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In JoVE (2)
- De cultuur van primaire motorische en sensorische neuronen in de gedefinieerde media op electrospun Poly-L-lactide Nanovezel Steigers
- Electrospinning Fundamentals: Het optimaliseren van Solution en Apparatuur Parameters
Other Publications (17)
- Guang Pu Xue Yu Guang Pu Fen Xi = Guang Pu
- Guang Pu Xue Yu Guang Pu Fen Xi = Guang Pu
- Guang Pu Xue Yu Guang Pu Fen Xi = Guang Pu
- Guang Pu Xue Yu Guang Pu Fen Xi = Guang Pu
- Guang Pu Xue Yu Guang Pu Fen Xi = Guang Pu
- Sichuan Da Xue Xue Bao. Yi Xue Ban = Journal of Sichuan University. Medical Science Edition
- Journal of Colloid and Interface Science
- Biotechnology Letters
- Biomaterials
- Biomaterials
- Medical Hypotheses
- Biomaterials
- Biomedical Materials (Bristol, England)
- Biomedical Materials (Bristol, England)
- Journal of Biomedical Nanotechnology
- Journal of Neuroscience Methods
- International Journal of Pharmaceutics
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Articles by Zhang-Qi Feng in JoVE
JoVE Neuroscience
De cultuur van primaire motorische en sensorische neuronen in de gedefinieerde media op electrospun Poly-L-lactide Nanovezel Steigers
1Department of Biomedical Engineering, University of Michigan, 2State Key Laboratory of Bioelectronics, Southeast University, 3Department of Neurology, University of Michigan, 4Geriatric Research, Education and Clinical Center, Veterans Affairs Ann Arbor Health System
Uitgelijnd electrospun vezels direct de groei van neuronen in vitro en zijn een potentieel onderdeel van de zenuw regeneratie steigers. We beschrijven een procedure voor het bereiden van electrospun vezels substraten en de serum-vrije cultuur van primaire rat E15 sensorische (DRG) en de motor neuronen. Visualisatie van de neuronen door middel van immunocytochemie is ook inbegrepen.
JoVE Bioengineering
Electrospinning Fundamentals: Het optimaliseren van Solution en Apparatuur Parameters
1Department of Biomedical Engineering, University of Michigan, 2State Key Laboratory of Bioelectronics, Southeast University, 3Department of Neurology, University of Michigan, 4Geriatrics Research, Education and Clinical Center, Veterans Affairs Ann Arbor Healthcare Center
Electrospinning technieken kan een verscheidenheid van nanofibrous scaffolds voor tissue engineering of andere toepassingen. We beschrijven hier een procedure om de parameters van de electrospinning oplossing en apparatuur te optimaliseren om vezels te verkrijgen met de gewenste morfologie en uitlijning. Veel voorkomende problemen en het oplossen van problemen technieken worden ook gepresenteerd.
Other articles by Zhang-Qi Feng on PubMed
[Determination of Trace Elements in Shenrong Heixi Wan]
Shenrong Heixi Wan is a pure traditional Jiangxi medicine which has been mainly used to cure coma in clinic as its main function is resuscitation. In this paper, four trace elements in Shenrong Heixi Wan and other five traditional Chinese medicines have been determined and contrasted by AAS. The results show that there are abundant benificial trace elements in Shenrong Heixi Wan while pernicious trace elements such as Hg, Cd etc. are low. So the medicine is safe to take.
[Study on Trace Elements in Wuji Baifeng Wan and Its Preparation]
We studied the amount of trace elements in the traditional Chinese medicine Wuji Baifeng Wan by cluster analysis, and found that the clustering results of the trace elements in Twelve Wuji Baifeng Wan (the southern preparation) and Wuji Baifeng Wan (the northern preparation) were not in the same group. In this paper, AAS was used for the determination of trace elements in Wuji Baifeng Wan and its preparation. The results showed that there were great differences between Twelve Wuji Baifeng Wan and Wuji Baifeng Wan , while the difference between Chinese Taihe Chicken and Native Chicken was slight. So we drew a conclusion that the great differences between Twelve Wuji Baifeng Wan and Wuji Baifeng Wan were caused by other medicine, not in its preparation.
