Potent antitumor efficacy of human dental pulp stem cells armed with YSCH-01 oncolytic adenovirus.

BACKGROUND: Systemic administration of oncolytic adenovirus for cancer therapy is still a challenge. Mesenchymal stem cells as cell carriers have gained increasing attention in drug delivery due to their excellent tumor tropism, immunosuppressive modulatory effects, and paracrine effects. However, the potential of human dental pulp stem cells (hDPSCs) loaded with oncolytic adenovirus for cancer biotherapy has not been investigated yet. METHODS: The stemness of hDPSCs was characterized by FACS analysis and Alizarin red staining, Oil Red O staining, and immunofluorescence assays. The biological fitness of hDPSCs loaded with oncolytic adenovirus YSCH-01 was confirmed by virus infection with different dosages and cell viability CCK-8 assays. Additionally, the expression of CAR receptor in hDPSCs was detected by qPCR assay. Tumor tropism of hDPSC loaded with YSCH-01 in vitro and in vivo was investigated by Transwell assays and living tumor-bearing mice imaging technology and immunohistochemistry, Panoramic scanning of frozen section slices assay analysis. Furthermore, the antitumor efficacy was observed through the different routes of YSCH-01/hPDSCs administration in SW780 and SCC152 xenograft models. The direct tumor cell-killing effect of YSCH-01/hDPSCs in the co-culture system was studied, and the supernatant of YSCH-01/hDPSCs inhibited cell growth was further analyzed by CCK-8 assays. RESULTS: hDPSCs were found to be susceptible to infection by a novel oncolytic adenovirus named YSCH-01 and were capable of transporting this virus to tumor sites at 1000 VP/cell infectious dosage in vitro and in vivo. Moreover, it was discovered that intraperitoneal injection of hDPSCs loaded with oncolytic adenovirus YSCH-01 exhibited potential anti-tumor effects in both SW780 and SCC152 xenograft models. The crucial role played by the supernatant secretome derived from hDPSCs loaded with YSCH-01 significantly exerted a specific anti-tumor effect without toxicity for normal cells, in both an active oncolytic virus and an exogenous protein-independent manner. Furthermore, the use of hDPSCs as a cell carrier significantly reduced the required dosage of virus delivery in vivo compared to other methods. CONCLUSIONS: These findings highlight the promising clinical potential of hDPSCs as a novel cell carrier in the field of oncolytic virus-based anti-cancer therapy.

Transcatheter Arterial Embolization with N-Butyl-2 Cyanoacrylate Glubran 2 for the Treatment of Acute Renal Hemorrhage Under Coagulopathic Conditions.

BACKGROUND: Transcatheter arterial embolization (TAE) for acute renal hemorrhage (RH) under coagulopathic conditions with N-butyl-2 cyanoacrylate (NBCA) is rarely described in the literature, and a consensus on the efficacy and safety of NBCA under this condition has not been reached. The present study aimed to evaluate the efficacy and safety of TAE using NBCA Glubran 2 in the treatment of acute RH under coagulopathic conditions. METHODS: Eight patients who underwent TAE with NBCA Glubran 2 for acute RH under coagulopathic conditions were collected. RESULTS: NBCA Glubran 2 was employed as the sole embolic material in 6 patients. In the remaining 2 patients, NBCA Glubran 2 was employed for secondary embolization. Under coagulopathic conditions, both technical success and clinical success were achieved in treating acute RH with NBCA Glubran 2 in all patients. During a mean follow-up time of 30.1 months, neither persistent nor recurrent active hemorrhage required a repeated endovascular or surgical treatment for hemostasis. No Glubran 2-related complications occurred. In addition, there was no significant difference between the evaluated glomerular filtration rate level before and after one week of Glubran 2 embolization (P = 0.88; CI, -32.4 to 37.4). CONCLUSIONS: TAE with NBCA Glubran 2 may be a safe alternative treatment for the management of RH under coagulopathic conditions. In particular, this method appears to be a potentially attractive alternative when conventional embolic materials fail in patients with ongoing hemodynamic instability or even under severe coagulopathic conditions.

Evaluation of skeletal muscle perfusion in canine hind limb ischemia model using color-coded digital subtraction angiography.

