Applications of nanotechnology in drug delivery and design – Part 1
Arthur C. Clarke was the first, in 1956, to write on the nanotechnology concept, in a short story called “The Next Tenants”. This is considered to be the first work of fiction broadly describing what is today known as nanotechnology. Today, the application of nanotechnology is gaining prominence in the pharmaceutical and health care industries as it offers some exciting possibilities that were only imagined decades ago. For example, Nanosensors have been developed to monitor inflammatory diseases by checking the level of nitric oxide in the bloodstream, using carbon nanotubes embedded in a gel that can be injected under the skin.
Nanotechnology is the study, design, synthesis, manipulation, and application of functional materials at nanometer scale, where one nanometer equals to a billionth of a meter. Imagine the largest nano base material which has a size of 100nm is about half the size of smallest cellular form in existence – the bacteria called mycoplasma which has a diameter of 200nm. Many functional nanomaterials, also called nanoparticles (NPs), having the size of macromolecules such as DNA and proteins, have been developed.
Nanoparticles have unique mechanical, optical, magnetic, electrical and biochemical properties, making them suitable in drug delivery systems, diagnostics & monitoring techniques, bio-sensing (biosensors), blood purification, cell repair and tissue engineering. This emerging field of medicine, commonly called nanomedicine, is attracting great interest from researchers as it has opened up new vistas in chemotherapy, providing the possibility of delivering and targeting pharmaceutical, therapeutical and diagnostic agents to cancer cells.
Nanoparticles have been successfully used as drug delivery materials because of their high drug-carrying capacity and stability in the blood stream. The surface of nanoparticles are usually coated with ligands to enhance their affinity towards specific cells and co-polymers and to protect them from immune cells. The self-controlling system of drug releasing helps to reduce the plasma fluctuation and minimises the side effects.
Nanoparticles used in drug delivery include polymers in drug delivery system (DDS) such as polymeric miscelles, polymeric NPs, polymeric drug conjugates, dendrimers, nano crystals and lipid-based NPs like liposomes and solid lipids nanoparticles. These types of nano particles are organic based, whereas inorganic based nanoparticles include silica base materials such as Xerogels and mesoporous silica NPs, and Metal NPs such as gold, silver, iron, platinum, quantum dots.
Mode of application
Nanoparticles can be incorporated, encapsulated, conjugated, or absorbed with drugs, using different techniques such as electrospinning technique (electrospunnanofibres), nano-precipitation technique, emulsification based methods, layer by layer synthesis, non-covalent complexation and conjugation to polymeric carrier via liable linkers.
The resulting formulation constitutes a drug delivery systems which have the ability to recognise and deliver the active drug to the target cell by receptor mediated endocytosis. The localised therapeutic activity ensures reduced toxic side effects, provide improved therapeutic index, reduced drug dosage, and ultimately reduces the cost of drugs. These merits have led to the more precise and improved treatments of conditions such as cancer, heart disease, diabetes among others.
- Wanigasekara J and Witharana C. (2016) “Applications of Nanotechnology in Drug Delivery and Design – An Insight” Current Trends in Biotechnology and Pharmacy Vol. 10 (1) 78-91
- Earl Boysen of Hawk’s Perch Technical Writing, LLC. “Nanotechnology in Drug Delivery” http://www.understandingnano.com/nanotechnology-drug-delivery.html
- Wikipedia “Nanomedicine”