China
Africa
Explore chapters and articles related to this topic
The Advantages and Versatility of Carrier-Free Nanodrug and Nanoparticle Systems for Cancer Therapy
Published in Loutfy H. Madkour, Nanoparticle-Based Drug Delivery in Cancer Treatment, 2022
Most chemotherapeutic agents are not specific to the cancer cells they are intended to treat, and they can harm healthy cells, leading to numerous adverse effects. Due to this nonspecific targeting, it is not feasible to administer high doses that may harm healthy cells. Moreover, low doses can cause cancer cells to acquire resistance, thus making them hard to kill. A solution that could potentially enhance drug targeting and delivery lies in understanding the complexity of nanotechnology. Engineering pharmaceutical and natural products into nanoproducts can enhance the diagnosis and treatment of cancer. Novel nanoformulations such as liposomes, polymeric micelles, dendrimers, quantum dots (QDs), nanosuspensions, and gold nanoparticles (Au-NPs) have been shown to enhance the delivery of drugs. Improved delivery of chemotherapeutic agents targets cancer cells rather than healthy cells, thereby preventing undesirable side effects and decreasing chemotherapeutic drug resistance. Nanotechnology has also revolutionized cancer diagnosis by using nanotechnology-based imaging contrast agents that can specifically target and therefore enhance tumor detection. In addition to the delivery of drugs, nanotechnology can be used to deliver nutraceuticals like phytochemicals that have multiple properties, such as antioxidant activity, that protect cells from oxidative damage and reduce the risk of cancer. There have been multiple advancements and implications for the use of nanotechnology to enhance the delivery of both pharmaceutical and nutraceutical products in cancer prevention, diagnosis, and treatment [1].
Transient Quantum Transport in Nanostructures
Published in Klaus D. Sattler, st Century Nanoscience – A Handbook, 2019
Pei-Yun Yang, Yu-Wei Huang, Wei-Min Zhang
Today, there are many practical applications of nanostructures and nanomaterials. For example, the quantum Hall effect now serves as a standard measurement for resistance. Quantum dots are used in many modern application areas including quantum dot lasers in optics, fluorescent tracers in biological and medical settings, and quantum information processing. The theory of nanostructures involves a broad range of physical concepts, from the simple confinement effects to the complex many-body physics, such as the Kondo and fractional quantum Hall effects. Traditional condensed matter and quantum many-body theory all have the role to play in understanding and learning how to control nanostructures as a practically useful device. From the theoretical point of view, electron transport in nanostructures deals mainly with physics of systems consisting of a nanoscale active region (the device system) attached to multi-leads (including source and drain).
Contemporary Developments in Nanobiotechnology: Applications, Toxicity, Sustainability, and Future Perspective
Published in Alok Dhawan, Sanjay Singh, Ashutosh Kumar, Rishi Shanker, Nanobiotechnology, 2018
Anubhav Kaphle, Navya Nagaraju, Hemant Kumar Daima
Like CNTs, graphene is another carbon-based material that can provide a large surface area as well as modifiable functional moieties on the surface to load active molecules for therapy or diagnostic applications. The oxidized form of graphene, graphene oxide (GO), has been used in composite with copper oxide nanoparticles for effective sensing of glucose molecules and hydrogen peroxide (Liu et al. 2013b). Moreover, GO has been used very precisely for signal detection of pathogens based on conjugated biomarkers (Jung et al. 2010). Carbon dots are yet another group of carbon-based materials that have a luminous nature with a wide tunable absorption spectrum and narrow emission spectra (Yang et al. 2009b). Carbon dots have been used to deliver siRNA and DNA for successful silencing of genes and successful transfection of cells, respectively (Wang et al. 2014). Due to their low synthesis cost and amenable characteristics, carbon dots are extensively used for bio-imaging. Also, because of their organic nature, carbon dots have been found to pose less toxicity as compared to QDs, as QDs suffer from in solution leaching of heavy metals that are detrimental to whole biosystems.