[Determination of V, Mo, Ni, G in Chinese Traditional Cardiovascular Medicine by AAS]
Aimed at curing life-threatening cardiovascular diseases, many new drugs containing Chinese medicines have been developed for commercial use. It is critical that the contents of these drugs are well monitored and controlled. In the last five decades, understanding the effects of trace elements on treating cardiovascular diseases has drawn more and more attention of researchers. In the present study, AAS was used to measure the amounts of V, Mo, Ni and Hg in several Chinese medicines treating cardiovascular diseases, such as Di Ao Xinxue Kang capsule etc. The results revealed that all Chinese medicines under study are rich in trace elements. Furthermore, the authors' data exhibit the potential therapeutic effects of V, Mo and Ni in treating cardiovascular diseases. By providing the measurements and fingerprints of trace elements found in Chinese medicines treating cardiovascular diseases, the authors' report offers theoretical support to the potential effectiveness of trace elements in combating cardiovascular diseases.
[Exploration of Quality Control of Inorganic Elements in Chinese Herbal Medicines for Stimulating Blood Circulation and Relaxing Muscles and Joints by Atomic Absorption Spectrophotometry]
Researches have shown the close relationships between inorganic elements and curative efficiencies of various Chinese herbal medicines. Yet, in studies of chemical composition and quality control of Chinese herbal medicines for stimulating blood circulation and relaxing muscles and joints, inorganic substances are often overlooked. In order to improve and reestablish the standard of quality control of Chinese herbal medicines, the authors attempted a method that would incorporate the composition of inorganic elements as part of the quality control. In the present study, the authors used atomic absorption spectrophotometry to measure the contents of fifteen inorganic elements, namely, Cu, Ca, Fe, K, Mg, Mo, Ni, Sr, V, Mn, Zn, Na, Cr, Cd, and Hg, in several Chinese herbal medicines, including Da Huo Luo Wan. The authors then discussed the relationship between these inorganic elements and curative efficiencies of these Chinese herbal medicines. By comparing the levels of inorganic elements found in Da Huo Luo Wan with those found in other Chinese herbal medicines used in the study, it was revealed that trace elements, Fe, Cu, Mn, and Zn, contribute to the curative efficiency of Da Huo Luo Wan. The authors' results showed that the amounts of trace elements Fe, Cu, Mn and Zn found in Chinese herbal medicine Da Huo Luo Wan are related to the following curative effects of Da Huo Luo Wan: relieving rheumatism, rectifying breathing and alleviating phlegm, stimulating blood circulation and relaxing muscles and joints. The measurement and analysis of inorganic elements in Da Huo Luo Wan will also provide evidences and references for the fingerprint establishment of Da Huo Luo Wan in the future.
[Atomic Absorption Fingerprint and Identification Studies of Da Huo Luo Pill. I. Exploration of Inorganic Elements Fingerprint for Establishment of Industrial Standard]
The fingerprints for most of Chinese medicines based on their organic compositions have been well established. Nevertheless, there are very few known fingerprints which are based on inorganic elements. In order to identify the Da Huo Luo Dan and its efficiency from other Chinese medicines, the authors attempted to set up a fingerprint which could be determined by the measurement of inorganic elements in Da Huo Luo Dan and other Chinese medicines. In the present study, the authors first employed 28 batches of Da Huo Luo Dan produced by Zhang-Shu Pharmatheutical Company in Jiang Xi Province to screen 12 kinds of inorganic elements measured by atomic absorption spectrophotometer and established the atomic absorption fingerprints. Secondly, the authors tried to identify Da Huo Luo Dan and other Chinese medicines by using the similarly analysis of vectors and the statistical analysis of compositional data. The result showed that the methods the authors used here were predictable to tell the efficiency of Da Huo Luo Dan from others. The authors' study also proves that establishment of standard for quality control by analysis of inorganic elements in Chinese medicines is feasible. The present study provides a new idea and a new technique that serve for the establishment of industrial standards for analysis of inorganic elements fingerprint to explore the effects of Chinese medicines.
[Temporospatial Expression of BFGF and IGF-I in Growing Goats with Cranial Suture Distraction Osteogenesis]
To investigate the expression patterns of bFGF and IGF-I in the growing goats with distracted cranial suture.