OBJECTIVE: To evaluate perfusion alterations in skeletal muscle in a canine hind limb ischemia model using color-coded digital subtraction angiography (CC-DSA). METHODS: Twelve beagles underwent embolization at the branch of their left deep femoral artery. Right hind limbs were used as the control group. Angiography was performed before and immediately after embolization. Upon CC-DSA analysis, time to peak (TTP) was measured before embolization in both sides of the beagles' hind limbs at the middle iliac artery, and the distant, middle and proximal femoral artery. Regions of interest (ROI) peak and ROI peak time were symmetrically computed in proximal and distal thigh muscles before and immediately after embolization. The data were analyzed and compared using the Wilcoxon signed rank test. RESULTS: Before embolization, ROI peak in the proximal thigh was lower than in the ipsilateral distal thigh, whereas ROI peak time in the proximal thigh was longer than in the distal thigh. In the iliac femoral artery, there was no significant difference in ROI peak, ROI peak time, or TTP between right and left sides. After embolization, ROI peaks in proximal and distal skeletal muscles of the left hind limb were significantly lower than on the contralateral side. ROI peak time was significantly longer in the left proximal and left distal thigh compared to the contralateral side. There were no significant changes in ROI peak or ROI peak time in the right proximal and right distal thigh compared to pre-embolization values. Changes in ROI peak and ROI peak time were larger in the left proximal than in the left distal thigh. CONCLUSION: CC-DSA provided real-time measurement of changes in vascular hemodynamics and skeletal muscle perfusion without increasing X-ray usage or contrast agent dose.

Ultrahighly Charged Amphiphilic Polymer Brushes with Super-Antibacterial and Self-Cleaning Capabilities.

Bacterial infection on biomaterial devices and the subsequent medical risks pose a serious problem in both human healthcare and industrial applications, resulting in a prevalence of various antimicrobial materials. Cationic amphiphilic polymer has been proposed to be a new generation of efficient antibacterial material, but the surface modified by such types of polymers still shows incomplete bactericidal ability and easily contaminated performance. With this in mind, a novel kind of geminized cationic amphiphilic polymer brush surface has been developed in this study, presenting a complete antibacterial activity, because of the synergistic biocidal effect of electrostatic and hydrophobic interactions, as well as the minimized contact area between bacteria and polymer surface. A structure self-adjustment process of polymer brush construction has been proposed, in which the mutual interference among cationic head groups can be avoided and the electrostatic repulsion and hydrophobic attraction can be balanced, in the formation of a smooth and tight surface. A self-cleaning capability of polymer surface has been performed via hydrolysis and degradation, maintaining a high antibacterial activity. Therefore, we provide a facile and possible manipulation strategy to fabricate super-antibacterial and self-cleaning surfaces in a wide range of biomedical and industrial applications.

Rational Design of a Polymer with Robust Efficacy for Intracellular Protein and Peptide Delivery.

The efficient delivery of biopharmaceutical drugs such as proteins and peptides into the cytosol of target cells poses substantial challenges owing to their large size and susceptibility to degradation. Current protein delivery vehicles have limitations such as the need for protein modification, insufficient delivery of large-size proteins or small peptides, and loss of protein function after the delivery. Here, we adopted a rational approach to design a polymer with robust efficacy for intracellular protein and peptide delivery. The polymer is composed of a dendrimer scaffold, a hydrophobic membrane-disruptive region, and a multivalent protein binding surface. It allows efficient protein/peptide binding, endocytosis, and endosomal disruption and is capable of efficiently delivering various biomacromolecules including bovine serum albumin, R-phycoerythrin, p53, saporin, ß-galactosidase, and peptides into the cytosol of living cells. Transduction of apoptotic proteins and peptides successfully induces apoptosis in cancer cells, suggesting that the activities of proteins and peptides are maintained during the delivery. This technology represents an efficient and useful tool for intracellular protein and peptide delivery and has broad applicability for basic research and clinical applications.

Comparative efficacy of Glubran and polyvinyl-alcohol particles in the embolization of meningiomas.

