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1.
Zhongguo Zhong Yao Za Zhi ; 45(7): 1627-1632, 2020 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-32489042

RESUMO

Two medicinal PA type Perilla germplasms were planted at five planting densities(D1,2 500 plants/Mu;D2,5 500 plants/Mu;D3,8 500 plants/Mu;D4,11 500 plants/Mu;D5,14 500 plants/Mu;1 Mu≈667 m~2). A total of 17 traits, including leaf shape, plant type, yield, volatile oil content and composition, were recorded and studied. With the planting density increased, the leaves appeared narrow, plants small, the deciduous leaves increased, and the leaf yield per plant was low, but the leaf yield per Mu increases significantly with the planting density, and was basically stable after reaching D4. The extraction rate of volatile oil from leaves at planting density D2-D5 was about 0.1% higher than that of D1, and there was no significant difference in the relative content of perillaldehyde, among 5 density. In order to achieve high leaf yield, it is recommended to plant at a density of D4, 11 500 plants/Mu(plant spacing is 15 cm, and row spacing is 40 cm); while comprehensive leaf yield and leaf morphology are recommended to be planted at a density of D2, 5 500 plants/Mu(plant spacing is 30 cm, and row spacing is 40 cm). At the same time, dense planting resistance of two germplasms were different. Number of secondary branches, first section with leaves and plant types were most important feature for the evaluation of the density tolerance of PA-type Perilla. This study provided a reference for the suitable density of PA-type Perilla, and laid a foundation for further study of the tolerance characteristics of different Perilla.


Assuntos
Óleos Voláteis , Perilla frutescens , Folhas de Planta
2.
Neuron ; 2020 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-32353253

RESUMO

Optogenetics is among the most widely employed techniques to manipulate neuronal activity. However, a major drawback is the need for invasive implantation of optical fibers. To develop a minimally invasive optogenetic method that overcomes this challenge, we engineered a new step-function opsin with ultra-high light sensitivity (SOUL). We show that SOUL can activate neurons located in deep mouse brain regions via transcranial optical stimulation and elicit behavioral changes in SOUL knock-in mice. Moreover, SOUL can be used to modulate neuronal spiking and induce oscillations reversibly in macaque cortex via optical stimulation from outside the dura. By enabling external light delivery, our new opsin offers a minimally invasive tool for manipulating neuronal activity in rodent and primate models with fewer limitations on the depth and size of target brain regions and may further facilitate the development of minimally invasive optogenetic tools for the treatment of neurological disorders.

3.
Artigo em Inglês | MEDLINE | ID: mdl-32424859

RESUMO

The chemical structures and topologies of the crosslinks in supramolecular networks play a crucial role in their properties and functions. Herein, the preparation of a type of poly(N-isopropylacrylamide) (PNIPAAM)-based supramolecular networks crosslinked by emissive hexagonal metallacycles is presented. The topological connections in these networks greatly affect their properties, as evidenced by their differences in absorption, emission, lower critical solution temperature, and modulus along with the variation of crosslinking densities. The integration of PNIPAAM and metallacycles in the networks benefits them improved bioavailability, making them serve as reagents for bacterial imaging and killing. This study provides a strategy to prepare cavity-crosslinked polymer networks for antibacterial applications.

4.
Biomacromolecules ; 21(5): 1841-1852, 2020 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-32388998

RESUMO

As the abuse of antibiotics continues to increase, the emergence of antibiotic resistance and unknown drug-resistant bacterial infections pose a great threat on people worldwide. In this work, we aimed to develop a series of injectable antimicrobial conductive hydrogels based on glycidyl methacrylate functionalized quaternized chitosan (QCSG), gelatin methacrylate (GM), and graphene oxide (GO) for drug-resistant bacterial disinfection and infectious wound healing. The rheology, morphology, mechanical properties, and electrical and photothermal properties of the hydrogels were characterized. Furthermore, the good in vitro and in vivo intrinsic antibacterial, photothermal antibacterial, and antibiotics released antibacterial properties of this multiantibacterial hydrogel were verified. The good biocompatibility of these hydrogels was also investigated by cytocompatibility, hemocompatibility, and histocompatibility tests. In the drug-resistant Methicillin-resistant Staphylococcus aureus (MRSA) infected mouse full-thickness defect model, the wound closure rate, the length of dermal tissue gap, number of blood vessels and hair follicles in hematoxylin-eosin (HE) staining, the amount of collagen in Masson staining, and the related cytokines for the expression of inflammation (interleukin-6, IL-6) and regeneration of blood vessels (vascular endothelial growth factor, VEGF) in immunofluorescence were all further studied. All the results demonstrated the better wound healing effect of these multiantibacterial injectable conductive hydrogel in infectious skin tissue defect repair, indicating their great potential for infected wound healing.

