Injectable bio-multifunctional hyaluronic acid-based hydrogels loaded with poly ADP-ribose polymerase inhibitors for ovarian cancer therapy.

The recent use of PARP inhibitors (PARPi) in the maintenance treatment of ovarian tumor has significantly improved the survival rates of cancer patients. However, the current oral administration of PARP inhibitors fails to realize optimal therapeutic effects due to the low bioavailability in cancerous tissues, and often leads to a range of systemic adverse effects including hematologic toxicities, digestive system reactions, and neurotoxicities. Therefore, the demand for an advanced drug delivery system that can ensure effective drug administration while minimizing these unfavorable reactions is pressing. Injectable hydrogel emerges as a promising solution for local administration with the capability of sustainable drug release. In this study, we developed an injectable hydrogel made from aminated hyaluronic acid and aldehyde-functionalized pluronic127 via Schiff base reaction. This hydrogel exhibits excellent injectability with short gelation time and remarkable self-healing ability, and is applied to load niraparib. The drug-loaded hydrogel (HP@Nir hydrogel) releases drugs sustainably as tested in vitro as well as displays significant anti-proliferation and anti-migratory properties on human epithelial ovarian cancer cell line. Notably, HP@Nir hydrogel effectively suppresses the growth of ovarian cancer, without significant adverse reactions as demonstrated in animal studies. Additionally, the developed hydrogel is gradually degraded in vivo for around 20 d, while maintaining good biocompatibility. Overall, the injectable hydrogel loaded with niraparib provides a secure and efficient strategy for the treatment and management of ovarian cancer.

Nonlinear-mirror mode-locked crystal waveguide laser by intracavity fourth-harmonic loss modulation: publisher's note.

This publisher's note contains a correction to Opt. Lett.48, 6064 (2024)10.1364/OL.509275.

Nonlinear-mirror mode-locked crystal waveguide laser by intracavity fourth-harmonic loss modulation.

We present a nonlinear-mirror (NLM) mode-locked crystal waveguide laser. By adding nonlinear crystals into traditional NLM devices, the fourth harmonic is generated to form loss modulation, which suppresses the Q-switching instability of mode-locked lasers and achieves the optimal equivalent transmittance. The NLM mode-locked laser delivers ∼30 W average power with a repetition rate of 32.2 MHz and a pulse width of 950 fs. It is revealed that this novel, to the best of our knowledge, design with simple, robust, and reliable structure has a great potential in the development of high-power mode-locked laser.

Recent progress in carbon dots for anti-pathogen applications in oral cavity.

Background: Oral microbial infections are one of the most common diseases. Their progress not only results in the irreversible destruction of teeth and other oral tissues but also closely links to oral cancers and systemic diseases. However, traditional treatment against oral infections by antibiotics is not effective enough due to microbial resistance and drug blocking by oral biofilms, along with the passive dilution of the drug on the infection site in the oral environment. Aim of review: Besides the traditional antibiotic treatment, carbon dots (CDs) recently became an emerging antimicrobial and microbial imaging agent because of their excellent (bio)physicochemical performance. Their application in treating oral infections has received widespread attention, as witnessed by increasing publication in this field. However, to date, there is no comprehensive review available yet to analyze their effectiveness and mechanism. Herein, as a step toward addressing the present gap, this review aims to discuss the recent advances in CDs against diverse oral pathogens and thus propose novel strategies in the treatment of oral microbial infections. Key scientific concepts of review: In this manuscript, the recent progress of CDs against oral pathogens is summarized for the first time. We highlighted the antimicrobial abilities of CDs in terms of oral planktonic bacteria, intracellular bacteria, oral pathogenic biofilms, and fungi. Next, we introduced their microbial imaging and detection capabilities and proposed the prospects of CDs in early diagnosis of oral infection and pathogen microbiological examination. Lastly, we discussed the perspectives on clinical transformation and the current limitations of CDs in the treatment of oral microbial infections.

Probiotic-loaded calcium alginate/fucoidan hydrogels for promoting oral ulcer healing.

