Nanoscience & Nanotechnology Letters by Abu Faisal Hasan

"Retina cell breakthrough could help treat blindness
by harness nanotechnology to help tackle a common cause of sight loss...,

Nanotechnology to create a 3D ‘scaffold’ to grow cells from the retina –paving the way for potential new ways of treating a common cause of blindness.

By successfully grow retinal pigment epithelial (RPE) cells that stay healthy and viable for up to 150 days. RPE cells sit just outside the neural part of the retina and, when damaged, can cause vision to deteriorate.

It is the first time this technology, called ‘electrospinning’, has been used to create a scaffold on which the RPE cells could grow, and could revolutionise treatment for one of age-related macular degeneration, one of the world’s most common vision complaints.

When the scaffold is treated with a steroid called fluocinolone acetonide, which protects against inflammation, the resilience of the cells appears to increase, promoting growth of eye cells. These findings are important in the future development of ocular tissue for transplantation into the patient’s eye.

Age-related macular degeneration (AMD) is a leading cause of blindness in the developed world and is expected to increase in the coming years due to an ageing population

AMD can be caused by changes in the Bruch’s membrane, which supports the RPE cells, and breakdown of the choriocapillaris, the rich vascular bed that is adjacent to the other side of the Bruch’s membrane.

The most common way sight deteriorates is due to an accumulation of lipid deposits called drusen, and the subsequent degeneration of parts of the RPE, the choriocapillaris and outer retina. In the developing world, AMD tends to be caused by abnormal blood vessel growth in the choroid and their subsequent movement into the RPE cells, leading to haemorrhaging, RPE or retinal detachment and scar formation.

The replacement of the RPE cells is among several promising therapeutic options for effective treatment of sight conditions like AMD, and researchers have been working on efficient ways to transplant these cells into the eye.

How the Physicochemical Properties of Manufactured Nanomaterials Affect Their Performance in Dispersion and Their Applications in Biomedicine

Example -

Dispersibility of Carbon Nanomaterials

More so than the dispersion of inorganic, metallic, or metal oxide nanoparticles, the prevention of aggregation in carbon nanomaterials is of utmost importance, since their agglomeration may hinder the realization of their excellent properties. Enhanced dispersion and stabilization of carbon nanomaterials (CNMs), such as graphene oxide, graphene, carbon nanotubes, and fullerenes, especially in water, is a critical challenge, because of their tendency to aggregate, particularly in aqueous systems, due to significant van der Waals attractions and their specific hydrophobic interactions. It is both the physicochemical properties of the carbon nanomaterials and the properties of the dispersion medium that influence the dispersion stability, which is further enhanced in aqueous media with NOM, due to the enhanced interactions assisted by the CNMs hydrophobic surfaces. Both single- and multi-wall carbon nanotubes (SWCNTs and MWCNTs) were found to disperse better in media with NOM than in natural water ); nevertheless, functionalization of the MWCNTs Dispersibility of Carbon Nanomaterials

More so than the dispersion of inorganic, metallic, or metal oxide nanoparticles, the prevention of aggregation in carbon nanomaterials is of utmost importance, since their agglomeration may hinder the realization of their excellent properties. Enhanced dispersion and stabilization of carbon nanomaterials (CNMs), such as graphene oxide, graphene, carbon nanotubes, and fullerenes, especially in water, is a critical challenge, because of their tendency to aggregate, particularly in aqueous systems, due to significant van der Waals attractions and their specific hydrophobic interactions. It is both the physicochemical properties of the carbon nanomaterials and the properties of the dispersion medium that influence the dispersion stability, which is further enhanced in aqueous media with NOM, due to the enhanced interactions assisted by the CNMs hydrophobic surfaces. Both single- and multi-wall carbon nanotubes (SWCNTs and MWCNTs) were found to disperse better in media with NOM than in natural water, nevertheless, functionalization of the MWCNTs can improve the dispersion and lead to differences among the different media. The presence of proteins, lipids, or protein/lipid components is crucial for the dispersion of carbon nanomaterials such as fullerenes and single- and multi-wall carbon nanotubes in various media as well whereas vehicles lacking lipids or proteins lead to the formation of the largest agglomerates.can improve the dispersion and lead to differences among the different media. The presence of proteins, lipids, or protein/lipid components is crucial for the dispersion of carbon nanomaterials such as fullerenes and single- and multi-wall carbon nanotubes in various media as well, whereas vehicles lacking lipids or proteins lead to the formation of the largest agglomerates.

