Immobilization of laccase on magnetic PEGDA-CS inverse opal hydrogel for enhancement of bisphenol A degradation in aqueous solution.

Endocrine disruptors such as bisphenol A (BPA) adversely affect the environment and human health. Laccases are used for the efficient biodegradation of various persistent organic pollutants in an environmentally safe manner. However, the direct application of free laccases is generally hindered by short enzyme lifetimes, non-reusability, and the high cost of a single use. In this study, laccases were immobilized on a novel magnetic three-dimensional poly(ethylene glycol) diacrylate (PEGDA)-chitosan (CS) inverse opal hydrogel (LAC@MPEGDA@CS@IOH). The immobilized laccase showed significant improvement in the BPA degradation performance and superior storage stability compared with the free laccase. 91.1% of 100 mg/L BPA was removed by the LAC@MPEGDA@CS@IOH in 3 hr, whereas only 50.6% of BPA was removed by the same amount of the free laccase. Compared with the laccase, the outstanding BPA degradation efficiency of the LAC@MPEGDA@CS@IOH was maintained over a wider range of pH values and temperatures. Moreover, its relative activity of was maintained at 70.4% after 10 cycles, and the system performed well in actual water matrices. This efficient method for preparing immobilized laccases is simple and green, and it can be used to further develop ecofriendly biocatalysts to remove organic pollutants from wastewater.

Eco-friendly chitosan microspheres as a novel one-step sorbent for the rapid purification and determination of pesticides and veterinary drug multi-residues in aquatic products with HPLC-MS/MS.

A modified QuEChERS method was developed to determine multi-class pesticide and veterinary residues in aquatic products. Chitosan microspheres were conveniently synthesized and utilized as the cleanup adsorbent in the QuEChERS procedure, showcasing rapid filtration one-step pretreatment ability for the determination of drug multi-residues in aquatic products. Compared to conventional synthetic sorbents, chitosan microspheres not only have good purification performance, but also have renewable and degradable properties. This novel sorbent worked well in the simultaneous determination of 95 pesticides and veterinary drug residues in aquatic products after being combined with an improved one-step vortex oscillating cleanup method. We achieved recoveries ranging from 64.0% to 115.9% for target drugs in shrimp and fish matrix. The limits of detection and quantification were 0.5-1.0 and 1.0-2.0 µg kg-1, respectively. Notably, hydrocortisone was detected with considerable frequency and concentration in the tested samples, underscoring the necessity for stringent monitoring of this compound in aquatic products.

Development and antimicrobial activity of composite edible films of chitosan and nisin incorporated with perilla essential oil-glycerol monolaurate emulsions.

Aquatic products are highly susceptible to spoilage, and preparing composite edible film with essential oil is an effective solution. In this study, composite edible films were prepared using perilla essential oil (PEO)-glycerol monolaurate emulsions incorporated with chitosan and nisin, and the film formulation was optimized by response surface methodology. These films were applied to ready-to-eat fish balls and evaluated over a period of 12 days. The films with the highest inhibition rate against Staphylococcus aureus were acquired using a polymer composition of 6 µL/mL PEO, 18.4 µg/mL glycerol monolaurate, 14.2 mg/mL chitosan, and 11.0 µg/mL nisin. The fish balls coated with the optimal edible film showed minimal changes in appearance during storage and significantly reduced total bacterial counts and total volatile basic nitrogen compared to the control groups. This work indicated that the composite edible films containing essential oils possess ideal properties as antimicrobial packaging materials for aquatic foods.

Continuous production of chitooligosaccharides in a column reactor by the PUF-immobilized whole cell enzymes of Mucor circinelloides IBT-83.