PURPOSE: Preoperative embolization of meningiomas decreases intraoperative bleeding and shortens operation time. However, in meningiomas predominantly vascularized by the internal carotid artery (ICA) or vertebral artery (VA) branches, embolization of external carotid artery feeder branches may lead to a hemodynamic increase in blood supply from the ICA or VA, whereas embolization of ICA or VA feeder branches with particle embolic agents may be associated with complications. This study investigated the safety and efficacy of Glubran, a liquid embolic agent, for the embolization of this type of meningioma compared with polyvinyl-alcohol (PVA) particles. MATERIALS AND METHODS: From January 2006 to June 2015, 157 consecutive patients (98 females; mean age = 48.3 years) who suffered from meningiomas and were preoperatively referred for embolization were retrospectively analyzed. Glubran (n = 40) and PVA (n = 55) were used to devascularize tumors. Sixty-two patients were not embolized because of dangerous anastomosis or other tumor characteristics. Intraoperative blood loss, intraoperative time, degree of angiographic devascularization and embolization-related complications were analyzed. RESULTS: The intraoperative blood loss and operative time were significantly lower in the Glubran-embolized versus non-embolized group. Furthermore, Glubran embolization significantly reduced intraoperative blood loss and operative time for meningiomas that received their primary blood supply from the ICA and/or VA compared with PVA embolization. CONCLUSIONS: Preoperative meningioma embolization with Glubran decreases intraoperative blood loss and operative time. Furthermore, embolization with Glubran produces more effective devascularization compared with PVA for meningiomas supplied by the ICA and/or VA. Thus, Glubran may represent a better embolic agent for this meningioma subtype.

Uniaxially aligned electrospun all-cellulose nanocomposite nanofibers reinforced with cellulose nanocrystals: scaffold for tissue engineering.

Uniaxially aligned cellulose nanofibers with well oriented cellulose nanocrystals (CNCs) embedded were fabricated via electrospinning using a rotating drum as the collector. Scanning electron microscope (SEM) images indicated that most cellulose nanofibers were uniaxially aligned. The incorporation of CNCs into the spinning dope resulted in more uniform morphology of the electrospun cellulose/CNCs nanocomposite nanofibers (ECCNN). Polarized light microscope (PLM) and transmission electron microscope (TEM) showed that CNCs dispersed well in ECCNN nonwovens and achieved considerable orientation along the long axis direction. This unique hierarchical microstructure of ECCNN nonwovens gave rise to remarkable enhancement of their physical properties. By incorporating 20% loading (in weight) of CNCs, the tensile strength and elastic modulus of ECCNN along the fiber alignment direction were increased by 101.7 and 171.6%, respectively. Their thermal stability was significantly improved as well. In addition, the ECCNN nonwovens were assessed as potential scaffold materials for tissue engineering. It was elucidated from MTT tests that the ECCNN were essentially nontoxic to human cells. Cell culture experiments demonstrated that cells could proliferate rapidly not only on the surface but also deep inside the ECCNN. More importantly, the aligned nanofibers of ECCNN exhibited a strong effect on directing cellular organization. This feature made the scaffold particularly useful for various artificial tissues or organs, such as blood vessel, tendon, nerve, and so on, in which cell orientation was crucial for their performance.

Microenvironment-responsive bilayer hydrogel microspheres with gelatin-shell for osteoarthritis treatment.

Osteoarthritis is a long-term degenerative condition of the joints that is characterized by the breakdown of cartilage and inflammation of the synovial membrane. The presence of an inflammatory microenvironment and the degradation of the extracellular matrix produced by chondrocytes leads to the aggravation of cartilage injury, hindering the treatment of osteoarthritis. A promising approach to address this issue is to apply a combined strategy that is sensitive to the specific conditions in osteoarthritic joints and possesses properties that can reduce inflammation and promote cartilage healing. Here, inspired by the structure of chocolate-covered peanuts, we developed an injectable, environment-responsive bilayer hydrogel microsphere using microfluidics technology. The microsphere applied chondroitin sulfate methacryloyl (ChsMA) as its core and was coated with a methacryloyl gelatin (GelMA) shell that was loaded with celecoxib (CLX) liposomes (ChsMA+CLX@Lipo@GelMA). CLX was released from the liposomes when the GelMA shell rapidly degraded in response to the osteoarthritic microenvironment and suppressed the generation of inflammatory agents, demonstrating a beneficial impact of the outer shell in reducing inflammation. While the inner methacryloyl microsphere core degraded, chondroitin sulfate was released to promote chondrocyte anabolism and facilitate cartilage repair. Thus, the synthesized bilayer hydrogel microspheres hold great potential for treating osteoarthritis.

Amphiphilic Dendrimer Doping Enhanced pH-Sensitivity of Liposomal Vesicle for Effective Co-delivery toward Synergistic Ferroptosis-Apoptosis Therapy of Hepatocellular Carcinoma.

