Nanotechnology: When Micro Takes A Quantum Leap

Nanotechnology refers to the fields of science and engineering in which phenomena occurring at nanometer scales are used in the design, characterization, manufacture, and application of materials, structures, devices, and systems.

It is the Science, engineering, and technology at the nanoscale, which ranges from 1 to 100 nanometers.

Although there are many examples of structures with nanometer dimensions or the nanoscale in the natural world, including essential molecules within the human body and food components, It has only become conceivable in the last quarter-century to actively and intentionally change molecules and structures in this size range.

Nanomaterials‘ unique features enable them to engage with complicated biological functions in novel ways—at the size of biomolecules. This rapidly expanding discipline permits cross-disciplinary researchers to create and develop multifunctional nanoparticles capable of targeting, diagnosing, and treating diseases such as cancer.

This article provides biologists with an overview of nanotechnology and discusses “nanotech” methodologies and constructions that have previously demonstrated in vitro and in vivo efficacy.

In general, it is reasonable to expect that the deployment of nanotechnology will benefit both individuals and organizations. Several of these applications involve new materials that provide dramatically different qualities by operating at the nanoscale, where new phenomena are connected with the extremely huge surface area to volume ratios seen at these dimensions, as well as quantum effects not observed at larger sizes.

Materials in the form of very thin films are employed in catalysis and electronics, two-dimensional nanotubes and nanowires are utilized in optical and magnetic systems, and nanoparticles are used in cosmetics, medicines, and coatings.

The information and communications sector, including electronic and optoelectronic fields, food technology, energy technology, and the medical products sector, which includes many different facets of pharmaceuticals and drug delivery systems, diagnostics, and medical technology, are the industrial sectors most readily embracing nanotechnology. Nanotechnology goods may potentially present fresh challenges for environmental pollution mitigation as well. 

1. The Beginning Of Nanotechnology

In 1959, American scientist and Nobel Prize winner Richard Feynman proposed the concept of nanotechnology. Feynman delivered a talk titled “There’s Plenty of Space at the Bottom” at the California Institute of Technology during the annual conference of the American Physical Society.

In this presentation, Feynman posed the question “Why can’t we write the complete 24 volumes of the Encyclopedia Britannica on the top of a pin?” and detailed a vision of utilizing machines to build smaller machines, all the way down to the molecular level. This new notion indicated that Feynman’s hypotheses were valid, and he is regarded as the founder of modern nanotechnology for these reasons.

After fifteen years, Norio Taniguchi, a Japanese scientist, was the first to adopt and define the term “nanotechnology” as “the processing of separation, consolidation, and deformation of materials by one atom or one molecule” 

Following Feynman’s discovery of this new field of inquiry, which piqued the curiosity of many scientists, two methodologies outlining the various possibilities for nanostructure synthesis were established. These manufacturing approaches are classified into two types: Top-down and Bottom-up.

1.1. Top-Down Method

The top-down technique entails reducing the bulk material to nanosized structures or particles. Top-down synthesis techniques are an extension of those used to create micron-sized particles. They are inherently simpler and rely on either bulk material removal or division or bulk manufacturing process downsizing to generate the desired structure with adequate attributes.

The most serious issue with the top-down method is surface structural flaws. This can be accomplished by utilizing advanced techniques developed and improved by industry in recent decades, such as precision engineering and lithography.

Precision engineering serves the bulk of the microelectronics sector across the whole manufacturing process, and high performance can be attained by combining advancements. They include the utilization of advanced nanostructures based on the diamond or cubic boron nitride, as well as size control sensors, in conjunction with numerical control and advanced servo-drive technologies.

Lithography is the process of patterning a surface by exposing it to light, ions, or electrons, and then depositing material on that surface to generate the desired substance.

1.2. Bottom-Up Method

The bottom-up approach refers to the construction of nanostructures from the ground up, atom by atom or molecule by molecule, using nanoscale (1 nm to 100 nm) physical and chemical processes and controlled manipulation of atom and molecule self-assembly.

Chemical synthesis is a technique for creating raw materials that can be employed directly in products in their bulk disordered form, or as building blocks for more advanced ordered materials. The bottom-up strategy of self-assembly involves atoms or molecules organizing themselves into structured nanostructures through chemical-physical interactions.

Positional assembly is the sole technique that allows single atoms, molecules, or clusters to be freely positioned one by one. A number of these approaches are still in development or are only now being used commercially to produce nanopowders.

Several well-known bottom-up procedures for the manufacture of luminous nanoparticles include the oregano-metallic chemical route, the revere-micelle route, sol-gel synthesis, colloidal precipitation, hydrothermal synthesis, template-assisted sol-gel, electrodeposition, and so on.

Based on Feynman‘s ideas, K. E. Drexler proposed “molecular nanotechnology” in his book Engines of Creation in 1986, where he proposed employing tiny molecular structures to guide and activate the synthesis of bigger molecules in a machine-like manner.

