Molecular signaling pathways in osteoarthritis and biomaterials for cartilage regeneration: a review

Osteoarthritis is a prevalent degenerative joint disease characterized by cartilage degradation, synovial inflammation, and subchondral bone alterations, leading to chronic pain and joint dysfunction. Conventional treatments provide symptomatic relief but fail to halt disease progression. Recent advancements in biomaterials, molecular signaling modulation, and gene-editing technologies offer promising therapeutic strategies. This review explores key molecular pathways implicated in osteoarthritis, including fibroblast growth factor, phosphoinositide 3-kinase/Akt, and bone morphogenetic protein signaling, highlighting their roles in chondrocyte survival, extracellular matrix remodeling, and inflammation. Biomaterial-based interventions such as hydrogels, nanoparticles, and chitosan-based scaffolds have demonstrated potential in enhancing cartilage regeneration and targeted drug delivery. Furthermore, CRISPR/Cas9 gene editing holds promise in modifying osteoarthritis-related genes to restore cartilage integrity. The integration of regenerative biomaterials with precision medicine and molecular therapies represents a novel approach for mitigating osteoarthritis progression. Future research should focus on optimizing biomaterial properties, refining gene-editing efficiency, and developing personalized therapeutic strategies. The convergence of bioengineering and molecular science offers new hope for improving joint function and patient quality of life in osteoarthritis management.

Biomimetic peptide conjugates as emerging strategies for controlled release from protein-based materials

Biopolymers, such as collagens, elastin, silk fibroin, spider silk, fibrin, keratin, and resilin have gained significant interest for their potential biomedical applications due to their biocompatibility, biodegradability, and mechanical properties. This review focuses on the design and integration of biomimetic peptides into these biopolymer platforms to control the release of bioactive molecules, thereby enhancing their functionality for drug delivery, tissue engineering, and regenerative medicine. Elastin-like polypeptides (ELPs) and silk fibroin repeats, for example, demonstrate how engineered peptides can mimic natural protein domains to modulate material properties and drug release profiles. Recombinant spider silk proteins, fibrin-binding peptides, collagen-mimetic peptides, and keratin-derived structures similarly illustrate the ability to engineer precise interactions and to design controlled release systems. Additionally, the use of resilin-like peptides showcases the potential for creating highly elastic and resilient biomaterials. This review highlights current achievements and future perspectives in the field, emphasizing the potential of biomimetic peptides to transform biopolymer-based biomedical applications.

In vivo toxicity of chitosan-based nanoparticles: a systematic review

Chitosan nanoparticles have been extensively utilised as polymeric drug carriers in nanoparticles formulations due to their potential to enhance drug delivery, efficacy, and safety. Numerous toxicity studies have been previously conducted to assess the safety profile of chitosan-based nanoparticles. These toxicity studies employed various methodologies, including test animals, interventions, and different routes of administration. This review aims to summarise research on the safety profile of chitosan-based nanoparticles in drug delivery, with a focus on general toxicity tests to determine LD50 and NOAEL values. It can serve as a repository and reference for chitosan-based nanoparticles, facilitating future research and further development of drugs delivery system using chitosan nanoparticles. Publications from 2014 to 2024 were obtained from PubMed, Scopus, Google Scholar, and ScienceDirect, in accordance with the inclusion and exclusion criteria.The ARRIVE 2.0 guidelines were employed to evaluate the quality and risk-of-bias in the in vivo toxicity studies. The results demonstrated favourable toxicity profiles, often exhibiting reduced toxicity compared to free drugs or substances. Acute toxicity studies consistently reported high LD50 values, frequently exceeding 5000 mg/kg body weight, while subacute studies typically revealed no significant adverse effects. Various routes of administration varied, including oral, intravenous, intraperitoneal, inhalation, and topical, each demonstrating promising safety profiles.

On the behavior of Hoechst 33258 in DNA-PEG mixtures

Most of the studies on the interaction of fluorescent dyes with DNA have been performed under conditions radically different from those occurring in situ. Among others, this includes diluteness of experimental solutions, their homogeneity, and presence of a large amount of free water. To a certain extent, some model systems can help to approach the biological conditions. Thus, since some features of liquid-crystalline-like packaging of DNA were found in a number of living systems, to shed light on the behavior of Hoechst 33258 in biological-like conditions, we performed a detailed study of its properties in DNA-PEG mixtures, and, in particular, in the dispersed mesophases formed via polymer and salt induced (psi-) condensation. Being in complex with DNA, Hoechst 33258 shows a high sensitivity to the changes in osmotic conditions - the addition of PEG leads to a release of the dye molecules. However, this effect nonlinearly depends on osmolality. Individually, neither PEG nor NaCl at the studied concentrations significantly affect its complex with nucleic acid. The effect is caused precisely by their synergistic action. In cases of the dispersed systems formation, significant fraction of Hoechst 33258 molecules is retained within the resulting particles and is protected even from further increase in osmolality. This is partly due to competition between the processes of the dye releasing and formation of the dispersed particles.

Investigation of the biodegradation kinetics and associated mechanical properties of 3D-printed polycaprolactone during long-term preclinical testing

Polycaprolactone (PCL) is a bioresorbable polymer increasingly utilized for customized tissue reconstruction as it is readily 3D printed. A critical design requirement for PCL devices is determining the in vivo bioresorption rate and the resulting change in device mechanics suited for target tissue repair applications. The primary challenge with meeting this requirement involves accurate prediction of degradation in the target tissues. PCL undergoes bulk hydrolytic degradation following first order kinetics until an 80-90 % drop in the starting number average molecular weight (Mn) after 2-3 years in vivo. However, initial polymer architecture, composite incorporation, manufacturing modality, device architecture, and target tissue can impact degradation. In vitro models do not fully capture device degradation, and the limited long-term (2-3 year) models primarily utilize subcutaneous implants. In this study, we investigate the degradation rate of 3D-printed airway support devices (ASDs) comprised of PCL and 4 % hydroxyapatite (HA) when implanted on Yucatan porcine tracheas for two years. After one year of degradation, we report a mass loss of less than 1 % and Mn reduction of 25 %. After two years, mass and Mn decreased by 10 % and 50 % respectively. These changes are accompanied by an increase in elastic modulus from 146.7 ± 5.2 MPa for freshly printed ASDs to 291.7 ± 16.0 MPa after one year and 362.5 ± 102.4 MPa after two years. Additionally, there was a decrease in yield strain, and increase in yield stress from implantation to 1-year (p < 0.001). Plastic strain completely diminished by two years, resulting in brittle failure at a yield stress of 12.5 MPa. The significantly lower rate of hydrolysis coupled with hydrolytic embrittlement indicates alternate degradation kinetics compared to subcutaneous models. Fitting a new model for degradation and predicting elastic and damage properties of this new degradation paradigm provide significant advancements for 3D-printed device design in clinical repair applications.

Redox-active graphene dispersant and its ability to improve the conductivity and pseudo-capacitance of carbon film

HYPOTHESIS

Strong van der Waals force and π-π interaction make graphene difficult to be uniformly distributed in basic matrix for fabricating graphene-based composites. Employing dispersant is a major solution, however, current existing dispersants such as commercially available surfactants and polymer stabilizers scarcely provide ideal effect. Besides, they are always "useless" in final composites but difficult to remove. Therefore, endowing dispersant with specific property that matching the application of the final composite is essential.

EXPERIMENTS

Herein, a redox-active graphene dispersant (RAGD) is developed based on the grafting of p-phenylenediamine (PDA) with epoxy groups and further reacting with ethylamine. Homogeneous aqueous graphene dispersion is prepared by tip-sonication, and uniform graphene-based films are prepared via vacuum filtration method.

FINDINGS

Graphene can be homogenously dispersed in water with concentration up to 15 mg mL-1 in the presence of RAGD, and it can stably exist at room temperature for over six months. The π-π interaction of RAGD with graphene is tunable due to the PDA conjugated center is redox-active, and RAGD can be partially eliminated from graphene under alkali treatment. The electrical conductivity of the graphene film increases by about 34% after treated by 1 mol L-1 NH3·H2O. Additionally, the graphene-based film including RAGD also shows much higher specific charge capacitance than those made with commonly used surfactants.