Probiotics are beneficial bacteria located in the oral cavity which exhibit antimicrobial properties and contribute to the regulation of immune function and the modulation of tissue repair. Fucoidan (FD), a marine prebiotic, may further enhance the ability of probiotics to promote ulcer healing. However, neither FD nor probiotics are attached to the oral cavity and neither are well-suited for oral ulcer healing owing to the wet and highly dynamic environment. In this study, probiotic-loaded calcium alginate/fucoidan composite hydrogels were developed for use as bioactive oral ulcer patches. The well-shaped hydrogels exhibited remarkable wet-tissue adhesion, suitable swelling and mechanical properties, sustained probiotic release, and excellent storage durability. Moreover, in vitro biological assays demonstrated that the composite hydrogel exhibited excellent cyto/hemocompatibility and antimicrobial effects. Importantly, compared to commercial oral ulcer patches, bioactive hydrogels show superior therapeutic capability for promoting ulcer healing in vivo by enhancing cell migration, inducing epithelial formation and orderly collagen fiber deposition, as well as facilitating neovascularization. These results demonstrate that this novel composite hydrogel patch demonstrates great potential for the treatment of oral ulcerations.

Protease-Loaded CuS Nanoparticles with Synergistic Photothermal/Dynamic Therapy against F. nucleatum-Induced Periodontitis.

Periodontitis is a chronic inflammatory disease induced by a plaque biofilm, which can lead to the destruction of the periodontal support tissue and even teeth loss. The common strategies of periodontitis treatment are to eliminate bacterial/biofilm-related inflammation and subsequently inhibit alveolar bone resorption, for which antibiotic therapy is the most traditional one. However, impenetrable polymeric substances on bacterial biofilms make it difficult for traditional antimicrobial agents to take effect. In this study, a novel nanoparticle protease-loaded CuS NPs was developed, combining the advances of photodynamic and photothermal therapy from CuS and enzymatic degradation of the biofilm by a protease. The photothermal activity and the reactive oxygen generation capacity of the designed nanoparticles were verified by the experimental results, constituting the basis of antibacterial function. Next, the high antimicrobial activity of CuS@A NPs onFusobacterium nucleatumand its biofilm was demonstrated. The proper hemo/cytocompatibility of CuS-based NPs was demonstrated by in vitro assays. Last, effective treatment against periodontitis was achieved in a rat periodontitis model through the significant efficacy of inhibiting bone resorption and alleviating inflammation. Thus, the developed CuS@A NPs prove a promising material for the management of periodontitis.

Development of ε-poly(L-lysine) carbon dots-modified magnetic nanoparticles and their applications as novel antibacterial agents.

Magnetic nanoparticles (MNPs) are widely applied in antibacterial therapy owing to their distinct nanoscale structure, intrinsic peroxidase-like activities, and magnetic behavior. However, some deficiencies, such as the tendency to aggregate in water, unsatisfactory biocompatibility, and limited antibacterial effect, hindered their further clinical applications. Surface modification of MNPs is one of the main strategies to improve their (bio)physicochemical properties and enhance biological functions. Herein, antibacterial ε-poly (L-lysine) carbon dots (PL-CDs) modified MNPs (CMNPs) were synthesized to investigate their performance in eliminating pathogenic bacteria. It was found that the PL-CDs were successfully loaded on the surface of MNPs by detecting their morphology, surface charges, functional groups, and other physicochemical properties. The positively charged CMNPs show superparamagnetic properties and are well dispersed in water. Furthermore, bacterial experiments indicate that the CMNPs exhibited highly effective antimicrobial properties against Staphylococcus aureus. Notably, the in vitro cellular assays show that CMNPs have favorable cytocompatibility. Thus, CMNPs acting as novel smart nanomaterials could offer great potential for the clinical treatment of bacterial infections.

Chemical signal regulated injectable coacervate hydrogels.

In the quest for stimuli-responsive materials with specific, controllable functions, coacervate hydrogels have become a promising candidate, featuring sensitive responsiveness to environmental signals enabling control over sol-gel transitions. However, conventional coacervation-based materials are regulated by relatively non-specific signals, such as temperature, pH or salt concentration, which limits their possible applications. In this work, we constructed a coacervate hydrogel with a Michael addition-based chemical reaction network (CRN) as a platform, where the state of coacervate materials can be easily tuned by specific chemical signals. We designed a pyridine-based ABA triblock copolymer, whose quaternization can be regulated by an allyl acetate electrophile and an amine nucleophile, leading to gel construction and collapse in the presence of polyanions. Our coacervate gels showed not only highly tunable stiffness and gelation times, but excellent self-healing ability and injectability with different sized needles, and accelerated degradation resulting from chemical signal-induced coacervation disruption. This work is expected to be a first step in the realization of a new class of signal-responsive injectable materials.

