Occurrence and seasonal variation of Perkinsus sp. Infection in wild mollusk populations from coastal waters of Qingdao, northern China.

Perkinsosis has been recognized as one of the major threats to natural and farmed bivalve populations, many of which are of commercial as well as environmental significance. Three Perkinsus species have been identified in China, and the Manila clam (Ruditapes philippinarum) was the most frequently infected species in northern China. Although the occurrence and seasonal variation of Perkinsus spp. have previously been examined, the pathological characteristics of these infections in wild Manila clams and sympatric species in China have seldom been reported. In the present study, the prevalence and intensity of Perkinsus infection in wild populations of Manila clams and 10 sympatric species from three sites were investigated by Ray's fluid thioglycolate medium (RFTM) assay seasonally across a single year. Perkinsus infection was only identified in Manila clams, with a high prevalence (274/284 = 96.48 %) and low intensity (89.8 % with a Mackin value ≤ 2, suggesting generally low-intensity infections) throughout the year. Heavily infected clams were mainly identified in Tianheng in January, which displayed no macroscopic signs of disease. An overview of the whole visceral mass section showed that the trophozoites mostly aggregated in gills and connective tissue of the digestive tract, to a lesser extent in the mantle and foot, and even less frequently in adductor muscle and connective tissues of the gonad. PCR and ITS-5.8S rRNA sequencing of 93 representative RFTM-positive samples revealed a 99.69 to 100 % DNA sequence identity to Perkinsus olseni. Unexpectedly, significantly higher infection intensities were usually identified in January and April when the Condition Index (CI) was relatively high. We propose that factors associated with the anthropogenic harvesting pressure and irregular disturbances should be responsible for the uncommon seasonal infection dynamics of perkinsosis observed in the present study.

Growth, immunity and transcriptome response to different stocking densities in Litopenaeus vannamei.

The effects of different stocking densities on Litopenaeus vannamei were investigated from the aspects of growth performance, immune response and transcriptome in this experiment. L. vannamei (initial body weight: 0.30 ± 0.02 g) were reared for 8 weeks at three stocking densities of 100 (LSD), 200 (MSD) and 300 (HSD) shrimp/m³, respectively. The results showed that the survival rate (SR), final body weight (FBW), weight gain rate (WGR), specific growth ratio (SGR) and protein efficiency ratio (PER) of L. vannamei significantly decreased, while the feed factor (FCR) significantly increased with the increase of stocking density. After Vibrio parahemolyticus infection, the SR of L. vannamei in the HSD group was significantly lower than that in the LSD and MSD groups. Increasing stocking density significantly increased the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lysozyme (LYS) while significantly decreased the activities of catalase (CAT) and phenol oxidase (PO) in the serum of L. vannamei. Similar changes of the gene expression as the activities of immune enzymes were found in the hemocytes. Pairwise comparison between the LSD, MSD and HSD group in the transcriptome analysis identified that there were 304, 1376 and 2083 differentially expressed genes (DEGs) in LSD vs MSD, MSD vs HSD and LSD vs HSD, respectively. Among them, most of the immune-related DEGs were down-regulated and metabolism-related DEGs were up-regulated with the increasing stocking density. In addition, KEGG enrichment pathway analysis revealed that several immune and metabolic related pathways including PI3K-Akt signaling pathway and AMPK signaling pathway were significantly enriched. Of these, the PI3K-Akt signaling pathway had the most DEGs and was also the most significantly enriched pathway. Furthermore, 16 DEGs (such as FOXO, PCK2 and CTSC, etc.) and partial immune enzyme activity (such as AST, CAT and PO, etc.) changes were closely correlated with the increase of stocking density when partial immune-related DEGs and immune-related enzymes were analyzed jointly. All these results indicated that changes in stocking density had a significant effect on the growth performance, immunity and transcriptome of L. vannamei.

The enhancement effect of low-dose dietary lipopolysaccharide on the growth and immunity of Litopenaeus vannamei, and transcriptome analysis.