Facile approach developed for low-pressure separation of ethanol-water using cellulose membrane grafted with acrylic polyelectrolyte

Conventional ethanol separation from low-concentration aqueous solutions is energy-intensive and can affect flavor, highlighting the need for efficient, economical alternatives. This study presents a selective, porous polyelectrolyte membrane fabricated by grafting polyacrylate salt (PAS) onto regenerated cellulose membranes using surface-initiated atom transfer radical polymerization (SI-ATRP). The pH-responsive PAS layer enables tunable selectivity, achieving ethanol rejection rates up to 80 % for 15 vol% ethanol solutions at pressures ≤ 0.2 MPa which shows improved comprehensive separation performance and development potential compared to commercial separation membranes. In addition, molecular dynamics simulations (MDS) reveal the interactions of polyelectrolyte chain behavior and ethanol-water molecules, as well as free volume changes drive separation. This green, scalable fabrication strategy offers a potential and promising pathway for ethanol/water separation, which is desirable for applications in areas such as efficient bioethanol dehydration and processing of low-content alcoholic beverages.

High-performance piezoelectric flexible nanogenerators based on GO and polydopamine-modified ZnO/P(VDF-TrFE) for human motion energy capture, shared bicycle nanoenergy harvesting, and self-powered devices

Traditional inorganic/organic composite piezoelectric films suffer from cracking and a poor dispersion of inorganic fillers, which degrades performance. In this study, zinc oxide nanoparticles (ZnO NPs) were surface-modified with polydopamine (PDA) to obtain PDA-coated ZnO NPs (PDA@ZnO NPs). Then, graphene oxide (GO) in different proportions and these PDA@ZnO NPs were used to prepare GO-PDA@ZnO/polyvinylidene difluoride-trifluoroethylene (P(VDF-TrFE)) piezoelectric nanohybrid films. An appropriate GO content was found to significantly enhance the piezoelectric performance of the material. The GO-PDA@ZnO/P(VDF-TrFE) piezoelectric nanohybrid films exhibited superior properties for use in a flexible piezoelectric nanogenerator (FPENG), which could effectively harvest mechanical energy from human activities and convert it into electrical energy. Furthermore, FPENG showed excellent prospects for applications in wearable electronic products and as an energy harvester for shared bicycles. The high-performance FPENG designed in this study provides a novel strategy for realizing diverse energy harvesting.

Versatile corn starch-based sustainable food packaging with enhanced antimicrobial activity and preservative properties

Biodegradable active packaging has garnered significant research interest owing to growing concerns over plastic pollution and food safety. However, current food packaging materials still suffer from drawbacks such as complex synthesis processes, high production costs, and inadequate safety performance in terms of antimicrobial resistance and biodegradability. Typically, their performance in preserving fresh food is also inferior to that of plastics. Herein, a versatile corn starch-based sustainable food packaging (DC) was proposed, utilizing natural corn starch (CS) and carboxymethyl chitosan (CMCS) as raw materials. The focus was on evaluating the mechanical properties, antioxidant properties, and antimicrobial activity, and to further explore the degradability and biocompatibility of the DC films, as well as their application in fruit preservation. The results confirmed the good water vapor barrier properties, antioxidant activity (DPPH scavenging of the DC4 film reached 98.10 ± 0.32 %), Ultraviolet (UV) resistance (more than 99.8 % absorption of both UV-A and UV-B radiation), water resistance, mechanical properties, and bacteriostatic and bactericidal effect (the DC4 film reached 99.67 ± 0.58 % against Escherichia coli and 99.83 ± 0.29 % against Staphylococcus aureus) of the DC. Meanwhile, the DC exhibited favorable biodegradability in the natural environment. Finally, fruit preservation experiments confirmed that the DC could significantly extend the shelf life of fresh fruits at room temperature. Overall, this research presented a sustainable and cost-effective biomass-derived packaging film that could replace conventional petroleum-based plastics, thereby reducing environmental pollution and showing significant potential for use in food packaging.

A PEG-based strategy to improve detection of clinical microRNA 155 by bio-Field Effect Transistor in high ionic strength environment

microRNAs are small oligonucleotides involved in post-transcriptional gene regulation whose alteration is found in several diseases, including cancer, and therefore their detection is crucial for diagnosis, prognosis, and treatment purposes. Field-Effect Transistor-based biosensors (bioFETs) represent a promising technology for the clinical detection of microRNAs. However, one of the main challenges associated with this technology is the Debye screening, becoming significant at the high ionic strengths required for effective hybridization. We aimed at detecting oncogenic microRNA-155 by using a bioFET system using as capture element a complementary RNA probe (antimiR-155) combined with the introduction of PEG molecules (20 kDa, PEG20), at an ionic strength of 300 mM. We optimized the co-immobilization ratio between antimiR-155 and PEG20 and assessed its impact on the interactions between the oligonucleotides. The kinetics can be well described by the Langmuir-Freundlich isotherm with an affinity constant within the range typical of nucleic acid interactions. The introduction of PEG20 significantly enhanced the detection sensitivity of miR-155 by reaching a level of less than 200 pM, together with excellent discrimination against other clinically relevant microRNAs. Our findings demonstrate that the incorporation of PEG20 constitutes an effective strategy to mitigate the Debye screening effects and facilitates bioFET-based clinical applications at physiological ionic strengths.

Engineered ratiometric Sensory electrospun fibers for oxygen mapping in complex cultures and tumor microenvironment

Monitoring the hypoxic microenvironment is fundamental due to its implication in tumor aggressiveness and progression. In this work, we propose the fabrication of ratiometric fluorescent fibers via electrospinning of poly(trimethylsylil)propine (PTMSP) polymer, an optically clear and gas permeable polymer, for oxygen (O2) sensing in a melanoma tumor model. The ratiometric sensing configuration was obtained by entrapping tris(4,7-diphenyl-1,10-phenanthroline) ruthenium (II) dichloride, capable of detecting dissolved O2 variations, together with rhodamine B isothiocyanate, serving as a reference dye, within the polymer matrix. The fibers were characterized to point out morphology, porosity, and hydrophilicity. The sensing ability of the fibrous mat was deeply investigated by means of microplate reader and confocal imaging, showing a strict correlation between the fluorescent ratiometric read-out and the increasing concentration of dissolved O2 in aqueous-based media. Moreover, the fibers exhibited high photostability, reversibility and excellent cytocompatibility, allowing monitoring O2 gradients over time and space in vitro melanoma co-cultures. Overall, the optimized micrometric sensing system holds potential for real-time assessments of dissolved O2 levels in vitro complex cell systems and heterogeneous tumour microenvironments, and can open up new engineering possibilities by means of using O2-sensitive dyes in tissue engineering scaffolding strategies.

High-contrast electrochromic nano fiber films changing from yellow-green to black based on butterfly monomer for smart windows and self-adaptive camouflage

High contrast electrochromic (EC) materials have attracted much attention due to their great potential for applications in fields such as electronic displays, smart windows (thermal management) and adaptive camouflage. However, obtaining EC materials with high contrast and long term stability is still a challenge. Herein, we designed and synthesized a butterfly (large planar core-distorted periphery) diamine monomer (DCTPA-NH2) by fusing two triphenylamine (TPA) units on edge of 7H-dibenzocarbazolyl, and prepared four polyamides (PAs) through polycondensation of the monomer with different diacids, which exhibit excellent solution processability, thermal stability, electrochemical redox reversibility. The PAs aggregate to form fibrous film. Among them, the fibrous DCTPA-SA film exhibits high contrast in visible regions (optical contrast of 85 % at 960 nm and 63 % at 555 nm) and near infrared region, fast voltage-optical response (coloring time/bleaching time, 1.5 s/2.0 s), high coloring efficiency (241 cm2 C-1), and good cycling stability (optical contrast after 500 cycles is 76 % of the initial one) due to fast diffuse of ions. In addition, DCTPA-CA exhibits fluorescence (PL) quantum efficiency up to 30.1 % and is sensitive to trinitrophenol (TNP), which is expected to be applied in explosives detection. At last, DCTPA-SA fibrous film device was fabricated for EC devices, smart windows and self-adaptive camouflage models, showing promising application.

