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Nanomaterials, with the advantages of unique microstructure, have been widely used in the fields of material manufacturing, microelectronics and computer technology, medicine and health, environment and energy. Compared with traditional hemostatic materials, nanomaterials can improve the bioavailability and stability of traditional hemostatic drugs to a certain extent, enhance the controlled and targeted release of drugs, which lay a good foundation for the development of new-style modern hemostatic nanomaterials. This paper reviews the advanced design and application progress of various nanomaterials in hemostasis, such as liposomes, nanoparticles, self-assembled nano peptides, nanofibers, etc. Finally, the challenges and prospects of hemostatic nanomaterials are briefly described.
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In this study, the fibers of invasive species
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La producción de nanofibra en scaffolds utilizando la tecnología de electrospinning abarca muchos parámetros tanto físicos como químicos que han sido estudiados y que todavía no se han dilucidado completamente. Tanto la utilización de polímeros naturales, que por sus características tienen una mayor afinidad y una mayor biocompatibilidad con los procesos celulares, así mismo, una biomimetizacion similar a la estructura de la matriz celular natural del cuerpo; sin embargo, la falta de control sobre algunas sus características físicas repercuten directamente en características biológicas de la célula. Por otro lado, la utilización de polímeros sintéticos nos permite controlar características físicas, pero esto afecta el desarrollo de las células. Por ello, este artículo presenta una breve revisión de artículos científicos acerca del electrospinning y los biomateriales más utilizados para la obtención de scaffolds en el campo de la biomedicina.
Nanofiber production in scaffolds using electrospinning technology encompasses many physical and chemical parameters that have been studied and have not yet been fully elucidated. Both the use of natural polymers, which due to their characteristics have a higher affinity and a greater biocompatibility with cellular processes, as well as a biomimetization similar to the structure of the body's natural cellular matrix; however, the lack of control over some of its physical characteristics directly affects the biological characteristics of the cell. On the other hand, the use of synthetic polymers allows us to control physical characteristics, but this affects the development of cells. For this reason, this article presents a brief review of scientific articles about Electrospinning and the most used materials for obtaining scaffolds in the field of biomedicine.
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The utilization of electrospinning in drug delivery has thrived in recent years, with the ability to incorporate drugsand enhance dissolution; this technique is employed to improve the dissolution of poorly water-soluble selectivephosphodiesterase-5 inhibitor, tadalafil. The strategy involved direct electrospinning of tadalafil/polyvinylpyrrolidoneand polyethylene oxide (PEO) solution. The optimization process included a 32 full factorial design based on theinfluence of polymers concentration as independent variables on the electrospun yield, loading efficiency, nanofibersdiameter, number of beads, and in vitro release. Optimization studies revealed the negative influence of bothpolymers on the electrospun yield, while the loading efficiency and in vitro dissolution rate were reduced by the PEOconcentration solely. The higher polymer concentrations were favorable for the declination of beads number, and adriving factor for fiber diameter reduction. Further physicochemical characterization of the optimized formulationrevealed the presence of the drug in an amorphous state or molecular dispersion within the polymer matrix. In vitrodissolution studies revealed about 81.5% ± 8.34% release in less than 2 minutes compared to a negligible dissolutionof free drug. From the derived outcomes, the electrohydrodynamic spun tadalafil-loaded nanofibers pave the way fordissolution enhancement for insoluble low bioavailability class II drugs.