In this study, the effects of dietary lipopolysaccharide (LPS) on Litopenaeus vannamei were investigated to determine whether LPS could play a role as a potential immunostimulant in shrimp. L. vannamei with an initial body weight of 0.30 ± 0.02 g were fed a diet containing LPS at doses of 0, 0.2, 1, 5, 25 or 125 mg kg-1 for eight weeks (groups LPS0, LPS0.2, LPS1, LPS5, LPS25 and LPS125, respectively). After eight weeks of feeding, the growth performance, immunity and transcriptome response of L. vannamei were analysed. Only dietary LPS at 0.2 and 1 mg kg-1 resulted in a significant increase in the growth of L. vannamei (P < 0.05). According to the weight gain rate (WGR) and specific growth rate (SGR), the optimum dietary LPS level was 2.462 and 2.455 mg kg-1, respectively. When compared with the control group, the survival rate (SR) of L. vannamei in the LPS0.2 group was significantly increased after white spot syndrome virus (WSSV) infection and the SR of L. vannamei in the LPS1 group was significantly increased after Vibrio parahaemolyticus infection (both P < 0.05). Compared with the LPS0 group, immune enzyme activity in the serum of L. vannamei could be significantly increased and the content of maleic dialdehyde (MDA) significantly decreased by dietary LPS. Transcriptome analysis of the haemocytes of L. vannamei identified 399 up-regulated differentially expressed genes (DEGs) and 5000 down-regulated DEGs in the LPS0.2 compared to the control group. Most of the DEGs were significantly enriched in the following pathways: phosphatidylinositol signalling, Wnt signalling, Jak-STAT signalling and inositol phosphate metabolism. In conclusion, this study revealed that diets supplemented with low-dose LPS had positive effects on the growth and immunity of L. vannamei.

Double-Modified Bacterial Cellulose/Soy Protein Isolate Composites by Laser Hole Forming and Selective Oxidation Used for Urethral Repair.

In this study, a double-modified bacterial cellulose/soybean protein isolate (DMBC/SPI), a new type of urethral tissue engineering scaffold with good biocompatibility, biodegradability, and cell-oriented growth, was prepared. Bacterial cellulose (BC) was physically and chemically modified by laser hole forming and selective oxidation to obtain the double-modified bacterial cellulose (DMBC). The soybean protein isolate (SPI) was compounded on DMBC to obtain DMBC/SPI with better biocompatibility. DMBC/SPI was used to repair the damaged urethra in rabbits. The results showed that DMBC/SPI was beneficial to heal the damaged urethra and did not cause a milder inflammatory response. The repaired urethra was smooth and continuous. DMBC/SPI has a good urethral repair effect and is expected to be used as a new urethral reconstruction material in clinical applications. In addition, FT-IR spectroscopy, SEM, static contact angle measurements, mechanical property investigation, and cell experiments were also performed to characterize the properties of DMBC/SPI composites.

Catalytic and regulatory subunits of casein kinase 2 in Penaeus vannamei: Cloning, identification, expression profiles and functional analysis.

As a highly conserved serine/threonine kinase with catalytic and regulatory subunits distributed ubiquitously in eukaryotic organisms, casein kinase 2 (CK2) is involved in multiple cellular functions, including immune regulation. In this study, two variants of the catalytic subunit (designated PvCK2α-1 and PvCK2α-2) and the regulatory subunit homologs (designated PvCK2ß-1 and PvCK2ß-2) in Penaeus vannamei were cloned and characterised. PvCK2α-1 and PvCK2α-2 shared the same genomic sequence consisting of six exons and five introns and encoded the same protein of 350 amino acids with an S_TKc domain, although there was a sequence deletion in 3'-UTR in PvCK2α-2 when compared with PvCK2α-1. Because of the sequence deletion in the ORF, PvCK2ß-1 and PvCK2ß-2 encoded different proteins with a CK_II_beta domain. The gene structures of PvCK2ß-1 and PvCK2ß-2 were identical and consisted of four exons and three introns. Semi-quantitative RT-PCR analyses revealed that PvCK2α and PvCK2ß were constitutively expressed in all P. vannamei tissues tested, with higher levels detected in the immune-related tissues including hemocytes, hepatopancreas, gills and intestine. In these four tissue types, all variants of PvCK2α and PvCK2ß were induced upon challenge with white spot syndrome virus (WSSV), Vibrio parahaemolyticus and Staphyloccocus aureus. The inhibition of PvCK2α, PvCK2ß-1 and PvCK2ßComb (the amount of PvCK2ß-1 and PvCK2ß-2) significantly reduced the survival rates of P. vannamei after WSSV infection and significantly increased the WSSV viral loads. Knockdown of PvCK2 by RNAi could distinctly decrease the expression of NF-κB related genes. All of these results suggest that PvCK2 plays an important role in the innate immune response to pathogen challenges in P. vannamei, with a positive role in anti-WSSV response which may be mediated through regulating the expression of NF-κB drived antimicrobial peptide genes.