Farnborough Airport’s became the world’s first business aviation airport to achieve carbon neutral status.

From Airport’s environment manager

Do you have any other targets for the future?

There are three areas that we will always have to address: carbon reduction, waste management and noise pollution. Achieving carbon neutral status was just one milestone, and as we apply for that certification each year, we will have to offset less emissions as the years move on. We have already achieved zero waste to landfill and want to improve our recycling rates, and we are also going to wage war on single-use plastic. Noise is also an issue that we have addressed in the past, engaging with our local community. We have had an airspace change proposal approved, and we invite the public to talk to us. I have gone out and had cups of tea in people’s gardens, talking about the concerns they have and trying to build better relationships. This is all part of a continuous improvement for the long term.

Source : IEMA

Image credit: iStock

SUSTAINABILITY AS A DRIVER OF INNOVATION

""In order to unlock creativity and access their organizations' problem-solving potential, leaders ought to communicate a positive message regarding opportunities related to sustainability."

Title : Nanotechnology and Renewable Energy Technologies

1). Solar energy technology:
Energy challenges, energy mix, renewables, legislation landscape.

Climate change and local air pollution are among the key drivers for energy transition worldwide.

The energy transition must reduce emissions substantially, while ensuring that sufficient energy is available for economic growth. The analysis shows that the CO2 emissions intensity of global economic activity needs to be reduced by 85% between 2015 and 2050, and CO2 emissions need to decline by more than 70% compared to the Reference Case in 2050. The result is an annual decline of energy related CO2 emissions by 2.6% on average, or 0.6 Gigatonnes (Gt) on absolute terms, resulting in 9.7 Gt of energy CO2 emissions per year in 2050.

2). Solar cell materials :
fundamentals of solar cell materials, common solar materials including c-Si, a-Si, organic materials, nanomaterials and nanostructures. The connectivity between developing materials and it being used for energy generation and building of supply chains to provide technology solutions.

Silicon - The Most Popular Material for Solar Cells, Polycrystalline Thin Films - Reducing Material Required in Solar Cells, Copper Indium Diselenide - CIS, Cadmium Telluride - CdTe, Gallium Arsenide - GaAs, Perovskite materials, Organic/polymer materials and Dye-sensitized materials

2.1) Quantum dots
Nanoparticles, a few nm in size, called quantum dots are another type of emerging materials used in solar cells. They are low bandgap semiconductor materials such as CdS, CdSe, and PbS. Their bandgaps can be tuned over a wide range by changing the size of the particles. Many common materials used for fabricating quantum dots such as Cd and Pb are considered toxic, hence other alternative materials such as copper indium selenide are being developed.

2.2) Lighting
The creation and usage of energy efficient LEDs based on inorganic and organic semiconductor materials was the first nanotechnology application in the field of lighting. LED technology has already tapped huge commercial potentials in the illumination of displays, buildings, and cars due to its compact form, flexible color scheme, and high energy yield. It was created with the purpose of enhancing the energy efficiency of LEDs by using quantum dots.

3.Solar cell devices:
fundamentals of solar cell (photovoltaic devices) structure and operation, efficiency, common solar cell structures, organic and inorganic heterostructures, multi-junction devices. Nanotechnology applications for efficient photons management.

Nanoparticles exhibited the following advantages in the solar power plants: -
3.1. Because of the small particle sizes, nanomaterials can easily pass through pumps and plumbing with no adverse effects.
3.2. Owing to high ability of nanofluids to absorb energy directly, they exceeded intermediate heat transfer steps.
3.3. High optical selectivity of nanofluids (i.e., low emittance in the infrared range and high absorption in the solar range).
3.4. Solar collector with nanomaterials exhibited more uniform receiver temperature, which associated with a reduction in material constraints.
3.5. The enhancement of the heat transfer after incorporating nanoparticles, as a result of thermal conductivity and higher convection may improve receiver performance.
3.6. The efficiency of absorption could be improved by tuning the nanoparticle shape and size to the appropriate application

4). Energy storage :
Structure and operation of fuel cells. Supercapacitors, batteries for Internet–of-Things devices and remote sensors. Current and future challenges in nanotechnology applications.

4.1) Fuel cell
Nanostructured materials are being successfully used to increase the conversion of hydrogen energy into electricity via fuel cells. Fuel cell technologies have emerged as one of the most promising approaches to various energy resources, as well as to energy sustainability and the environment.