2. Different Types Of Nanoparticles

2.1. Semiconductor Nanoparticles

The size, shape, composition, crystallinity, and structure of semiconductor nanoparticles all have a significant impact on their properties.

Semiconductor nanoparticles have properties similar to metals and nonmetals and can be found in groups II-VI, III-V, or IV-VI of the periodic table. These nanoparticles feature large band gaps, which can be tuned to provide varied properties.

Semiconductor nanoparticles include GaN, GaP, InP, and InAs from group III-V, ZnO, ZnS, CdS, CdSe, and CdTe from group II-VI, and silicon and germanium from group IV.

They have distinct physical features that lend themselves to numerous potential applications in nonlinear optics, luminescence, electrochemistry, catalysts, solar energy conversion, and optoelectronics.

2.2 Magnetic Nanoparticles

Magnetic materials are also highly influenced by nanoparticles’ small size scale. They are being researched for use in cancer diagnosis and treatment. A variety of technical hurdles must be overcome before nanoparticles may be used widely in medicine.

They include but are not limited to, the creation of consistently sized, harmless particles and the coating of the particles to allow them to adhere to specific tissues.

Magnetic fields can alter ferromagnetic (superparamagnetic) nanoparticles, which have the potential to be a strong tool in medicine and pharmacology.

Magnetic nanoparticles must meet several strict conditions before they can be used within the body. Biocompatibility, ease of dispersion into a solution for injection, and, most significantly, nontoxicity is among these parameters.

2.3. Carbon-Based Nanoparticles

Carbon nanotubes (CNTs) and fullerenes are formed from carbon-based nanoparticles. Because these nanoparticles are 100 times stronger than steel, they are commonly used in structural reinforcement.

CNTs are divided into two types: single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs).  CNTs are unique in that they are thermally conductive along their length but not across the tube.

Fullerenes are carbon allotropes that have a hollow cage structure composed of sixty or more carbon atoms. C60’s structure is known as Buckminster fullerenes, and it resembles a hollow football.

The carbon units in these structures are arranged in pentagonal and hexagonal patterns. Because of their electrical conductivity, structure, high strength, and electron affinity, carbon-based nanoparticles have economic applications. But, they are also widely used for Biomedical applications.

2.4. Ceramic Nanoparticles

Ceramic nanoparticles (CeNPs) are inorganic metalloid solids composed of oxides, carbides, carbonates, and phosphates formed by high-temperature heating followed by fast cooling. 

These nanoparticles function well as drug delivery agents by manipulating their specific properties such as size, surface area, porosity, and surface-to-volume ratio.

Ceramic nanoparticles have been successfully used as a medication delivery mechanism for a variety of disorders including bacterial infections, glaucoma, and cancer.

Ceramic nanoparticles offer strong heat resistance and chemical inertness, making them useful in photocatalysis, dye photodegradation, drug delivery, and biological imaging.

3. Modern World Use Of Nanotechnology

Nanotechnology has a greater impact on our life. Its goal is to offer a new and improved method of cancer diagnosis and therapy.

3.1. Softwares

Nanotechnology provides numerous biological processes and instruments, as well as faster, smaller, and more powerful computers and carbon nanotubes, which can be vital in maintaining computer power development. 

3.2. Industries

Nanotechnology is used in many common commercial products on the market. Transparent nanoparticles or membranes over computer displays, cameras, glasses, windows, and other surfaces can help make them waterproof, anti-reflective, UV or IR radiation-resistant, scratch-resistant, or electrically conductive.

3.3. Textiles

Nanotechnology has also made its way into consumer products, with billions of microscopic nanowhiskers – each roughly 10 nanometers long – molecularly linked to natural and synthetic fibers to improve stain resistance in garments and fabrics.

3.4. Skin Products

Invisible sunscreens made of zinc oxide nanocrystals protect against UV radiation, and silver nanocrystals are used in bandages to kill bacteria and prevent infection.

3.5. Green Environment

Nanomaterials are being used to create a new generation of solar cells, hydrogen fuel cells, and unique hydrogen storage devices capable of bringing clean energy to countries that are still dependent on non-renewable, polluting fuels.

3.6. Biomedicine

The most significant achievements in nanotechnology, however, have been made in the broad field of biomedicine, particularly in cancer therapies, due to their considerable potential to offer creative solutions to overcome the constraints imposed by existing chemotherapy and radiotherapy approaches.

3.7. Vivo Imaging

A number of nanoscale particles have already been used in animal models and human clinical trials to image tumors and the tumor microenvironment. Some of the most cutting-edge research in this field employs dextran-coated, ultra-small superparamagnetic iron oxide (USPIO) nanoparticles to scan lymph nodes containing micrometastases in prostate cancer patients.

Nanotechnology applications are being taught in many developed countries’ classrooms. The United States was among the first countries to alter the curriculum to include this topic in order to better prepare and guide future learners.