Morphological advances and innovations in conjugated polymer films for high-performance gas sensors

Conjugated polymers (CPs) are considered one of the most important gas-sensing materials due to their unique features, combining the benefits of both metals and semiconductors, along with their outstanding mechanical properties and excellent processability. However, CPs with conventional morphological structures, such as largely amorphous and bulky matrices, face limitations in practical applications because of their inferior charge transport characteristics, low surface area, and insufficient sensitivity. Therefore, the design and development of novel morphological nanostructures in CPs have attracted significant attention as a promising strategy for improving morphological and electrical characteristics, thereby enabling a considerable increase in the sensing performance of corresponding gas sensors. Numerous CP nanostructures have been developed and implemented for high-performance gas sensors. Highlighting the morphological advances and bottlenecks of these nanostructures is crucial for providing an overview of developing trends, potential strategies, and emerging areas for the future development of CP nanostructures in the field. In this regard, this study describes state-of-the-art CP nanostructures, emphasizing their attractive morphological and electrical characteristics to help readers and researchers better understand emerging trends, promising future directions, and key obstacles for the application of CP nanostructure-based gas sensors. The most crucial aspects of CP nanostructures, including advanced preparation techniques, morphological properties, and sensing characteristics, are discussed and assessed in detail. Moreover, development strategies and perspectives for achieving high sensing efficiency in CP nanostructure-based flexible and wearable sensors are summarized and emphasized.

Salt-induced gelation of nonionic sucrose ester dispersions

HYPOTHESIS

The dispersions of nonionic sucrose ester surfactants in water exhibit a highly negative zeta-potential, though its origin remains controversial. The addition of electrolytes to these dispersions may influence their zeta-potential, thus potentially affecting their physicochemical properties.

EXPERIMENTS

The electrolyte- and pH- driven gelation of aqueous dispersions of commercial sucrose stearate (S970) containing ca. 1:1 monoesters and diesters was studied using optical microscopy, rheological and zeta-potential measurements, and small-angle X-ray scattering techniques.

FINDINGS

At low electrolyte concentrations and pH ≳ 5, 0.5-5 wt% S970 dispersions exhibited low viscosities and behaved as freely flowing liquids. The addition of electrolytes of low concentrations, e.g. 9 mM NaCl or 1.5 mM MgCl2, induced the formation of a non-flowing gels. This sol-gel transition occurred due to the partial screening of the diesters particles charge, allowing the formation of an attractive gel network, spanning across the dispersion volume. Complete charge screening, however, led to a gel-sol transition and phase separation. Gel formation was observed also by pH variation without electrolyte addition, whereas the addition of free fatty acids had negligible impact on dispersion properties. These findings support the hypothesis that the negative charge in sucrose ester dispersions arises from hydroxyl anions adsorption on particles surfaces. Gels were formed using just 1.3 wt% surfactant, and the critical electrolyte concentration for gelation was found to scale approximately with the square of the cation charge, in agreement with the low surface charge density theory. The biodegradable sucrose esters gels offer a sustainable alternative for structuring personal and home care products, replacing the wormlike micelles of synthetic surfactants typically used at much higher surfactant and salt concentrations.

Adaptive microgel films with enhancing cohesion, adhesion, and wettability for robust and reversible bonding in cultural relic restoration

Hydrogel adhesives hold significant promise for applications in flexible intelligent systems and biomedical engineering. However, reconciling high toughness with strong, durable, and repeatable interfacial adhesion remains a daunting challenge. Herein, a new strategy was proposed involving the utilization of physically crosslinked microgels to fabricate a high-toughness adhesive microgel film, optimizing cohesion, adhesion, and wettability to significantly enhance interfacial adhesion performance. The microgels were synthesized using polyzwitterions and acrylic acid through inverse emulsion method, leveraging on their intrinsic ability to readily form abundant non-covalent interactions. The resultant microgel-based adhesive film, formed through physical crosslinking and chain entanglement mechanisms, exhibited a tensile strength of 0.34 MPa, an exceptional elongation at break of 1107.79 %, and a toughness of 2842.17 kJ/m3. Furthermore, this adhesive film demonstrated a remarkable adhesive strength of 1740.9 kPa, with its adhesion performance retaining stable and effective even under extreme environmental conditions, including elevated temperatures and complete submersion in aqueous environments. In contrast to conventional hydrogel adhesives, this microgel system achieves superior mechanical robustness, interfacial adhesion, and environmental resistance, highlighting their promising potential candidate for applications in cultural heritage conservation.

Polyaniline-based hybrid membrane for single-molecule protein nanopore analysis under high voltage

In vitro reconstituted lipid bilayers are the key to the birth of bio-nanopore technology, although they are fragile and inadequately stable for long-term monitoring applications. Amphiphilic copolymers with high robustness have been developed to circumvent this issue. However, it remains a major challenge to achieve the required fluidity for protein insertion. Here we engineered a polyaniline-based hybrid membrane (PANIM) that exhibits the stability needed for fabricating high-throughput biosensors. This enhanced durability enables prolonged operation without compromising the functional properties of embedded α-hemolysin (α-HL) nanopores. Based on this, we demonstrate high voltage analysis for G-triplex conformations through α-HL in PANIM, which facilitates in-depth study of molecular conformations and provides a novel platform that has great potential for nanopore sensing.

Advancements in membrane technology for efficient POME treatment: A comprehensive review and future perspectives

The treatment of POME related contamination is complicated due to its high organic contents and complex composition. Membrane technology is a prominent method for removing POME contaminants on account of its efficiency in removing suspended particles, organic substances, and contaminants from wastewater, leading to the production of high-quality treated effluent. It is crucial to achieve efficient POME treatment with minimum fouling through membrane advancement to ensure the sustainability for large-scale applications. This article comprehensively analyses the latest advancements in membrane technology for the treatment of POME. A wide range of membrane types including forward osmosis, microfiltration, ultrafiltration, nanofiltration, reverse osmosis, membrane bioreactor, photocatalytic membrane reactor, and their combinations is discussed in terms of the innovative design, treatment efficiencies and antifouling properties. The strategies for antifouling membranes such as self-healing and self-cleaning membranes are discussed. In addition to discussing the obstacles that impede the broad implementation of novel membrane technologies in POME treatment, the article concludes by delineating potential avenues for future research and policy considerations. The understanding and insights are expected to enhance the application of membrane-based methods in order to treat POME more efficiently; this will be instrumental in the reduction of environmental pollution.

Supramolecular assembly of multi-purpose tissue engineering platforms from human extracellular matrix

Recapitulating the biophysical and biochemical complexity of the extracellular matrix (ECM) remains a major challenge in tissue engineering. Hydrogels derived from decellularized ECM provide a unique opportunity to replicate the architecture and bioactivity of native ECM, however, they exhibit limited long-term stability and mechanical integrity. In turn, materials assembled through supramolecular interactions have achieved considerable success in replicating the dynamic biophysical properties of the ECM. Here, we merge both methodologies by promoting the supramolecular assembly of decellularized human amniotic membrane (hAM), mediated by host-guest interactions between hAM proteins and acryloyl-β-cyclodextrin (AcβCD). Photopolymerization of the cyclodextrins results in the formation of soft hydrogels that exhibit tunable stress relaxation and strain-stiffening. Disaggregation of bulk hydrogels yields an injectable granular material that self-reconstitutes into shape-adaptable bulk hydrogels, supporting cell delivery and promoting neovascularization. Additionally, cells encapsulated within bulk hydrogels sense and respond to the biophysical properties of the surrounding matrix, as early cell spreading is favored in hydrogels that exhibit greater susceptibility to applied stress, evidencing proper cell-matrix interplay. Thus, this system is shown to be a promising substitute for native ECM in tissue repair and modelling.