4.2) The applications of nanotechnology in batteries are discussed as follows: -

Firstly, the modification of the active substance in the electrode material (cathode or anode) by adding nanomaterials.
Secondly, the application of nanotechnology to improve the performance of electrodes by using of nanocoatings. For example, nanodimensional additives such as nanocarbons, graphene, and carbon nanotubes have better electron conduction, or the use of nanothick coatings on the active material to prevent unwanted reactions with the electrolyte resulting the electrode stability and stress modulation. Regarding LiFePO4 cathode, the amount of electron conductivity is poor. Hence, the conductivity is enhanced by using a conductive carbon coating on its particles or applying a conductive carbon material as an additive. Also, LiCoO2 cathode is unstable at high currents in the vicinity of the electrolyte; for stabilization, nanothick oxide coating can be utilized. Accordingly, carbon coating increases conductivity, capacity, and consequently the cell power. However, the research in this area (to create this coating) is still insufficient. Therefore, research in the field of synthesis methods is very important

5). Energy scavenging :
Thermoelectric and piezoelectric energy harvesters, solar thermal energy capture. Triboelectric energy harvesters. Role of nanomaterials for sustainable future technologies.

5.1). Harvesting solar energy

Solar energy is commonly harvested using photovoltaic cells (PV cells). Photovoltaic cells convert light energy (from the sun) directly into electricity using a principle known as the “photovoltaic effect”. The photovoltaic effect essentially refers to the process in which photons (units of light energy) excite electrons into a higher energy state thereby causing an electric current to be generated.

There are four categories of PV cells:

Single and multi-junction cells
Thin-film cells
Crystalline Si cells
Emerging PV technologies
PV cells generally tend to be expensive. Instead of using PV cells, LEDs (light-emitting diodes) and photodiodes can be used to harness light energy and provide energy for low-power devices such as IoT edge-devices. LEDs are relatively less expensive; Photodiodes are more expensive when compared to LEDs but supply more energy.

Injectable Multistage Nanovectors (MSV) for Improved Therapy and Diagnosis

An abundance of barriers reduce the likelihood that drugs and imaging agents will reach the site of action. For drugs delivered by intravenous injection, these include enzymatic degradation, uptake by the reticulo-endothelial system and crossing the endothelial barrier, cellular membranes and cellular efflux pumps. For diseases like cancer, there is an urgent need to achieve efficient concentrations of drugs in the target tissue with minimal distribution in healthy tissue. Overcoming these biological barriers, delivering one or multiple entities and personalizing therapy have historically been addressed by trying to endow individual drug molecules with one or all of these capabilities.

Nanotechnology offers unprecedented opportunities to develop treatments that increase therapeutic efficacy, decrease undesired side effects and effectively achieve the personalization of intervention for conditions, such as cancer and cardiovascular and infectious diseases. The majority of current nanotherapeutics/nanodiagnostics in clinics and under investigation accommodate single or multiple functionalities on the same entity. However, due to a multiplicity of heterogeneous biological barriers, therapeutic and imaging agents are unable to reach their intended targets in sufficient concentrations. Thus we envisioned and introduced a multistage nanovector (MSV) in which different nanocomponents (or stages) responsible for a variety of functions are decoupled but act in a synergistic manner.

Stage 1 mesoporous silicon particles (S1MP) were rationally designed and fabricated using semiconductor fabrication techniques, photolithography and electrochemical etching in a non-spherical geometry to enable superior blood margination and to increase cell surface adhesion. The main task of S1MP is to efficiently transport the payload nanoparticles, termed Stage 2 nanoparticles (S2NP), which are loaded into the porous structure. Depending on the S1MP surface modifications and porosity, a variety of S2NPs (such as liposomes, micelles, metal particles and carbon structures) or nanoparticle “cocktails” can be loaded and efficiently delivered to the disease site, enabling simultaneous functions.

The versatility of the MSV platform allows for a multiplicity of applications. For example, loading of contrast agents for magnetic resonance imaging to hemispherical and discoidal S1MP enabled a significant increase in contrast efficiency (up to 50 times compared to clinically available agents.) Furthermore, administration of a single dose of MSV loaded with nanoliposomes containing siRNA, enabled sustained gene silencing for at least 21 days and, as a result, reduced tumor burden in orthotopic ovarian cancer models. We have also shown that intracellular trafficking and cell-to-cell communication can be controlled by surface modifications of S1MP and S2NP. The therapeutic and imaging potential of MSV is being investigated in primary and disseminated tumors as well as in cardiovascular and infectious diseases.