5.
ACS Appl Mater Interfaces ; 12(23): 26432-26443, 2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32429664

RESUMO

The development of a highly effective photosensitizer (PS) that can be activated with a low-power single light is a pressing issue. Herein, we report a PS for synergistic photodynamic and photothermal therapy constructed through self-assembly of poly(selenoviologen) on the surface of core-shell NaYF4:Yb/Tm@NaYF4 upconversion nanoparticles. The hybrid UCNPs/PSeV PS showed strong ROS generation ability and high photothermal conversion efficiency (∼52.5%) under the mildest reported-to-date irradiation conditions (λ = 980 nm, 150 mW/cm2, 4 min), leading to a high efficiency in killing methicillin-resistant Staphylococcus aureus (MRSA) both in vitro and in vivo. Remarkably, after intravenous injection, the reported PS accumulated preferentially in deep MRSA-infected tissues and achieved an excellent therapeutic index. This PS design realizes a low-power single-NIR light-triggered synergistic phototherapy and provides a simple and versatile strategy to develop safe clinically translatable agents for efficient treatment of deep tissue bacterial inflammations.

6.
Brain Res ; 1739: 146823, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32272097

RESUMO

Cerebral venous infarction (CVI) caused by the injury of cortical bridging veins (CBVs), is one of the most serious complications following neurosurgical craniotomy. Different from cerebral artery infarction, this CVI pathological process is more complicated, accompanied by acute venous hypertension, brain edema, cerebral ischemia and hemorrhage in the veins bridged brain area. Therefore, a reliable and stable small animal model is particularly important for the pathological study of CVI induced by surgical CBV interruption (CBVi). A mouse model established by cutting off the right CBVs from bregma to lambda with microsurgical technique is used for the assessment of the pathological process. Adult male mice underwent craniotomy after transection of the parietal skin under anesthesia. The right CBVs were exposed by removing the right skull along the right lateral edge of the sagittal sinus (forming a 4 mm × 3 mm bone window from bregma to lambda) with a drill under the operating microscope. Following the final inspection of the cerebral veins, the CBVs (30% one, 60% two, 10% none) were sacrificed using bipolar coagulation technique. Intracranial pressure (ICP) monitoring, motor function examination, brain edema assessment and brain histopathological observation after perfusion were performed at different time points (6 h, 12 h, 24 h, and 48 h) in the postoperative mice. Cerebral hemisphere swelling, midline shift and subcortical petechial hemorrhage were found on histological sections 6 h after CBVs dissection. The change of ICP was consistent with cerebral edema and peaked at 12 h after surgery, as well as the disruption of the blood-brain barrier assessed by Evans Blue staining. Tissue necrosis, nerve cell loss and monocytes infiltration were also dynamically increased in the postoperative hemispheric cortex. Behavioral tests showed obvious somato- and forelimb-motor dysfunction, and severe somatosensory disorder on the operative mice at 12 h, which were substantially recovered at 48 h. Our study provided a novel mouse model of CVI caused by surgical CBVi that was close to clinical practice, and preliminarily confirmed its pathological process. This model might become an important tool to study the clinical pathology and the molecular mechanism of nerve injury following CVI.