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BACKGROUND: The application of tissue engineering in the repair of spinal cord injury is a focus of research in recent years, and most of the studies are still in vitro stage. OBJECTIVE: To explore the effect of repairing spinal cord injury with tissue-engineered spinal cord that was composed of new collagen nanofiber membrane and neural stem cells. METHODS: Collagen was used as raw material, and the nanofiber membrane with parallel arrangement and staggered arrangement of fibers was prepared by electronic spinning technology. The spinal cord derived neural stem cells of neonate rats were cultured on two kinds of nanofibers for 7 days to construct the tissue-engineered spinal cord. Sprague-Dawley rat models of spinal cord hemisection were randomly divided into five groups. In the blank control group, any material was not used. In the parallel tissue engineering group and cross tissue engineering group, corresponding tissue-engineered spinal cord was used. In the parallel group and cross group, corresponding nanofiber membrane was used. At 1-8 weeks after the operation, modified BBB scores of the rats were recorded. At 8 weeks after operation, the spinal cord was taken and stained with hematoxylin and eosin and received immunohistochemistry. The experiments were approved by experimental animal welfare and Ethics Management Committee of Harbin Medical University. RESULTS AND CONCLUSION: (1) The BBB scores in the parallel tissue engineering group were higher than those in the other four groups (P < 0.05). The BBB scores in the staggered tissue engineering group, the parallel group and the staggered group were all higher than those in the blank control group (P < 0.05). The BBB scores in the staggered tissue engineering group were higher than those in the parallel group and the staggered group at 2-8 weeks after operation (P < 0.05). The BBB scores in the parallel group were higher than those in the staggered group at 1 and 2 weeks after operation (P < 0.05). (2) Hematoxylin-eosin staining showed that there was almost no cell structure in the injury area of the blank control, and a large number of scar tissue formation was seen. The formation of scar tissue was inhibited in the parallel group and the staggered group, and the tissue repair was not obvious; the scar formation in the adjacent tissue and no cell connection was established between the injury area and the surrounding area. There were a large number of cell components in the scaffold degradation area of the two tissue engineering groups, and there were obvious tissue regeneration, more cells distributed along the direction of the scaffold; connections were built among the cells and with normal tissues. (3) Immunohistochemistry staining showed that neurons were seen in the two tissue engineering groups. (4) The results showed that the effect of nano tissue engineering on the repair of spinal cord injury was good, and the effect of parallel nano fiber membrane was better.
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Nanofibers can mimic natural tissue structure by creating a more suitable environment for cells to grow, prompting a wide application of nanofiber materials. In this review, we include relevant studies and characterize the effect of nanofibers on mesenchymal stem cells, as well as factors that affect cell adhesion and osteogenic differentiation. We hypothesize that the process of bone regeneration in vitro is similar to bone formation and healing in vivo, and the closer nanofibers or nanofibrous scaffolds are to natural bone tissue, the better the bone regeneration process will be. In general, cells cultured on nanofibers have a similar gene expression pattern and osteogenic behavior as cells induced by osteogenic supplements in vitro. Genes involved in cell adhesion (focal adhesion kinase (FAK)), cytoskeletal organization, and osteogenic pathways (transforming growth factor-β (TGF-β)/bone morphogenic protein (BMP), mitogen-activated protein kinase (MAPK), and Wnt) are upregulated successively. Cell adhesion and osteogenesis may be influenced by several factors. Nanofibers possess certain physical properties including favorable hydrophilicity, porosity, and swelling properties that promote cell adhesion and growth. Moreover, nanofiber stiffness plays a vital role in cell fate, as cell recruitment for osteogenesis tends to be better on stiffer scaffolds, with associated signaling pathways of integrin and Yes-associated protein (YAP)/transcriptional co-activator with PDZ-binding motif (TAZ). Also, hierarchically aligned nanofibers, as well as their combination with functional additives (growth factors, HA particles, etc.), contribute to osteogenesis and bone regeneration. In summary, previous studies have indicated that upon sensing the stiffness of the nanofibrous environment as well as its other characteristics, stem cells change their shape and tension accordingly, regulating downstream pathways followed by adhesion to nanofibers to contribute to osteogenesis. However, additional experiments are needed to identify major signaling pathways in the bone regeneration process, and also to fully investigate its supportive role in fabricating or designing the optimum tissue-mimicking nanofibrous scaffolds.