Molecular Dynamics Simulation of NiTi Shape Memory Alloys Produced by Laser Powder Bed Fusion: Laser Parameters on Phase Transformation Behavior.

In this study, the deposition, powder spreading, and laser fusion processes during the laser powder bed fusion (L-PBF) process were studied using molecular dynamics (MD) simulation. The effect of Ni content on the characteristic phase transformation temperatures was also investigated. Shape memory effect and superelasticity of NiTi alloys with Ni content ranged from 48.0% to 51.0% were analyzed. By employing MEAM potentials, the effects of the laser power, spot diameter, and scanning speed on the molten pool size and element evaporation were studied. Simulation results showed that a larger spot diameter renders a higher Ni content in the molten pool, also a larger molten pool. A faster scanning speed leads to a higher Ni content in the molten pool, and a smaller molten pool. The element is difficult to evaporate using small laser power and a large spot diameter. The element in the molten pool expresses a great evaporation effect when the Es is larger than 0.4 eV/ų. According to Ni content within the molten pool during laser fusion, characteristic phase transition temperatures in single crystalline NiTi alloys with variant Ni content were investigated by employing a 2NN-MEAM potential. Characteristic phase transition temperature changes as the Ni content increases from 48.0% to 51.0%. Austenite boundaries and Ni content in the boundary were found to be the keys for controlling the characteristic phase transformation temperature.

Transient Host-Guest Complexation To Control Catalytic Activity.

Signal transduction mechanisms are key to living systems. Cells respond to signals by changing catalytic activity of enzymes. This signal responsive catalysis is crucial in the regulation of (bio)chemical reaction networks (CRNs). Inspired by these networks, we report an artificial signal responsive system that shows signal-induced temporary catalyst activation. We use an unstable signal to temporarily activate an out of equilibrium CRN, generating transient host-guest complexes to control catalytic activity. Esters with favorable binding toward the cucurbit[7]uril (CB[7]) supramolecular host are used as temporary signals to form a transient complex with CB[7], replacing a CB[7]-bound guest. The esters are hydrolytically unstable, generating acids and alcohols, which do not bind to CB[7], leading to guest reuptake. We demonstrate the feasibility of the concept using signal-controlled temporary dye release and reuptake. The same signal controlled system was then used to tune the reaction rate of aniline catalyzed hydrazone formation. Varying the ester structure and concentration gave access to different catalyst liberation times and free catalyst concentration, regulating the overall reaction rate. With temporary signal controlled transient complex formation we can tune the kinetics of a second chemical reaction, in which the signal does not participate. This system shows promise for building more complex nonbiological networks, to ultimately arrive at signal transduction in organic materials.

16.9†W average power from a diode-pumped picosecond Yb:YAG laser with a large-size rectangular core crystalline waveguide.

We demonstrate a high-power all-solid-state picosecond laser based on a passive mode-locking laser with a large-size rectangular core crystalline waveguide and a semiconductor saturable-absorber mirror. An average power of 16.9 W is achieved with a 1.96 ps duration and a 31.74 MHz repetition frequency. This is the first demonstration of a mode-locked laser with a large-size rectangular core crystalline waveguide to our knowledge.

Tuneable Control of Organocatalytic Activity through Host-Guest Chemistry.

Dynamic regulation of chemical reactivity is important in many complex chemical reaction networks, such as cascade reactions and signal transduction processes. Signal responsive catalysts could play a crucial role in regulating these reaction pathways. Recently, supramolecular encapsulation was reported to regulate the activities of artificial catalysts. We present a host-guest chemistry strategy to modulate the activity of commercially available synthetic organocatalysts. The molecular container cucurbit[7]uril was successfully applied to change the activity of four different organocatalysts and one initiator, enabling up- or down-regulation of the reaction rates of four different classes of chemical reactions. In most cases CB[7] encapsulation results in catalyst inhibition, however in one case catalyst activation by binding to CB[7] was observed. The mechanism behind this unexpected behavior was explored by NMR binding studies and pKa measurements. The catalytic activity can be instantaneously switched during operation, by addition of either supramolecular host or competitive binding molecules, and the reaction rate can be predicted with a kinetic model. Overall, this signal responsive system proves a promising tool to control catalytic activity.