Bioactive polymers as stimulus-responsive anti-metastatic combination agents to treat pancreatic cancer

The intractable and devastating nature of pancreatic ductal adenocarcinoma (PDAC) necessitates an urgent need for novel therapies. This study presents the development of a novel polymer prodrug system for the combination treatment of PDAC, based on an optimized pharmacologically active anti-metastatic macromolecular carrier, PCQ, conjugated with gemcitabine (GEM). Structure-activity relationship evaluations showed that random PCQ copolymers exhibited superior anti-migratory activity compared to the gradient PCQ analogs. GEM was incorporated into the random PCQ copolymers using disulfide linker to prepare a reduction-responsive prodrug, PCQ(r)6-SS-GEM12. The resultant therapeutic system presents a pharmacologically active delivery strategy that targets both the proliferative and the metastatic phenotype in PDAC. The PCQ(r)6-SS-GEM12 prodrug demonstrated a selective release of GEM under the reductive tumor environment leading to a significant inhibition of tumor growth with pronounced anti-metastatic effect. Collectively, our data show that the combination of anti-metastatic PCQ and cytotoxic GEM-based reduction-responsive prodrug polymer offers an innovative strategy to treat PDAC.

A multi-modal embolic gel system for long-term fluorescence imaging and photothermal therapy

Gel embolic agents are increasingly recognized for their versatility in minimally invasive vascular interventions. However, their application in real-time imaging, post-operative monitoring, and thermal treatment remains underexplored. In this study, we present a novel transcatheter injectable nanoclay-alginate (NCA) gel embolic agent integrated with indocyanine green (ICG) for dual fluorescence imaging and thermal ablation. The NCA/ICG embolic gel exhibits excellent shear-thinning properties, transcatheter injectability, and mechanical stability. Furthermore, the mechanism to enhance fluorescence for real-time imaging enhancement and extended post-operative monitoring was discussed. A 28-day fluorescence persistence shows the NCA/ICG gel's long-lasting fluorescent signal, which was significantly stronger and longer compared to current clinically used ICG aqueous solution. Furthermore, the gel can effectively convert near-infrared (NIR) laser energy into heat for potential photothermal therapy. The biocompatibility and enhanced antibacterial properties further highlight the potential clinical benefits of this embolic agent as a multifunctional agent for vascular embolization.

Tetrabutylammonium hydroxide and zinc salts in cellulose-based colloidal systems enhance fruit shelf life

This study explores the development of cellulose-based active colloidal systems to enhance the antimicrobial properties of absorbent food pads and prolong the shelf life of cherry tomatoes. Food pads impregnated with colloidal systems made of microcrystalline cellulose dissolved in tetrabutylammonium hydroxide (TBAH) with zinc salts (ZnCl2 and ZnSO4) were tested for their antifungal efficacy. In vitro results revealed complete fungal suppression by TBAH alone and in combination with ZnCl2. The interaction between TBAH and ZnSO4 exhibited synergistic antifungal activity, while an additive effect was observed with ZnCl2. In vivo tests showed a significant reduction in fruit rot, with ZnCl₂-treated pads reducing rot by 91 % after 14 days. TBAH was partially bound to cellulose chains, minimizing the risk of fruit contamination, as confirmed by 1H nuclear magnetic resonance.

Oriented structure design of pectin/Ag nanosheets film with improved barrier and long-term antimicrobial properties for edible fungi preservation

Improving the antimicrobial control, barrier properties, and mechanical performance of bio-based food packaging materials is crucial for advancing their practical applications. In this study, oriented pectin/Ag nanosheet composite films were fabricated using a uniaxial stretching method. By adjusting the stretching ratio, the horizontal alignment of Ag nanosheets and pectin chains was promoted, resulting in increased crystallinity and orientation of the composite films. The stretching orientation improved the tensile strength and anti-UV capability of the composite films. In particular, the gas permeability was further reduced. The Pec/PAg-S30 % composite films, with a 30 % stretching ratio, exhibited more than a 70 % improvement in water vapour and oxygen barrier properties compared to pure pectin films. Additionally, the stretching orientation effect slowed and reduced Ag+ release, contributing to the long-term antimicrobial effect of the composite films. The films demonstrated excellent biosafety and effectively delayed the browning and spoilage of Agaricus bisporus.

High through-plane thermal conductivity of graphite films with opened micro-window arrays

Graphene's ultrahigh in-plane thermal conductivity makes it an ideal material for thermally conductive films in various electronic applications. However, the inherently weak interlayer interaction in conventional graphite films (GrF) results in low through-plane thermal conductivity. Here, we firstly developed a novel structure of opened micro-window arrays in the graphite film (MW-GrF) to significantly enhance the through-plane thermal conductivity by the laser-etching-assisted and micro-origami methods. The opened micro-window arrays are acted as bridges to promote interfacial thermal transport via utilizing the ultrahigh in-plane thermal conductivity of micro-windows, which can achieve a reduction of ∼ 60 % in through-plane thermal resistance, with the lowest value of 0.286 K cm2 W-1. Meanwhile, the through-plane thermal conductivity of MW-GrF was greatly improved to 82.4-89.6 W m-1 K-1 compared to the original GrF with 4.4-6.9 W m-1 K-1. This work provides a simple, scalable and programmable method for finely tailoring the through-plane thermal properties of graphene films, making them promising candidates for highly efficient heat dissipation in future high-power chips.

Preparation of zein-rutin supramolecular nanoparticles using pH-ultrasound-shifting: binding mechanism, functional properties, and in vitro release kinetics

The limited solubility of rutin necessitates the development of efficient delivery systems. This study developed zein-rutin supramolecular nanoparticles (Z-R-P-U) using a pH-ultrasound-shifting method, achieving high encapsulation efficiency (87.89 ± 1.28 %) and loading capacity (23.97 ± 0.56 %). Multispectral analysis and molecular docking results indicated that hydrogen bonding, van der Waals forces, and hydrophobic interactions are the dominant supramolecular forces in the binding between zein and rutin. Z-R-P-U exhibited a uniform spherical structure with a particle size of approximately 150 nm, maintaining stability below 200 nm after 28 days of storage. Compared to free rutin, Z-R-P-U increased solubility by 9.2 times and significantly enhanced antioxidant activities, including DPPH scavenging capacity (10.26 %), ABTS+ scavenging capacity (12.23 %), and ferric-reducing antioxidant power (31.43 %). Additionally, bioaccessibility improved notably, and in vitro release followed first-order kinetics governed by Fickian diffusion. This method efficiently encapsulates polyphenols, offering novel strategies for their application in food and pharmaceutical industries.

Reprogrammable soft actuators based on a photochromic organic-inorganic hybrid membrane with modulatable NIR photothermal conversion

Shape-transformation soft actuators that can quickly respond to external stimuli have been potential candidates in biomimetic soft robots and flexible driving devices. However, the lack of shape reprogrammability restricts their complexity of deformation as well as reusability in practical application. Herein, we present a unique reprogrammable actuator based on asymmetric bilayer compounding with UV-modulated photochromic complex (NEU20) through a sequential polymerization process. The UV-induced electron transfer photochromic behavior synergistic with NIR photothermal effect of NEU20 fillers endows the soft actuator with rapid (∼90°/s) and customizable actuation under external NIR stimuli. Through the joint modulation of UV exposure region and duration, the UV-induced photothermal conversion efficiency is also adjustable at each local, facilitating the spatio-temporally programmable actuation process of the hybrid bilayer actuator. Significantly, the programmed actuation process of the actuator also features thermal-erasing and UV-reprogramming capacities, highlighting the unique recyclability of the hybrid actuator. In addition, the proposed reprogrammable actuator also demonstrates good universality in combination with other thermal-responsive active material systems. This work offers insight into the design and fabrication of reprogrammable soft actuators, shining enlightenment for potential application in bioinspired soft robots and smart mechanical devices.