One-step Synthesis of Highly Monodisperse Hybrid Silica Spheres in Aqueous Solution
An effective and reproducible method of preparing highly monodisperse organic-inorganic hybrid silica spheres was studied. One process, one precursor (organosilane) and one solvent (water) were used in our experiments. The size of hybrid silica spheres could be adjusted from 360 to 770 nm with relative standard deviation below 2% by controlling the concentration of the organosilane precursor and the ammonia catalyst. The increasing of the precursor concentration increases the particle size while the catalyst concentration has a reverse effect on the particle size. The concept of homogeneous nucleation and growth processes are introduced to explain the formation mechanism and the effect of reaction conditions. The scanning electron microscopy (SEM) images illustrate the copiousness in quantity and the uniformity in size/shape of the particles that could be routinely accomplished in this synthesis. Fourier transform infrared (FT-IR) and (29)Si nuclear magnetic resonance (NMR) spectra confirm the structure of vinyl hybrid silica spheres, where the vinyl group (-CH=CH(2)) exists and connects to the silicon atom. This method has also been extended to design and prepare other organic-inorganic hybrid materials especially in monodisperse surface-modified silica spheres.
Chitosan Nanofiber Scaffold Enhances Hepatocyte Adhesion and Function
To enhance cell attachment and promote liver functions of hepatocytes cultured in bioreactors, a chitosan nanofiber scaffold was designed and prepared via electrospinning. Effects of the scaffold on hepatocyte adhesion, viability and function were then investigated. Data showed that hepatocytes on chitosan nanofiber scaffold exhibited better viability and tighter cell-substrate contact than cells on regular chitosan film. In addition, urea synthesis, albumin secretion and cytochrome P450 activity of hepatocytes on chitosan nanofiber scaffold were all 1.5 to 2 folds higher than the controls. Glycogen synthesis was also increased as compared with the controls. These results suggested the potential application of this chitosan nanofiber scaffold as a suitable substratum for hepatocyte culturing in bioreactors.
The Effect of Nanofibrous Galactosylated Chitosan Scaffolds on the Formation of Rat Primary Hepatocyte Aggregates and the Maintenance of Liver Function
Liver tissue engineering requires a perfect extracellular matrix (ECM) for primary hepatocytes culture to maintain high level of liver-specific functions and desirable mechanical stability. The aim of this study was to develop a novel natural nanofibrous scaffold with surface-galactose ligands to enhance the bioactivity and mechanical stability of primary hepatocytes in culture. The nanofibrous scaffold was fabricated by electrospinning a natural material, galactosylated chitosan (GC), into nanofibers with an average diameter of approximately 160 nm. The GC nanofibrous scaffolds displayed slow degradation and suitable mechanical properties as an ECM for hepatocytes according to the evaluation of disintegration and Young's modulus testing. The results of morphology characterization, double-staining fluorescence assay and function detection showed that hepatocytes cultured on GC nanofibrous scaffold formed stably immobilized 3D flat aggregates and exhibited superior cell bioactivity with higher levels of liver-specific function maintenance in terms of albumin secretion, urea synthesis and cytochrome P-450 enzyme than 3D spheroid aggregates formed on GC films. These spheroid aggregates could be detached easily during culture period from the flat GC films. We suggest such GC-based nanofibrous scaffolds could be useful for various applications such as bioartificial liver-assist devices and tissue engineering for liver regeneration as primary hepatocytes culture substrates.
In Vitro Evaluation of a Multi-layer Radial-flow Bioreactor Based on Galactosylated Chitosan Nanofiber Scaffolds
Clinical use of bioartificial livers (BAL) strongly relies on the development of bioreactors. In this study, we developed a multi-layer radial-flow bioreactor based on galactosylated chitosan nanofiber scaffolds and evaluated its efficacy in vitro. The bioreactor contains 65 layers of stacked flat plates, on which the nanofiber scaffolds were electrospinned for hepatocyte immobilization and aggregation. Culture medium containing pig red blood cells (RBCs) was perfused from the center to periphery, so that exchange materials are sufficient to afford enough oxygen. We determined the parameters for hepatocyte-specific function and general metabolism and also measured the oxygen consumption rate (OCR). Microscope and scanned electron microscopy observation showed a tight adhesion between cells and scaffolds. Compared with the control (bioreactors without nanofiber scaffolds), the number of adhered cells in our bioreactor was 1.59-fold; the protein-synthesis capacity of hepatocytes was 1.73-fold and urea was 2.86-fold. Moreover, the OCR of bioreactors with RBCs was about 1.91-fold that of bioreactors without RBCs. The galactosylated chitosan nanofiber scaffolds introduced into our new bioreactor greatly enhanced cell adhesion and function, and the RBCs added into the culture medium were able to afford enough oxygen for hepatocytes. Importantly, our new bioreactor showed an exciting efficiency, and it may afford the short-term support of patients with hepatic failure.