BACKGROUND: Chitosan oligosaccharides (COS) have great potential for applications in several fields, including agriculture, food industry or medicine. Nevertheless, the large-scale use of COS requires the development of cost-effective technologies for their production. The main objective of our investigation was to develop an effective method of enzymatic degradation of chitosan in a column reactor using Mucor circinelloides IBT-83 cells, immobilized in a polyurethane foam (PUF). These cells serve as a source of chitosanolytic enzymes. RESULTS: The study revealed that the process of freeze-drying of immobilized mycelium increases the stability of the associated enzymes during chitosan hydrolysis. The use of stabilized preparations as an active reactor bed enables the production of COS at a constant level for 16 reactor cycles (384 h in total), i.e. 216 h longer compared to non-stabilized mycelium. In the hydrolysate, oligomers ranging in structure from dimer to hexamer as well as D-glucosamine were detected. The potential application of the obtained product in agriculture has been verified. The results of phytotests have demonstrated that the introduction of COS into the soil at a concentration of 0.01 or 0.05% w/w resulted in an increase in the growth of Lepidium sativum stem and root, respectively (extensions by 38 and 44% compared to the control sample). CONCLUSIONS: The research has verified that the PUF-immobilized M. circinelloides IBT-83 mycelium, which has been stabilized through freeze-drying, is a promising biocatalyst for the environmentally friendly and efficient generation of COS. This biocatalyst has the potential to be used in fertilizers.

Sequential release of vancomycin and BMP-2 from chitosan/nano-hydroxyapatite thermosensitive hydrogel for the treatment of chronic osteomyelitis.

In this study, we developed scaffolds materials with microspheres to form a double sustained release system.Chitosan/nano-hydroxyapatite (CS-HA) was used as a drug carrier to construct a sustained-release system for Bone morphogenetic protein-2(BMP-2) and Vancomycin (VAN). Furthermore, VAN and BMP-2 loaded microspheres (Ms) were prepared by the emulsion ultrasonic method.The resultant composites were characterized by Scanning electron microscope (SEM), compressive strength, porosity, and biodegradation. The characterization results showed uniform porous and rough surface, enhanced thermal stability, and highest compressive strength ((1.912 ± 0.012) Kpa, the surface of the two microspheres was slightly folded and showed a regular spherical shape.The loading rate of BMP-2 was (59.611 × 10-4 ± 0.023 × 10-4)% and the encapsulation rate was (6.022 ± 0.005)%. The release rate of vancomycin and BMP-2 was 57.194% and 12.968% respectively. Osteogenic differentiation of Bone marrow mesenchymal stem cells (BMSCs) was confirmed by alkaline phosphatase quantification. The deposition of late osteogenic markers (calcium phosphates) detected by Alizarin red, which indicated extracellular matrix mineralization. The results showed that BMP-2/VAN in CS-HA hydrogel successfully achieved the sequential release of the double drugs, which could benefit bone regeneration.

Polycaprolactone Hybrid Scaffold Loaded With N,O-Carboxymethyl Chitosan/Aldehyde Hyaluronic Acid/Hydroxyapatite Hydrogel for Bone Regeneration.

Hydrogels have emerged as potential materials for bone grafting, thanks to their biocompatibility, biodegradation, and flexibility in filling irregular bone defects. In this study, we fabricated a novel NAH hydrogel system, composed of N,O-carboxymethyl chitosan (NOCC), aldehyde hyaluronic acid (AHA), and hydroxyapatite (HAp). To improve the mechanical strength of the fabricated hydrogel, a porous polycaprolactone (PCL) matrix was synthesized and used as a three-dimensional (3D) support template for NAH hydrogel loading, forming a novel PCL/NAH hybrid scaffold. A mixture of monosodium glutamate (M) and sucrose (S) at varied weight ratios (5M:5S, 7M:3S, and 9M:1S) was used for the fabrication of 3D PCL matrices. The morphology, interconnectivity, and water resistance of the porous PCL scaffolds were investigated for optimal hydrogel loading efficiency. The results demonstrated that PCL scaffolds with porogen ratios of 7M:3S and 9M:1S possessed better interconnectivity than 5M:5S ratio. The compressive strength of the PCL/NAH hybrid scaffolds with 9M:1S (561.6 ± 6.1 kPa) and 7M:3S (623.8 ± 6.8 kPa) ratios are similar to cancellous bone and all hybrid scaffolds were biocompatible. Rabbit models with tibial defects were implanted with the PCL/NAH scaffolds to assess the wound healing capability. The results suggest that the PCL/NAH hybrid scaffolds, specifically those with porogen ratio of 7M:3S, exhibit promising bone healing effects.

Vanillin loaded-physically crosslinked PVA/chitosan/itaconic membranes for topical wound healing applications.

