Papers by Keyword: Cell Culture

Abstract: In-vitro cell culture offers the ability to grow individual cells and monitor their behaviour in a controlled environment over a certain time. During culture, different parameters have to be controlled to ensure a vital growth of cells. The most important parameters are temperature, pH-value, oxygen and carbon dioxide levels as well as the glucose concentration. All of these parameters influence the growth ability of the cell culture and should be monitored online. The online monitoring of glucose was achieved with a novel GOD based sensor which enabled a real-time measurement of glucose during cell culture. A first-time characterisation of the sensor was carried out in the culture medium DMEM. In addition, material properties of the culture system were investigated. At first to establish a baseline measurement, the sensor was placed in different glucose concentrations dissolved in Water-KCl mixture at 25 °C inside a batch chamber under constant stirring. Afterwards, the temperature was increased to 37 °C to simulate a cell culture environment. In addition, the system was transferred into a flow-through reaction chamber. The highest response signal and the most stable signal was achieved at 37 °C with DMEM during flow-through measurement. Based on these measurements online glucose monitoring in cell culture was possible to determine the glucose consumption for each cell which is important for future human-on-a-chip devices to prevent diabetic metabolisms.

Abstract: Calcium aluminate cement (CAC) is a penitential candidate for bone replacements with good bioactivity but relative lower strength. In this study, biodegradable PGA fiber was incorporated into the CAC paste in order to improve the strength of the material. And MC3T3 cells were seeded on the surface of CAC and CAC/fiber to study their in vitro biocompatibility. The results indicate that the PGA fiber can improve the compressive strength of CAC without changing the crystalline phases and micromorphology. Calcium aluminate oxide hydrate, katoite and Gibbsite crystals were detected by XRD. Plate-like crystals can be observed under FESEM. The MC3T3 cells were attached well on both CAC and CAC/fiber composite, indicating their good in vitro biocompatibility. In summary, fiber reinforcement can be an effective way to improve the properties of calcium aluminate cement for orthopaedic application.

Abstract: The simultaneous combination of optical and magnetic properties of nanoparticles would greatly benefit in vivo disease diagnosis as well as in situ monitoring of cell in cell culture. The most promising application of magnetic particles in biomedicine is MRI contrast enhancement and magnetic hyperthermia. Another important thing is the determination of exact localization of nanoparticles in the cell culture that can be defined by e.g. optical way. In our investigation we used the iron nanoparticles encapsulated in carbon as a magnetic component and carbon quantum dots as an optical labels to provide the photostability and fluorescence in a wide range of wavelengths. In order to avoid the fluorescence quenching in bimodal particles the optical and magnetic components should be separated by insulator layer. To create the optimal bimodal nanoparticles for this purpose the non-typical configuration of nanocomposites was realized, namely, a fluorescent core was separated from the coated magnetic particles by silicon dioxide matrix. Finally, it was shown that these bimodal nanocomposites demonstrate the high magnetic properties, good visualized ability and low toxicity for living cells as well.

Abstract: In tussue engineering, hydrogel-based scaffold is one of the most common method for bone tissue engineering. Gelatin is a common material for scaffold, whereas hydroxyapatite (HA) has a similar composition and structure to natural bone mineral. HA can also increase cell adhesion ability of the scaffold. This research focuses on the fabrication of hydrogel scaffolds using gelatin composite with nanocrystalline hydroxyapatite (nHA). Then the mechanical and physical caharacteristics of the scaffold is investigetad. Low contents nHA is introduced into gelatin in order to modulate mesenchymal stem cell (MSC) behavior. There are three types of scaffolds which contain various HA content. The gelatin is crosslinked with glutaraldehyde before freeze-drying. The Young’s modulus of the surface is investigated using Atomic force microscopy (AFM). The pore size is investigated using scanning electron microscope (SEM). Human MSCs are culture on the scaffold for 3 weeks. The result shows the sucesse in cell cultivation. However, the human MSCs cultured on the fabricated hydrogels do not show any lineage-specific differentiation.

Abstract: Microwell plates are widely used in various cell-based assay and drug screening. Usually these plates are made from non-biodegradable materials such as polystyrene or polyethylene. In this report, we propose the use of wax-impregnated cotton fabrics as an alternative microwell plate that is easy to fabricate, simple to use, sustainable and environmentally friendlier. Several researchers recently used soft lithography and photolithography technique to fabricate various cell culture platforms. Our proposed method consists instead of simple dipping and drying process. The platform is made of a series of fabrics being stacked and held together with various wax formulations. With the exception of the base layer, each fabric layer has a circular hole opening with increasing diameter towards the top layer; thereby forming a well where cells are cultured at its flat bottom. We characterized the chemical and physical properties of the platform surface which affect cells attachment and proliferation. These properties include the surface chemistry, hydrophobicity and roughness. We cultured human skin fibroblast (HSF 1184 Cell Line) on the platform as our preliminary proof of concept. We observed proliferation of the cells after 24 hours. The result indicates the potential use of the platform for future cell-based assay applications.

