Recent progress on cellulose‐based ionic compounds for biomaterials

Glycans play important roles in all major kingdoms of organisms, such as archea, bacteria, fungi, plants, and animals. Cellulose, the most abundant polysaccharide on the Earth, plays a predominant role for mechanical stability in plants, and finds a plethora of applications by humans. Beyond traditional use, biomedical application of cellulose becomes feasible with advances of soluble cellulose derivatives with diverse functional moieties along the backbone and modified nanocellulose with versatile functional groups on the surface due to the native features of cellulose as both cellulose chains and supramolecular ordered domains as extractable nanocellulose. With the focus on ionic cellulose‐based compounds involving both these groups primarily for biomedical applications, a brief introduction about glycoscience and especially native biologically active glycosaminoglycans with specific biomedical application areas on humans is given, which inspires further development of bioactive compounds from glycans. Then, both polymeric cellulose derivatives and nanocellulose‐based compounds synthesized as versatile biomaterials for a large variety of biomedical applications, such as for wound dressings, controlled release, encapsulation of cells and enzymes, and tissue engineering, are separately described, regarding the diverse routes of synthesis and the established and suggested applications for these highly interesting materials.Ionic cellulose‐based compounds as either polymeric cellulose derivatives or ionic nanocellulose have gained tremendous attention within the last years due to their remarkable properties, especially their biological properties. Recent advances about various ionic cellulose‐based compounds with diverse functional moieties either along the cellulose chains or on the surface of nanocellulose for biomedical applications are systematically summarized. imag

Indomethacin protects rats from neuronal damage induced by traumatic brain injury and suppresses hippocampal IL-1β release through the inhibition of Nogo-A expression

BACKGROUND: Nogo-A is a member of the reticulon family of membrane-associated proteins and plays an important role in axonal remodeling. The present study aimed to investigate alterations in Nogo-A expression following traumatic brain injury (TBI)-induced inflammation and neuronal damage. METHODS: A weight-drop device was used to deliver a standard traumatic impact to rats. Western blot, RT-PCR and ELISA were used to analyze the expression of Nogo-A and IL-1β. Nogo-A antisense, and an irrelevant control oligonucleotide was intracerebroventricularly infused. We also performed H & E staining and luxol fast blue staining to evaluate the neuronal damage and demyelination resulting from TBI and various treatments. RESULTS: Based on RT-PCR and western blot analyses, the expression of Nogo-A was found to be significantly upregulated in the hippocampus beginning eight hours after TBI. In addition, TBI caused an apparent elevation in IL-1β levels and severe neuronal damage and demyelination in the tested animals. All of the TBI-associated molecular and cellular consequences could be effectively reversed by treating the animals with the anti-inflammatory drug indomethacin. More importantly, the TBI-associated stimulation in the levels of both Nogo-A and IL-1β could be effectively inhibited by a specific Nogo-A antisense oligonucleotide. CONCLUSIONS: Our findings suggest that the suppression of Nogo-A expression appears to be an early response conferred by indomethacin, which then leads to decreases in the levels of IL-1β and TBI-induced neuron damage

Kinematic strategies for obstacle-crossing in older adults with mild cognitive impairment

IntroductionMild cognitive impairment (MCI) is considered a transitional stage between soundness of mind and dementia, often involving problems with memory, which may lead to abnormal postural control and altered end-point control when dealing with neuromechanical challenges during obstacle-crossing. The study aimed to identify the end-point control and angular kinematics of the pelvis-leg apparatus while crossing obstacles for both leading and trailing limbs.Methods12 patients with MCI (age: 66.7 ± 4.2 y/o; height: 161.3 ± 7.3 cm; mass: 62.0 ± 13.6 kg) and 12 healthy adults (age: 67.7 ± 2.9 y/o; height: 159.3 ± 6.1 cm; mass: 61.2 ± 12.0 kg) each walked and crossed obstacles of three different heights (10, 20, and 30% of leg length). Angular motions of the pelvis and lower limbs and toe-obstacle clearances during leading- and trailing-limb crossings were calculated. Two-way analyses of variance were used to study between-subject (group) and within-subject (obstacle height) effects on the variables. Whenever a height effect was found, a polynomial test was used to determine the trend. A significance level of α = 0.05 was set for all tests.ResultsPatients with MCI significantly increased pelvic anterior tilt, hip abduction, and knee adduction in the swing limb during leading-limb crossing when compared to controls (p < 0.05). During trailing-limb crossing, the MCI group showed significantly decreased pelvic posterior tilt, as well as ankle dorsiflexion in the trailing swing limb (p < 0.05).ConclusionPatients with MCI adopt altered kinematic strategies for successful obstacle-crossing. The patients were able to maintain normal leading and trailing toe-obstacle clearances for all tested obstacle heights with a specific kinematic strategy, namely increased pelvic anterior tilt, swing hip abduction, and knee adduction during leading-limb crossing, and decreased pelvic posterior tilt and swing ankle dorsiflexion during trailing-limb crossing. The current results suggest that regular monitoring of obstacle-crossing kinematics for reduced toe-obstacle clearance or any signs of changes in crossing strategy may be helpful for early detection of compromised obstacle-crossing ability in patients with single-domain amnestic MCI. Further studies using a motor/cognitive dual-task approach on the kinematic strategies adopted by multiple-domain MCI will be needed for a complete picture of the functional adaptations in such a patient group

