Nanotechnology and Nanomaterials in Drug Delivery Systems: An Update View PDF

Gayatri Varikuti
Department Of Biochemistry, GITAM Institute Of Science, GITAM University, Visakhapatnam, India

Published on: 2020-12-21

Abstract

Due to the advances in the field of nanotechnology, nano-based systems are gaining more interest and is currently holding tremendous potential as an effective drug delivery system. Within the past few decades, the research on nanotechnology and nanomaterials has been immense and now it is possible to cure some previously incurable diseases and treat complicated conditions [1,2]. These nano-based drug delivery systems are engineered technologies that can target, deliver and control the release of therapeutic agents as needed. Nanosystems with different compositions and biological properties have been extensively investigated for drug and gene delivery applications [3]. Nanoparticles are in general the most used nano-based drug delivery systems for their efficient work in targeted drug delivery and controlled release. These nanoparticle drug delivery systems are <100 nm in at least one dimension consisting of different biodegradable materials like natural or synthetic polymers, lipids, or metals [3].

The small size and their efficiency have influenced the applications of these nanoparticles in nanomedicine starting from biosensors, microfluidics, drug delivery and microarray tests to tissue engineering [4-7]. The research on nanosystems and nanomaterials is proven to be a bridge between the biological and physical sciences by applying nanostructures and nanophases in various fields of science [7]. The nanoparticle-based drug delivery systems have different applications based on their characteristics like size, properties and material [2].

Keywords

Nanotechnology, Nanomaterials, Drug Delivery Systems

Nano-based Drug Delivery Systems

With the progression of nanomedicine, due to the advancement of the drug design and drug delivery systems, various therapeutic procedures have been proposed to increase the drug specificity and diagnostic accuracy [7]. New routes of drug administration are being explored to ensure their targeted action in specific regions, thus reducing their toxicity and increasing their bioavailability in the organism [8]. While this being the case, it is also important to create the ideal nanoparticle-based drug delivery system with ideal shape and size, surface properties, and drug loading and releasing characteristics [2]. These characteristics play an important role in the mechanisms and the behavior of a nanoparticle drug delivery system. Many anti-cancer drugs paclitaxel, doxorubicin, 5-fluorouracil and dexamethasone have been successfully formulated using nanomaterials [9-13].

The working of the nano-drug delivery systems has been explained by Suri SS, et al. (2007) [3], where the nanoparticles are guided to the infected cells and how the drug is released. Another study explains the different mechanisms like diffusion, solvent, chemical reaction, and stimuli-controlled release of different nanoparticles that are being used [7]. An ideal nano-drug delivery system should be able to reach, recognize, bind and deliver the drug to specific pathologic tissues which should minimize or avoid drug-induced damage to healthy tissues. Stimuli-responsive nanocarriers have shown the ability to control the release profile of drugs using external factors such as ultrasound, heat, magnetism, light, pH, and ionic strength [7,14-22]. Now, studies are focused on the synthesis of nanocarriers based on environmentally safe chemical reactions by implementing plant extracts and microorganisms have increased [23].

Nano-based drug delivery systems are widely used in the field of nanomedicine from treating normal diseases to cancer and cardiovascular diseases. The following are some of the common nano-based drug delivery systems and their features.

Liposomes

Liposomes are lipid vesicles formed by ordered phospholipid bilayer with cell-like structure [24]. The liposomes show many advantages such as non-toxic, sustained-release drugs, non-immunogenicity, prolonging drug action time, improving drug treatment index, changing drug distribution in vivo, reducing drug side effects, and many more [25,26].

Polymer Micellar Co-delivery System

These nanoparticles are made of non-biodegradable and biodegradable materials which include poly(lactic-co-glycolic acid) (PLGA), polyvinyl imine (PEI), polycaprolactone (PCL), polyvinyl alcohol (PVA), etc. [26-28]. These polymers exhibit biocompatibility, non-toxicity and no teratogenicity. While some of them have some drawbacks like, chitosan, a natural polymer that is incompatible with biological fluids that leads to particle degradation and reduce work efficiency [26].

Dendritic Macromolecules

These macromolecules are synthetic, various shaped and usually branched while sphere-shaped macromolecules can be are mostly used as nanocarriers for the administration and dissolution of insoluble targeted drugs [26]. Due to their excellent biological properties, these are widely used in biomedical and pharmaceutical fields.

Metal Nanomaterials

These are mostly gold and silver nanoparticles that are shaped in different structures like nanoparticles, nanorods, nanocapsules, nanocuboid, and nanowires [26,29]. The therapeutic drugs are physically loaded into gold or silver nanostructures or chemically bonded to the surface of nanoparticles for targeted drug delivery [26,30]. But these are limited in vivo because the gold nanoparticles are slow to remove from the human body and silver nanoparticles are toxic in the treatment of chronic diseases [26].

Inorganic Non-metallic Nanomaterials

These are quantum dots, iron oxides, silicon and grapheme nanomaterials [30]. Quantum dots are particularly focused on fluorescence imaging because of their unique luminous properties, iron oxides are used for the study of new MRI contrast agents [31-34]. These nanomaterials can be used to improve the transport efficiency of drugs and genes in cells by integrating different functional groups [26].

Composite Nanomaterials

The composite nanomaterials are like a hybrid of metal nanomaterials and inorganic nanomaterials. The properties of the metal and inorganic nanomaterials are changed by adding polymers or lipids to them. The metal and inorganic nanomaterials are enhanced to improve their properties, behavior and compatibility [26].

Advantages

All the above-mentioned nanoparticles are in general the most used in the field of nanomedicine for the treatment of diseases, therapy and pharmaceutical purposes. Most of the nanoparticles used are highly efficient in targeted drug delivery while having very few drawbacks. While having some drawbacks in using some of these nanoparticles which is only increasing the research towards a better nanoparticle. The most noteworthy advantages of the nano-based drug delivery systems are the treatment of cardiovascular diseases, cancer therapy, diagnostic testing, HIV and AIDS treatment, nutraceutical delivery, controlling inflammation, treating infections, imaging techniques and so on. These drug delivery systems will improve the ability to deliver drugs that are poorly water-soluble, targeted drug delivery will only deliver the drug to the unhealthy cells, the extension of drug bioactivity through protection from the biological environment, transportation of drugs across epithelial and endothelial barriers, and to combine therapeutic and diagnostic modalities into one agent [35].

Conclusion

In conclusion, the nano-based drug delivery systems are effectively increasing the reach of the drug that needs to be delivered to the unhealthy cells. The recent advances in the field of nanotechnology and the understanding of nanomaterials help to diagnose, precise drug delivery, treatment of diseases. With the progressing research, these nanosystems are only going to increase their efficiency over time and are going to be used for more medical purposes while decreasing their toxicity and other drawbacks. This article has explained the basic knowledge available on the nano-based drug delivery systems, their mechanisms, and the advantages of these systems.