Scientific publications

Catechol-modified polymers, such as DOPA-functionalized systems, have recently gained significant interest for a variety of biomedical applications, particularly in their role as antibacterial adjuvants due to their oxidative activity and ability to generate reactive oxygen species (ROS). Current catechol-functionalized polymers, however, often suffer from a restricted number of catechol groups, limited biocompatibility and solubility, and low stability due to the rapid oxidation under physiological conditions. In this study, we developed a water-soluble, biocompatible DOPA-modified biodynamer (DOPA-BD), leveraging the principles of constitutional dynamic chemistry (CDC). DOPA-BD was synthesized via polycondensation of DOPA-hydrazide and the hexaethylene glycol-conjugated carbazole dialdehyde (CA-HG), forming dynamic imine and acylhydrazone linkages between the monomers. As a result of its dynamic covalent backbone, DOPA-BD exhibits biodegradability and undergoes pH-responsive degradation under mildly acidic conditions typically found at infection sites, leading to a more than 3-fold increase in DOPA-hydrazide release compared to physiological pH. Interestingly, driven by CDC, DOPA-BD folds into a nanorod structure with a hydrodynamic diameter of ∼7.8 nm, surrounded by HG chains that offer water solubility and biocompatibility. Moreover, the incorporation of the DOPA-derivative in each repeating unit yields a polymer with exceptionally high catechol content, which remains stable and resistant to oxidation for 72 h in physiological buffer conditions. Regarding its antibacterial applicability, DOPA-BD demonstrated synergistic antibacterial activity with Azithromycin (AZM) against AZM-resistant E. coli, enhancing the antibiotic’s efficacy by 4-fold. Our study indicates that DOPA-BD induces ROS production in the respective bacterial strain, suggesting ROS generation as one of the possible mechanisms contributing to the observed synergy. Overall, DOPA-BD represents a promising alternative strategy to potentiate antibacterial activity against resistant strains, holding strong potential for future antibacterial applications.

Impaired angiogenesis is a central barrier in the treatment of chronic and deep tissue wounds, preventing progression through the normal healing cascade. While the combination of near infrared (NIR) photobiomodulation and pro-angiogenic growth factors has shown synergistic therapeutic benefit, the clinical translation of growth factor therapy is hindered by high cost, instability, and the need for localized dosing to avoid aberrant vasculature. Peptidomimetics such as the VEGF-derived QK peptide offer a more stable and predictable alternative, but still require a means for localized, tunable presentation. Here, we establish an engineered living material-based delivery system that responds to clinically relevant NIR light to produce and release a QK-Fusion protein directly at the target site. The probiotic Escherichia coli Nissle 1917 was engineered with an 800 nm-responsive optogenetic circuit and encapsulated within an optimized alginate core–shell hydrogel that ensures biocontainment while allowing controlled outward diffusion of the secreted peptide. The released peptide remains non-cytotoxic, capable of binding extracellular matrix analogs, and promotes angiogenesis in endothelial cultures and the chick chorioallantoic membrane assay. We thus establish a strategy for developing engineered living materials toward remote-controlled angiogenic stimulation.

The applicability of current upconverting lanthanide doped luminescent thermometers is limited by signal discriminability and thermal sensitivity. We overcome these limitations by creating fluorescent nanocomposites in biodegradable polyhydroxyalkanoates (PHA). Nanocomposites were designed that combine different lanthanide based upconverting nanoparticles. We create mixed emitter composites with bright red (Mn 2+ doped with Er 3+ , Yb 3+ in NaYF4), green (Er 3+ , Yb 3+ in BaYF5) and blue (Tm 3+ , Yb 3+ in CaF2) emitting particles to obtain clearly distinguishable and intense fluorescent signals. The resulting nanocomposites had maximum relative thermal sensitivities of 34% K -1 , outperforming existing thermometers.Importantly, their readout requires detection only in visible wavelength ranges, making them particularly suitable for dronebased environmental monitoring purposes. To demonstrate their applicability in this field, we integrate the nanocomposites into plant-inspired artificial fliers, creating self-deployable and biocompatible units for wireless monitoring of environmental temperature. The surface temperature of topsoil is reconstructed based on the fluorescence intensity ratio among the RGB (red-green-blue) wavelengths of the upconverting nanocomposites integrated into the fliers.

