Introduction
As long as humans have lived, we have used plant-based medication to treat illnesses of all kinds. While plants have been and continue to be a great basis for pharmaceutical drugs, the method of delivering them through the human body is something we have been juggling for some time. Delivering drugs to a target area in the body using large objects can pose many different obstacles, including the drugs spreading to areas of the body where they aren’t meant to go. This could be quite toxic to some organs if not handled carefully. Nanotechnology is a tool that can be used to combat this issue.
In recent years, nanotechnology has taken over many fields, including medicine. This is for good reason, too. Nanotechnology allows us to gather all the functions of a larger object into a small 1 to 100 nm material. Nanotechnology offers us a way to deal with and understand things on a microscopic level, such as cells and their biology. Having easy and safe access to the body through these nanotechnologies allows for precision and speed in combating ailments of the human body.
In this article, we will go through ways in which nanotechnology can help serve us in the medical field, in terms of its safety, versatility, and ability to directly deliver drugs and needed therapeutic agents to the precise location.
Types of nanocarriers
The nanocarriers, which are the materials used to deliver the drugs, come in many different forms. I will discuss each and its unique functionality. There are metallic nanocarriers that come in gold. These are used a lot due to their strong covalent and non-covalent bonds. Silver nanocarriers have a broad range of antimicrobial activity and high electrical conductivity. Metals such as Titanium, Magnesium, Iron, and Zinc also have their advantages, such as high control of drug release, a high chemotherapeutic effect, and low toxicity towards normal cells.
Another very functional nanocarrier is the carbon nanotube. These nanotubes have a very high external surface area, making them ideal for carrying large doses of drugs. Because they contain optical, mechanical, and electronic properties, they can be used as biological sensors and imaging contrast agents.
Silica nanocarriers help deflect the attention of viral and non-viral vectors due to the presence of the silanol group on the surface of the nanocarrier, acting as a coat or cover. However, it is important to mention that these silanol groups on the nanocarriers may interact with cell membranes, causing membranolysis. To help improve these nanocarriers, the silica can be mixed with other materials such as polymers, lipids, and inorganic particles.
There are also nanocarriers made from natural or synthetic polymers such as PEG. They are called polymeric nanocarriers, and they seal the drug to be delivered in a kind of spherical bilateral shape while tightly holding the drug during circulation and releasing it when it reaches the site of the illness. Another carrier is nanohydrogels, known for their ability to absorb water, better method of dispersion, high bioadhesion, biodegradability, and biocompatibility.
Lipid-based nanocarriers, also called solid lipid nanoparticles (SLNP), are a great addition to the list of nanocarriers as they are biocompatible, cost-effective, and able to incorporate drug molecules.(Hamimed, Jabberi & Chatti, 2022)
Diagnosis using nanotechnology
Nanotechnology has been a great assistance in terms of diagnosing diseases. Diagnosis is something that is very important to be done correctly, quickly, and without too many complications. It determines whether someone has a certain disease or not. With the help of nanotechnology, imaging has been acquired, making it a non-invasive way of finding symptoms without undergoing surgery. Within imaging, there are biological markers. These markers detect changes on a cellular level, making it easy to determine symptoms of an illness early on. These markers also help in closely monitoring the distribution of the drugs and the progress they are making.
Nanotechnology is used as contrast agents in molecular imaging in machines such as X-rays and ultrasounds (Sim & Wong, 2021). A contrast agent in these machines helps improve resolution and specificity by showing the site of the disease at a molecular level. The machines by themselves are only able to examine changes on the tissue surface, and that too relatively late in the disease progression. Contrast agents help to improve that, but the currently used ones are small molecules that have fast metabolism with non-specific distribution, which gives off toxic side effects. However, with the use of nanotechnology, there is the advantage of low toxicity, making it more desirable.
Challanges
To engineer optimal nanotechnologies, we must understand the biological barriers of the body and how we can overcome them so we may deliver the drugs safely and accurately. These barriers are spread throughout the body, and at the site of the target disease, they can even be altered for extra protection. Different diseases have different barriers in place, and every patient has their own unique barriers. The characteristics of the nanoparticles themselves determine how the barriers will react to them. These are all factors to consider when engineering the nanoparticles and determining which ones are to deliver the specific drugs.
Things such as PEG are used as coats to protect the nanoparticles. PEG helps improve circulation time and shields nanoparticles from enzymes that may degrade, secrete, or clear them out. However, PEG itself is not completely immune to the barriers. As the body gets exposed to PEG, it creates anti-PEG antibodies in people who have been exposed to PEG in other places outside of nanotechnology for drug delivery. This would cause the nanoparticle to be expelled from some people’s bodies soon after circulation. Another way to exhibit stealth in nanoparticles is by using platelet membrane cloaking. These nanoparticles are covered in the ligands found on actual platelets, making them seem non-threatening to other platelets, so they can be used to target the disease at sites where there is an accumulation of platelets.
While the nanoparticles are in the bloodstream, they face a couple of different obstacles. There is the rate of blood flow, which could possibly damage the drugs inside the nanoparticles and remove the coatings that make them familiar to the body. This issue is combated by slightly altering the size and shape of the nanoparticles. They are enlarged just a bit, and the shape is made to be non-spherical. The shape of the nanoparticle helps make the rate of flow proportional to the nanoparticle itself, so it may not be too high of a flow for the nanoparticle to handle.
There are also environmental factors such as temperature and pH levels that affect the nanoparticles in the body. The gastrointestinal tract, for example, is a place with many varying pH levels, including areas of extreme pH levels. These pH levels are not ideal for many nanoparticles and greatly hinder the delivery process. Certain diseases also cause a range of temperatures and pH levels to arise in the body, making it not ideal for many nanoparticles. These environmental factors also have their advantages, though, as there are pH and temperature-sensitive nanoparticles that only release the drugs at a specific pH or temperature, making it easy to effectively target certain diseases.
Conclusion
Even though at the beginning, nanotechnology was aimed at enhancing the solubility, absorption, availability, and control of the release of the drugs into the body, it has grown far beyond just those. Nanotechnology has advanced greatly and is now helping out in many fields of medicine. Even though there are many uncertainties and complications when it comes to nanotechnology, we continue to further discover remedies for our issues and not be stopped by barriers that can and will continue to be overcome. Nanotechnology has been and will continue to be the cause of many great evolutions in not only medicine but many other fields of life. It has made the efficiency of our current drugs and machines much better and, with time, will make them even more efficient. With time, nanotechnology will continue to bring upon more machines and tools that will further help develop medicine into something that is precise and revolutionary for our health and general well-being. Nanotechnology has greatly improved life for many patients worldwide and is one of the leading healthcare procedures for diagnosis and treatment.
One of the greatest challenges in nanodelivery is figuring out which nanocarrier is appropriate for delivering to a particular disease site. We will continue to research and experiment until we find more precise formulas for the nanoparticles to deliver the drugs efficiently. The market for nanotechnology continues to expand, which will create a more efficient system for its development. If we continue to go down this path, there will be a bright future ahead for medical diagnosis and therapy.
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