Raman structural analysis of L-lactide/ε-caprolactone copolymers and poly(L-lactide)/poly(ε-caprolactone) blends

We present Raman study of the L-lactide/ε-caprolactone (PLCL) copolymers with the L-lactide (LLA) content from 10 to 90 mol %. The copolymers were synthesized by bulk ring-opening polymerization. As additional method, we used the wide-angle X-ray scattering analysis to obtain the crystallinity degree of the poly(L-lactide) (PLLA) and poly(ε-caprolactone) (PCL) blocks. We extend the previously proposed method of determination of the crystallinity degree of PLLA areas in the PLCL copolymers up to the ε-caprolactone (CL) content of 50 mol %. The method includes analysis of the ratio of the peak intensities of the PLLA bands at 411 and 874 cm-1. We also suggest for the first time using the PCL bands at 958 and 1110 cm-1 to evaluate the crystallinity degree of PCL blocks in the PLCL copolymers. Besides, we extend the previously proposed method of evaluation of the relative contents of the comonomers in the PLCL copolymers to the whole range of the CL content as well as to analysis of melt-mixed PLLA/PCL blend. The method is based on the measurement of the ratio of the peak intensities of the PLLA band at 2947 cm-1 and the PCL band at 2914 cm-1.

Investigation on the interaction between catalase and typical phthalates with different side chain lengths

Phthalates (PAEs), a category of plasticizers released from plastic products, have been widely detected in various environmental media and pose potential ecological risks to humans. Although the exposure risks of PAEs to organisms have been studied, the differences in the interactions between PAEs with different side chain lengths and biomolecules remain poorly understood at molecule levels. In this study, three commonly used PAEs (dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP)) were employed to investigate the influence of their side chain lengths on interactions with catalase (CAT), a key antioxidant enzyme. The effects of PAEs on CAT enzyme activity and their interaction mechanisms were investigated using multi-spectral technique and molecular docking techniques. The results indicate that the order of reduced enzyme activity by PAEs is DMP > DEP > DBP, which inversely correlates with the alkyl chain length of PAEs. Molecular docking analysis reveal that DBP failing to bind to the central cavity of CAT likely contributes to its minimal impact on enzyme activity. The multiple spectrums demonstrate that the binding affinity of PAEs to CAT and the changes of CAT conformational structure align with the observed decline in enzyme activity as alkyl chain length increased. Since enzyme activity ties to its structure, the structural alterations in CAT induced by PAEs would inevitably affect its functional expression in vivo. This study offers a comprehensive assessment on the possible toxicity of PAEs with different side chain lengths at the molecular levels, providing insights into their ecological risks.

Cationic lipid-polymer hybrid carrier for delivery of miRNA and peptides

The clinical translation of therapeutic peptides and miRNAs is hindered by challenges such as short half-life, rapid clearance, and high dosage requirements. To address these limitations, cationic polymeric nanoparticles have been explored, but their development is often limited by toxicity and low transfection efficiency. In this study, we present a novel biocompatible delivery system using a combination of cationic and cholesterol-containing polymers to overcome these issues. The system was formulated into nanocomplexes (NCs) for the delivery of C Peptide (CPep) and miRNA-29b (miR29b). The formulation process involved electrostatic complexation of CPep/miR29b with the polymeric carriers, avoiding harsh conditions or chemical modifications. Native-PAGE, gel retardation, and heparin competition assays confirmed stable complexation. Cell uptake and transfection studies showed efficient delivery of both CPep and miR29b via NCs. In vitro models of oxidative and metabolic stress demonstrated enhanced cell viability with CPep NCs compared to free CPep, with increased glutathione and reduced nitric oxide levels. Similarly, miR29b NCs exhibited potent anti-inflammatory effects compared to free miR29b. This study presents a promising polymer-based carrier system for effective peptide and miRNA delivery through electrostatic interactions alone without any chemical reaction involved to preserve the integrity of the therapeutic.

Application of biodegradable implants in pediatric orthopedics: shifting from absorbable polymers to biodegradable metals

Over the past two decades, advances in pediatric orthopedics and closed reduction combined with percutaneous internal fixation techniques have led to significant growth in pediatric orthopedics surgery. Implants such as Kirschner-wires, cannulated screws and elastic stabilization intramedullary nails are commonly used in these procedures. However, traditional implants made of metal or inert materials are not absorbable, leading to complications that affect treatment outcomes. To address this issue, absorbable materials with excellent mechanical properties, good biocompatibility, and controlled degradation rates have been developed and applied in clinical practice. These materials include absorbable polymers and biodegradable metals. This article provides a comprehensive summary of these resorbable materials from a clinician's perspective. In addition, an in-depth discussion of the feasibility of their clinical applications and related research in pediatric orthopedics is included. We found that the applications of absorbable implants in pediatric orthopedics are shifting from absorbable polymers to biodegradable metals and emphasize that the functional characteristics of resorbable materials must be coordinated and complementary to the treatment in pediatric orthopedics.

Advanced 3D biomimetic scaffolds with bioactive glass and bone-conditioned medium for enhanced osteogenesis

The study focuses on developing and evaluating 3D biomimetic fibrous scaffolds to enhance osteoblast differentiation and bone tissue regeneration. Utilizing a synergistic approach, biological and chemical factors were compartmentalized within the fibrous scaffolds through co-axial electrospinning. Bioactive glass (BG) was used for osteo-conductivity, and Bone-Conditioned Medium (BCM) for osteoinduction. The BCM, derived from ovine bone chips, was investigated for its optimal concentration using pre-osteoblast cells. Comprehensive assessment of the scaffolds included physicochemical properties, drug release, cell viability, and osteogenic potential. The scaffold's architecture, confirmed by Scanning electron microscopy (SEM) analysis, effectively emulated the natural extracellular matrix (ECM). Energy Dispersive X-ray Spectroscopy (EDX) and Fourier Transform Infrared Spectroscopy (FTIR) analyses verified the successful integration of BG and BCM, while UV-Vis spectroscopy demonstrated controlled BCM release. Both BG and BCM scaffolds notably enhanced osteoblast differentiation, as evident with Alizarin red staining. The combined use of BG and BCM in scaffolds synergistically promoted osteogenic differentiation and viability of MC3T3-E1 cells. Furthermore, these scaffolds significantly increased the expression of Bone Sialoprotein (BSP), Osteocalcin (OCN), and Runt-related transcription factor 2 (RUNX2) which indicate increase in osteogenic differentiation. This study provides evidence for advanced scaffold systems that can guide cell responses for effective bone tissue regeneration.

A novel multifunctional self-assembled nanocellulose based scaffold for the healing of diabetic wounds

The healing of chronic diabetic wounds remains a key challenge due to its susceptibility to bacterial infection, the inflammatory wound microenvironment, and difficulty in angiogenesis. Herein, we devised a smart scaffold of nanocellulose with silk fibroin-loaded cerium oxide nanoparticles for the treatment of diabetic wounds. The smart scaffold dressing displays excellent porosity, water absorption, air permeability, water retention, controlled degradability, and antioxidant properties. In vitro experiments demonstrated that the scaffold was capable of promoting the degradation of the scaffolds through uncross linking and exhibited antibacterial activity against both Gram-positive (S. aureus) and Gram-negative (E. coli) bacteria. Furthermore, in vivo experiments showed that smart scaffold dressing can reduces inflammation at the wound site of diabetic mice and promote collagen deposition, angiogenesis and re-epithelialization during wound healing in diabetic mice, exhibiting favorable biocompatibility and biodegradability. Its efficacy surpassed that of the current commercially available membrane dressings (3 M dressings) and medical PELNAC dressings (Class III medical device). These findings suggest that the smart scaffold dressing is a promising and innovative dressing for the treatment of diabetic wounds.