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Nanofibers can mimic natural tissue structure by creating a more suitable environment for cells to grow, prompting a wide application of nanofiber materials. In this review, we include relevant studies and characterize the effect of nanofibers on mesenchymal stem cells, as well as factors that affect cell adhesion and osteogenic differentiation. We hypothesize that the process of bone regeneration in vitro is similar to bone formation and healing in vivo, and the closer nanofibers or nanofibrous scaffolds are to natural bone tissue, the better the bone regeneration process will be. In general, cells cultured on nanofibers have a similar gene expression pattern and osteogenic behavior as cells induced by osteogenic supplements in vitro. Genes involved in cell adhesion (focal adhesion kinase (FAK)), cytoskeletal organization, and osteogenic pathways (transforming growth factor-β (TGF-β)/bone morphogenic protein (BMP), mitogen-activated protein kinase (MAPK), and Wnt) are upregulated successively. Cell adhesion and osteogenesis may be influenced by several factors. Nanofibers possess certain physical properties including favorable hydrophilicity, porosity, and swelling properties that promote cell adhesion and growth. Moreover, nanofiber stiffness plays a vital role in cell fate, as cell recruitment for osteogenesis tends to be better on stiffer scaffolds, with associated signaling pathways of integrin and Yes-associated protein (YAP)/transcriptional co-activator with PDZ-binding motif (TAZ). Also, hierarchically aligned nanofibers, as well as their combination with functional additives (growth factors, HA particles, etc.), contribute to osteogenesis and bone regeneration. In summary, previous studies have indicated that upon sensing the stiffness of the nanofibrous environment as well as its other characteristics, stem cells change their shape and tension accordingly, regulating downstream pathways followed by adhesion to nanofibers to contribute to osteogenesis. However, additional experiments are needed to identify major signaling pathways in the bone regeneration process, and also to fully investigate its supportive role in fabricating or designing the optimum tissue-mimicking nanofibrous scaffolds.
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The radiotherapy modulators used in clinic have disadvantages of high toxicity and low selectivity. For the first time, we used the
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Electrospinning technology opens up a new method for the construction of drug delivery system. The unique fiber structures of drug-loaded electrospinning nanofibers with the characteristics of similar to the extracellular matrix,good air permeability and hygroscopicity are very suitable for transdermal drug delivery systems.In this paper, the definition, characteristics, matrix selection, preparation methods, drug-loaded forms and drug-released profiles of drug-loaded electrospinning nanofibers are summarized and analyzed. Meanwhile, the application of drug-loaded electrospinning nanofbiers in the transdermal drug delivery systems is analyzed. This review is to provide support for the further studies on electrospun nanofiber transdermal drug delivery system.
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The concept of cellular reprogramming was developed to generate induced neural precursor cells (iNPCs)/dopaminergic (iDA) neurons using diverse approaches. Here, we investigated the effects of various nanoscale scaffolds (fiber, dot, and line) on iNPC/iDA differentiation by direct reprogramming. The generation and maturation of iDA neurons (microtubule-associated protein 2-positive and tyrosine hydroxylase-positive) and iNPCs (NESTIN-positive and SOX2-positive) increased on fiber and dot scaffolds as compared to that of the flat (control) scaffold. This study demonstrates that nanotopographical environments are suitable for direct differentiation methods and may improve the differentiation efficiency.
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Cellular Reprogramming , Nanofibers , Neurons , TyrosineABSTRACT
Purpose: The purpose of the study was to evaluate tissue reaction to polycaprolactone (PCL) nanofiber patches in the cornea, conjunctiva, and anterior chamber (AC) in rabbit eyes and to assess their biocompatibility for use as patch grafts. Methods: Two 100 ? PCL patches were implanted under the conjunctiva and in the corneal stroma of one albino New Zealand rabbit, and pathologic evaluation was done after 3 weeks. In the next step, two PCL patches were implanted; one in the corneal stroma and the other in the AC of two rabbits followed by pathologic evaluation after 3 months. Results: On slit-lamp examination, there was minimum inflammation in all cases. Pathologic examination showed that the contact and probably merging between the host tissue and PCL fibers were achieved with minimal tissue reaction. Conclusion: As a biocompatible material, PCL nanofibers seem to be a promising modality for the repair of different tissue defects including melting, thinning, and perforation. They may also be a suitable material for manufacturing keratoprostheses.
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A new method was proposed for analysis of the organic compounds in cigarette smoke by high resolution Orbitrap mass spectrometry based on polyacrylonitrile-silica (PAN-SiO2) nanofiber membrane extraction and methanol elution.Hydrophobic PAN-SiO2 nanofiber membrane which was used to enrich small molecular organic compounds in cigarette smoke was prepared by the technology of electrospinning.Several parameters including the concentrations of PAN and SiO2 nanopartical,elecrospining voltage,needle aperture and flow rate of spinning solution were optimized.Under the optimal conditions,a PAN-SiO2 nanofiber membrane with good adsorption performance and great physical strength was obtained.A total of 21 compounds including acetone,styrene,acrolein,isoprene,and acrylonitrile were identified by analyzing the cigarette smoke with Orbitrap MS spectrometry in the positive ion mode.Six organic acids including salicylic acid,malic acid and lactic acid were detected in negative ion mode.The limits of detection and quantification for nicotine were 0.071 ng/L and 0.236 ng/L,respectively.