Fabrication of gold-immobilized quantum dots/silica core–shell nanoparticles and their multimodal imaging properties
Published in Particulate Science and Technology, 2022
M. Tayama, T. Inose, N. Yamauchi, K. Nakashima, M. Tokunaga, C. Kato, K. Gonda, Y. Kobayashi
Cadmium compounds such as CdS, CdSe, and CdTe are representative examples of the luminescent semiconductors. Their nanoparticles are called quantum dots (QDs) and have often been applied as fluorescent markers for in vivo imaging of mouse models and in vitro imaging of human pathological tissues (Gonda et al. 2010; Hamada et al. 2011; Gonda et al. 2015; Miyashita et al. 2016; Ra, Schiffmanb, and Balakrishna 2018; Liu et al. 2019). However, cadmium-based QD nanoparticles are harmful for living organisms. Limiting the contact of these QDs with living organisms may reduce their adverse effects on health. It is usually done by coating QDs with shells harmless to living organisms and chemically stable in various solvents or by fabricating core–shell particles composed of a QD core and a harmless chemically stable shell to make the shells function as the physical barrier preventing living organisms from interacting with the QD core. Apart from being harmless and chemically stable, the colloidal stability of the core–shell particles in the blood vessels must also be taken into account, because the particle aggregation arising from the colloidal instability of the particles prevents their flow, followed by thrombosis in mouse models.
Bacteria-targeting chitosan/carbon dots nanocomposite with membrane disruptive properties improve eradication rate of Helicobacter pylori
Published in Journal of Biomaterials Science, Polymer Edition, 2021
Muhammad Arif, Mohamed Sharaf, Quanjiang Dong, Lili Wang, Zhe Chi, Chen-Guang Liu
Carbon dots (CDs) have recently emerged as effective nanomaterials due to their appealing possessions such as chemical and optical stability, superior water dispersibility, excellent biocompatibility, and low cytotoxicity [15]. By causing oxidative stress, CDs have a great potential to destroy bacterial membranes. CDs have the potential to replace organic dyes, expensive fluorescent agents, and semiconductor quantum dots. On the other hand, CDs fluorescence assays are limited due to the nanoparticles' lack of selectivity [16]. Chitosan is a natural, linear polysaccharide of 2-amino-2-deoxy—β-D-glucan with glycosidic bonds produced through alkaline deacetylation of chitin [17]. Chitosan is a biodegradable mucoadhesive material. Chitosan contains a high concentration of essential amino groups, making it an excellent candidate for therapeutic applications. Chitosan can ionically cross-link with multivalent anionic polymers and attracts drugs, resulting in biomaterials such as drug delivery systems, wound dressings, and antibacterial materials [18].
Precursor sources dependent formation of colloidal CdSe quantum dots for UV-LED applications
Published in Particulate Science and Technology, 2023
Naina Lohia, Shailesh Narain Sharma, D. Haranath
In the current era, futuristic flat panel displays and solid-state lighting have some challenges in the areas of improving efficiency, brightness, color saturation, and thus flexible substrate compatibility (Sekitani et al. 2009; White et al. 2013; Yokota et al. 2016; Kim, Ghaffari, and Kim 2017; Huang, Parashar, and Gijs 2021; Kiprotich, Dejene, and Onani 2022) owing to have their potential application. Current studies on the fascinating optical performance of colloidal nanocrystal (NC) quantum dots (QDs) of compounds in columns II–VI of the periodic table have recommended that QD-light emitting diodes (LEDs) could be a better cost-effective alternative. Particularly, the exceptionally narrow band emission of the monodispersed NCs QD populations resulted in full width at half maximum (FWHM) of ∼18–30 nm (Talapin et al. 2010; Shirasaki et al. 2013). In comparison with the organic LEDs and liquid crystal displays, QD-LEDs produce red and green color emissions with much high spectral purities. Spectral purities of QD-LEDs were observed to be 30% greater than that of the still preferred cathode ray tubes for exhibiting excellent color rendition (Xu et al. 2005; Moeller and Coe-Sullivan 2006; Steckel et al. 2006; Thomas et al. 2021; Mohammed et al. 2022). Since the QD-LED display system have the potential to create a wide range of colors by changing the relative intensities of the three primary colors, i.e., red, green, and blue (RGB) subpixels in each of the screen pixel cell (Moeller and Coe-Sullivan 2006). Thus the superior color purity of RGB-based QD-LEDs will consequently improve the variety of colors that would be displayed in an unprecedented fashion (Rizzo et al. 2007; Talapin et al. 2010; Shirasaki et al. 2013; Chen et al. 2014).