A Potential Therapeutic Method for Conductive Hearing Loss in Growing Children-orthodontic Expansion Treatment
Conductive hearing loss, the second most common type of hearing loss, happens when there is a problem transmitting sound waves into inner ear, which will bring a lot of inconvenience to the patient in life and put the impaired person at a competitive disadvantage. Although conductive hearing loss could be relieved by hearing aids, the inconvenience of using these removable aids or the surgery trauma of the implanted ones should not be overlooked. Transversal maxillary deficiency and high palatal arches are often found in patients with conductive hearing loss. Some researchers have reported that there is close relationship between the maxillary contraction and hearing damage. Luckily, rapid maxillary expansion (RME) has been proved to be an effective treatment method for the transversal maxillary deficiency in clinical orthodontics for more than 40 years. Thus, we hypothesized that RME treatment would be a potential therapeutic method for conductive hearing loss in growing children with maxillary constriction.
Rat Hepatocyte Aggregate Formation on Discrete Aligned Nanofibers of Type-I Collagen-coated Poly(L-lactic Acid)
Primary hepatocytes cultured in three dimensional tissue constructs composed of multicellular aggregates maintain normal differentiated cellular function in vitro while cultured monolayers do not. Here, we report a technique to induce hepatocyte aggregate formation using type-I collagen-coated poly(L-lactic acid) (PLLA) discrete aligned nanofibers (disAFs) by providing limited cell-substrate adhesion strength and restricting cell migration to uniaxial movement. Kinetics of aggregate formation, morphology and biochemical activities of rat hepatocyte aggregates were tested over a 15 day culture period. Evidence was provided that physical cues from disAFs quickly induced the formation of aggregates. After 3 days in culture, 88.3% of free hepatocytes on disAFs were incorporated into aggregates with an average diameter of 61 +/- 18 microm. Hepatocyte aggregates formed on disAFs displayed excellent cell retention, cell activity and stable functional expression in terms of albumin secretion, urea synthesis and phase I and II (CYP1A and UGT) metabolic enzyme activity compared to monolayer culture of hepatocytes on tissue culture plastic (TCP) with type-I collagen as well as on meshes of type-I collagen-coated PLLA random nanofibers (meshRFs). These results suggest that disAFs may be a suitable method to maintain large-scale hepatic cultures with high activity for tissue engineering research and potential therapeutic applications, such as bioartificial liver devices.
Cellular Compatibility of RGD-modified Chitosan Nanofibers with Aligned or Random Orientation
Aligned and randomly oriented chitosan nanofibers were prepared by electrospinning. The fibers were modified with the RGD cell-adhesive peptide through a heterobifunctional crosslinker containing a segment of poly(ethylene glycol) (PEG). PEG rendered the surface hydrophilic and provided flexible spacers, allowing the preservation of the bioactivity of further captured RGD peptides. NIH 3T3 cells were used to test the cellular compatibility of these chitosan nanofibrous scaffolds. Cell morphology and viability were investigated by SEM, fluorescent staining and cell counting. The results indicate that RGD-modified surfaces significantly improve the cellular compatibility of chitosan nanofibers and suggest a good candidate as a scaffold employed in tissue engineering.