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Electrospinning is a simple and versatile technique to fabricate continuous fibers with diameter ranging from micrometers to a few nanometers. To date, the number of polymers that have been electrospun has exceeded 200. In recent years, electrospinning has become one of the most popular scaffold fabrication techniques to prepare nanofiber mesh for tissue engineering applications. Collagen, the most abundant extracellular matrix protein in the human body, has been electrospun to fabricate biomimetic scaffolds that imitate the architecture of native human tissues. As collagen nanofibers are mechanically weak in nature, it is commonly cross-linked or blended with synthetic polymers to improve the mechanical strength without compromising the biological activity. Electrospun collagen nanofiber mesh has high surface area to volume ratio, tunable diameter and porosity, and excellent biological activity to regulate cell function and tissue formation. Due to these advantages, collagen nanofibers have been tested for the regeneration of a myriad of tissues and organs. In this review, we gave an overview of electrospinning, encompassing the history, the instrument settings, the spinning process and the parameters that affect fiber formation, with emphasis given to collagen nanofibers' fabrication and application, especially the use of collagen nanofibers in skin tissue engineering.
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Humans , Biomimetics , Collagen , Extracellular Matrix , Human Body , Nanofibers , Polymers , Porosity , Regeneration , Skin , Tissue EngineeringABSTRACT
Investigating the effect of electrospun fiber diameter on endothelial cell proliferation provides an important guidance for the design of a fabric scaffold. In this study, we prepared biodegradable poly(D,L-lactic-co-glycolic acid) (PLGA) fibrous nonwoven mats with different fiber diameters ranged from 200 nm to 5 µm using the electrospinning technique. To control the fiber diameters of PLGA mats, 4 mixture solvents [hexafluoro-2-propanol, 2,2,2,-trifluoroethanol:dimethylformamide (9:1), 2,2,2,-trifluoroethanol:hexafluoro-2-propanol (9:1), chloroform] were used. Average diameters were 200 nm, 600 nm, 1.5 µm, and 5.0 µm, respectively. Stereoscopic structure and spatial characterization of fibrous PLGA mats were analyzed using atomic force microscopy and a porosimeter. The mechanical properties of PLGA mats were analyzed using a universal testing machine. The spreading behavior and infiltration of endothelial cells on PLGA mats were visualized by field emission scanning electron microscopy and hematoxylin and eosin staining. Cell proliferation on different PLGA fibers with different diameters was quantified using the MTT assay. Cells on 200 nm diameter PLGA mats showed rapid attachment and spreading. However, the cells did not penetrate the PLGA mat. Cells cultured on 600 nm and 1.5 µm diameter fibers could infiltrate the pores and cell proliferation was dramatically increased after 14 days. Secreted prostacyclin from endothelial cells on each mat was measured to examine the ability to inhibit platelet activation. This basic study on cell proliferation and fiber diameter with physical characterization provides a foundation for studies examining nonwoven fibrous PLGA mats as a tissue engineering scaffold.
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Cell Proliferation , Endothelial Cells , Eosine Yellowish-(YS) , Epoprostenol , Hematoxylin , Microscopy, Atomic Force , Microscopy, Electron, Scanning , Nanofibers , Platelet Activation , Solvents , Tissue EngineeringABSTRACT
The performances and characteristics of the functional electrospinning nanofibers were introduced in the field of protection against biological and chemical warfare agents, whose present situation, prospects and advantages were summarized. It's suggested that the functional nanofibers might contribute to increasing the protection ability of the textile against the biological and chemical agents. The difficulty and future trends of the functional nanofibers were analyzed also.
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OBJECTIVE: To investigate the preparation of sustained release drug-loaded nanofibers by using a modified coaxial electrospinning process, in which only solvent is exploited as sheath fluid. METHODS: Ethanol was used as sheath fluid and ethyl cellulose (EC) and ferulic acid (FA) were taken as filament-forming matrix and active pharmaceutical ingredient, respectively. RESULTS: Drug-loaded EC nanofibers were smoothly and continuously generated without any clogging through the coaxial process. Field-emission scanning electron microscopic observations demonstrated that the nanofibers' diameters could be manipulated through adjusting the flow rate of sheath fluid. The composite nanofibers were in essential a molecular solid dispersion of EC and FA based on the hydrogen bonding between them, as verified by XRD and FTIR results. In vitro dissolution tests showed that FA in the nanofibers had a fine sustained release profile via a typical Fickian diffusion mechanism. CONCLUSION: The modified coaxial electrospinning with solvent as sheath fluid can be a useful tool for developing novel sustained release drug delivery systems.