Novel guaiacol-based high-performance dimethacrylate containing fluorenyl cardo structure for dental restorative resins

In dentistry, the use of bisphenol A glycidyl methacrylate (Bis-GMA) is being questioned since bisphenol A is regarded as an endocrine disruptor. As alternative candidates to Bis-GMA, bio-based dental resins face the crucial challenge of low mechanical strength and high water sorption. In this study, a novel guaiacol-based dimethacrylate containing fluorenyl cardo-structure was developed to effectively improve the hydrophobicity, enhance the mechanical properties, and reduce the polymerization shrinkage of bio-based dental restorative resins. Therefore, 9, 9-bis(3-methoxy-4-glycerolate methacrylate)fluorene (BMHF-GMA) was synthesized from a new guaiacol-based bisphenol, 9, 9-bis(3-methoxy-4-phenol)fluorene (BMHF), which is a lower estrogenic activity bisphenol monomer than commercial bisphenols from the results of cell proliferation test. The experimental dental resin (5 MHMA5T) was prepared containing BMHF-GMA and triethylene glycol dimethacrylate in a 1:1 ratio. The control group (5B5T) replaced BMHF-GMA completely with Bis-GMA. Evaluation of both dental resins revealed that 5 MHMA5T possessed comparable double bond conversion (>50 % in 20 s), better volumetric polymerization shrinkage (7.19 ± 0.09 %), shrinkage stress (0.92 ± 0.01 MPa in 1200 s), water sorption (39.9 ± 0.52 μg mm-3), water solubility (0.99 ± 0.04 μg mm-3) and lower cytotoxicity compared with 5B5T. 5 MHMA5T had superior mechanical properties (flexural strength: 122.30 ± 5.00 MPa; flexural modulus: 3.49 ± 0.02 GPa; Vickers hardness number: 25.21 ± 0.56 HV). Especially, after water immersion, it still maintained adequate mechanical properties (flexural strength: 97.34 ± 5.00 MPa; flexural modulus: 2.92 ± 0.02 GPa; Vickers hardness number: 19.33 ± 0.61 HV). Therefore, the new dimethacrylate BMHF-GMA shows great potential in complex and wet oral environments and offers a promising alternative to Bis-GMA in dental restorative resins.

Innovative approaches in bioadhesive design: A comprehensive review of crosslinking methods and mechanical performance

In biomedical applications, bioadhesives have become a game-changer, offering novel approaches to tissue engineering, surgical adhesion, and wound healing. This comprehensive review paper provides a thorough analysis of bioadhesives and their categorization according to application site and crosslinking process, bonding efficacy, and mechanical characteristics. The use of bioadhesives to stop bleeding and seal leaks is also covered in the review. The article delves into the various crosslinking techniques used in bioadhesives, including chemical, physical, and hybrid approaches. It emphasizes on how these mechanisms control the adhesive's elasticity, durability, and structural integrity. In addition, the review looks at the mechanical strength of bioadhesives, taking important characteristics like shear strength, toughness, elasticity, and tensile strength into account. It is highlighted how important bioadhesives are to the life sciences because they drive innovation and interdisciplinary cooperation, address present healthcare issues, and create new avenues for therapeutic development. The paper also explores some vital characteristics of bioadhesives that, when strategically combined with one another, improve their efficacy and usefulness in a variety of surgical and medical applications. The analysis concludes by examining nature-inspired adhesives, including those based on geckos, mussels, and tannic acid, and their unique bonding mechanisms and potential for use in advanced biomedical applications.

Poly(lactide acid)-based microneedles enhanced by tunicate cellulose nanocrystals for potential diabetic periodontitis treatment

Diabetic periodontitis, characterized by persistent inflammation and impaired periodontal tissue regeneration under hyperglycemic conditions, urgently requires innovative therapeutic strategies. Microneedle (MN) technique has recently emerged as a promising solution for diabetic periodontitis by enabling minimally invasive and localized drug delivery. In this study, we developed poly(lactic acid) (PLA)-based MNs reinforced with PLA-grafted tunicate cellulose nanocrystals (TCNC-g-PLA@PLA-MNs), demonstrating favorable mechanical strength and biocompatibility. After loading with irisin and interleukin-1 (IL-1) receptor antagonist (IL-1ra) via surface polydopamine functionalization, the MNs exhibited anti-inflammatory effects by markedly reducing the expressions of IL-6 by 0.53-fold, IL-8 by 0.23-fold, and MCP-1 by 0.41-fold in human periodontal ligament cells (hPDLCs). Additionally, they significantly promoted osteogenic differentiation, increasing the expressions of ALP by 1.87-fold, OPN by 2.21-fold, OCN by 1.39-fold, and Runx2 by 2.28-fold, which was further supported by enhanced ALP staining. Furthermore, the MNs improved the migration ability of hPDLCs under inflammatory and high-glucose culture conditions. Our findings highlight that the TCNC-g-PLA@PLA-MNs effectively integrate structural reinforcement and therapeutic functionality, providing a novel and potential platform to promote periodontal regeneration in the context of diabetic periodontitis.

Chitin-binding protein behavior at chitosan interface studied by quartz crystal microbalance with dissipation monitoring (QCM-D): Binding quantification, orientation and affinity constants

A full comprehension of chitosan interaction with proteins is yet to be achieved, in view of the complexity of the physico-chemical behaviors found in the chitosan family, and the diversity of possible protein interaction mechanisms. In this work, we studied the interactions between chitosans and wheat germ agglutinin (WGA), a lectin that can bind chitin thanks to an amino-acid pattern called the hevein-like chitin-binding domain (CBD). The specificity of CBD interactions with chitin/chitosan chains and the impact of the degree of acetylation (DA) of chitosan have been studied by quartz crystal microbalance with dissipation monitoring (QCM-D). The mass per unit area of WGA adsorbed on chitosan was six times higher than that of immunoglobulin G (IGG), which does not contain a CBD. The mass per unit area of deposited WGA was also almost twice as high at higher chitosan DAs (54 %, 67 %, 76 %) than at lower DAs (0.5 %, 15 %, 35 %), evidencing more specific interaction with "chitin-like" chitosans. WGA is a dimer at neutral pH and presents 4 CBDs on each monomer. The repartition of these CBDs seems to allow for reorganization of WGA on the chitosan surface in order to favor the interactions of this chitosan with a higher number of proteins. Furthermore, the binding kinetics have been assessed and modelled with a two-step association model, providing insights on the observed association constants. These results indicate that QCM-D constitutes a suitable method for the analysis of lectin CBD-chitosan dynamic interactions and could be applied to other types of proteins, in particular CBD proteins or further used in biosensor elaboration or biomaterial coating assessment with chitosan of different DAs.

Imaging probes for the detection of brain microenvironment

The brain microenvironment (BME) is a highly dynamic system that plays a critical role in neural excitation, signal transmission, development, aging, and neurological disorders. BME consists of three key components: neural cells, extracellular spaces, and physical fields, which provide structures and physicochemical properties to synergistically and antagonistically regulate cell behaviors and functions such as nutrient transport, waste metabolism and intercellular communication. Consequently, monitoring the BME is vital to acquire a better understanding of the maintenance of neural homeostasis and the mechanisms underlying neurological diseases. In recent years, researchers have developed a range of imaging probes designed to detect changes in the microenvironment, enabling precise measurements of structural and biophysical parameters in the brain. This advancement aids in the development of improved diagnostic and therapeutic strategies for brain disorders and in the exploration of cutting-edge mechanisms in neuroscience. This review summarizes and highlights recent advances in the probes for sensing and imaging BME. Also, we discuss the design principles, types, applications, challenges, and future directions of probes.

Balancing performance and stability characteristics in organic electrochemical transistor

Nowadays organic electrochemical transistors (OECTs) are becoming a promising platform for bioelectronics and biosensing due to its biocompatibility, high sensitivity and selectivity, low driving voltages, high transconductance and flexibility. However, the existing problems associated with degradation processes within the OECT during long-term operation hinder their widespread implementation. Moreover, trade-offs often arise between OECT transconductance and speed, fast ion transport and electron mobility, electrochemical stability and sensitivity, cycling stability and signal amplification, and other metrics. Ensuring high performance characteristics and achieving enhanced stability in OECTs are distinct strategies that do not always align, as progress in one aspect often necessitates a trade-off with the other. This dynamic arises from the need to find a balance between reversible and irreversible processes in the behavior of OECT active layers, and providing simultaneously favorable conditions for ion and electron transport and their efficient charge coupling. This review article systematically summarizes the phenomenological and physical-chemical aspects associated with factors and mechanisms that determine both performance and long-term stability of OECT, paying special attention to the consideration of existing and promising approaches to extend the OECT lifespan, while maintaining (or even increasing) high effectiveness of its operation.