Vanillin loaded-physically crosslinked hydrogel membranes made of PVA/chitosan/itaconic acid (PVA-CS-IA) were prepared using freezing-thawing (F-T) cycle method. To ensure the entanglement of PVA-CS-IA chains, three F-T cycles were repeated. The polymeric chains entanglements were confirmed and characterized by different instrumental characterizations. Physicochemical properties for example, swelling ratio, mechanical characteristics, gel fraction percentage (GF%), hydrolytic degradation, and thermal stability of PVA-CS-IA membrane were discussed in detail. The findings showed that the swelling ratio, mechanical characteristics, and hydrolytic degradation of the crosslinked membranes enhanced with increasing CS-IA contents in membranes composition; however, GF% gradually declined with CS-IA content. Additionally, cell viability test using HFB-4 cell line and antimicrobial activity against Staphylococcus aureus and Escherichia coli were evaluated using MTT assay and the bacterium growth inhibition percentage method; respectively. Notably, with varying incubation durations and membrane concentrations, all examined constructed hydrogels showed significant cell survival percentages. The findings supported the notion that produced hydrogel membranes might be used in a professional setting as antibacterial dressings or biomaterials for quick wound healing rate.

Anti-Helicobacter pylori activity of nanocomposites from chitosan/broccoli mucilage/selenium nanoparticles.

Helicobacter pylori can infect most people worldwide to cause hazardous consequences to health; the bacteria could not easily be controlled or disinfected. Toward exploring of innovative biocidal nanoformulations to control H. pylori, broccoli seeds (Brassica oleracea var. italica) mucilage (MBS) was employed for biosynthesizing selenium nanoparticles (MBS/SeNPs), which was intermingled with chitosan nanoparticles (NCT) to generate bioactive nanocomposites for suppressing H. pylori. The MBS could effectually generate and stabilize SeNPs with 13.61 nm mean diameter, where NCT had 338.52 nm mean diameter and positively charged (+ 39.62 mV). The cross-linkages between NCT-MBS-SeNPs were verified via infrared analysis and the nanocomposites from NCT:MBS/SeNPs at 1:2 (T1), 1:1 (T2) and 2:1 (T3) ratios had mean diameters of 204, 132 and 159 nm, respectively. The entire nanomaterials/composites exhibited potent anti- H. pylori activities using various assaying methods; the T2 nanocomposite was the utmost bactericidal agent with 0.08-0.10 mg/L minimal concentration and 25.9-27.3 mm inhibition zones. The scanning microscopy displayed the ability of nanocomposite to attach the bacterial cells, disrupt their membranes, and completely lyse them within 10 h. The NCT/MBS/SeNPs nanocomposites provided effectual innovative approach to control H. pylori.

Ultrasonically assisted fabrication of electrochemical platform for tinidazole detection.

Based on sonochemistry, green synthesis methods play an important role in the development of nanomaterials. In this work, a novel chitosan modified MnMoO4/g-C3N4 (MnMoO4/g-C3N4/CHIT) was developed using ultrasonic cell disruptor (500 W, 30 kHz) for ultra-sensitive electrochemical detection of tinidazole (TNZ) in the environment. The morphology and surface properties of the synthesized MnMoO4/g-C3N4/CHIT electrode were characterized using X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and transmission electron microscope (TEM). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques were utilized to assess the electrochemical performance of TNZ. The results indicate that the electrochemical detection performance of TNZ is highly efficient, with a detection limit (LOD) of 3.78 nM, sensitivity of 1.320 µA·µM-1·cm-2, and a detection range of 0.1-200 µM. Additionally, the prepared electrode exhibits excellent selectivity, desirable anti-interference capability, and decent stability. MnMoO4/g-C3N4/CHIT can be successfully employed to detect TNZ in both the Songhua River and tap water, achieving good recovery rates within the range of 93.0 % to 106.6 %. Consequently, MnMoO4/g-C3N4/CHIT's simple synthesis might provide a new electrode for the sensitive, repeatable, and selective measurement of TNZ in real-time applications. Using the MnMoO4/g-C3N4/CHIT electrode can effectively monitor and detect the concentration of TNZ in environmental water, guiding the sewage treatment process and reducing the pollution level of antibiotics in the water environment.

Optimization and evaluation of a chitosan-coated PLGA nanocarrier for mucosal delivery of Porphyromonas gingivalis antigens.