Ferroptosis, characterized by the accumulation of reactive oxygen species and lipid peroxides, has emerged as an attractive strategy to reverse drug resistance. Of particular interest is the ferroptosis-apoptosis combination therapy for cancer treatment. Herein, a nanoplatform is reported for effective co-delivery of the anticancer drug sorafenib (S) and the ferroptosis inducer hemin (H), toward synergistic ferroptosis-apoptosis therapy of advanced hepatocellular carcinoma (HCC) as a proof-of-concept study. Liposome is an excellent delivery system; however, it is not sufficiently responsive to the acidic tumor microenvironment (TME) for tumor-targeted drug delivery. The pH-sensitive vesicles are therefore developed (SH-AD-L) by incorporating amphiphilic dendrimers (AD) into liposomes for controlled and pH-stimulated release of sorafenib and hemin in the acidic TME, thanks to the protonation of numerous amine functionalities in AD. Importantly, SH-AD-L not only blocked glutathione synthesis to disrupt the antioxidant system, but also increased intracellular Fe2+ and ·OH concentrations to amplify oxidative stress, both of which contribute to enhanced ferroptosis. Remarkably, high levels of ·OH also augmented sorafenib-mediated apoptosis in tumor cells. This study demonstrates the efficacy of ferroptosis-apoptosis combination therapy, as well as the promise of the AD-doped TME-responsive vesicles for drug delivery in combination therapy to treat advanced HCC.

Ions play different roles in virus removal caused by different NOMs in UF process: Removal efficiency and mechanism analysis.

In this study, we investigated the effect of different compositions of aquatic natural organic matter (NOM) and ions on virus removal by ultrafiltration (UF). MS2 bacteriophage was used as a surrogate. Humic acid (HA) improved the MS2 removal rate from 1.95 ± 0.09 LRV to 2.40 ± 0.03 LRV at the HA dosage of 9 mg/L through the combined mechanisms of size exclusion, electrostatic repulsion and hydrophobicity. MS2 removal rate further increased to 3.10 ± 0.05 LRV by 10 mmol/L Na+ dosage and 3.19 ± 0.12 LRV by Ca2+ 1 mmol/L in the HA-containing UF system. Size exclusion turned into the dominant virus removal mechanism according to the results of the fouling model fitting and the weakening of electrostatic repulsion and hydrophobicity. The complexation of Ca2+ also played a role in MS2 removal based on the analysis of interaction force. MS2 removal rate by bovine serum albumin (BSA) was poor, which was 2.07 ± 0.06 LRV at the BSA dosage of 9 mg/L. Hydrophobicity was greatly reduced and the dominant virus removal mechanisms were size exclusion and electrostatic repulsion. 10 mmol/L Na+ in the presence of BSA deteriorated MS2 removal rate to 2.02 ± 0.07 LRV by the weakening of electrostatic repulsion, hydrophobicity and size exclusion. Electrostatic repulsion severely decreased by 1 mmol/L Ca2+ and the enhanced adsorption barrier represented competitive adsorption of Ca2+ by BSA and MS2 contributed for MS2 removal further decline (1.99 ± 0.05 LRV). Complex components in water will have different effects on virus removal due to their properties and interactions. This study can provide references for selecting more efficient water treatment methods according to the different compositions of raw water in actual water treatment applications during the UF process. Moreover, the retention of virus by UF can be predicted based on our study results.

How to create a nervous system aneurysm model in canines? ligation of the lingual artery is a simple and effective method.

Background: The purpose of this research was to establish a safe, effective, and simple nervous system aneurysm model. This method could quickly and stably establish an exact canine tongue aneurysm model. This paper summarizes the technique and key points of the method. Methods: Under the condition of anesthesia by inhaling isoflurane with a mask, we punctured the femoral artery of the canine, and the tip of the catheter was placed in the common carotid artery for intracranial arteriography. The positions of the lingual artery, external carotid artery, and internal carotid artery were identified. Then, the skin near the mandible was cut according to the positioning and separated layer by layer until the bifurcation of the lingual artery and external carotid artery was exposed. The lingual artery were then sutured with 2-0 silk sutures approximately 3 mm from the external carotid/lingual artery bifurcation. The final angiographic review showed that the aneurysm model was successfully established. Results: The lingual artery aneurysm was successfully established in all 8 canines. All canines obtained a stable model of nervous system aneurysm and confirmed by DSA angiography. Conclusion: We have established a safe, effective, stable and simple method to establish a canine nervous system aneurysm model with controllable size. In addition, this method has the advantages of no arteriotomy, less trauma, constant anatomical location, and low risk of stroke.

