Humans with their boundless spirit have ushered upon an era where anything is possible but yet limited by their inability to pursue some desired goals, where human intellect fails technology comes in to help us better understand, anticipate and direct our skills towards perfection.
What is actually nanotechnology-based nanomedicine? Nanotechnology is the fascinating art of finding cures. Although the bio-nano stuff seems spooky, because of human’s unfamiliarity to these minute particles which are usually between 1 and 100 nanometers. We can appreciate the environment and natural sources which have shown us the biological importance of the nanostructures, such as how the nanostructures present in a gecko’s paw allow it to stick to almost any surface through hydrogen bonding. The biological system is like self-assembling nanotechnology having a built-in programming language. That is why the term “Nanomedicine” has brought revolutionary changes in the drug delivery systems being a versatile carrier of drugs with unique features to interact specifically with receptors. Nanotherapeutics are the nanoscale structured materials and nanodevices, having the potential not only to treat but also to prevent and diagnose the disease at the molecular level using molecular tools and knowledge, thus improving human health.[1,2,3]
Figure: Nanotechnology derived Nanomedicine drug delivery system.[3]
There are several types of nanomedicine drug delivery systems along with their vast advantageous applications. This drug delivery involves nano-colloidal drug carriers, known as nanocarriers based on lipids and polymers. The lipid-based ones are further subdivided into vascular nanosystems and nanocarriers based on particulate matter and emulsion. The liposomes are the most commonly studied lipid-based nanocarriers. Liposomes are bilayer vesicles composed of phospholipid (natural/ synthetic), cholesterol and stabilizer; which can encapsulate both hydrophilic drugs in aqueous core and lipophilic drug inside the lipid bilayer respectively. Nowadays, there are some other vesicles capable of enhancing the penetration of substances through the skin, increasing the localization of therapeutic compounds, imaging agents, radiosensitizers, and genetic medicines with enhanced permeability and retention effect such as transferosomes, niosomes and ethosomes. Ethosomal systems are composed of ethanol, phospholipid, water and stabilizers. The high percentage of ethanol helps penetration into the stratum corneum that is beneficial in the treatment of psoriasis. Betamethasone dipropionate and salicylic acid-loaded nanoemulsion for topical application against psoriasis has reported 72.1% reduction in inflammatory response due to enhanced skin penetration via nanotechnology.[4–6]
Nanomedicine has become a milestone as an anticancer therapeutic strategy. Several drug delivery systems for the treatment of cancer have been developed, most notable ones are nanococktail and nanorobotics. Nanococktail is defined as a “cocktail” of different nanometer-sized particles that work within the bloodstream to locate, adhere and kill cancerous tumours. Two different nanomaterials of the size of only a few nanometers constitute a nanococktail. One nanomaterial was designed to find and adhere to tumours and the second nanomaterial was fabricated to kill those tumours. Responder particle Nanoworms, containing nanoparticles with strings of iron oxides, have shown up brightly in magnetic resonance imaging. In such a way, they would be useful to identify the size and shape of a tumour in a patient before surgery. The second type is hollow nanoparticles loaded with the anticancer drug doxorubicin and they might be used to kill the tumour, thus sometimes avoiding the need for surgery. Optical microfiber (OMF) biosensor using gold nanoparticles (GNPs) has become a promising platform for clinical cancer diagnosis, by detecting alpha-fetoprotein (AFP) in serum samples with very high sensitivity and selectivity.[7,8]
One of the recent strategies of the dermatological and cosmetological science is using nanocosmeceuticals of metal and metal oxides against bacterial and fungal skin infection in order to destroy biofilm formation, to protect against skin damage due to UV exposure and for skin rejuvenation. Nanocosmeceuticals are reaching about 155.8 million dollars in the global cosmetics market. Creams containing nanorobots remove the right amount of dead skin and excess oil curing several skin diseases. L'Oreal, the world's largest cosmetics manufacturer, is investing nearly $ 600 millions of its $17 billion sales on Nano patents and has already patented dozens of “nanosome particles”, including Freeze 24/7, DDF (Doctor's Dermatologic Formula), and Colorescience.[9,4] UV filters such as titanium dioxide and zinc oxide in their nanoforms (TiO2NPs and ZnONPs) exerts more effective and transparent texture with a reduced photoallergic reaction on skin. RBC Life Science’s “Nanoceuticals Citrus Mint Shampoo and Conditioner” are made with nanoclusters, giving hair a healthy shine. L'Oréal's Revitalift Double Lifting anti-wrinkle cream containing Pro-Retinol Nanosomes readjusts the skin rapidly and reduce the appearance of wrinkles. Using "Hydroxyapatite Nanoparticles” in Ace Silver Plus Nanosilver toothpaste encourages oral health, promoting natural healing by reducing the bacterial attack and inflammation. It is also claimed that carbon fullerenes, the tiny carbon spheres have anti-ageing properties and low concentration of gold nanoparticles, AuNPs (<5 ppm) increases the proliferation of keratinocytes.[9,10]
Figure: Different forms of nanomedicine drug delivery system and diverse application of nanotechnology.[11]
Anyway, there are some limitations to the development of nanomedicine as well. For example, I) difficulty in the standardization of the safety assessment profile of these nanoparticles, as nanoparticles have a heterogeneous composition: organic, inorganic, anthropogenic, metal or metal oxide-based, lipid-based, DNA and peptide-based, synthetic, natural etc. II) Moreover, the toxicological profile of many nanomaterials is still unknown. III) The altered size and shape of nanomedicine can have an unpredictable physiological effect. IV) An expensive technology that does not discourage the illegal use of nanomedicine along with performance-enhancing drugs. As the nanoparticles can target specific cell types, so that they remain stuck in some tissue as muscles cells, but less in blood and urine and thus making them difficult to be detected by regulatory officials. V) The entrance of nanomaterials into the human body through several ports could interfere with vital organs causing enhanced oxidative stress, cytotoxicity, fibrosis such as carbon black nanoparticles interfere with cell signalling, ZnONPs and TiO2NPs may lead to the production of reactive oxygen species (ROS), which play a crucial role in the photocancerogenicity and skin ageing.[12,13]
To sum up, technology has helped scientists to make a more precise diagnosis, targeted treatment and to increase perception about the pathophysiology of the disease process to improve their approach towards faster and more effective cures. Despite all the advantages of nanotechnology, there are a number of issues to take into account to actually validate the efficacy of nanomedicine.