Earthquake Probability Assessment for the Active Faults in Central Taiwan: A Case Study

Frequent high seismic activities occur in Taiwan due to fast plate motions. According to the historical records the most destructive earthquakes in Taiwan were caused mainly by inland active faults. The Central Geological Survey (CGS) of Taiwan has published active fault maps in Taiwan since 1998. There are 33 active faults noted in the 2012 active fault map. After the Chi-Chi earthquake, CGS launched a series of projects to investigate the details to better understand each active fault in Taiwan. This article collected this data to develop active fault parameters and referred to certain experiences from Japan and the United States to establish a methodology for earthquake probability assessment via active faults. We consider the active faults in Central Taiwan as a good example to present the earthquake probability assessment process and results. The appropriate “probability model” was used to estimate the conditional probability where M ≥ 6.5 and M ≥ 7.0 earthquakes. Our result shows that the highest earthquake probability for M ≥ 6.5 earthquake occurring in 30, 50, and 100 years in Central Taiwan is the Tachia-Changhua fault system. Conversely, the lowest earthquake probability is the Chelungpu fault. The goal of our research is to calculate the earthquake probability of the 33 active faults in Taiwan. The active fault parameters are important information that can be applied in the following seismic hazard analysis and seismic simulation

An Integrated Edge and Fog System for Future Communication Networks

Put together, the edge and fog form a large diverse pool of computing and networking resources from different owners that can be leveraged towards low latency applications as well as for alleviating high traffic volume in future networks including 5G and beyond. This paper sets out a framework for the integration of edge and fog computing and networking leveraging on ongoing specifications by ETSI MEC ISG and the OpenFog Consortium. It also presents the technological gaps that need to be addressed before such an integrated solution can be developed. These noticeably include challenges relating to the volatility of resources, heterogeneity of underlying technologies, virtualization of devices, and security issues. The framework presented is a Launchpad for a complete solution under development by the 5G-CORAL consortium.This work has been partially funded by the H2020 collaborative Europe/Taiwan research project 5G-CORAL (grant num. 761586

Spatial control of Draper receptor signaling initiates apoptotic cell engulfment.

The engulfment of apoptotic cells is essential for tissue homeostasis and recovering from damage. Engulfment is mediated by receptors that recognize ligands exposed on apoptotic cells such as phosphatidylserine (PS). In this study, we convert Drosophila melanogaster S2 cells into proficient phagocytes by transfecting the Draper engulfment receptor and replacing apoptotic cells with PS-coated beads. Similar to the T cell receptor (TCR), PS-ligated Draper forms dynamic microclusters that recruit cytosolic effector proteins and exclude a bulky transmembrane phosphatase, consistent with a kinetic segregation-based triggering mechanism. However, in contrast with the TCR, localized signaling at Draper microclusters results in time-dependent depletion of actin filaments, which facilitates engulfment. The Draper-PS extracellular module can be replaced with FRB and FKBP, respectively, resulting in a rapamycin-inducible engulfment system that can be programmed toward defined targets. Collectively, our results reveal mechanistic similarities and differences between the receptors involved in apoptotic corpse clearance and mammalian immunity and demonstrate that engulfment can be reprogrammed toward nonnative targets

Continuous harvest of stem cells via partial detachment from thermoresponsive nanobrush surfaces

Stem cell culture is typically based on batch-type culture, which is laborious and expensive. Here, we propose a continuous harvest method for stem cells cultured on thermoresponsive nanobrush surfaces. In this method, stem cells are partially detached from the nanobrush surface by reducing the temperature of the culture medium below the critical solution temperature needed for thermoresponse. The detached stem cells are harvested by exchange into fresh culture medium. Following this, the remaining cells are continuously cultured by expansion in fresh culture medium at 37 °C. Thermoresponsive nanobrush surfaces were prepared by coating block copolymers containing polystyrene (for hydrophobic anchoring onto culture dishes) with three types of polymers: (a) polyacrylic acid with cell-binding oligopeptides, (b) thermoresponsive poly-N-isopropylacrylamide, and (c) hydrophilic poly(ethyleneglycol)methacrylate. The optimal coating durations and compositions for these copolymers to facilitate adequate attachment and detachment of human adipose-derived stem cells (hADSCs) and embryonic stem cells (hESCs) were determined. hADSCs and hESCs were continuously harvested for 5 and 3 cycles, respectively, via the partial detachment of cells from thermoresponsive nanobrush surfaces