The Influence of Type-I Collagen-coated PLLA Aligned Nanofibers on Growth of Blood Outgrowth Endothelial Cells
Nanofibrous scaffolds have been applied widely in tissue engineering to simulate the nanostructure of natural extracellular matrix (ECM) and promote cell bioactivity. The aim of this study was to design a biocompatible nanofibrous scaffold for blood outgrowth endothelial cells (BOECs) and investigate the interaction between the topography of the nanofibrous scaffold and cell growth. Poly(L-lactic acid) (PLLA) random and aligned nanofibers with a uniform diameter distribution were fabricated by electrospinning. NH(3) plasma etching was used to create a hydrophilic surface on the nanofibers to improve type-I collagen adsorption; the conditions of the NH(3) plasma etching were optimized by XPS and water contact angle analysis. Cell attachment, proliferation, viability, phenotype and morphology of BOECs cultured on type-I collagen-coated PLLA film (col-Film), random fibers (col-RFs) and aligned fibers (col-AFs) were detected over a 7 day culture period. The results showed that collagen-coated PLLA nanofibers improved cell attachment and proliferation; col-AFs induced the directional growth of cells along the aligned nanofibers and enhanced endothelialization. We suggest that col-AFs may be a potential implantable scaffold for vascular tissue engineering.
Electrospun Chitosan Nanofibers for Hepatocyte Culture
In this study, we developed a method to obtain high surface area nanofiber meshes composed of chitosan of a number of molecular weights. This method required decreasing the viscosity and surface tension of the chitosan solution as well as optimization of the electrospinning parameters such as applied voltage and environmental humidity. These chitosan nanofiber meshes were developed as a culture substrate for hepatocytes. The fibers exhibited a uniform diameter distribution (average diameter: 112 nm) and FTIR results indicate that the chemical structure of chitosan is stable during the electrospinning process. The attachment, morphology and activity of hepatocytes cultured on the chitosan nanofiber meshes were tested. The results showed that the chitosan nanofibers are biocompatible with hepatocytes and that these chitosan nanofiber meshes could be useful tissue culture substrates for various applications, including bioartificial liver-assist devices and tissue engineering for liver regeneration.
Stages of Neuronal Morphological Development in Vitro--an Automated Assay
Following plating in vitro, neurons pass through a series of morphological stages as they adhere and mature. These morphological stage transitions can be monitored as a function of time to evaluate the relative health and development of neuronal cultures under different conditions. While morphological development is usually quite obvious to the experienced eye, it can often be difficult to quantify in a meaningful way. Morphology quantification typically relies on manual image measurement and can therefore be tedious, time consuming and prone to human error. Here we report the successful development of an automated process using the commercially available image analysis program MetaMorph(®) to analyze the morphology and quantify the growth of embryonic spinal motor neurons in vitro. Our process relied on the Neurite Outgrowth and Cell Scoring modules included in MetaMorph(®) and on analyzing the exported data with an algorithm written in MATLAB(®). We first adopted a series of stages of motor neuron development in vitro. Neurons were classified into these stages directly from the available output of MetaMorph(®) using the algorithm written in MATLAB(®). We validated the results of the automated analysis against a manual analysis of the same images and found no statistically significant difference between the two methods. When properly configured, automated image analysis with MetaMorph(®) is a rapid and reliable alternative to manual measurement and has the potential to accelerate the research process.
Erythropoietin-loaded Oligochitosan Nanoparticles for Treatment of Periventricular Leukomalacia
In this study, a single intraperitoneal injection of erythropoietin (EPO) loaded oligochitosan nanoparticles (epo-NPs) (average diameter 266 nm) was investigated as a treatment for periventricular leukomalacia (PVL). Nanoparticles were fabricated using a gelation technology process. PVL rats models were prepared to examine the therapeutic efficacy of epo-NPs and analyze the mechanism by which epo-NPs protect white matter. The metabolization of epo-NPs in the liver was also investigated. The pathology and behavioral data show that this single injection of a low quantity of epo-NPs had an excellent therapeutic effect on the rat model of PVL. The EPO release curve in phosphate buffered saline solution was a good fit with the zero-order kinetics distribution and was maintained at around 25% in 48 h. In vivo experiments demonstrated that 50 IU/kg epo-NPs had the same effect as a 5000 IU/kg direct injection of free EPO. Nanoparticles prolonged the time course of EPO metabolization in the liver and the stable release of EPO from the nanoparticles kept the plasma concentration of EPO at around 100 IU/ml during the 8-12h post-injection. Therefore, we suggest that oligochitosan based nanoparticles are an effective vehicle for drug delivery.