7.
Biochim Biophys Acta Mol Basis Dis ; 1866(8): 165806, 2020 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-32320827

RESUMO

Diabetic cardiomyopathy (DCM) accounts for increasing deaths of diabetic patients, and effective therapeutic targets are urgently needed. Myocardial lipotoxicity, which is caused by cardiac non-oxidative metabolic fatty acids and cardiotoxic fatty acid metabolites accumulation, has gained more attention to explain the increasing prevalence of DCM. However, whether mammalian Ste20-like kinase 1 (Mst1) plays a role in lipotoxicity in type 2 diabetes-induced cardiomyopathy has not yet been illustrated. Here, we found that Mst1 expression was elevated transcriptionally in the hearts of type 2 diabetes mellitus mice and palmitic acid-treated neonatal rat ventricular myocytes. Adeno-associated virus 9 (AAV9)-mediated Mst1 silencing in db/db mouse hearts significantly alleviated cardiac dysfunction and fibrosis. Notably, Mst1 knockdown in db/db mouse hearts decreased lipotoxic apoptosis and inflammatory response. Mst1 knockdown exerted protective effects through inactivation of MAPK/ERK kinase kinase 1 (MEKK1)/c-Jun N-terminal kinase (JNK) signaling pathway. Moreover, lipotoxicity induced Mst1 expression through promoting the binding of forkhead box O3 (FoxO3) and Mst1 promoter. Conclusively, we elucidated for the first time that Mst1 expression is regulated by FOXO3 under lipotoxicity stimulation and downregulation of Mst1 protects db/db mice from lipotoxic cardiac injury through MEKK1/JNK signaling inhibition, indicating that Mst1 abrogation may be a potential treatment strategy for DCM in type 2 diabetic patients.

8.
Nat Neurosci ; 23(4): 520-532, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32123378

RESUMO

Hyper-reactivity to sensory input is a common and debilitating symptom in individuals with autism spectrum disorders (ASD), but the neural basis underlying sensory abnormality is not completely understood. Here we examined the neural representations of sensory perception in the neocortex of a Shank3B-/- mouse model of ASD. Male and female Shank3B-/- mice were more sensitive to relatively weak tactile stimulation in a vibrissa motion detection task. In vivo population calcium imaging in vibrissa primary somatosensory cortex (vS1) revealed increased spontaneous and stimulus-evoked firing in pyramidal neurons but reduced activity in interneurons. Preferential deletion of Shank3 in vS1 inhibitory interneurons led to pyramidal neuron hyperactivity and increased stimulus sensitivity in the vibrissa motion detection task. These findings provide evidence that cortical GABAergic interneuron dysfunction plays a key role in sensory hyper-reactivity in a Shank3 mouse model of ASD and identify a potential cellular target for exploring therapeutic interventions.

9.
Steroids ; 156: 108587, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31982423

RESUMO

A phytochemical study on the rhizomes of Trillium tschonoskii led to the isolation of fourteen new steroidal saponins, trillitschosides S1-S14 (1-14), along with ten known analogues (15-24). Their structures were established mainly by spectroscopic analyses as well as necessary chemical evidence. All isolated compounds were screened for the cytotoxicity against HepG2 cells, and the results demonstrated that only the known compounds 21-24 exhibited the remarkable cytotoxic activity against HepG2 cells which is much better than the positive control of 5-FU.

10.
Prog Neurobiol ; 184: 101721, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31704315

RESUMO

Although exogenous nerve growth factor (NGF) demonstrated great potential for post-traumatic stress disorder (PTSD) treatment, its therapeutic effect and underlying cytological mechanism were not fully elucidated so far. We employed a controlled, prospectively designed modified single prolonged stress mice model to investigate the role of exogenous NGF on the modified single prolonged stress induced PTSD-like symptoms and hippocampal cytoarchitecture impairment, as well as the potential neuronal signaling modulation. We discovered that the modified single prolonged stress-exposure induced significant PTSD-like symptoms as well as mildly impaired hippocampal Cornu Ammonis 1 (CA1) subregion cytoarchitecture, but not dentate gyrus neurogenesis, together with a gradual inhibition of TrkA-CREB-ERK signalings in hippocampal CA1 subregion. NGF treatment dose-dependently ameliorated the modified single prolonged stress induced PTSD-like symptoms. NGF increased the cytoplasm/nucleus ratio and improved the neuronal plasticity, mainly via the TrkA-ERK-CREB pathway. Our study offered the translational evidence for the potential application of exogenous NGF for treating or early preventing PTSD after stress exposure.