Recent advances in understanding Alzheimer's disease (AD) suggest the possibility of an infectious etiology, with Porphyromonas gingivalis emerging as a prime suspect in contributing to AD. P. gingivalis may invade systemic circulation via weakened oral/intestinal barriers and then cross the blood-brain barrier (BBB), reaching the brain and precipitating AD pathology. Based on the proposed links between P. gingivalis and AD, a prospective approach is the development of an oral nanovaccine containing P. gingivalis antigens for mucosal delivery. Targeting the gut-associated lymphoid tissue (GALT), the nanovaccine may elicit both mucosal and systemic immunity, thereby hampering P. gingivalis ability to breach the oral/intestinal barriers and the BBB, respectively. The present study describes the optimization, characterization, and in vitro evaluation of a candidate chitosan-coated poly(lactic-co-glycolic acid) (PLGA-CS) nanovaccine containing a P. gingivalis antigen extract. The nanocarrier was prepared using the double emulsion solvent evaporation method and optimized for selected experimental factors, e.g. PLGA amount, surfactant concentration, w1/o phase ratio, applying a d-optimal statistical design to target the desired physicochemical criteria for its intended application. After nanocarrier optimization, the nanovaccine was characterized in terms of particle size, polydispersity index (PdI), ζ-potential, encapsulation efficiency (EE), drug loading (DL), morphology, and in vitro release profile, as well as for mucoadhesivity, stability under simulated gastrointestinal conditions, antigen integrity, in vitro cytotoxicity and uptake using THP-1 macrophages. The candidate PLGA-CS nanovaccine demonstrated appropriate physicochemical, mucoadhesive, and antigen release properties for oral delivery, along with acceptable levels of EE (55.3 ± 3.5 %) and DL (1.84 ± 0.12 %). The integrity of the encapsulated antigens remained uncompromised throughout NPs production and simulated gastrointestinal exposure, as confirmed by SDS-PAGE and Western blotting analyses. Furthermore, the nanovaccine showed effective in vitro uptake, while exhibiting low cytotoxicity. Taken together, these findings underscore the potential of PLGA-CS NPs as carriers for adequate antigen mucosal delivery, paving the way for further investigations into their applicability as vaccine candidates against P. gingivalis.

Development of 5-fluorouracil/etoposide co-loaded electrospun nanofibrous scaffold for localized anti-melanoma therapy.

Nanofibrous scaffolds have emerged as promising candidates for localized drug delivery systems in the treatment of cutaneous cancers. In this study, we prepared an electrospun nanofibrous scaffold incorporating 5-fluorouracil (5-FU) and etoposide (ETP) for chemotherapy targeting melanoma cutaneous cancer. The scaffold was composed of polyvinyl alcohol (PVA) and chitosan (CS), prepared via the electrospinning process and loaded with the chemotherapeutic agents. We conducted relevant physicochemical characterizations, assessed cytotoxicity, and evaluated apoptosis against melanoma A375 cells. The prepared 5-FU/ETP co-loaded PVA/CS scaffold exhibited nanofibers (NFs) with an average diameter of 321 ± 61 nm, defect-free and homogenous morphology. FTIR spectroscopy confirmed successful incorporation of chemotherapeutics into the scaffold. Additionally, the scaffold demonstrated a hydrophilic surface, proper mechanical strength, high porosity, and efficient liquid absorption capacity. Notably, sustained and controlled drug release was observed from the nanofibrous scaffold. Furthermore, the scaffold significantly increased cytotoxicity (95%) and apoptosis (74%) in A375 melanoma cells. Consequently, the prepared 5-FU/ETP co-loaded PVA/CS nanofibrous scaffold holds promise as a valuable system for localized eradication of cutaneous melanoma tumors and mitigation of adverse drug reactions associated with chemotherapy.

[Remediation Mechanism of Chitosan-modified Biochar on Cd-contaminated Farmland Soil and Its Effect on Bacterial Community].