Effects of replacing fish meal with cottonseed protein concentrate on the growth, immune responses, digestive ability and intestinal microbial flora in Litopenaeus vannamei.

The effects of cottonseed protein concentrate (CPC) in place of fishmeal on the growth performance, immune response, digestive ability and intestinal microbiota of Litopenaeus vannamei were investigated in this study. L. vannamei (initial body weight: 0.42 ± 0.01g) was fed for 8 weeks by four isonitrogenous and isolipid feeds with CPC replacing fishmeal (FM) at 0% (control), 15% (CPC15), 30% (CPC30) and 45% (CPC45), respectively. At the end of the study, the final body weight (FBW), weight gain rate (WGR), specific growth rate (SGR) and protein efficiency ratio (PER) of L. vannamei in CPC15 and CPC30 groups were significantly increased, while the feed conversion ratio (FCR) of L. vannamei in the CPC30 group was significantly reduced when compared with the FM group (P < 0.05). After Vibrio parahaemolyticus infection, the cumulative mortality of L. vannamei in CPC15 within 24 hpi was significantly lower than that of the control group (P < 0.05). When compared with the control group, the activities and expression of the immunity-related enzymes in the hepatopancreas had almost the same obvious change trend in the CPC-containing groups, which indicated that the replacement for fishmeal by CPC led to significant immune response in L. vannamei. Besides, significant up-regulation of the digestive enzyme activities were observed in the CPC-containing groups. Analysis of intestinal microbiota showed that significant difference in alpha diversity existed between the CPC-containing groups and the control group. The relative abundances of several top 10 dominated species at the phylum and genus levels were significantly changed in the CPC-containing groups compared with the control group (P < 0.05). Functional prediction of the microbiota indicated that the pathway of protein digestion and absorption was significantly more abundant while the pathways of nitrotoluene degradation, aminobenzoate degradation, atrazine degradation, dioxin degradation and xylene degradation were significantly less abundant in the CPC-containing groups than the FM group (P < 0.05). In summary, optimal dietary CPC replacement of FM could improve the growth, immunity, digestive capacity and the diversities of the intestinal microbial flora of L. vannamei. However, parts of the functions of the intestinal microbial flora were decline.

An updated review on the potential antineoplastic actions of oleuropein.

Oleuropein is an ester of elenolic acid and hydroxytyrosol (3, 4-dihydroxyphenylethanol). It is a phenolic compound and the most luxuriant in olives. The detailed information related to the anticancer effects of oleuropein was collected from the internet database PubMed/Medline, ResearchGate, Web of Science, Wiley Online Library, and Cnki using appropriate keywords until the end of October 2021. Oleuropein has been shown to have antioxidant, anticancer, antiinflammatory, cardioprotective, neuroprotective, and hepatoprotective effects. Previous studies also revealed that oleuropein could effectively inhibit the malignant progression of esophageal cancer, gastric cancer, breast cancer, lung cancer, liver cancer, pancreatic cancer, ovarian cancer, prostate cancer, and cervical cancer. Recently, the role of oleuropein in inhibiting tumor cell proliferation, invasion, and migration and inducing tumor cell apoptosis has gained extensive attention. In this review, we have summarized the latest research progress related to the antioncogenic mechanisms and the potential role of oleuropein in targeting different human malignancies. Based on these findings, it can be concluded that oleuropein can function as a promising chemopreventive and chemotherapeutic agent against cancer, but its more detailed anticancer effects and underlying mechanisms need to be further validated in future preclinical as well as clinical studies.

Antibacterial activity and inflammation inhibition of ZnO nanoparticles embedded TiO2 nanotubes.