Variation of blending ratio and drying temperature optimize the physical properties and compatibility of HPMC/curdlan films.

Hydroxypropyl methylcellulose (HPMC) and curdlan (CL) were used to prepare uniform films. The influence of the composition ratios and drying temperature on the microstructures, compatibility and physical performance of HPMC/CL films were studied. The crystalline peaks corresponding to CL component of HPMC/CL films increased with the increasing CL content. Increasing CL content resulted in increased hydrogen bonds in HPMC/CL film, reduced transmittance at 500 nm, oxygen permeability and water solubility of the HPMC/CL films. Higher drying temperature led to increased phase separation and decreased physical properties of pure HPMC film, and led to increased compatibility, cross-section smoothness, oxygen barrier property and mechanical properties of pure CL and blending films.

In-situ utilization of membrane foulants (FeOx+MnOx) for the efficient membrane cleaning.

Preoxidation-ultrafiltration process is an effective method for Fe2+ and Mn2+removal, in which Fe2+ (Mn2+) are firstly oxidized to FeOx (MnOx), then collected by the ultrafiltration membrane. However, the simultaneous presence of Fe2+, Mn2+, and organics in feed can cause severe membrane fouling, which inhibits the overall performance of this method prominently. In this study, a novel FeOx+MnOx+H2O2 membrane cleaning method is proposed based on the idea of turning in-situ generated membrane foulants, i.e., FeOx+MnOx, into the catalysts for membrane cleaning. The results demonstrate that the FeOx+MnOx+H2O2 system can achieve more than 95% membrane flux recovery and remove almost all irreversible membrane foulants within only 5 min and with only 0.5%wt% H2O2 solution. The outstanding performance of the system is mainly attributed to the catalytic decomposition of H2O2 to generate both highly reactive radicals, such as hydroxyl radicals (·OH), and abundant oxygen. In addition, when the membrane is loaded by only MnOx, polyaluminium chloride (PAC) as the coagulator demonstrates prominent influence on the performance of membrane cleaning. However, PAC makes almost no contribution to membrane cleaning when the membrane is loaded by FeOx. This is because coagulation induced by PAC exerts more prominent impact on the particle size distribution of MnOx than that of FeOx. In conclusion, the catalytic decomposition of H2O2 by in-situ generated FeOx+MnOx is a promising advanced oxidation process to achieve outstanding membrane cleaning performance under the condition of low H2O2 concentration and no extra dosage of catalysts. The novel membrane cleaning system exhibits high potential for the practical membrane treatment processes to treat water with high contents of Fe and Mn.

Novel sodium percarbonate-MnO2 effervescent tablets for efficient and moderate membrane cleaning.

Membrane flux recovery efficiency and durability are two key factors closely associated with the practical application for membrane cleaning process. However, conventional chemical membrane cleaning method by soaking the whole membrane module in highly concentrated chemical reagents has prominent drawbacks including the low mass transfer efficiency of reagents, long period of washing time, and the potential threat to membrane structure. Herein, for the first time, we report a facile approach to fabricate the sodium percarbonate-MnO2 effervescent tablets which show bubbling reaction to release oxygen and free radicals when being dispersed in water for membrane cleaning. Due to the synergistic effect of MnO2 and sodium percarbonate, the tablets are highly effective to clean the membrane fouled by humic acid within 5 min, with the terminal membrane flux being recovered from 0.50 to 0.95, and the irreversible fouling resistance being reduced by more than 90%, which is prominently more efficient than the conventional chemical cleaning methods. Moreover, even by consecutive membrane fouling and cleaning for 6 times, the membrane flux and filtration efficiency of the membrane could still be kept almost constant, and the moderateness of this membrane cleaning method was also verified by the systematic microscopic analysis. For mechanism study, results of Electron Spin Resonance (ESR) and quenching experiments indicated that the high-efficiency and robust durability of sodium percarbonate-MnO2 (SPC-MnO2) system for membrane cleaning was mainly attributed to the abundantly generated hydroxyl radicals and secondary free radicals (i.e. carbonate radicals). Conclusively, compared with the conventional membrane cleaning method with liquid cleaning reagents, the novel SPC-MnO2 system with remarkable advantages in terms of convenience and membrane cleaning performance demonstrated high potential for the wide application in practice.