Schematic summary of possible MSV mechanisms of action

Central compartment: hemispherical or disc-shaped nanoporous silicon S1MPs are engineered to exhibit an enhanced ability to marginate within blood vessels and adhere to disease-associated endothelium. Once positioned at the disease site, the S1MP can (top right) release the drug/siRNA-loaded S2NP to achieve the desired therapeutic effect, prior to the complete biodegradation of the carrier particle; release an imaging agent (top left) or external energy-activated S2NP (e.g., gold nanoparticles, nanoshells, bottom right). Another possible mechanism of action is cell-based delivery of the MSVs into the disease loci followed by triggered release of the S1MP/S2NP from the cells

Keeping Waste Where It Belongs:
Grain Size Explains How Spent Nuclear Fuel Enters the Environment

When compounds in spent nuclear fuel break down, they can release radioactive elements and contaminate the ground and water. To know that one spent fuel compound, neptunium dioxide, reacts with water, but still do not fully understand the process, advanced electron microscopy techniques to investigate how the microscopic structure of neptunium dioxide drives chemical reactions that lead it to dissolve into the environment. The results revealed that neptunium tends to dissolve where grains of the material come together, known as grain boundaries. Neptunium is less prone to dissolve at the grain boundaries of larger grains of material as compared to smaller grains of materials.

Nuclear power plants produce highly radioactive waste in the form of spent nuclear fuel. To prevent radiation from escaping, plant operators store spent fuel in pools and dry casks at nuclear reactor sites. However, this is not a permanent solution. To safely store radioactive materials for hundreds of thousands of years requires underground disposal in geologically stable sites. Planning this storage requires thorough predictions of how the waste can chemically transform to ensure that it is environmentally safe, processing neptunium dioxide in ways that yield larger grains and fewer defects drastically reduces neptunium’s solubility—its ability to dissolve. This reduces the environmental impact of nuclear waste. These insights will help inform policy decisions on legacy nuclear waste disposition.

Neptunium dioxide is found in legacy nuclear waste that shows a complex structure with nanoscale grains and prominent grain boundaries. Grain boundaries are sites where the crystal order of the solid is perturbed and often lead to increased diffusion and chemical reactivity. Grain boundaries in neptunium dioxide contain a soluble hydroxide phase, which is readily oxidized and easily dissolved when in contact with water and can result in increased neptunium concentrations in natural waters. The erosion of grain boundaries causes the breakage of entire grains from the matrix and eventually results in neptunium in both aqueous and colloidal solution, which can affect environmental fate and transport assessment, neptunium dioxide microstructure revealed that grain size can be increased by an order of magnitude by processing the material at high temperature. High temperature recrystallization induces grain growth, which decreases surface defects and surface area, lowering the free energy of the material. Larger neptunium dioxide grains result in increased stability and decrease solubility by two orders of magnitude. By examining dissolution mechanisms at the solid-water interface, a key gap for understanding environmental release of radioactive elements. The results are expected to have far-reaching environmental implications for performance assessment.

WEAVE (WHT Enhanced Area Velocity Explorer) is a powerful new multi-object spectrograph for the 4.2-m William Herschel Telescope at the Observatory, on La Palma in the Canary Islands. It will allow astronomers to take spectra of up to 1000 stars and galaxies in a single exposure. This huge leap in observing efficiency (currently a maximum of 100 objects can be observed simultaneously) will allow astronomers to tackle several astrophysical problems that until now have remained out of reach.

One of the most exciting of these is finding out how our Galaxy (the Milky Way) was assembled. To do this, astronomers need first to measure the current positions and motions of the galaxy's stars and then, in effect, run the clock backwards. The positions in three dimensions of about 1000 million of the Galaxy's stars will be measured by the European Space Agency's GAIA satellite, launched in 2013. The speeds of the stars towards or away from us can more accurately be measured from a ground-based telescope than by GAIA, and this is where WEAVE comes in. WEAVE will measure the speeds of several million of the stars mapped by GAIA. Astronomers will then be able to unravel the sequence of events which brought into being the Milky Way galaxy (and us).

All the main components of the William Herschel Telescope Enhanced Area Velocity Explorer (WEAVE) - the positioner, fibres, spectrograph and detectors - have now arrived on La Palma and are being integrated with the telescope. After that, WEAVE will begin its on-sky commissioning phase. WEAVE will extend the telescope's field of view to two degrees on the sky, or four times the apparent diameter of the Moon, allowing it to observe up to a thousand stars per hour and survey the sky over five years. It will enable scientists to follow up on ESA's Gaia sources, and to study everything from white dwarfs in the neighbourhood of the Sun to the galaxies that host gravitational wave sources.