Titanium (Ti) with nanoscale structure on the surface exhibits excellent biocompatibility and bone integration. Once implanted, the surgical implantation may lead to bacterial infection and inflammatory reaction, which cause the implant failure. In this work, irregular and nanorod-shaped ZnO nanoparticles were doped into TiO2 nanotubes (TNTs) with inner diameter of about 50 nm by electro-deposition. The antibacterial properties of ZnO incorporated into TiO2 nanotubes (TNTs/ZnO) were evaluated using Staphylococcus aureus (S. aureus). Zn ions released from the nanoparticles and the morphology could work together, improving antibacterial effectiveness up to 99.3% compared with the TNTs. Macrophages were cultured on the samples to determine their respective anti-inflammatory properties. The proliferation and viability of macrophages were evaluated by the CCK-8 method and Live&Dead stain, and the morphology of the cells was observed by scanning electron microscopy. Results indicated that TNTs/ZnO has a significant inhibitory effect on the proliferation and adhesion of macrophages, which could be used to prevent chronic inflammation and control the inflammatory reaction. Besides, the release of Zn ions from the ZnO nanoparticles is a long-term process, which could be beneficial for bone integration. Results demonstrate that ZnO deposited into TNTs improved the antibacterial effectiveness and weakened the inflammatory reaction of titanium-based implants, which is a promising approach to enhance their bioactivity.

Stimuli-responsive microcarriers and their application in tissue repair: A review of magnetic and electroactive microcarrier.

Microcarrier applications have made great advances in tissue engineering in recent years, which can load cells, drugs, and bioactive factors. These microcarriers can be minimally injected into the defect to help reconstruct a good microenvironment for tissue repair. In order to achieve more ideal performance and face more complex tissue damage, an increasing amount of effort has been focused on microcarriers that can actively respond to external stimuli. These microcarriers have the functions of directional movement, targeted enrichment, material release control, and providing signals conducive to tissue repair. Given the high controllability and designability of magnetic and electroactive microcarriers, the research progress of these microcarriers is highlighted in this review. Their structure, function and applications, potential tissue repair mechanisms, and challenges are discussed. In summary, through the design with clinical translation ability, meaningful and comprehensive experimental characterization, and in-depth study and application of tissue repair mechanisms, stimuli-responsive microcarriers have great potential in tissue repair.

Finite element analysis of meniscus contact mechanical behavior based on kinematic simulation of abnormal gait.

The meniscus plays a crucial role in the proper functioning of the knee joint, and when it becomes damaged, partial removal or replacement is necessary to restore proper function. Understanding the stress and deformation of the meniscus during various movements is essential for developing effective materials for meniscus repair. However, accurately estimating the contact mechanics of the knee joint can be challenging due to its complex shape and the dynamic changes it undergoes during movement. To address this issue, the open-source software SCONE can be used to establish a kinematics model that monitors the different states of the knee joint during human motion and obtains relevant gait kinematics data. To evaluate the stress and deformation of the meniscus during normal human movement, values of different states in the movement gait can be selected for finite element analysis (FEA) of the knee joint. This analysis enables researchers to assess changes in the meniscus. To evaluate meniscus damage, it is necessary to obtain changes in its mechanical behavior during abnormal movements. This information can serve as a reference for designing and optimizing the mechanical performance of materials used in meniscus repair and replacement.

Calibrating ultrasonic sensor measurements of crop canopy heights: a case study of maize and wheat.

Canopy height serves as an important dynamic indicator of crop growth in the decision-making process of field management. Compared with other commonly used canopy height measurement techniques, ultrasonic sensors are inexpensive and can be exposed in fields for long periods of time to obtain easy-to-process data. However, the acoustic wave characteristics and crop canopy structure affect the measurement accuracy. To improve the ultrasonic sensor measurement accuracy, a four-year (2018-2021) field experiment was conducted on maize and wheat, and a measurement platform was developed. A series of single-factor experiments were conducted to investigate the significant factors affecting measurements, including the observation angle (0-60°), observation height (0.5-2.5 m), observation period (8:00-18:00), platform moving speed with respect to the crop (0-2.0 m min-1), planting density (0.2-1 time of standard planting density), and growth stage (maize from three-leaf to harvest period and wheat from regreening to maturity period). The results indicated that both the observation angle and planting density significantly affected the results of ultrasonic measurements (p-value< 0.05), whereas the effects of other factors on measurement accuracy were negligible (p-value > 0.05). Moreover, a double-input factor calibration model was constructed to assess canopy height under different years by utilizing the normalized difference vegetation index and ultrasonic measurements. The model was developed by employing the least-squares method, and ultrasonic measurement accuracy was significantly improved when integrating the measured value of canopy heights and the normalized difference vegetation index (NDVI). The maize measurement accuracy had a root mean squared error (RMSE) ranging from 81.4 mm to 93.6 mm, while the wheat measurement accuracy had an RMSE from 37.1 mm to 47.2 mm. The research results effectively combine stable and low-cost commercial sensors with ground-based agricultural machinery platforms, enabling efficient and non-destructive acquisition of crop height information.