Review of research advances in microbial sterilization technologies and applications in the built environment

As globalization accelerates, microbial contamination in the built environment poses a major public health challenge. Especially since Corona Virus Disease 2019 (COVID-19), microbial sterilization technology has become a crucial research area for indoor air pollution control in order to create a hygienic and safe built environment. Based on this, the study reviews sterilization technologies in the built environment, focusing on the principles, efficiency and applicability, revealing advantages and limitations, and summarizing current research advances. Despite the efficacy of single sterilization technologies in specific environments, the corresponding side effects still exist. Thus, this review highlights the efficiency of hybrid sterilization technologies, providing an in-depth understanding of the practical application in the built environment. Also, it presents an outlook on the future direction of sterilization technology, including the development of new methods that are more efficient, energy-saving, and targeted to better address microbial contamination in the complex and changing built environment. Overall, this study provides a clear guide for selecting technologies to handle microbial contamination in different building environments in the future, as well as a scientific basis for developing more effective air quality control strategies.

Development of temperature-regulating CR/PVA bionanocomposite films with phase change materials and antibacterial properties for ice cream packaging

This study focuses on the development of active packaging for anti-heating food packaging using film materials based on Carrageenan (CR) and polyvinyl alcohol (PVA). The aim is to effectively manage the temperature of food products during storage and transportation to preserve their quality and freshness. Temperature-controlled bionanocomposite films were synthesized by incorporating phase change materials (PCMs) into the CR/PVA blend matrix. Specifically, polyethylene glycol (PEG) was grafted onto cellulose nanocrystals supported by copper nanoparticles to create a solid-solid PCM-Cu with exceptional thermal storage efficiency. The resulting nanocomposite films exhibited buffering properties at cold chain temperatures compared to pure CR/PVA films. The presence of copper nanoparticles also contributed antibacterial activity, further ensuring food safety. These nanocomposite films demonstrate significant potential for application in food packaging, as they effectively address temperature-related challenges within the food industry. The findings highlight the effectiveness of these innovative films in preserving the freshness of ice cream even when exposed to periods outside the freezer.

Microplastics in the marine environment: Challenges and the shift towards sustainable plastics and plasticizers

The United Nations (UN) estimate that around 75-199 million tons of plastic is floating in the world's oceans today. Continuous unintentional disposal of plastic waste in marine environments has and continues to cause significant biological impacts to various marine organisms ranging from mild difficulties in swimming or superficial damage to critical organ malfunctions and mortality. Over time, plastics in these environments degrade into microplastics which are now acknowledged as a pervasive harmful pollutant found in the cryosphere, atmosphere and hydrosphere. In response to this issue, the production of bespoke biodegradable bioplastics derived from renewable resources, such as vegetable oils, starch and plant fibres, is emerging to mitigate our reliance on environmentally persistent conventional fossil fuel-based plastics. While bioplastics degrade more readily than conventional plastics, they present new challenges, including leaching of toxic chemical additives and plasticizers into the environment. Consequently, various techniques have been explored in the search for sustainable plasticizers, from cheap, non-toxic compounds, such as vegetable oils and sugars to hyperbranched structures with limited migration. This article seeks to explain the intricate relationship between the problem of microplastics in marine environments and the strategies that have been investigated to address it thus far.

The role of donor units in band gap engineering of donor-acceptor conjugated polymers

Most used 60 distinct electron-donating units have been modelled, analyzed, and compared using density functional theory (DFT) for tetramer structures in the form (D-B-A-B)4 with fixed acceptor and bridge units, where D, A and B represents donor, acceptor and bridge, respectively. The frontier orbitals and reorganization energy of tetramers with alternating donor units were analyzed to assess their potential applicability in organic electronic applications. Key structural properties including dihedral angles between the acceptor, donor, and bridge units, bond order, and bond length alternation were found to significantly influence the frontier electronic energy levels affecting the planarity, conjugation and electron delocalization of polymer backbone. While extended conjugation and planar structures generally lower the band gap; the specific electronic impact of substituents, such as methoxy or fluorine groups, depend on their position and interaction within the conjugated system. Similarly, the incorporation of heavier heteroatoms, such as selenium, germanium or silicon, introduces steric and electronic effects that can either enhance or disrupt π-conjugation due to the change in the strength of donor unit. Additionally, substitution effects and morphological variations in donor units play a crucial role in defining the physical properties of D-A conjugated polymers. This study establishes a benchmark by providing essential insights into the band gap engineering and the molecular design of D-A copolymers by alternating donor units, thereby supporting significant advancements in organic electronic applications.

Innovative properties of sustainable galactomannans from seeds of Adenanthera pavonina, Caesalpinia pulcherrima and Delonix regia

Given the importance of new renewable resources for the industrial sector, this study aimed to assess the innovative technological and biological properties of galactomannans derived from the seeds of Adenanthera pavonina (BioAp), Caesalpinia pulcherrima (BioCp), and Delonix regia (BioDr). The biopolymers were evaluated using various parameters, including texture, spreadability, cytocompatibility, hemocompatibility, antimicrobial assays, mucoadhesiveness, and irritation potential by HET-CAM test. The absence of cytotoxicity, hemolysis, and irritation showed the potential of the three biopolymers for applications in biomedical fields. BioAp and BioDr samples exhibited the most effective antimicrobial activity, with MICs of 512 μg mL-1 against Staphylococcus aureus, Escherichia coli, and Candida albicans strains. The BioDr sample would be ideal for developing mucoadhesives due to its superior mucoadhesiveness in both powder and colloidal dispersion forms, achieving the highest Fmax adhesion force values of 0.46 N and 0.08 N, respectively. These findings expand the range of applications for these biopolymers and highlight their potential for integration into innovative polymer products in the food, cosmetics, and pharmaceutical sectors.

Chiroptical hybrid nanomaterials based on metal nanoparticles and biomolecules

Chirality at the nanoscale has recently attracted renewed attention from the scientific community. As a result, various strategies have been proposed to develop chiral nanomaterials based on metal nanoparticles and chiral biomolecules such as DNA, amino acids, or proteins. We review herein the past and recent literature related to the functionalization of metal nanoparticles with various chiral biomolecules and their assembly into biomaterials with chiroptical response. We divide the review into two main parts, according to the class of biomolecules. We first discuss mechanisms employed to obtain chiral bioconjugates based on metal nanoparticles and amino acids or their derivatives (peptides and proteins), including mechanisms for chirality transfer from chiral biomolecules to achiral nanoparticles. We also review the use of amino acids/peptides as either chiral inducers for the growth of chiral nanoparticles or templates for the chiral arrangement of achiral nanoparticles. In the second part we present an overview of methods to prepare bioconjugates comprising DNA and metal nanoparticles, as well as selected examples of helical nanoparticle arrangements that employ DNA as a chiral template.