11.
Nanoscale ; 12(3): 1224-1246, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31859313

RESUMO

Conductive hydrogels have generated great interest in biomedical and electrical fields. However, conventional conductive hydrogels usually lack self-healing properties, which might be unfavorable for their application. Conductive self-healing hydrogels with excellent performance for applications in the biomedical and electrical fields are growing in number. In this review paper, the progress related to conductive self-healing hydrogels is summarized. The self-healing mechanism is classified to demonstrate the design and synthesis of conductive self-healing hydrogels and their applications in tissue engineering, wound healing, electronic skin, sensors and self-repaired circuits are presented and discussed. The future development of conductive self-healing hydrogels and problems that need to be solved are also described.

12.
Biomaterials ; 229: 119584, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31704468

RESUMO

Muscle tissues are soft tissues that are of great importance in force generation, body movements, postural support and internal organ function. Muscle tissue injuries would not only result in the physical and psychological pain and disability to the patient, but also become a severe social problem due to the heavy financial burden they laid on the governments. Current treatments for muscle tissue injuries all have their own severe limitations and muscle tissue engineering has been proposed as a promising therapeutic strategy to treat with this problem. Conductive biomaterials are good candidates as scaffolds in muscle tissue engineering due to their proper conductivity and their promotion on muscle tissue formation. However, a review of conductive biomaterials function in muscle tissue engineering, including the skeletal muscle tissue, cardiac muscle tissue and smooth muscle tissue regeneration is still lacking. Here we reviewed the recent progress of conductive biomaterials for muscle regeneration. The recent synthesis and fabrication methods of conductive scaffolds containing conductive polymers (mainly polyaniline, polypyrrole and poly(3,4-ethylenedioxythiophene), carbon-based nanomaterials (mainly graphene and carbon nanotube), and metal-based biomaterials were systematically discussed, and their application in a variety of forms (such as hydrogels, films, nanofibers, and porous scaffolds) for different kinds of muscle tissues formation (skeletal muscle, cardiac muscle and smooth muscle) were summarized. Furthermore, the mechanism of how the conductive biomaterials affect the muscle tissue formation was discussed and the future development directions were included.

13.
Cell Mol Neurobiol ; 40(5): 801-812, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31863221

RESUMO

Cerebral glycogen is principally localized in astrocytes rather than in neurons. Glycogen metabolism has been implicated in higher brain functions, including learning and memory, yet the distribution patterns of glycogen in different types of astrocytes have not been fully described. Here, we applied a method based on the incorporation of 2-NBDG, a D-glucose fluorescent derivative that can trace glycogen, to investigate glycogen's distribution in the brain. We identified two types of astrocytes, namely, 2-NBDGI (glycogen-deficient) and 2-NBDGII (glycogen-rich) cells. Whole-cell patch-clamp and fluorescence-activated cell sorting (FACS) were used to separate 2-NBDGII astrocytes from 2-NBDGI astrocytes. The expression levels of glycogen metabolic enzymes were analyzed in 2-NBDGI and 2-NBDGII astrocytes. We found unique glycogen metabolic patterns between 2-NBDGI and 2-NBDGII astrocytes. We also observed that 2-NBDGII astrocytes were mainly identified as fibrous astrocytes but not protoplasmic astrocytes. Our data reveal cell type-dependent glycogen distribution and metabolism patterns, suggesting diverse functions of these different astrocytes.