Low-Temperature Extrusion of Waterborne Polyurethane-Polycaprolactone Composites for Multi-Material Bioprinting of Engineered Elastic Cartilage.

3D bioprinting of elastic cartilage tissues that are mechanically and structurally comparable to their native counterparts, while exhibiting favorable cellular behavior, is an unmet challenge. A practical solution for this problem is the multi-material bioprinting of thermoplastic polymers and cell-laden hydrogels using multiple nozzles. However, the processing of thermoplastic polymers requires high temperatures, which can damage hydrogel-encapsulated cells. In this study, the authors developed waterborne polyurethane (WPU)-polycaprolactone (PCL) composites to allow multi-material co-printing with cell-laden gelatin methacryloyl (GelMA) hydrogels. These composites can be extruded at low temperatures (50-60 °C) and high speeds, thereby reducing heat/shear damage to the printed hydrogel-capsulated cells. Furthermore, their hydrophilic nature improved the cell behavior in vitro. More importantly, the bioprinted structures exhibited good stiffness and viscoelasticity compared to native elastic cartilage. In summary, this study demonstrated low-temperature multi-material bioprinting of WPU-PCL-based constructs with good mechanical properties, degradation time-frames, and cell viability, showcasing their potential in elastic cartilage bio-fabrication and regeneration to serve broad biomedical applications in the future.

Fabrication of a modified bacterial cellulose with different alkyl chains and its prevention of abdominal adhesion.

Abdominal hernia mesh is a common product which is used for prevention of abdominal adhesion and repairing abdominal wall defect. Currently, designing and preparing a novel bio-mesh material with prevention of adhesion, promoting repair and good biocompatibility simultaneously remain a great bottleneck. In this study, a novel siloxane-modified bacterial cellulose (BC) was designed and fabricated by chemical vapor deposition silylation, then the effects of different alkyl chains length of siloxane on surface properties and cell behaviors were explored. The effect of preventing of abdominal adhesion and repairing abdominal wall defect in rats with the siloxane-modified BC was evaluated. As the grafted alkyl chains become longer, the surface of the siloxane-modified BC can be transformed from super hydrophilic to hydrophobic. In vivo results showed that BC-C16 had good long-term anti-adhesion effect, good tissue adaptability and histocompatibility, which is expected to be used as a new anti-adhesion hernia repair material in clinic.

A dual dynamically cross-linked hydrogel promotes rheumatoid arthritis repair through ROS initiative regulation and microenvironment modulation-independent triptolide release.

High oxidative stress and inflammatory cell infiltration are major causes of the persistent bone erosion and difficult tissue regeneration in rheumatoid arthritis (RA). Triptolide (TPL) has become a highly anticipated anti-rheumatic drug due to its excellent immunomodulatory and anti-inflammatory effects. However, the sudden drug accumulation caused by the binding of "stimulus-response" and "drug release" in a general smart delivery system is difficult to meet the shortcoming of extreme toxicity and the demand for long-term administration of TPL. Herein, we developed a dual dynamically cross-linked hydrogel (SPT@TPL), which demonstrated sensitive RA microenvironment regulation and microenvironment modulation-independent TPL release for 30 days. The abundant borate ester/tea polyphenol units in SPT@TPL possessed the capability to respond and regulate high reactive oxygen species (ROS) levels on-demand. Meanwhile, based on its dense dual crosslinked structure as well as the spontaneous healing behavior of numerous intermolecular hydrogen bonds formed after the breakage of borate ester, TPL could remain stable and slowly release under high ROS environments of RA, which dramatically reduced the risk of TPL exerting toxicity while maximized its long-term efficacy. Through the dual effects of ROS regulation and TPL sustained-release, SPT@TPL alleviated oxidative stress and reprogrammed macrophages into M2 phenotype, showing marked inhibition of inflammation and optimal regeneration of articular cartilage in RA rat model. In conclusion, this hydrogel platform with both microenvironment initiative regulation and TPL long-term sustained release provides a potential scheme for rheumatoid arthritis.