Involvement of the Cav3.2 T-type calcium channel in thalamic neuron discharge patterns

<p>Abstract</p> <p>Background</p> <p>Mice that have defects in their low-threshold T-type calcium channel (T-channel) genes show altered pain behaviors. The changes in the ratio of nociceptive neurons and the burst firing property of reticular thalamic (RT) and ventroposterior (VP) neurons in Cav3.2 knockout (KO) mice were studied to test the involvement of thalamic T-channel and burst firing activity in pain function.</p> <p>Results</p> <p>Under pentobarbital or urethane anesthesia, the patterns of tonic and burst firings were recorded in functionally characterized RT and VPL neurons of Cav3.2 KO mice. Many RT neurons were nociceptive (64% under pentobarbital anesthesia and 50% under urethane anesthesia). Compared to their wild-type (WT) controls, fewer nociceptive RT neurons were found in Cav3.2 KO mice. Both nociceptive and tactile RT neurons showed fewer bursts in Cav3.2 KO mice. Within a burst, RT neurons of Cav3.2 KO mice had a lower spike frequency and less-prominent accelerando-decelerando change. In contrast, VP neurons of Cav3.2 KO mice showed a higher ratio of bursts and a higher discharge rate within a burst than those of the WT control. In addition, the long-lasting tonic firing episodes in RT neurons of the Cav3.2 KO had less stereotypic regularity than their counterparts in WT mice.</p> <p>Conclusions</p> <p>RT might be important in nociception of the mouse. In addition, we showed an important role of Cav3.2 subtype of T-channel in RT burst firing pattern. The decreased occurrence and slowing of the bursts in RT neurons might cause the increased VP bursts. These changes would be factors contributing to alternation of pain behavior in the Cav3.2 KO mice.</p

Development of biomaterial surfaces with and without microbial nanosegments

Infections by microorganisms are a major problem in public health throughout the world. Artificial materials, including biomedical goods, inherently lack defense against microbial development. Therefore, microbial cells can adhere on any type of artificial surface, particularly in a moist environment, and start to multiply to form a huge population. In this review, we will discuss a strategy for designing antimicrobial polymers and antimicrobial surfaces. Generally, there are five types of antimicrobial polymers: (a) polymeric biocides, (b) biocidal polymers, (c) biocide-releasing polymers, (d) bioactive oligopeptides, and (e) antimicrobial surfaces. Antimicrobial surfaces preventing the growth of microorganisms are a promising method to inhibit the spread of microbial infections. The antimicrobial surfaces can reject the attachment of microbes and/or kill microbes in the vicinity and can be designed to kill microbes on contact. It is recommended that the material surface not release biocidal substances, therefore preventing exhaustion of biocide release to kill microbes. Furthermore, the antimicrobial surfaces are desired to be nontoxic to human cells. The development of contact-active antimicrobial surfaces by grafting antimicrobial nanosegments onto the material surface will be an important topic in the future

Emodin Induces Apoptotic Death in Murine Myelomonocytic Leukemia WEHI-3 Cells In Vitro

Emodin is one of major compounds in rhubarb (Rheum palmatum L.), a plant used as herbal medicine in Chinese population. Although many reports have shown that emodin exhibits anticancer activity in many tumor cell types, there is no available information addressing emodin-affected apoptotic responses in the murine leukemia cell line (WEHI-3) and modulation of the immune response in leukemia mice. We investigated that emodin induced cytotoxic effects in vitro and affected WEHI-3 cells in vivo. This study showed that emodin decreased viability and induced DNA fragmentation in WEHI-3 cells. Cells after exposure to emodin for 24 h have shown chromatin condensation and DNA damage. Emodin stimulated the productions of ROS and Ca2+ and reduced the level of ΔΨm by flow cytometry. Our results from Western blotting suggest that emodin triggered apoptosis of WEHI-3 cells through the endoplasmic reticulum (ER) stress, caspase cascade-dependent and -independent mitochondrial pathways. In in vivo study, emodin enhanced the levels of B cells and monocytes, and it also reduced the weights of liver and spleen compared with leukemia mice. Emodin promoted phagocytic activity by monocytes and macrophages in comparison to the leukemia mice group. In conclusions, emodin induced apoptotic death in murine leukemia WEHI-3 cells and enhanced phagocytosis in the leukemia animal model