Abstract: The importance of this work is development of two methods to try to improve the bone tissue regeneration. The surface of scaffold was modified in order to favor cell interaction, through adhesion and proliferation. PLA and gelatin were used. PLA has shown in literature good results in bone tissue engineering. The gelatin is used as coating in cell culture plates to improve cell attachment for a variety of cell types, including osteoblast. Hydroxyapatite (HA) and tricalcium phosphate (TCP) were used due to its known properties in tissue engineering. It was used the polymer foam replication technique to produce the scaffolds. For characterization were used: scanning electron microscopy (SEM), optical microscopy (OP), stereoscopy, transmission electron microscopy (TEM), X-ray microtomography (Micro-CT), X-ray diffraction (XRD) and X-ray fluorescence (XRF). The scaffolds showed morphology with adequate porosity for tissue engineering and the in vitro test showed evidence of not being cytotoxic.

Abstract: The fusion solution is a significant factor for the effect of the cell electrofusion, traditional buffer solution is different from the cell culture solution, researchers would spend lots of time and money to move the cells from the culture solution (DMEM) into the fusion buffer. The aim of this study is to explore a new formula on the basis of DMEM solution instead of Zimmerman solution. Theoretically its feasible to instead of fusion solution when the ratio of DMEM solution and water is less than 9:500.

Abstract: The hepatopancreatic cell culture of the kuruma prawn, Litopenaeusvannamei, was conducted to identify the effects of zinc on cell division. The culturesystem consists of medium 199 (M 199) supplemented with 0.060 mol/L NaCl,1.011g/L glucose, 1000 UI/ml penicillin, 1000 μg/ml treptomycin, 20% heatinactivated fetal calf serum (FCS) for primary cells and 10 % for subculture cells. TheRNA/DNA ratio in cultured cells was measured. The results show that the celldivision of cultured hepatopancreas cells in L. vannamei was increased by the optimalconcentration of Zn2+, 80 μg/L.

Abstract: The microfluidic chip with well-defined structure is an important platform for cell research. The existing techniques for chip fabrication especially in cell biology and tissue engineering have many defects, for example, poor processing precision, high processing cost, as well as sophisticated manufacturing procedure. Thus, fabrication of simple and practicable microfluidic chip with highly efficient cell control ability and low-cost is turned to be the main target for bioengineering application. Poly(ethylene glycol) (PEG) is a hydrophilic polymer. Substituting terminal hydroxyl groups with acrylates, forming poly(ethylene glycol) diacrylate (PEGDA), allows the polymer to be cross-linked to form a three-dimensional polymer network. Meanwhile the use of photopolymerization can realize precise and temporal control of polymerization for formation of complex shapes. Herein, we utilize PEGDA hydrogel’s highly tunable characteristic, using photopolymerization method to obtain desirable micro-structure. Each chip has four of uniform micro-structures, which can carry multiple parallel experiments at the same time. We also add 2-Hydroxyethyl Methacrylate (HEMA) to the PEGDA prepolymer in order to increase the cell adhesion capacity of the microchip surface for cell culture. The experimental results showed that this method can achieve double-layer cell culture with short time treatment. Cells can be well captured and cultured in the hydrogel microfluidic chip with excellent activity. The hydrogel microfluidic chip has the potential of practicable application once large-scale preparation is accomplished.

Abstract: New types of polymer hydrogels and nanocomposites, i.e., nanocomposite gels (NC gels) and soft, polymer nanocomposites (M-NCs), with novel organic/inorganic network structures have been fabricated. Both NC gels and M-NCs were synthesized by in-situ free-radical polymerization in the presence of exfoliated clay platelets in aqueous systems and were obtained in various forms and sizes with a wide range of clay contents. Here, disk-like inorganic clay nanoparticles act as multi-functional crosslinkers to form new types of network systems. NC gels have extraordinary optical, mechanical, and swelling/deswelling properties, as well as a number of new characteristics relating to optical anisotropy, polymer/clay morphology, biocompatibility, stimuli-sensitive surfaces, micro-patterning, self-healing, etc. The M-NCs also exhibit dramatic improvements in optical and mechanical properties including ultra-high reversible extensibility and well-defined yielding behavior, despite their high clay contents. The M-NC also showed thermoresponsive cell adhesion/detachment. Thus, the serious disadvantages (intractability, mechanical fragility, optical turbidity, poor processing ability, low stimulus sensitivity, etc.) associated with the conventional, chemically-crosslinked polymeric materials were overcome in NC gels and M-NCs.