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Light-induced and spontaneously occurring (in the dark) spectral shifts can be observed in a wide variety of systems where pigments are embedded in a somewhat amorphous environment, for instance, organic glasses, polymers, and proteins. They are observed directly in single-molecule spectroscopy experiments and serve as the basis for nonphotochemical spectral hole burning (NPHB). These shifts reflect small rearrangements of the local environment of the pigment that can be represented as transitions between the minima of the respective energy landscape. While methodology for determining the parameters of the energy landscapes from the results of optical spectroscopy experiments has been developed over the years, rigor has been sometimes sacrificed for the sake of clarity, and this may be the reason for the discrepancies between theories and experiments. Here, we demonstrate an application of rigorous quantum-mechanical (QM) approaches to modeling the results of single molecule (or single pigment-protein complex) spectroscopy and nonphotochemical hole burning. We employ rectangular and parabolic energy landscapes, with a linear or an angular generalized coordinate, and include phonon-assisted tunneling. Under these assumptions, the same transition rates are obtained for lower barriers and/or md² or moment of inertia compared with those predicted by the semiclassical model generally utilized in the analysis of NPHB data.

Sensitive skin caused by environmental and seasonal factors has become a global issue, and daily skin care can help alleviate symptoms through gentle formulations with effective ingredients. This study aimed to develop and evaluate a multifunctional lotus-leaf-extract-based nanoformulation for sensitive skin care, integrating whitening, barrier restoration, and moisturizing effects. The cream was structurally characterized as an oil-in-water (O/W) emulsion through oil/water dilution, cobalt chloride paper impregnation, and microscopic analyses, which collectively confirmed its O/W structure. Rheological testing and stability analysis revealed pseudoplastic behavior with low viscosity, ensuring rapid absorption and minimal residue, while maintaining stability and robustness under extreme temperatures (-20 to 45 °C, 72 h) and centrifugation (3000 rpm for 30 min). Functional assessments demonstrated strong antioxidant activity (71.01% DPPH scavenging at 0.10 g mL^-1) and sustained moisturization (65.23% retention over 24 h), along with broad-spectrum UV absorbance (280-400 nm) indicating photoprotective potential comparable to standard UV filters. Safety profiling confirmed biological compatibility through pH testing and antimicrobial efficacy against E. coli and S. aureus and showed mild irritation in CAM assays, with an ES score of 3.0 indicating a mild level of irritation. Mechanistically, the formulation acts via synergistic antioxidant and anti-inflammatory pathways to mitigate oxidative stress, restore epidermal barrier integrity, and suppress melanogenesis, and these mechanistic insights are inferred from the literature evidence rather than direct in vitro or in vivo experiments. Overall, these findings highlight the lotus-leaf-extract-based nanoformulation as a dual-action therapeutic strategy for sensitive skin, effectively combining whitening efficacy with barrier repair.

The global shortage of freshwater, intensified by rising salinity in natural water sources, calls for scalable and energy-efficient desalination technologies. Interfacial solar-driven evaporation offers a promising solution, yet its practical implementation is hindered by high-cost photothermal materials and complex fabrication. Herein, we develop a flexible, self-floating electrospun bilayer membrane composed of Ce-doped Cu-based MOFs, multiwalled carbon nanotubes, polyvinylidene fluoride, and polyacrylonitrile, which was designed for efficient photothermal seawater desalination. A key distinguishing feature lies in the Ce doping strategy. During calcination, Cu-MOFs yield CuO and undesired Cu₂O, which reduce photothermal efficiency. The introduced cerium species form CeO₂/Ce₂O₃ can catalytically oxidize residual Cu₂O into CuO to enhance light absorption. X-ray photoelectron spectroscopy confirms the formation of CeO₂/CuO heterojunctions with improved interfacial synergy. Under 1 kW·m^-2 solar irradiation, the optimized membrane reaches a surface temperature of 61.4 °C and delivers a high evaporation rate of 1.98 kg·m^-2·h^-1. The membrane exhibits strong mechanical strength, reaching a tensile value of 9.92 MPa. It also demonstrates a rapid thermal response by cooling from 61.4 to 26.1 °C within 90 min, which highlights its focus on efficient evaporation dynamics rather than heat retention. This work offers a cost-effective and scalable strategy for interfacial solar-driven evaporation membrane fabrication and introduces a Ce-assisted catalytic route to enhance photothermal conversion via compositional control and interfacial engineering.

The mechanical properties of the extracellular matrix play a key role in regulating cellular functions, yet many in vitro models lack the mechanical complexity of native tissues. Traditional hydrogel-based substrates offer tunable stiffness but are often limited by instability, porosity, and coupled changes in both mechanical and structural properties, making it difficult to isolate the effects of stiffness alone. Here, we introduce a spatially patterned dual-cure polydimethylsiloxane (DC-PDMS) system, a nonporous, mechanically tunable polymer that allows for precise spatial control of stiffness over a range of patho-physiological values. This platform enables the design and creation of in vitro models for studying the influence of spatial mechanical cues on cellular behavior. To demonstrate its utility, we examined primary cardiac fibroblast responses across different substrate stiffness conditions. Fibroblasts on soft regions exhibited rounded morphologies with disorganized actin networks, while those on stiffer regions became more elongated with highly aligned stress fibers, indicating stiffness-dependent cytoskeletal remodeling. Stiff substrates also led to nuclear compression and increased nucleus curvature, correlating with increased nuclear localization of YAP, a key mechanotransduction regulator. By allowing cells to interact with mechanically distinct regions within a single substrate, this system provides a powerful approach for investigating mechanotransduction processes relevant to fibrosis and other mechanically regulated diseases. The ability to create stiffness patterns with subcellular resolution makes DC-PDMS a valuable tool for studying cell-material interactions, enabling new insights into mechanobiology-driven cellular responses and therapeutic targets.