14.
J Colloid Interface Sci ; 556: 514-528, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31473541

RESUMO

Infection is a major obstacle to wound healing. To enhance the healing of infected wounds, dressings with antibacterial activities and multifunctional properties to promote wound healing are highly desirable. Herein, gelatin-grafted-dopamine (GT-DA) and polydopamine-coated carbon nanotubes (CNT-PDA) were used to engineer antibacterial, adhesive, antioxidant and conductive GT-DA/chitosan/CNT composite hydrogels through the oxidative coupling of catechol groups using a H2O2/HRP (horseradish peroxidase) catalytic system. The addition of the antibiotic doxycycline endowed the hydrogels with antimicrobial activity to treat infected full-thickness defect wounds. Additionally, CNT-PDA endowed these hydrogels with an excellent photothermal effect, leading to good in vitro and in vivo antibacterial activities against Gram-positive and Gram-negative bacteria. The catechol group and polydopamine imparted tissue adhesiveness, and the hemostatic and antioxidant abilities of these hydrogels were also investigated. The porosity, degradability, swelling, rheological, mechanical, and conductive behaviors of these hydrogels were finely regulated by changing the concentration of CNT-PDA. Hemolysis and cytocompatibility tests using L929 fibroblast cells confirmed the good biocompatibility of these hydrogels. The wound closure, collagen deposition, histomorphological examination and immunofluorescence staining results demonstrated the excellent effects of these hydrogels in an infected full-thickness mouse skin defect wound. In summary, the adhesive antibacterial and conductive GT-DA/chitosan/CNT hydrogels showed great potential as multifunctional bioactive dressings for the treatment of infected wounds.


Assuntos
Antibacterianos , Antioxidantes , Infecções Bacterianas/terapia , Bandagens , Bactérias Gram-Negativas/crescimento & desenvolvimento , Bactérias Gram-Positivas/crescimento & desenvolvimento , Hidrogéis , Infecção dos Ferimentos/terapia , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Infecções Bacterianas/patologia , Bivalves , Linhagem Celular , Feminino , Fibroblastos/metabolismo , Fibroblastos/patologia , Hidrogéis/química , Hidrogéis/farmacologia , Teste de Materiais , Camundongos , Infecção dos Ferimentos/patologia
15.
Int J Mol Sci ; 20(16)2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-31426439

RESUMO

Epimedium wushanense (Berberidaceae) is recorded as the source plant of Epimedii Wushanensis Folium in the Chinese Pharmacopoeia. However, controversies exist on the classification of E. wushanense and its closely related species, namely, E. pseudowushanense, E. chlorandrum, E. mikinorii, E. ilicifolium, and E. borealiguizhouense. These species are often confused with one another because of their highly similar morphological characteristics. This confusion leads to misuse in the medicinal market threatening efficiency and safety. Here, we studied the plastid genomes of these Epimedium species. Results show that the plastid genomes of E. wushanense and its relative species are typical circular tetramerous structure, with lengths of 156,855-158,251 bp. A total of 112 genes were identified from the Epimedium plastid genomes, including 78 protein-coding, 30 tRNA, and 4 rRNA genes. A loss of rpl32 gene in E. chlorandrum was found for the first time in this study. The phylogenetic trees constructed indicated that E. wushanense can be distinguished from its closely related species. E. wushanense shows a closer relationship to species in ser. Dolichocerae. In conclusion, the use of plastid genomes contributes useful genetic information for identifying medicinally important species E. wushanense and provides new evidence for understanding phylogenetic relationships within the Epimedium genus.


Assuntos
Epimedium/genética , Genomas de Plastídeos , Uso do Códon , DNA de Plantas/genética , Epimedium/classificação , Genômica , Filogenia , Plastídeos/classificação , Plastídeos/genética
16.
Int J Biol Macromol ; 140: 255-264, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31421175

RESUMO

Dextran with good biocompatibility and degradability shows great potentials for drug delivery and tissue engineering applications. Electro-responsive drug delivery system can provide on-demand and localized drug release. However, dextran-based conductive hydrogel with electrical stimuli responsiveness as drug delivery system has not been reported. Herein, we designed and fabricated a kind of biocompatible biodegradable conductive hydrogel system with the property of electro-responsiveness as a new smart drug delivery system for localized drug release. These series of hydrogels were synthesized by mixing dextran and electroactive aniline trimer with hexamethylene diisocyanate as crosslinker to form hydrogel network. These series of hydrogels exhibited stable rheological property and controllable swelling ratio. These hydrogels showed good conductivity and desirable electric stimuli ability to control drug release. Furthermore, this kind of hydrogel was controlled by external electrical stimuli to generate a kind of "on-off" precise drug release system. When extra voltage was applied, they released more drug intelligently and less drug molecule without external stimuli. The hydrogel showed good cytocompatibility and in vivo biocompatibility by using H&E staining and Toluidine blue staining. All together, these results indicated that these series of biocompatible conductive dextran-based hydrogels were promising candidates as smart drug delivery systems in future biomedical field.


