1,721,041 research outputs found
Nanostructured Materials as Molecular Transporters and Cell Growth Substrates For Drug Delivery and Tissue Engineering Applications.
Get PDFCarbon nanotubes (CNTs) are increasingly finding applications in many fields such as tough composites, electronics, and biomedicine, due to their outstanding properties. In terms of biomedical applications, CNTs can be used as cellular growth scaffolds which mimic the structural design of tissue at the nanoscale. This is for tissue engineering applications. CNTs are also being used as cellular transporters of biomolecules or drugs for controlled drug delivery to cells. This thesis reports the use of functionalized CNTs for delivery of peptides into cells, and studies of CNT assemblies-based tissue engineering scaffolds. The uptake into mammalian cells of CNTs both with and without designed peptide was studied in Chinese Hamster Ovary (CHO) cells. Cells were incubated with CNTs and the uptake mechanism, translocation, and their potential toxicity are studied. The CNT-peptide composites were found to be readily taken up but they did not reach the cytoplasm, instead they were restricted to endosomes and lysosomes. The exploration of CNT assemblies as cell growth substrates and the effects of substrate topography on cell adhesion and function was carried out using human hepatoma (Huh7) and CHO cells, and primary liver cells (rat hepatocytes). The results with perhaps the greatest potential are those for the primary liver cells, particularly for liver-tissue engineering for applications in drug discovery where liver cells growing on CNT-based substrates could serve as an in vitro liver model for screening for liver toxicity. In vivo, the environment of cells is 3D and this thesis contains preliminary results on cells including primary liver cells growing on 3D CNT-based yam substrates. In this thesis the challenges associated with evaluation of the toxicity of CNTs are discussed too. In addition, CHO cell adhesion and growth on protein fibronectin-nanopatterned substrates prepared using block-copolymer surfaces are also evaluated
Nanostructured Materials as Molecular Transporters and Cell Growth Substrates For Drug Delivery and Tissue Engineering Applications.
No full textCarbon nanotubes (CNTs) are increasingly finding applications in many fields such as tough composites, electronics, and biomedicine, due to their outstanding properties. In terms of biomedical applications, CNTs can be used as cellular growth scaffolds which mimic the structural design of tissue at the nanoscale. This is for tissue engineering applications. CNTs are also being used as cellular transporters of biomolecules or drugs for controlled drug delivery to cells. This thesis reports the use of functionalized CNTs for delivery of peptides into cells, and studies of CNT assemblies-based tissue engineering scaffolds. The uptake into mammalian cells of CNTs both with and without designed peptide was studied in Chinese Hamster Ovary (CHO) cells. Cells were incubated with CNTs and the uptake mechanism, translocation, and their potential toxicity are studied. The CNT-peptide composites were found to be readily taken up but they did not reach the cytoplasm, instead they were restricted to endosomes and lysosomes. The exploration of CNT assemblies as cell growth substrates and the effects of substrate topography on cell adhesion and function was carried out using human hepatoma (Huh7) and CHO cells, and primary liver cells (rat hepatocytes). The results with perhaps the greatest potential are those for the primary liver cells, particularly for liver-tissue engineering for applications in drug discovery where liver cells growing on CNT-based substrates could serve as an in vitro liver model for screening for liver toxicity. In vivo, the environment of cells is 3D and this thesis contains preliminary results on cells including primary liver cells growing on 3D CNT-based yam substrates. In this thesis the challenges associated with evaluation of the toxicity of CNTs are discussed too. In addition, CHO cell adhesion and growth on protein fibronectin-nanopatterned substrates prepared using block-copolymer surfaces are also evaluated
Carbon nanomaterials as drug transporter for cancer therapy
Get PDFThere is a vigorous and growing research effort developing carbon nanotubes (CNTs) for medical applications. It is now known that nanocomposites of Single Wall Nanotubes (SWNTs) can be used to deliver anti-cancer drugs to cells. Also, SWNTs are efficient at converting near infrared (NIR) light to heat, and can do so in a cell, and so cancer cells can be targeted for destruction by NIR radiation, once the cells have taken up SWNTs. SWNTs are highly insoluble in water, but can be functionalized via physical or covalent attachment of solubilizing molecules and drugs of interest. Once this is done, they are readily taken up by cells. We found evidence that our CNT nanocomposites were found to enter cells via endocytosis (the mechanism cells use to take up nutrients); this agrees with earlier work by Dai and coworkers. Herein, we perform systematic study of the internalization, delivery and subcellular localization and possible adverse effects of SWNTs dispersed in culture media and SWNTs wrapped with different fluorescently labelled peptide (FLP-SWNTs) on Chinese hamster ovary (CHO) cells and SWNTs attached with anti-cancer drug on two common cancerous cell lines, human epithelial carcinoma cell line (HeLa) and colorectal cancer cell lines (WiDr)
Drug release and kinetic study of tamoxifen citrate conjugated with magnetite nanoparticle for drug delivery application
