights and predictions on the path toward the clinical implementation of cancer nano-immunotherapies, highlighting the potential of pBAE polymers for advancements in this field. Graphical abstract

In this paper, we present an evolutionary design methodology of Central Pattern Generator (CPG)-based locomotion systems for hexapod and quadrupedal robots. The CPGs are built as Spiking Neural Networks, whose synaptic connections and weights are directly configured by an evolutionary algorithm in order that CPGs generate rhythmic and periodical signals to carry out robotic locomotion. The CPGs are fully designed and implemented using Nengo simulator. There were obtained CPGs for different locomotion patterns for both, hexapod and quadruped robots. The obtained CPGs achieve behaviours reported in the state of the art with smaller architectures.