Nanotechnology education is an important need in the twenty-first century, given technological and scientific advancements and global rivalry. Numerous conferences and seminars have emphasized the importance of incorporating nanotechnology into the curriculum so that students do not see a disconnect between school and their daily lives.

Nanotechnology is regarded as an essential component of “STEM” education (Science, Technology, Engineering, and Mathematics). Like engineering practice, it is no longer limited to university students. This technology may benefit, enjoy, and be learned by everyone, including children, teachers, and graduate students.

4. Definitions And Terms Related To Nanotechnology

1. Nanoparticle: A nanoparticle is a tiny particle that ranges in size from 1 to 100 nanometers.
2. Nanoscience: The study of events and manipulation of materials at atomic, molecular, and macromolecular sizes.
3. Carbon Nanotube: A carbon molecule that is cylindrical in shape. CNTs have exceptional tensile, electrical, and thermal qualities due to their structure and chemical bonding.
4. Fullerene: Buckminster Fuller’s geodesic spheres inspired this class of roughly spherical carbon nanoscale constructions.
5. Nanocrystals: Nanocrystals are aggregates of hundreds to thousands of atoms that combine to produce a crystalline form of matter known as a “cluster.” Nanocrystals, which are typically around ten nanometers in diameter, are larger than molecules but smaller than bulk materials.
6. Nanosensor: A device for sensing radiation, pressures, chemicals, or biological agents in which some of the devices operate at the nanoscale, for as by having receptors into which the molecules to be sensed fit.
7. Quantum dot: A nanoscale crystal with a diameter ranging from 2 to 20 nm with unique electrical and optical properties that vary with size. They are being investigated as components in spintronic quantum computers and have a wide range of potential scientific and industrial applications.
8. Lithography: a method of manufacturing nanoscale objects that involves pressing a mold with 3D surface designs against a superheated cast.
9. Nano manipulator: An atomic force microscope is a tool for moving individual molecules or tiny objects.
10. 3D printing: A top-down printing technique in which polymers are deposited layer by layer to create a three-dimensional object.

5. Limitations Of Nanotechnology

Despite its numerous applications and numerous benefits, nanomedicine is not without flaws. One compelling argument for this conclusion is that as the transition from micro to nanoparticles begins, the size range narrows significantly and the number of surface atoms increases. Inter-particular friction and sticking become more severe as the surface area increases.

Furthermore, because nanoparticles are so small, their clearance rate from the body may be high enough to preclude their utility in diagnosis or drug administration. The trapping of nanoparticles by the mononuclear phagocytic system is advantageous for hepatic targeting.

The same feature, however, can pose a challenge for nano-structures intended for drug action elsewhere in the body. The mononuclear phagocytic system identifies these particles and initiates phagocytosis, resulting in particle elimination from the body. PEGylation impedes this and prolongs the existence of nanoparticles in the body.

The increased surface area of the nanoparticles resulted in enhanced chemical reactivity, raising concerns about how these particles may react under diverse conditions and their ability to cross cell membranes and enter cells. Because of the enhanced chemical reactivity of nanoparticles, reactive oxygen species (ROS) are produced, which can induce oxidative stress, inflammation, and damage to DNA, proteins, and membranes, ultimately leading to toxicity.

One significant disadvantage of nanomedicine is that nanoparticles share no characteristics other than their size. As a result, each particle must be evaluated independently. Changes in shape and size can also result in different physical and chemical interactions; for example, a material that is non-toxic at 100nm can become poisonous at 1 nm, and vice versa.

Another restriction is that these particles are dependent on their surroundings; particles may dissolve or aggregate, resulting in size changes and toxicity. The chemical composition, surface structure, surface charge, solubility, and presence of functional groups on the nanoparticles are all factors that may influence toxicity.

Nanoparticles generate ROS and oxidative stress, which can lead to neurological illnesses including Alzheimer’s and Parkinson’s. As previously discussed, the surface charge of the nanoparticles is a critical element in determining their BBB toxicity.

Nanomedicine has a bright future, particularly for disorders such as cancer. Nanomedicine, scientists think, will improve the efficacy of medication delivery to the target tissue as well as regulate drug release at the precise place, resulting in an increase in the therapeutic index.

Yet, one significant barrier is the ability of nanoparticles to induce lung damage. Nanoparticles have the potential to generate lung inflammation, immunological responses, and systemic consequences which cause great harm to the human body.

6. Conclusion

Nanotechnology aids in overcoming the constraints of traditional dosage forms. This technique has the potential to be employed in both illness therapy and diagnostics with high efficacy. As a result, nanomedicine has grown in popularity.

Although there is a general consensus that the technological foundation in nanotechnology has been sufficiently developed to allow biologists to make ready use of these tools and materials, fundamental questions about these materials remain unanswered if nanotechnology is to have a significant impact that extends beyond the laboratory and into the clinic.

As more biologists learn about the capabilities of nanotechnology and form cross-disciplinary collaborations with physicists, engineers, and material scientists, the magnitude and quantity of these advances are bound to increase.

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