[Effects of polystyrene microplastics (PS-MPs) on the growth, physiology, and biochemical characteristics of Hydrilla verticillata]. / 聚苯乙烯微塑料对黑藻生长及生理生化特征的影响.

In order to evaluate the effects of polystyrene microplastics (PS-MPs) on the growth, physiology, and biochemical characteristics of submerged plants, we exposed a typical submerged plant, Hydrilla verticillata, to a series of concentrations (i.e. 0, 5, 10, 30, 50, 100 mg·L-1) of 3 µm polystyrene microplastics (PS-MPs) and measured parameters including height, biomass, chlorophyll content, antioxidant enzyme activity, photosynthetic fluorescence. The results showed that the height of H. Verticillata significantly decreased at the high PS-MP concentrations (50 to 100 mg·L-1), while the fresh weight significantly increased at the low PS-MP concentration (5 mg·L-1). The fresh weight of H. verticillata gradually decreased with the increasing PS-MP concentration but the dry weight did not change. The total amount of chlorophyll, chlorophyll a, and chlorophyll a/b significantly decreased with the increases of the PS-MP concentrations, while the chlorophyll b did not change. PS-MPs affected the antioxidant enzyme activities of H. verticillata. The activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) were first increased and then decreased with the increasing PS-MP concentration. The chlorophyll fluorescence parameters (Fo, Fm, Fv/Fm) decreased with the increasing concentration of PS-MP and the 1-Qp-Lss value (reflective of the closing of PSⅡ reaction center) was increased under the stable state, probably due to the inhibited PSⅡ reaction center. The overall intensity of fluorescence imaging of H. verticillata decreased with the increasing concentration of PS-MPs. When the PS-MP concentration was lower than 10 mg·L-1, the photosynthetic activity of the leaves was normal. In contrast, when the PS-MP concentration was higher than 30 mg·L-1, it caused significant adverse effects on leaves, including weaker photosynthetic intensity and the presence of yellow or withered leaves. Our results suggested that H. verticillata could tolerate PS-MP pollution but its growth and photosynthesis would be inhibited at high concentrations (>30 mg·L-1). Our results provided basic information to better understand the eco-physiological effects of PS-MPs in the freshwater environment.

Opposite impacts of K+ and Ca2+ on membrane fouling by humic acid and cleaning process: Evaluation and mechanism investigation.

Understanding the influences of cations on membrane fouling was important to improve the performance of membrane filtration system, however, opposite conclusions were made in different studies. Meanwhile, although the influences of cation concentration have been studied extensively, few attentions have been paid to the cation valence. To clarify it, the effects of typical cations on membrane fouling and cleaning, as well as the related mechanisms were investigated systemically in this study. K+ and Ca2+ were chosen as the representative cations, and humic acid (HA) was chosen as the membrane foulants. The results demonstrated Ca2+ promoted the formation of reversible fouling, meanwhile higher removal efficiency of HA could also be achieved with the assistance of filtration cake containing HA + Ca2+. However, K+ led to the formation of more recalcitrant irreversible fouling. By comparing the concentration of cations in feed and permeate, analyzing the influence of cations on size of HA flocs, and the detailed SEM, AFM and TEM observation, it could be found that different mechanisms dominated the interaction between cations and HA. The bridging effect induced by Ca2+ attributed to the extension of HA molecules, while the electrostatic shielding effect induced by K+ led to the compression of them. Moreover, the different characteristics of hydrated Ca2+ and K+ also contributed to the different structures of foulant layers formed by HA + Ca2+ and HA + K+. Given the abundance of K+ and Ca2+ in natural water, results of this study can provide valuable advice for practical membrane filtration process.

Fully organic compliant dry electrodes self-adhesive to skin for long-term motion-robust epidermal biopotential monitoring.

Wearable dry electrodes are needed for long-term biopotential recordings but are limited by their imperfect compliance with the skin, especially during body movements and sweat secretions, resulting in high interfacial impedance and motion artifacts. Herein, we report an intrinsically conductive polymer dry electrode with excellent self-adhesiveness, stretchability, and conductivity. It shows much lower skin-contact impedance and noise in static and dynamic measurement than the current dry electrodes and standard gel electrodes, enabling to acquire high-quality electrocardiogram (ECG), electromyogram (EMG) and electroencephalogram (EEG) signals in various conditions such as dry and wet skin and during body movement. Hence, this dry electrode can be used for long-term healthcare monitoring in complex daily conditions. We further investigated the capabilities of this electrode in a clinical setting and realized its ability to detect the arrhythmia features of atrial fibrillation accurately, and quantify muscle activity during deep tendon reflex testing and contraction against resistance.