Get PDFBreast cancer is affecting about 23 % of all cancers diagnosed in women. So, it is crucial to develop the treatment for breast cancer patient. Tamoxifen (TAM) has been used for treating estrogen receptor (ER)-positive breast cancer however TAM suffer from non-specific delivery to the breast cancer. TAM was introduce to magnetite nanoparticle (MNP) to increase tissue selectivity using Poly (d,l-lactice-co-glycolide acid) (PLGA-TAM-OAMNP) via oil in water emulsion and evaporation process. It was discovered that the size of the modified nanoparticle is 384 ± 17 nm while also maintaining its superparamagnetic nature. The percentage of drug loading and entrapment efficiency of TAM inside the PLGA-TAMOAMNP is around 6% and 80% respectively. Then, drug release was conducted for the next 96 hours releasing about 90% of the drug. The in vitro drug release was due to autocatalysis of PLGA
Advantages and applications of sustainable and green synthesis of titania: a review
Get PDFThe methods that applicable to synthesis titanium dioxide (TiO2) nanoparticles have been thoroughly reviewed. In this review, the focus will be on both the chemical and green synthesis of TiO2. Presently, green synthesis innovated by various researchers to prepare TiO2 nanoparticles due to their advantages offers where green synthesis does not require high quantity of chemical reagents and its offers sustainability. Green synthesis consists of and not limited to plant based, it can also originate from an aquatic animal, as well as enzymes where all of these categorized as natural resources that can be exploited for the green synthesis of nanomaterials coupled with the low cost and non-toxic final product. Although the chemical synthesis approach capable in producing large batch of nanoparticles, the disadvantages is it can harm the ecosystem due to their byproduct’s formation. In addition, green synthesis will produce minimum chemical waste in comparison to chemical synthesis. Herein, details comparisons between these two approaches are properly reviewed
Development of mobile learning application for electricity and magnetism physics on Android platform
No full textThis paper presents the design and development of Mobile Learning application for Physics II subject focusing mainly on Electricity and Magnetism Physics. The mobile learning application is developed on Android Platform using Java programming language. The aim is to help students in Physics II course at the Department of Physics, Faculty of Science, Universiti Putra Malaysia. With this mobile application, student could learn and revise the key elements in the topic “Electricity and Magnetism” anywhere and anytime at their own pace. Our approach is to incorporate definition, formula, and animation concept with command language in creating comprehensive, fun and informal environment in presenting Electricity and Magnetism Physics. This mobile learning application intends to complement the requirement for student centred learning and e-learning systems due to the great potential of mobile apps in enhancing students’ learning process
Hydrothermal synthesis of Carbon Quantum Dots: an updated review
No full textCarbon Quantum Dots (CQDs) have exceptionally solid and tuneable fluorescence properties which empower their application in vast fields. The hydrothermal approach is regarded as direct and efficient, through polymerization and carbonization reactions, and has been widely applied to prepare various materials due to the high reactivity of the reactants, easy control of the solution, little harm to the environment and low energy consumption under hydrothermal condition. The attracting feature of this route is that neither any strong acid nor post-synthetic surface passivation is necessary. As of now, a lot of important progress in the hydrothermal synthesis of carbon quantum dots such as materials use as precursors and influence of hydrothermal synthesis parameters. Hydrothermal synthesis is one of the most commonly used methods for preparation of nanomaterials. It is basically a solution reaction-based approach. In this review, the main focus is to review the hydrothermal route for carbon quantum dots using different source of materials and their fundamental characterizations, followed by the influence of hydrothermal synthesis conditions to carbon quantum dots
Antibacterial properties of silver nanoparticle (AgNPs) on stainless steel 316L
No full textObjective(s) : The probability of contracting an infection when implanting an Stainless Steel 316L (SS316L) implant has been increasing. Infection due to implant placement is called osteomyelitis which is bone inflammation caused by biofilms formed by pyogenic bacteria. Biofilms can be prevented by giving antibacterial agents. This study aims to examine the potential of silver nanoparticles (AgNPs) as an antibacterial agent in SS316L implants. Methods : AgNPs are made through a chemical synthesis process using the Gallic acid reduction method. AgNPs solution with 5 variations of precursor concentration, namely 0.1 mM, 1 mM, 10 mM, 100 mM each added with gelatin was sprayed on SS316L by the airbrush spray coating method with a distance between nozzle and substrate of 20 cm at a pressure of 40 psi. Result : AgNPs solutions produced from various concentrations of AgNO3 precursors have a range of λmax = 401.5 nm- 424.5 nm and a particle size distribution of 0.97 - 4.88 nm. The AgNPs layer on SS316L was characterized by its crystalline phase, crystal size, and anti-bacterial activity. It has a cubic structure with a phase fraction of 6.5-19%. Based on the antibacterial activity test, all AgNPs layer samples had inhibitory zone diameters in the range of 12-16 mm. AgNPs (10mM) + Gelatin layer showed the best antibacterial ability with an inhibitory zone diameter of 16.63 mm. Conclusion : The variation in the concentration of the 10 mM AgNPs precursor-Gelatin can be developed into a coating on the surface of the SS316L implant material
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