Assuntos
Compostos de Anilina/síntese química , Materiais Biocompatíveis/síntese química , Dextranos/síntese química , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Hidrogéis/síntese química , Compostos de Anilina/uso terapêutico , Materiais Biocompatíveis/uso terapêutico , Dextranos/uso terapêutico , Desenho de Fármacos , Condutividade Elétrica , Estimulação Elétrica , Hidrogéis/uso terapêutico , Engenharia Tecidual
17.
Biochem Biophys Res Commun ; 518(2): 344-350, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31421827

RESUMO

Hippocampal SIRT1 dysfunction and gene variation have previously been found potentially involved in depressive and anxiety disorders. However, the exact role of SIRT1 in post-traumatic stress disorder (PTSD) is not well understood. Here, we employed multiple genetic and pharmacological approaches targeting SIRT1 to verify the effects of SIRT1 on SPS-induced PTSD-like behaviors and its potential cellular and molecular mechanisms. We first demonstrated that Sirt1 knockout mice showed milder PTSD-like behavior after single prolonged stress (SPS) induction than wild type mice. Moreover, the expression of SIRT1 in the ventral CA1 (vCA1) region of hippocampus showed no significant changes following SPS induction, but the activity of SIRT1 enzyme was significantly increased post-SPS. Osmotic administration of EX527 in vCA1, a SIRT1 inhibitor, was shown to normalize the SIRT1 activity in SPS mice. Mechanically, EX527 rescued the acetylation of helix-loop-helix transcription factor 2 (NHLH2) and transcriptionally inhibited the increase of MAO-A expression in the vCA1, which thus suppressed the decomposition of the neurotransmitter serotonin into 5-hydroxydoleacetic acid (5-HIAA). Morphologically, Golgi staining showed that EX527 treatment improved the abnormal neuronal structure plasticity in the vCA1 region after SPS, including reversing the atrophic dendrites and the decreased dendritic spines. Finally, SIRT1 inhibitor effectively alleviated fear conditioning responses and anxiety-like behaviors. Our study first demonstrated that the development of PTSD-like behaviors was causatively related to the abnormal increase of SIRT1 activity in the ventral hippocampal CA1 region. And we also provided evidence that SIRT1 inhibition might exert therapeutic effects on PTSD by maintaining serotonin homeostasis through transcriptional inhibition of MAO-A, and thereby remodeled synaptic plasticity in the vCA1 region.

18.
Zhongguo Zhong Yao Za Zhi ; 44(9): 1857-1861, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31342713

RESUMO

The change of icariin( ICA) content in thirty-three samples of five Epimedium species listed in the Chinese Pharmacopoeia( 2015 edition),including E. brevicornu,E. sagittatum,E. pubescens,E. koreanum,and E. wushanense has been investigated in this study. The results indicated that the optimized process procedure was baking at 150 ℃ for 30 min,and 3'''-carbonyl-2″-ß-L-quinovosyl icariin( CQICA) could not be translated into ICA and ICA could be converted under this heating process condition. ICA increased remarkably after the heating process by 1-3 times in E. brevicornu,E. wushanense and E. koreanum,and increased lightly in E. brevicornum and E. pubescens,while ICA slightly increased or decreased in E. sagittatum and E. wushanense.