Nano: For Virus test Probes Could Help Make Rapid COVID-19 Testing More Accurate, Reliable

(Courtesy University of California San Diego)

The new and improved probes, known as positive controls, that could make it easier to validate rapid, point-of-care diagnostic tests for COVID-19 across the globe.

The positive controls, made from virus-like particles, are stable and easy to manufacture. The controls have the potential to improve the accuracy of new COVID-19 tests that are simpler, faster and cheaper, making it possible to expand testing outside the lab.

Positive controls are a staple in the lab—they are used to verify that a test or experiment indeed works. The positive controls that are primarily used to validate today’s COVID-19 tests are naked synthetic RNAs, plasmids or RNA samples from infected patients. But the issue is RNA and plasmids are not stable like viral particles. They can degrade easily and require refrigeration, making them inconvenient and costly to ship around the world or store for long periods of time.

By packaging segments of RNA from the SARS-CoV-2 virus into virus-like particles, they can create positive controls for COVID-19 tests that are stable—they can be stored for a week at temperatures up to 40 C (104 F), and retain 70% of their activity even after one month of storage—and can pass detection as the novel coronavirus without being infectious.

We have two different controls: one made from plant virus nanoparticles, the other from bacteriophage nanoparticles. Using them is simple. The controls are run and analyzed right alongside a patient sample, providing a reliable benchmark for what a positive test result should look like.

To make the plant virus-based controls, we use the cowpea chlorotic mottle virus, which infects black-eyed pea plants. They essentially open the virus, remove its RNA contents, replace them with a synthesized RNA template containing specific sequences from the SARS-CoV-2 virus, then close everything back up.

The process to make the bacteriophage-based controls starts with plasmids, which are rings of DNA. Inserted into these plasmids are the gene sequences of interest from the SARS-CoV-2 virus, as well as genes coding for surface proteins of the bacteriophage Qbeta. These plasmids are then taken up by bacteria. This process reprograms the bacteria to produce virus-like particles with SARS-CoV-2 RNA sequences on the inside and Qbeta bacteriophage proteins on the outside.

Both controls were validated with clinical samples. A big advantage, the researchers point out, is that unlike the positive controls used today, these can be used in all steps of a COVID-19 test.

“We can use these as full process controls—we can run the analysis in parallel with the patient sample starting all the way from RNA extraction,”

Other controls are usually added at a later step. So if something went wrong in the first steps, you won’t be able to know.”

So far, the researchers have adapted their controls for use in the CDC-authorized RT-PCR test. While this is currently the gold standard for COVID-19 testing, it is expensive, complex, and can take days to return results due to the logistics of sending samples off to a lab with PCR capability.

By adapting the controls for use in less complex diagnostic tests like the RT-LAMP test that can be done on the spot, out of the lab and provide results right away.

“It’s a relatively simple nanotechnology approach to make low-tech assays more accurate,”

This could help break down some of the barriers to mass testing of underserved populations in the U.S. and across the world.”

Below image - Illustration and TEM image of SARS-CoV-2 positive control made from plant virus-based nanoparticles (left) and bacteriophage nanoparticles (right).

How many space debris objects are currently in orbit?

The total number of space debris objects in Earth orbit to be in the order of:

• 29,000 - for sizes larger than 10 cm

• 670,000 - for sizes larger than 1 cm

• More than 170 million - for sizes larger than 1 mm.

Any of these objects can cause harm to an operational spacecraft. For example, a collision with a 10-cm object would entail a catastrophic fragmentation of a typical satellite, a 1-cm object would most likely disable a spacecraft and pe*****te the ISS shields, and a 1-mm object could destroy sub-systems on board a spacecraft. Typical satellites, a collision with an energy-to-mass ratio exceeding 40 J/g would be catastrophic.

http://astria.tacc.utexas.edu/AstriaGraph/

Images from the Perseverance Mars Rover Feb. 22, 2021

Deep Space Network - or DSN Now

Perseverance Rover Landing Site Map

https://youtu.be/gm0b_ijaYMQ

Watch NASA’s Perseverance Rover Land on Mars! Watch an epic journey unfold on Thursday, Feb. 18 as our Perseverance rover lands on Mars. To reach the surface of the Red Planet, the rover has to survive t...