Decellularized laser micro-patterned osteochondral implants exhibit zonal recellularization and self-fixing for osteochondral regeneration in a goat model.

Background: Osteochondral regeneration has long been recognized as a complex and challenging project in the field of tissue engineering. In particular, reconstructing the osteochondral interface is crucial for determining the effectiveness of the repair. Although several artificial layered or gradient scaffolds have been developed recently to simulate the natural interface, the functions of this unique structure have still not been fully replicated. In this paper, we utilized laser micro-patterning technology (LMPT) to modify the natural osteochondral "plugs" for use as grafts and aimed to directly apply the functional interface unit to repair osteochondral defects in a goat model. Methods: For in vitro evaluations, the optimal combination of LMPT parameters was confirmed through mechanical testing, finite element analysis, and comparing decellularization efficiency. The structural and biological properties of the laser micro-patterned osteochondral implants (LMP-OI) were verified by measuring the permeability of the interface and assessing the recellularization processes. In the goat model for osteochondral regeneration, a conical frustum-shaped defect was specifically created in the weight-bearing area of femoral condyles using a customized trephine with a variable diameter. This unreported defect shape enabled the implant to properly self-fix as expected. Results: The micro-patterning with the suitable pore density and morphology increased the permeability of the LMP-OIs, accelerated decellularization, maintained mechanical stability, and provided two relative independent microenvironments for subsequent recellularization. The LMP-OIs with goat's autologous bone marrow stromal cells in the cartilage layer have securely integrated into the osteochondral defects. At 6 and 12 months after implantation, both imaging and histological assessments showed a significant improvement in the healing of the cartilage and subchondral bone. Conclusion: With the natural interface unit and zonal recellularization, the LMP-OI is an ideal scaffold to repair osteochondral defects especially in large animals. The translational potential of this article: These findings suggest that such a modified xenogeneic osteochondral implant could potentially be explored in clinical translation for treatment of osteochondral injuries. Furthermore, trimming a conical frustum shape to the defect region, especially for large-sized defects, may be an effective way to achieve self-fixing for the implant.

Injectable and in situ foaming shape-adaptive porous Bio-based polyurethane scaffold used for cartilage regeneration.

Irregular articular cartilage injury is a common type of joint trauma, often resulting from intense impacts and other factors that lead to irregularly shaped wounds, the limited regenerative capacity of cartilage and the mismatched shape of the scaffods have contributed to unsatisfactory therapeutic outcomes. While injectable materials are a traditional solution to adapt to irregular cartilage defects, they have limitations, and injectable materials often lack the porous microstructures favorable for the rapid proliferation of cartilage cells. In this study, an injectable porous polyurethane scaffold named PU-BDO-Gelatin-Foam (PUBGF) was prepared. After injection into cartilage defects, PUBGF forms in situ at the site of the defect and exhibits a dynamic microstructure during the initial two weeks. This dynamic microstructure endows the scaffold with the ability to retain substances within its interior, thereby enhancing its capacity to promote chondrogenesis. Furthermore, the chondral repair efficacy of PUBGF was validated by directly injecting it into rat articular cartilage injury sites. The injectable PUBGF scaffold demonstrates a superior potential for promoting the repair of cartilage defects when compared to traditional porous polyurethane scaffolds. The substance retention ability of this injectable porous scaffold makes it a promising option for clinical applications.

The characterization of the concentration of the single-walled carbon nanotubes in aqueous dispersion by UV-Vis-NIR absorption spectroscopy.

Current and future applications of single-wall carbon nanotubes (SWCNTs) depend on the dispersion of the SWCNTs in aqueous solution and their quantitation. The concentration of SWCNTs is an important indicator to evaluate the dispersibility of the surfactant-dispersed SWCNTs suspension. Due to the complexity of the SWCNTs suspension, it is necessary to determine both the total concentration of the dispersed SWCNTs and the concentration of individually dispersed SWCNTs in aqueous suspensions, and these were evaluated through the absorbance and the resonance ratios of UV-Vis-NIR absorption spectra, respectively. However, there is no specific and reliable position assigned for either calculation of the absorbance or the resonance ratio of the UV-Vis-NIR absorption spectrum. In this paper, different ranges of wavelengths for these two parameters were studied. From this, we concluded that the wavelength range between 300 nm and 600 nm should be the most suitable for evaluation of the total concentration of dispersed SWCNTs in the suspension; also, wavelengths below 800 nm should be most suitable for evaluation of the concentration of individually dispersed SWCNTs in the suspension. Moreover, these wavelength ranges are verified by accurate dilution experiments.