To explore the remediation mechanism of chitosan-modified biochar （passivator） on Cd-contaminated farmland soil, pot experiments were conducted to determine the effects of passivator on soil physical and chemical properties, ryegrass biomass, enzyme activity, and the response of soil bacterial diversity and structure. The results showed that when the amount of passivating agent was increased from 0.5% to 3%, the content of available Cd in soil was significantly decreased compared with that in the control, and the above-ground and subsurface biomass of ryegrass was increased by 1.08-1.56 times and 1.00-1.68 times, respectively. The enrichment and running coefficients were reduced by 6.15%-30.00% and 10.42%-31.25%, respectively. The correlation analysis results showed that soil pH, CEC, SOM, AN, AP, and AK were significantly negatively correlated with DTPA-Cd, indicating that the application of a passivating agent promoted the passivation of Cd in soil by changing the physical and chemical properties of soil. High-throughput sequencing results showed that the application of the inactivation agent changed the structure and diversity of the soil bacterial community, which was manifested as a significant decrease in α diversity, significant isolation of bacteria between different treatment groups, and an increase in the relative abundance of beneficial bacteria such as Sphingomonas and Blastococcus. Moreover, the activities of soil urease and cellulase increased, whereas the activities of sucrase and catalase decreased with the addition of a passivator. This study provides a theoretical basis and technical reference for the application of modified biochar in the remediation of Cd-contaminated farmland soil.

Production and Characterization of Electrospun Chitosan, Nanochitosan and Hyaluronic Acid Membranes for Skin Wound Healing.

The development of new wound dressings made from biomaterials, which offer a better cost-benefit ratio and accelerate the healing process, is increasing nowadays. Various biopolymers can be electrospun to form functional membranes for wound healing. Therefore, in this study, chitosan and nanochitosan membranes with or without hyaluronic acid were prepared using the electrospinning technique, characterized and evaluated in the healing of skin wounds in rats. Chitosan and nanochitosan solutions, with or without hyaluronic acid, were prepared at concentrations of 1%-4% using PEO (polyethylene oxide) and subjected to the electrospinning process to obtain membranes characterized by scanning electron microscopy (SEM), mechanical tests, and antimicrobial activity. The healing effect of the membranes was evaluated by monitoring the area of the lesions, contraction of the wounds, histologic analysis, and induction of pro-inflammatory cytokine (IL-1 α and TNF-α) production in rats. The nanochitosan and nanochitosan membranes with hyaluronic acid achieved greater fiber diameter and uniformity, resistance, elasticity, and thermal stability, in addition to good adhesion to the wound bed and permeation capacity. Despite not presenting antimicrobial activity in vitro, they contributed to the production of pro-inflammatory interleukins in the animals tested, provided physical protection, reduced the wound area more markedly until the seventh day of the evaluation, with an acceleration of the healing process and especially when functionalized with hyaluronic acid. These results indicate that the membranes may be promising for accelerating the healing process of chronic wounds in humans.

Sprayable anti-adhesive hydrogel for peritoneal macrophage scavenging in post-surgical applications.

Post-surgical adhesions frequently occur after intra-abdominal surgery, leading to severe complications. Despite the development of various types of adhesion barriers to address post-surgical adhesions, several limitations persist, including off-target localization, handling difficulties, and potential immunogenicity. Here, we report a spray-type adhesion barrier for broad, fast application, forming two sequential networks. The first network is formed by a polyelectrolyte complex of sulfated hyaluronic acid and chitosan, while the second network is established through pluronic® F127 thermogelation. This sprayable barrier served as both a physical protector for the damaged peritoneum and an immunomodulator for peritoneal macrophages, as evidenced its effectiveness in a rat ischemic button model. Taken together, this efficient adhesion barrier presents a promising solution for post-surgical adhesions.

Assessing polylactic acid nanofibers with cellulose and chitosan nanocapsules loaded with chamomile extract for treating gram-negative infections.

This study presents the development and characterization of a novel nanocomposite wound dressing material based on polylactic acid (PLA) nanofibers incorporating chitosan nanocapsules loaded with chamomile extract and cellulose nanoparticles. The nanofibers were fabricated using a three-step synthesis and electrospinning techniques, resulting in uniform, bead-free fibers with an average diameter of 186 ± 56 nm. Fourier-transform infrared spectroscopy confirmed the successful incorporation of all components, while tensile strength tests demonstrated improved mechanical properties by adding nanoparticles. Water contact angle measurements revealed enhanced surface wettability of the PLA-Cellulose-Chitosan complex compared to pure PLA nanofibers. In vitro biocompatibility assessments using MTT assays showed excellent cell viability and proliferation, with the optimized composite exhibiting the best performance. Scanning electron microscopy imaging confirmed robust cell adhesion and interaction with the nanofibers. The nanocomposite demonstrated significant antimicrobial activity against Escherichia coli, with a 20 mm inhibition zone observed for chamomile extract-loaded samples. Additionally, the material showed superior hemostatic ability compared to commercial gauze and high hemocompatibility. These comprehensive results indicate that the developed nanocomposite is a promising candidate for advanced wound management applications, offering a multifunctional approach to wound healing by combining antimicrobial activity, cell compatibility, and hemostatic properties.