Electrochemical nitrate reduction (eNO3RR) mitigates environmental nitrate pollution while offering a sustainable approach for green NH3 synthesis, but is plagued by limited electrocatalytic activity and unsatisfactory stability. Accordingly, we adopted an exfoliation-induced in situ electrochemical deep reconstruction strategy to construct an amorphous/crystalline heterostructure using a multilayer CuCoAl layered double hydroxide (LDH) as a precursor. The characterization results illustrate that the few-layer CuCoAl LDH underwent a deep reconstruction process to transform into a structure with co-existing metallic Cu, crystalline Co(OH)2, and amorphous CoOOH. Among these, CoOOH can firmly anchor the Cu cluster to promote the transformation of NO3 – to NO2 -, while Co(OH)2 mainly facilitates the subsequent hydrogenation steps. These three species act cooperatively to endow the reconstructed few-layer LDH with extraordinary eNO3RR activity (99.5% Faradaic efficiency, 95.7% NH3 selectivity, and 1.92 mol h-1 g-1 yield rate at -0.57 V vs. RHE in 0.1 m nitrate) and stability. The Zn-NO3 – battery assembled with FA2-CuCoAl LDH simultaneously achieved environmental remediation, energy storage, and sustainable ammonia synthesis. Thus, this study reveals the reconstruction behavior of CuCoAl LDH, demonstrates the positive effect of the exfoliation step, and provides a novel strategy for designing efficient and stable eNO3RR catalysts based on amorphous/crystalline heterostructure engineering.

Silicon is a promising anode material for lithium-ion batteries due to its high capacity and potential for fast charging. However, its electrochemical behavior is dominated by pronounced voltage hysteresis, particle-size-dependent voltage plateaus, and relaxation processes induced by hysteresis. Conventional Doyle–Fuller–Newman models cannot capture these phenomena. Here, we present a multi-species, multi-reaction framework that explicitly considers the multiphase lithium–silicon system by assigning an independent equilibrium potential to each phase, derived from modified Nernst equations and parameterized with experimental and atomistic data. The model captures both asymmetric lithiation and delithiation pathways as well as phase-fraction evolution in silicon half-cells. Quantitative comparison yields root-mean-square errors of 5.4–36.9 mV during constant-current and pulse protocols, corresponding to a relative root mean square error of 0.6–4.1% of the overall voltage window. Simulations further reveal that phase fractions continue to evolve during relaxation through thermodynamic redistribution of lithium between phases, governed by phase-specific equilibrium potentials and kinetics. This cross-dimensional approach enables a mechanistic representation of voltage hysteresis, providing a pathway toward improved state estimation, cell design, and battery management.

Commercialization of lithium–sulfur batteries (Li–S) remains complex due to limited cycling stability related to the solubility of polysulfide intermediates, specifically higher-order polysulfides (Li2S4 to Li2S8). Some studies have utilized microporous carbons with pore sizes ≤0.7 nm, which can accommodate only short-chain polysulfides (Li2S2–4) to resolve the challenge of polysulfide shuttling. However, the discharge products of long-chain polysulfides, Li2S8 and Li2S6 molecules with diameters of 0.84 nm and 0.76 nm, are not entirely confined in the micropores due to the poor affinity of the carbon host and polysulfides. In this study, we created microporous carbon (AC900) with a pore size of 1.2 nm that can accommodate both long and short-chain polysulfides and infiltrated it with sulfur (AC900S). To mitigate capacity fading, we further modified the carbon using urea (AC900NS) and nickel sulfate (AC900S-Ni) treatments. The latter did not result in detectable Ni incorporation but induced partial changes in carbon hybridization and surface structure. The synthesis-driven structural adjustment in AC900S-Ni influenced solid-state conversion and improved electrochemical stability compared to AC900S and AC900NS. The AC900S-Ni cathode demonstrated a capacity retention of 72% with a capacity of 773 mAh gS−1 after 100 cycles and 1000 mAh gS−1 in the first cycle at C/20, higher than those of AC900S and AC900NS. An improvement in capacity retention to 96% was noted at C/10, with a discharge capacity of 722 mAh gS−1 after 100 cycles, compared to 805 mAh gS−1 in the first cycle. The results identify the factor contributing to capacity fading in unmodified AC900S and demonstrate that chemical/structural modification of microporous carbon combined with a carbonate electrolyte provides a promising pathway for Li–S systems. This study offers a facile approach to tune carbon hosts and expand their applicability in Li–S batteries.