Tailored fibro-porous structure of electrospun polyurethane membranes, their size-dependent properties and trans-membrane glucose diffusion.

The aim of this study was to develop polyurethane (PU) based fibro-porous membranes and to investigate the size-effect of hierarchical porous structure on permeability and surface properties of the developed electrospun membranes. Non-woven Selectophore™ PU membranes having tailored fibre diameters, pore sizes, and thickness were spun using electrospinning, and their chemical, physical and glucose permeability properties were characterised. Solvents, solution concentration, applied voltage, flow rate and distance to collector, each were systematically investigated, and electrospinning conditions for tailoring fibre diameters were identified. Membranes having average fibre diameters - 347, 738 and 1102 nm were characterized, revealing average pore sizes of 800, 870 and 1060 nm and pore volumes of 44, 63 and 68% respectively. Hydrophobicity increased with increasing fibre diameter and porosity. Effective diffusion coefficients for glucose transport across the electrospun membranes varied as a function of thickness and porosity, indicating high flux rates for mass transport. Electrospun PU membranes having significantly high pore volumes, extensively interconnected porosity and tailorable properties compared to conventional solvent cast membranes can find applications as coatings for sensors requiring analyte exchange.

In Situ Polymerization of Methylene Blue on Bacterial Cellulose for Photodynamic/Photoelectricity Synergistic Inhibition of Bacterial Biofilm Formation.

In the context of long-term antimicrobial treatment, the emergence of bacterial resistance poses a significant challenge. Therefore, there is a pressing need to develop novel antimicrobial materials and methods that can effectively and safely combat microbial infections. This study focuses on the synthesis of bacterial cellulose-polymethylene blue (BC-PMB) with integrated photodynamic and photoelectric antimicrobial properties. The polymerization of methyl blue (MB) onto bacterial celluloses (BC) was achieved, and through comprehensive computational analyses using density functional theory (DFT) and molecular dynamics simulations, it was confirmed that this polymerization greatly enhanced the binding efficiency between methylene blue and BC. Additionally, polymethylene blue (PMB) exhibited superior photoexcitation efficiency and conductivity compared to its precursor. When BC-PMB was exposed to a 30 mW 660 nm light source for 30 min, the material demonstrated a remarkable antimicrobial efficacy of 93.99% against Escherichia coli and 98.58% against Staphylococcus aureus. Furthermore, the synergistic effect of photodynamic and photoelectric antimicrobial mechanisms exhibited long-term inhibitory capabilities against bacterial biofilms.

Aldehyde-mediated adaptive membranes with self-healing and antimicrobial properties for endometrial repair.

Traditional treatment methods for irreversible endometrial damage face a number of challenges in clinical practice, the most important of which are bacterial infection and the inability to restore endometrial function. By modifying glucan, oxidized dextran (OD) with multifunctional aldehyde groups was obtained in this study. Based on the dynamic Schiff base reaction between gelatin (GA) and OD, a GA-OD adaptive membrane with good biocompatibility, self-healing, biodegradability, and antimicrobial properties was created. In vitro studies revealed that GA and OD cross-linking overcame GA's low gel temperature, accelerated gelling, and improved mechanical properties, hydrophilicity, and degradability. The dynamic bond formed by the reaction between GA and OD caused the GA-OD film to self-heal. Meanwhile, the GA-OD membrane had antibacterial properties. To assess the repair effect of GA-OD film, an in vivo rat endometrial injury model filled with GA-OD adaptive membrane was created. According to the results of the study, the GA-OD membrane was biocompatible, and the uterine tissue did not have edema and inflammation. Further study on the postoperative endometrial regeneration effect of GA-OD material showed that it had an excellent ability for epithelial reconstruction and cell proliferation. As a result, the use of GA-OD composite film in endometrial repair has promising therapeutic implications.