Facile fabrication of morphology-adjustable viologen-based ionic polymers for carbon dioxide immobilization and iodine vapor adsorption

Viologens, also referred as 1,1'-disubstituted-4,4'-bipyridinium salts, exhibit exceptional redox properties, identifying them as building blocks for functional organic polymer materials with a wide range of potential applications, including carbon dioxide (CO2) conversion and iodine capture. Herein, a series of viologen-derived ionic porous organic polymers (VIPOP-n), assembled from viologen derivatives, were designed and synthesized using a straightforward one-step strategy. The constructed polymer materials were subsequently characterized by Fourier Transform Infrared Spectroscopy (FT-IR), solid-state 13C nuclear magnetic resonance (13C NMR), X-ray photoemission spectroscopy (XPS), scanning electron microscopy (SEM), and nitrogen adsorption-desorption isotherms, among other techniques. Notably, the variation of synthetic solvents significantly influences the construction of polymer materials, resulting in observable changes in morphology and structure, which in turn affect their potential applications in CO2 cycloaddition reaction and iodine adsorption. The polymer VIPOP-3 exhibits superior catalytic performance under conditions of 80 °C and 1 atm CO2, producing valuable cyclic carbonates with yields reaching 94%. Density Functional Theory (DFT) calculations indicate that inert-hydrogen bonding can effectively activate both the epoxide and CO2, lowering the activation energy (Ea) of the cycloaddition reaction to 87.5 kJ mol-1, as corroborated by kinetic evaluations. Additionally, all polymers exhibited effective iodine vapor adsorption capacities, with VIPOP-7 emerging as the most efficient material, displaying an adsorption capacity of 2.96 g g-1. The adsorption process was investigated through various kinetic models, revealing that both physical and chemical adsorption were involved, with physical adsorption being the predominant process.

Solvent volatilization annealing-prepared Janus film with asymmetric bioadhesion and inherent biological functions to expedite oral ulcer healing

Fabrication of layered bioadhesives with asymmetric bioadhesion, on-demand detachment and inherent biological functions remains a great challenge. This work reports a novel and generalizable solvent volatilization-induced annealing (SVA) strategy to prepare a Janus film with an integrated dual layer structure, asymmetric adhesion, on-demand detachment and inherent biological functions. Depositing polyvinyl pyrrolidone/caffeic acid/lipoic acid (PVP/CA/LA) ethanol solutions onto an ethylcellulose (EC) layer and applying SVA strategy can integrate two layers in molecular-level to obtain the dual-layered Janus film. Porous PVP/p(CA-LA) surface pressed onto wet tissues can absorb interfacial water to form tight tissue contact, and their functional groups can form abundant bonds to induce robust bioadhesion. In contrast, dense EC surface limits water absorption and exhibits minimal adhesion of proteins, cells and tissues. Furthermore, the adhered Janus film can be detached by using a glutathione/sodium bicarbonate solution. Additionally, CA and LA provide the film with desired antibacterial, antioxidant, and anti-inflammatory properties. Finally, by providing the antibacterial and anti-inflammatory microenvironment, the Janus film promotes angiogenesis and significantly expedites the healing of the oral ulcers in rats. This work not only introduces a novel approach for preparing multi-layered and asymmetric materials, but also paving the way for developing adhesive materials with inherent biological functions.

A review: Carrier-based hydrogels containing bioactive molecules and stem cells for ischemic stroke therapy

Ischemic stroke (IS), a cerebrovascular disease, is the leading cause of physical disability and death worldwide. Tissue plasminogen activator (tPA) and thrombectomy are limited by a narrow therapeutic time window. Although strategies such as drug therapies and cellular therapies have been used in preclinical trials, some important issues in clinical translation have not been addressed: low stem cell survival and drug delivery limited by the blood-brain barrier (BBB). Among the therapeutic options currently sought, carrier-based hydrogels hold great promise for the repair and regeneration of neural tissue in the treatment of ischemic stroke. The advantage lies in the ability to deliver drugs and cells to designated parts of the brain in an injectable manner to enhance therapeutic efficacy. Here, this article provides an overview of the use of carrier-based hydrogels in ischemic stroke therapy and focuses on the use of hydrogel scaffolds containing bioactive molecules and stem cells. In addition to this, we provide a more in-depth summary of the composition, physicochemical properties and physiological functions of the materials themselves. Finally, we also outline the prospects and challenges for clinical translation of hydrogel therapy for IS.

Evaluation of the effects of cartilage decellularized ECM in optimizing PHB-chitosan-HNT/chitosan-ECM core-shell electrospun scaffold: Physicochemical and biological properties

Cartilage regeneration is still a highly challenging field due to its low self-healing ability. This study used a core-shell electrospinning technique to enhance cartilage tissue engineering by incorporating cartilage extracellular matrix (ECM). The core of fibers included poly(3-hydroxybutyrate)-Chitosan (PHB-Cs) and Halloysite nanotubes. The shell of fibers consisted of Cs and ECM (0, 1, 3, 5 wt%). Subsequently, the scaffolds were named 0E, 1E, 3E, and 5E. The study aimed to assess the impact of ECM on cellular behavior and chondrogenesis. Our findings indicate that ECM reduced fiber diameter from 775 nm for the 0E scaffold to 454 nm for the 1E scaffold. Water contact angle measurements revealed an increasing trend by ECM addition, from 42° for 0E to 67° for 1E. According to mechanical analysis, the 1E scaffold represented the highest strength (5.81 MPa) and strain (3.17%). Based on these analyses, the 1E was considered the optimum scaffold. MTT analysis showed cell viability of over 80% for the 0E and 1E. Also, the gene expression level was assessed for Collagen II, Aggrecan, SOX 9, and Collagen X. The results represented that in the 1E scaffold Collagen II, Aggrecan, and SOX 9 were more upregulated at the end of the 21st day. However, in the 1E scaffold collagen X, as a hypertrophy marker, was downregulated at the end of the experiment. Overall, these results confirmed the potential of the 1E scaffold to be introduced as a promising cartilage tissue engineering scaffold for further studies.

Functional barrier and recyclable packaging materials through microfibrillated cellulose bilayer composite coatings

Although microfibrillated cellulose (MFC) offers high barrier properties against air, oxygen, and oil, its limited water resistance restricts industrial applications. An innovative bilayer composite coating (BCC) has therefore been developed in response, consisting of a top layer providing water resistance and the MFC layer contributing to the gas & oil barrier and recyclability. The top coating integrates styrene-butadiene copolymer for its non-polar characteristics and nanoclay to create a hydrophobic surface that resists moisture with enhanced tortuosity. Scanning electron microscopy confirmed a stable interface between the paper substrate and the BCC. X-ray photoelectron spectroscopy (XPS) and Time-of-Flight Secondary Ion Mass Spectroscopy (ToF-SIMS) show that the BCC prevents intermixing between layers, enhancing barrier performance and fiber recovery with reduced stickies during recycling. The BCC significantly improved barrier properties, achieving a 56 % reduction in water vapor transmission rate, a ∼ 630-fold decrease in air permeability, an oil & grease resistance of kit rating 12, and < 5 % weight gain from the hot oil test. These improvements highlight the efficacy of the BCC system for enhanced barrier and recyclability, especially in stickies reduction. This research demonstrates that the strategic combination of conventional and novel MFC materials can provide sustainable packaging with functional barriers and recyclability for a circular economy.

Fully biodegradable ion-induced silk fibroin-based triboelectric nanogenerators with enhanced performance prevent muscle atrophy

Applying electrical stimulation (ES) on nerve or muscle denervation can significantly restore the nerve function and prevent muscle atrophy. The triboelectric nanogenerator (TENG) can couple the mechanical energy and electrical energy for ES. However, the triboelectric performance of fully biodegradable TENGs and the effect of ES need to be optimized and verified. Here, the triboelectric performance of silk fibroin (SF) is regulated by ions to fabricate SF-TENGs with full biodegradability, good biocompatibility, and excellent output. This SF-TENG shows a good electrostimulation recovery effect and is used for function restoration of the injured sciatic nerve and innervated muscle. Li+ effectively improves the dielectric constant and increases the positively charged ability of SF. The highest output power density of SF-TENG is 128 mW/m2, which is superior to most reported fully biodegradable TENGs. The morphology, protein expression levels, neural/muscular function are assessed to evaluate the recovery of damaged nerves and innervated muscle. The function restoration of the injured nerve and innervated muscle under ES of SF-TENG is significantly close to the normal nerve and muscle. This TENG has great potential to achieve in vivo energy generation, ES, and biodegradability as an implantable electrical stimulator for the therapy of nerve, muscle, and tissue injury.