Porous and functional cellulose-based materials play a key role in the field of novel sensors and membrane technologies, yet their full potential remains unexplored. This article elaborates on a procedure for creating porous coatings with reactive chemical groups on their surfaces by covering a cellulose membrane with hybrid core–shell particles. The silica cores of these particles, synthesized via the Stöber procedure, could easily be etched with hydrofluoric acid. The cross-linked polymer shell of the particles was synthesized via emulsion polymerization. These particles were analyzed via dynamic light scattering and transmission electron microscopy. After coating the cellulose and an etching process, the former core particles formed pores within the matrix of the shell polymer, as observed via scanning electron microscopy and atomic force microscopy. The coated area also featured chemical functionalities via appropriate polymers used in the shell of the particles, enabling further cellulose modification. In particular, hydroxy groups were incorporated into a copolymer containing 2-hydroxyethyl methacrylate, and epoxy groups were incorporated using glycidyl methacrylate. These functionalities can be combined to yield a wide range of specific properties. For this reason, this work paves the way for advanced smart and stimuli-responsive porous filtration systems, paper-based sensors, and adsorbers.

Developing biocompatible scaffolds with physicochemical properties suitable for regenerative medicine that also support cell adhesion and proliferation, while reducing local oxidative stress, exhibiting low immunogenicity and antimicrobial properties, represents a key objective in tissue engineering. Chitosan (CS), a biocompatible and biodegradable biopolymer, has attracted considerable attention in recent years as in tissue engineering. Herein, CS scaffolds were functionalized with bioactive antioxidant/antimicrobial molecules and reinforced with natural fillers to enhance these critical properties. The incorporation of a CS derivative containing 1-methylimidazole into CS-based scaffolds, and chitin nanowhiskers as reinforcement, was investigated. The resulting scaffolds exhibited an interconnected porous structure, facilitating nutrient diffusion and cell infiltration. Rheological analysis confirmed a predominantly soft and elastic behavior. Additionally, the antioxidant activity of the scaffolds was evaluated using the DPPH assay, while its antimicrobial effects were confirmed through bacterial inhibition tests. Fibroblast proliferation assays revealed an initial rapid growth phase followed by a stabilization. Immunological studies using macrophages demonstrated an initial activation of the NFκB transcription factor that did not result in the secretion of the pro-inflammatory cytokine IL-6, suggesting a transient macrophage activation. These findings highlight the potential of these CS-based scaffolds for biomedical applications by balancing structural integrity, cell compatibility and controlled immune response.

Chronic lung infections caused by Pseudomonas aeruginosa are a major contributor to morbidity and mortality in patients with cystic fibrosis. Biofilm formation and the emergence of antibiotic resistance limit the effectiveness of current inhaled therapies, highlighting the need for innovative formulation strategies that enhance local antibacterial efficacy while preserving epithelial integrity. This study explores a nano-in-micro inhalable formulation design that combines azithromycin (AZM) with the antibiotic adjuvant menadione (MEN) to enhance antibiofilm activity under biorelevant pulmonary exposure conditions. Nano-embedded microparticles (NEMs) were developed as an inhalable “Trojan particle” approach, combining AZM in a microparticle matrix with MEN-loaded polymeric nanoparticles. The formulations were produced by spray drying and characterized in terms of morphology, aerodynamic performance, solid-state properties and redispersibility. Antibiofilm activity against P. aeruginosa biofilms and epithelial safety in Calu-3 cells were evaluated using biorelevant aerosol exposure models, including nebulization and dry powder atomization. NEMs exhibited favorable aerodynamic properties suitable for bronchial delivery. Incorporation of MEN into the NEM system enhanced the antibiofilm efficacy of AZM compared with the microparticle matrix-only formulation, indicating that the adjuvant effect of MEN was retained upon translation into an inhalable formulation. Cytotoxicity studies demonstrated that neither nebulized nor dry powder–delivered formulations compromised the membrane integrity of Calu-3 cells. These results indicate that the combination of azithromycin and menadione within a NEM design preserves drug activity and adjuvant efficacy while enabling effective aerosol delivery. Future studies in more complex and disease-relevant models will further strengthen the understanding of the translational potential of this approach.