Assuntos
Medicamentos de Ervas Chinesas/química , Epimedium/química , Flavonoides/análise , Temperatura Alta , Compostos Fitoquímicos/análise , Manejo de Espécimes
19.
Acta Biomater ; 96: 175-187, 2019 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260823

RESUMO

Aligned topographical cue has been demonstrated as a critical role in neuronal guidance, and it is highly beneficial to develop a scaffold with aligned structure for peripheral nerve tissue regeneration. Although considerable efforts have been devoted to guiding neurite alignment and extension, it remains a remarkable challenge for developing a biomimetic scaffold for enhancing 3D aligned neuronal outgrowth. Herein, we present a core-shell scaffold based on aligned conductive nanofiber yarns (NFYs) within the hydrogel to mimic the 3D hierarchically aligned structure of the native nerve tissue. The aligned NFYs assembled by a bundle of aligned nanofibers composed of polycaprolactone (PCL), silk fibroin (SF), and carbon nanotubes (CNTs) are prepared by a developed dry-wet electrospinning method, which has the ability to induce neurite alignment and elongation when PC12 cells and dorsal root ganglia (DRG) cells are cultured on their 3D peripheral surface. Particularly, such an aligned nanofibrous structure also induces aligned neurite extension and cell migration from DRG explants along the direction of nanofibers. 3D core-shell scaffolds are fabricated by encapsulating NFYs within the hydrogel shell after photocrosslinking, and these 3D aligned scaffolds are able to control cellular alignment and elongation of nerve cells in this 3D environment. Our results suggest that such 3D hierarchically aligned core-shell scaffold consists of NFYs that mimic the aligned nerve fiber structure to induce neurite alignment and extension and a hydrogel shell that mimics the epineurium layer to protect nerve cell organization within a 3D environment, which is largely promising for the design of biomimetic scaffolds in nerve tissue engineering. STATEMENT OF SIGNIFICANCE: Designing scaffolds with 3D aligned structure has been paid more attention for peripheral nerve tissue regeneration, because the aligned topographical cue is able to induce neurites alignment and extension. However, developing scaffolds mimicking the hierarchically aligned structure of native nerve tissue for directing 3D aligned neuronal outgrowth without external stimulation remains challenging. This work presented a simple and efficient strategy to prepare a 3D biomimetic core-shell scaffold based on electrospun aligned conductive nanofiber yarns within photocurable hydrogel shell to mimic the hierarchically aligned structure of native nerve tissue. These 3D aligned composite scaffolds performed the ability to direct 3D cellular alignment and elongation of nerve cells along with the nanofiber yarn direction, and the hydrogel shell mimicking the epineurium layer was able to protect nerve cells organization within the 3D environment, which indicated their great potential in peripheral nerve tissue engineering applications.

20.
Zhongguo Zhong Yao Za Zhi ; 44(10): 2009-2014, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31355553

RESUMO

Ziziphi Spinosae Semen is one of the Chinese herbal medicine being susceptible to aflatoxins contamination. To investigate the sources of aflatoxins contamination and toxigenic fungi species on Ziziphi Spinosae Semen,32 samples were collected from multiple steps during the post-harvest processing in this study. Aflatoxins in these samples were determined by immunoaffinity column and HPLC coupled with post-column photochemical derivatization. The dilution-plate method was applied to the fungi isolation. The isolated fungi strains were identified by morphological characterization and molecular approaches. The results showed that aflatoxins were detected in 28 samples from every step during the processing of Ziziphi Spinosae Semen. Three samples were detected with aflatoxin B_1 and 2 samples with both aflatoxin B_1 and total aflatoxin exceeding the limit of Chinese Pharmacopoeia. Especially the samples from the washing step,with the highest detected amounts of AFB_1 and AFs were reached 94. 79,121. 43 µg·kg~(-1),respectively. All 32 samples were contaminated by fungi. The fungal counts on the newly harvested samples were 2. 20 × 10~2 CFU·g~(-1). Moreover,it increased as tphreocessing progresses,and achieved 1. 16×10~6 CFU·g~(-1) after washing. A total of 321 isolates were identified to 17 genera. Aspergillus flavus was the main source of aflatoxins during the processing and storage of Ziziphi Spinosae Semen. One isolate of A. flavus was confirmed producing AFB_1 and AFB_2. The fungal count was significantly increased by composting,and Aspergillus was the predominant genus after shell breaking. The contamination level of aflatoxins was increased by composting and washing.


Assuntos
Aflatoxinas/análise , Fungos/isolamento & purificação , Sementes/química , Sementes/microbiologia , Ziziphus/química , Aspergillus , Cromatografia Líquida de Alta Pressão
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