Novel H2O2-MnO2 system for efficient physico-chemical cleaning of fouled ultrafiltration membranes by simultaneous generation of reactive free radicals and oxygen.

The novel H2O2-MnO2 system was developed to achieve highly efficient membrane cleaning for both fouled PVDF and PES membranes in this study. Compared with conventional chemical cleaning process in which the whole membrane module had to be soaked in highly concentrated solution of chemical reagent for long period of time, the H2O2-MnO2 cleaning process conducting for only 5 min in 0.5 wt% H2O2 solution could achieve more than 95% recovery of permeate flux and almost total removal of the irreversible foulants. More importantly, the permeate flux and filtration efficiency of the membrane could be still kept stable after 6 runs of consecutive fouling and cleaning. Based on the systematic microscopic analyses, Electron Spin Resonance (ESR), Fourier Transform Infrared Spectroscopy (FTIR), as well as the quenching experiments with different free radical scavengers, the outstanding performance of H2O2-MnO2 system was attributed to the generation of both free radicals and abundant oxygen simultaneously, leading to the physico-chemical membrane cleaning. Conclusively, the newly developed H2O2-MnO2 system demonstrated noteworthy advantages on efficient membrane cleaning, and exhibited highly potential for the wide application in practical water treatment process.

A novel porous bioceramic scaffold by accumulating hydroxyapatite spheres for large bone tissue engineering. III: Characterization of porous structure.

Physical characteristics of bone tissue engineering scaffolds, including interconnectivity, microporosity, macroporosity, and pore geometry are known to play a crucial role in bone regeneration. In the present study, three-dimensional (3D) interconnected scaffolds were prepared by accumulating hydroxyapatite (HA) spheres in a titanium mesh tube (ф 1.5 × 3 cm). Three types of porous scaffolds were constructed using HA spheres with diameters of 1651-1981 µm, 830-1180 µm and a mixture of 1651-1981 µm and 830-1180 µm at a volumetric ratio of 1:1, respectively. The total porosity of the three scaffolds was 64.72%, 64.85% and 65.04%, while the macroporosity of the scaffolds was 37.56%, 38.86% and 38.01% by using images analysis of cross sections at various positions of the scaffolds. The variation curve of the macroporosity of the scaffolds along the axis perpendicular to the ground showed similarities to sinusoidal function curve. The macropore size was ranged from 0.73R to 2R (R means spheres radius). The average proportions of triangle macropores, quadrilateral macropores, as well as polygon macropores including pentagon, hexagon and irregular polygon macropores in the total macropore areas of each scaffold were 3.73 ±â€¯0.96%, 10.03 ±â€¯1.75% and 86.23 ±â€¯2.71%, respectively. In addition, the macropore size, microporosity and total porosity could be controlled by modifying the diameter and microstructure of HA spheres when the macroporosity was the same. The study and analysis of macropore structure of the spheres accumulated scaffolds can not only guide the design and fabrication of 3D scaffolds for bone tissue engineering, but also benefit to further understand the impact of macropore structure in 3D scaffolds on osteogenesis.

Fabrication and characterization of electrospun cellulose/nano-hydroxyapatite nanofibers for bone tissue engineering.

Nanofibrous scaffolds from cotton cellulose and nano-hydroxyapatite (nano-HA) were electrospun for bone tissue engineering. The solution properties of cellulose/nano-HA spinning dopes and their associated electrospinnability were characterized. Morphological, thermal and mechanical properties of the electrospun cellulose/nano-HA nanocomposite nanofibers (ECHNN) were measured and the biocompatibility of ECHNN with human dental follicle cells (HDFCs) was evaluated. Scanning electron microscope (SEM) images indicated that the average diameter of ECHNN increased with a higher nano-HA loading and the fiber diameter distributions were well within the range of natural ECM (extra cellular matrix) fibers (50-500nm). The ECHNN exhibited extraordinary mechanical properties with a tensile strength and a Young's modulus up to 70.6MPa and 3.12GPa respectively. Moreover, it was discovered that the thermostability of the ECHNN could be enhanced with the incorporation of nano-HA. Cell culture experiments demonstrated that the ECHNN scaffolds were quite biocompatible for HDFCs attachment and proliferation, suggesting their great potentials as scaffold materials in bone tissue engineering.