Hydrothermal polymerization towards fully biobased polyazomethines.

Microwave assisted polycondensation for the synthesis of (partially) biobased polyazomethines in water (hydrothermal polymerization) was investigated for the first time in this study. The polyazomethines prepared via this environmentally friendly and simple method show comparable characteristics as the polymers prepared via traditional methods in organic solvents.

One-Pot Synthesis of Active Carbon-Supported Size-Tunable Ni2P Nanoparticle Catalysts for the Pyrolysis Bio-Oil Upgrade.

Catalytic hydrodeoxygenation (HDO) over Ni2P-based catalysts is a promising technology for the pyrolysis bio-oil upgrading. However, substantial challenges still remain in the realization of the size effect for phosphide catalysts in catalyzing this reaction, and the precise size engineering of these catalysts is difficult. In this work, the Ni2P/active carbon (AC) catalysts with varying nickel phosphide nanoparticle sizes were one-pot prepared via the modified organic liquid chemical reaction method. The Ni2P-based catalysts were tested for HDO of the pyrolysis oil model compound (salicylaldehyde), and the conversion of salicylaldehyde first increases and then decreases with the increase of Ni2P nanoparticle size, demonstrating that the activity for HDO of salicylaldehyde can be controlled by using nickel phosphides of varying nanoparticle sizes. The Ni2P-2/AC catalyst with approximately 5.49 nm Ni2P nanoparticle size exhibited the highest activity with conversion of salicylaldehyde reaching over 99% within 180 min under 220 °C, 2 MPa H2 pressure, and the corresponding yield toward o-cresol was over 97%.

Asymmetric Synthesis of 4-Aryl-3,4-dihydrocoumarins by N-Heterocyclic Carbene Catalyzed Annulation of Phenols with Enals.

The highly enantioselective synthesis of 4-aryl-3,4-dihydrocoumarins was realized through direct annulation of phenols with enals catalyzed by dihydroisoquinoline-type NHC (DHIQ-NHC), an N-heterocyclic carbene derived from l-phenylalanine. The catalytic reaction proceeds with a wide scope of electron-rich phenols and enals providing structurally diverse 4-aryl-3,4-dihydrocoumarins in good to excellent yields and enantioselectivity. This method was useful in the synthesis of natural products and biologically relevant compounds from readily available starting materials.

Enantioselective annulation of enals with 2-naphthols by triazolium salts derived from l-phenylalanine.

A series of chiral triazolium salts have been synthesized from methyl l-phenylalaninate hydrochloride. The NHCs derived from this class of novel triazolium salts were found to be highly efficient catalysts in the annulation reaction of enals and 2-naphthols. These reactions proceeded with high chemoselectivity and wide substrate scope affording enantioenriched ß-arylsplitomicins in good yields with up to 96% ee.

[Molecular characterization of Japanese encephalitis virus isolated from Gansu province in 2008].

OBJECTIVE: To sequence PrM and E gene of the Japanese encephalitis virus isolated from Gansu province in 2008 and analysis the genotype of new JEV isolates and the molecular characterization of E gene. METHODS: Computer software was used to analyze nucleic acid sequence and deduced amino acid sequence, and draw phylogenetic trees, including ClustalX2.09, MegAlign and Mega4. RESULTS: The six JEV strains were clustered in genotype I. 87.5%-87.9% identity in nucleotide sequence and 96.8%-97.2% identity in amino acid sequence were found in E gene when compared with the vaccine strain SA14-14-2. Eleven common amino acid differences were observed in E protein between new isolates and the vaccine strain. CONCLUSION: Genotype I JEVs were isolated from mosquitoes collected in Gansu province. The amino acid difference occurred in sites that were not the key ones affecting the antigenic of JEV.