Battery-Free and Multifunctional Microfluidic Janus Wound Dressing with Biofluid Management, Multi-Indicator Monitoring, and Antibacterial Properties.

The sophisticated environment of chronic wounds, characterized by prolonged exudation and recurrent bacterial infections, poses significant challenges to wound recovery. Recent advancements in multifunctional wound dressings fall short of providing comprehensive, accurate, and comfortable treatment. To address these issues, a battery-free and multifunctional microfluidic Janus wound dressing (MM-JWD) capable of three functions, including exudate management, antibacterial properties, and multiple indications of wound infection detection, has been developed. During the treatment, the fully soft microfluidic Janus membrane not only demonstrated stable unidirectional fluid transport capabilities under various skin deformations for a longer period but also provided antibacterial effects through surface treatment with chitosan quaternary ammonium salts and poly(vinyl alcohol). Furthermore, integrating multiple colorimetric sensors within the Janus membrane's microchannels and a dual-layer structure enabled simultaneous monitoring of the wound's pH, uric acid, and temperature. The monitoring was facilitated by smartphone recognition of color changes in the sensors. In vivo and in vitro tests confirmed the exudate management, antibacterial, and sensing capabilities of the MM-JWD, proving its efficacy in monitoring and promoting the healing of wounds. Overall, this study provides a valuable method for the design of multifunctional wound dressings for chronic wound care.

Orally Deliverable Microalgal-Based Carrier with Selenium Nanozymes for Alleviation of Inflammatory Bowel Disease.

Excessive reactive oxygen species (ROS) is a hallmark of both the onset and progression of inflammatory bowel disease (IBD), where a continuous cycle of ROS and inflammation drives the progression of diseases. The design of oral antioxidant nanoenzymes for scavenging ROS has emerged as a promising strategy to intervene in IBD. However, the practical application of these nanoenzymes is limited due to their single catalytical property and significantly impacted by substantial leakage in the upper gastrointestinal tract. This study introduces a novel oral delivery system, SP@CS-SeNPs, combining natural microalgae Spirulina platensis (SP), which possesses superoxide dismutase (SOD)-like activity, with chitosan-functionalized selenium nanoparticles (CS-SeNPs) that exhibit catalase-like activity. The SP@CS-SeNPs system leverages the dual catalytic capabilities of these components to initiate a cascade reaction that first converts superoxide anion radicals (O2•-) into hydrogen peroxide (H2O2), and then catalyzes the decomposition of H2O2 into water and oxygen. This system not only utilizes the resistance of the microalgae carrier to gastric acid and its efficient capture by intestinal villi, thereby enhancing intestinal distribution and retention but also demonstrates significant anti-inflammatory effects and effective repair of the damaged intestinal barrier in a colitis mice model. These results demonstrate that this oral delivery system successfully combines the features of microalgae and nanozymes, exhibits excellent biocompatibility, and offers a novel approach for antioxidant nanozyme intervention in IBD.

Bimetallic Fe/Co-MOF dispersed in a PVA/chitosan multi-matrix hydrogel as a flexible sensor for the detection of lactic acid in sweat samples.