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Objective: To prepare Danshensu loaded polycaprolactone (DSS-PCL) nanofiber scaffold by using electrospin technology. Methods: Using dichloromethane-N, N-dimethyl formamide (CH2Cl2-DMF) 8:2 as solvent, nanofibers containing danshensu was prepared by electrospinning, fiber morphology was observed by SEM, danshensu in vitro release rule from drug loaded nanofiber scaffold was investigated, and the security of nanofiber was assessed by MTT and hemolysis test. Results: By using CH2Cl2-DMF as solvent, drug and materials could be well dissolved and successfully electrospun into nanofiber, the average fiber diameters were 210 and 190 nm, the in vitro release experiment showed that the drug release after a quick release into the slow release. MTT test indicated that PCL and DSS-PCL nanofiber showed no influence to the cell viability, and hemolysis test showed hemolysis ratio of nanofiber was under 5%. Conclusion: DSS-PCL nanofibers is easy to prepare by electrospinning.
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ZnO nanoparticle-containing carbon composite nanofiber ( ZnO-CNF ) was prepared by the electrospinning of the ZnCl2-PAN precursor, followed by preoxidation and carbonization. The ZnO nanoparticles were uniformly distributed on the surface of the carbon nanofiber with the size of 20-30 nm, confirmed by scanning electron microscopy ( SEM ) . The wettability of the ZnO-CNF was studied by water contact angle test. With Nafion as an additive, the ZnO-CNF modified electrode was successfully constructed by dip-coating. The surface morphology and electrochemical properties of the modified electrode were investigated by SEM and cyclic voltammetry. There was a sensitive response of the ZnO-CNF modified electrode on Pb ions in solution, demonstrated by square wave stripping voltammetry. Under the optimized conditions, a good linear relationship between peak current and Pb2+concentration was obtained in the range of 2. 4×10-10-2. 4×10-7 mol/L (R=0. 998) by 10 min preconcentration at -1. 0 V in 0. 1 mol/L NaAc buffer solution (pH=4. 6). The detection limit was 4. 8×10-11 mol/L. The practical analytical application of the ZnO-CNF modified electrode was assessed by the measurement of the actual water sample and the result was consistent with that obtained by ICP-MS.
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Objective To compare the biodistribution difference of peptide nanofibers, which were self-assembled by peptide composed of L-or D-amino acids, respectively, and provide the guidance for the in vivo applications of peptide nanofibers. Methods The Nap-GFFYGRGD (L-peptide) and Nap-GDFDFDYGRGD (D-peptide, F and Y were D-configura-tion) were synthesized with solid phase peptide synthesis (SPPS). The structure of the two peptides was identified by nuclear magnetic resonance spectroscopy (1H NMR) and high-resolution mass spectrometry (HR-MS). The two peptides could self-assemble into nanofibers during the cooling process after being boiled. The morphology of the nanofibers was observed with transmission electron microscope (TEM). The peptides were radiolabeled with iodine-125 and self-assembled into nanofi-bers, which were then administered into BALB/c mice via tail vein. The blood samples were collected and then mice were sacrificed at 1, 3, 6 and 12 hours. The main organs (heart, liver, spleen, lung, kidney, stomach, large intestine, small intes-tine, muscle and brain) were isolated and weighed. The radioactivity of organs was detected with a gamma counter. Results The two peptides could self-assemble into nanofibers with diameter of 10-20 nanometers. There were no significant differ-ences in the diameter and morphology between two naofibers. There was significant difference in the biodistribution between two nanofibers. The blood concentration of D-fiber was (8.17±0.32)%ID/g at one hour after injection and then cleared rapid-ly from the blood. The blood concentration of L-fiber was (5.96±0.30)%ID/g at one hour after injection and maintained at a stable level for six hours. The L-fiber was mainly distributed in stomach while the D-fiber was mainly accumulated in liver. Conclusion The configuration of amino acids (D/L) could affect the biodistribution of peptide nanofibers dramatically, which may provide the guidance for the medical applications of peptide nanofibers.