Hydrogels show great potential for mimicking human weight-bearing tissues due to their extremely high water content and desirable behavior, including softness and elasticity. However, developing joint cartilage-mimicking hydrogels with both superior mechanical properties and stable lubrication remains challenging. This study presents a self-assembled heterostructure hydrogel approach. A mechanically robust hydrogel with sustained lubrication properties is achieved by incorporating a hydrophilic network into a hydrophobic polyethyl acrylate (PEA) matrix. Two polymer networks interweave at the microstructural level, generating water-rich and water-poor phases. Outstanding load-bearing capacity is achieved by the flexible hydrophilic polymer network efficiently dispersing impact stress into the rigid hydrophobic network. Meanwhile, a hydrated lubricating layer forms on the hydrophilic network's surface, ensuring sustained lubrication. Moreover, the hydrophobic PEA network incorporation limits swelling in the hydrophilic network, imparting exceptionally stable antiswelling properties to the hydrogel. This study demonstrates that the heterostructure hydrogel maintains stable mechanical properties in aqueous solutions while providing lubricity, offering a novel approach to developing biomimetic materials with mechanical robustness and sustained lubricity.

Cell-ECM communication plays a critical role in the correct tissue development, disease progression, and therapeutic outcomes. The interest in controlling the mechanical properties of the ECM-mimetic systems has changed from the classical concept of elastic networks to mimic the viscoelastic behavior of the native tissue. Recently, the use of supramolecular chemistry has emerged as a promising strategy to achieve this behavior. In this work, alginate-based hydrogels were developed with a dual cross-linking system comprising dynamic cucurbit[8]uril host-guest homoternary complexes and covalent photo-cross-linking of methacrylate groups. By adjusting the ratio of covalent to dynamic bonds, control over the stress relaxation time scale was achieved, which offers an entry to mimic the viscoelastic properties of native soft tissues. Furthermore, this hydrogel formulation was found to be noncytotoxic and promotes cell survival, attachment, and alignment.

Chemo-immunotherapy has been an emerging synergistic strategy for melanoma treatment. However, major challenges still remain, including side effects of chemotherapeutic agents and insufficient efficacy of immunotherapy. In the present work, we designed a thermosensitive polypeptide hydrogel-based drug delivery system to achieve the codelivery of doxorubicin (DOX) and a Toll-like receptor (TLR)-9 agonist, CpG. The hydrogel system was engineered by incorporating cancer cell membrane enveloped hollow mesoporous silica loaded with DOX and the mPEG-ss-PEI/CpG nanocomplex, resulting in an enhanced therapeutic effect. Drug-loaded hydrogel system exhibited sustained drug release, enhanced immune cell activation, and induction of immunogenic cell death (ICD) of tumor cells. In vivo antitumor studies revealed that the drug-loaded hydrogel effectively inhibited tumor growth, and promoted expansion of CD8⁺ T cells and maturation of dendritic cells (DCs), facilitating favorable modulation of the tumor microenvironment. Hence, the developed drug-loaded hydrogel system has considerable potential as a platform for combinatorial chemo-immunotherapy in melanoma treatment.

The integration of excellent performance and facile closed-loop recycling of poly(butylene terephthalate) (PBT) copolyesters remains a significant challenge. Herein, a biobased rigid diol (denoted as HT) was prepared by an acid-catalyzed acetalization reaction from 5-hydroxymethylfurfural (HMF) and trimethylolpropane (TMP). HT was copolymerized with PBT to prepare a series of PBT_xTT_y copolyesters with high M_n up to 45.5 kDa. The insertion of HT led to excellent thermomechanical and UV shielding properties, such as the glass transition temperature (T_g of 47.3 °C) and strength (43 MPa) of PBT₈₀TT₂₀ outdistancing those of PBT. More importantly, the acetal-based HT enabled dual closed-loop recycling pathways for PBT_xTT_y copolyesters via selective cleavage of acetal or ester bonds, allowing the recovery of structures terminated with aldehyde/hydroxyl end groups or PBT. Both recycled products could be repolymerized. Overall, HT is an effective biobased precursor that can prepare PBT-based copolyesters with excellent physical properties and dual closed-loop recyclability.

Effective bone regeneration requires not only robust osteoinduction but also precise immunomodulation to orchestrate the complex healing process. In this study, we present a strategy for engineering multifunctional three-dimensional (3D) stem cell spheroids (Sphe-BP-IL4-BMP2) by integrating black phosphorus (BP) nanosheets coloaded with interleukin-4 (IL-4) together with recombinant human bone morphogenetic protein-2 (rhBMP-2). BP nanosheets served as a biodegradable scaffold and a delivery vehicle, enabling sustained release of rhBMP-2 and IL-4 to enhance osteogenic differentiation and to promote anti-inflammatory M2 macrophage polarization, respectively. The resulting spheroids exhibited a well-defined morphology, enhanced cell viability, and uniform BP nanosheet distribution. The in vitro studies demonstrated Sphe-BP-IL4-BMP2 has significantly upregulated osteogenic markers and ALP activity alongside potent immunomodulatory effects on macrophages. Further in vivo implantation into a rat calvarial defect model led to increased angiogenesis and accelerated bone regeneration without adverse effects. The results highlight the therapeutic synergy between osteoinductive and immunomodulatory cues within a 3D spheroid platform, offering a promising avenue for treating critical-sized bone defects.