A novel bimetallic Fe/Co-metal-organic framework (MOF) hydrogel-based wearable sweat sensor was developed. Morphological and structural analysis of the hydrogel shows uniformly sized spines and spindle-shaped particles of the Fe/Co-MOF, and it has a high surface area (132.306 m2 g-1) and porosity (0.059 cm3 g-1) as confirmed by Brunauer-Emmett-Teller (BET) studies. The integration of the bimetallic MOF into a polyvinyl alcohol/chitosan (PVA/CS)-mixed matrix resulted in a multiple network hydrogel. The optimisation study investigated  the effects of different pH of the PBS electrolyte, scan rates, and accumulation time in voltammetry. The electrochemical methods such as cyclic voltammetry (CV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS) provided information on the redox behaviour, electrochemical stability, and catalytic activity of the hydrogel. The sensor demonstrates a wide linear detection range from 0.05 µM to 100 mM, a superior sensitivity of 0.02 mA mM-1 cm-2, and a lower limit of detection of 0.01 µM . Active sites distributed over the hydrogel surface, specifically Fe2+ and Co2+ within the MOF structure, catalyse the oxidation of L-lactic acid, resulting in electron transfer and the formation of pyruvic acid. Notably, the fabricated sensor exhibits high selectivity, effectively discriminating against interfering species such as uric acid, ascorbic acid, glucose, urea, dopamine, NaCl, and CaCl2. Real-time analysis conducted in a simulated sweat sample via the standard addition method resulted in good recovery percentages of a minimum of 98%. The work presented here is a versatile and simple platform for point-of-care testing, especially for athletes and military personnel.

Hepatoma-Targeting and ROS-Responsive Polymeric Micelle-Based Chemotherapy Combined with Photodynamic Therapy for Hepatoma Treatment.

Background: The combination of nanoplatform-based chemotherapy and photodynamic therapy (PDT) is a promising way to treat cancer. Celastrol (Cela) exhibits highly effective anti-hepatoma activity with low water solubility, poor bioavailability, non-tumor targeting, and toxic side effects. The combination of Cela-based chemotherapy and PDT via hepatoma-targeting and reactive oxygen species (ROS)-responsive polymeric micelles (PMs) could solve the application problem of Cela and further enhance antitumor efficacy. Methods: In this study, Cela and photosensitizer chlorin e6 (Ce6) co-loaded glycyrrhetinic acid-modified carboxymethyl chitosan-thioketal-rhein (GCTR) PMs (Cela/Ce6/GCTR PMs) were prepared and characterized. The safety, ROS-sensitive drug release, and intracellular ROS production were evaluated. Furthermore, the in vitro anti-hepatoma effect and cellular uptaken in HepG2 and BEL-7402 cells, and in vivo pharmacokinetic, tissue distribution, and antitumor efficacy of Cela/Ce6/GCTR PMs in H22 tumor-bearing mice were then investigated. Results: Cela/Ce6/GCTR PMs were successfully prepared with nanometer-scale particle size, favorable drug loading capacity, and encapsulation efficiency. Cela/Ce6/GCTR PMs exhibited a strong safety profile and better hemocompatibility, exhibiting less damage to normal tissues. Compared with Cela-loaded GCTR PMs, the ROS-responsiveness of Cela/Ce6/GCTR PMs was increased, and the release of Cela was accelerated after combination with PDT. Cela/Ce6/GCTR PMs can efficiently target liver tumor cells by uptake and have a high cell-killing effect in response to ROS. The combination of GCTR PM-based chemotherapy and PDT resulted in increased bioavailability of Cela and Ce6, improved liver tumor targeting, and better anti-hepatoma effects in vivo. Conclusion: Hepatoma-targeting and ROS-responsive GCTR PMs co-loaded with Cela and Ce6 combined with PDT exhibited improved primary hepatic carcinoma therapeutic effects with lower toxicity to normal tissues, overcoming the limitations of monotherapy and providing new strategies for tumor treatment.

Phenomenological investigation of organic modified cements as biocompatible substrates interfacing model marine organisms.

Organic modification can generally endow inorganic materials with novel and promotional characteristics to fit into new functionalities. In this paper, new cement-based composite materials, with Portland cement as the substrate and polyacrylamide (PAM, alone) and PAM/chitosan as the functional components mixed with cement (bulk modified) or served as the surface coating (surface modified), were prepared and engineered as sampling substrates for biofilm and coral co-culture. In comparison to the bulk modified substrate and pure cement material, the surface modified substrate showed a balanced mechanical property, considering both bending and compressive strengths and distinctive surface features toward facilitating biofilm and coral growth, as characterized by spectroscopic, morphological, mechanical, and biofilm and coral co-culture experiments. We, thus, believe that the as-prepared surface modified substrate has the very potential to be applied as a substitute/alternative for the conventional cement material in the construction and engineering of artificial facilities with ecological protection functions.