Nanocarriers

A nanocarrier is nanomaterial being used as a transport molecule for another substance, such as a drug. Common examples include micelles, polymers, carbon-based materials, liposomes and other substances. Nanocarriers are currently being investigated for their use in drug delivery and their unique characteristics demonstrate potential use in chemotherapy. Structurally, nanocarriers range from sizes of diameter 1–1000 nm. However, due to the width of microcapillaries being 200 nm, nanomedicine often refers to devices <200 nm. Because of their small size, nanocarriers can deliver drugs to otherwise inaccessible sites around the body and alleviate symptoms leading to treatment of diseases. Since nanocarriers are so small, it is often difficult to provide large drug doses using them. The emulsion techniques used to make nanocarriers also often result in low drug loading and drug encapsulation, providing a difficulty for the clinical use. Nanocarriers to date include polymer conjugates, polymeric nanoparticles, lipid-based carriers, dendrimers, carbon nanotubes, and gold nanoparticles. Lipid-based carriers include both liposomes and micelles. Examples of gold nanoparticles are gold nanoshells and nanocages. Different types of nanomaterial being used in nanocarriers allows for hydrophobic and hydrophilic drugs to be delivered throughout the body. Since the human body contains mostly water, the ability to deliver hydrophobic drugs effectively in humans is a major therapeutic benefit of nanocarriers. This calls for functionalization of nanocarriers with water soluble groups. Micelles are able to contain either hydrophilic or hydrophobic drugs depending on the orientation of the phospholipid molecules. Some nanocarriers contain nanotube arrays allowing them to contain both hydrophobic and hydrophilic drugs.

One disadvantages with nanocarriers is unwanted toxicity from the type of nanomaterial being used. This must be taken into consideration when using the type of nanocarriers. Inorganic nanomaterial are toxic to the human body if it accumulates in certain cell organelles. Research  is currently being conducted to invent more effective, durable and safer nanocarriers. In this direction, protein based nanocarriers show promise for use therapeutically, since they occur naturally, and generally demonstrate less cytotoxicity than synthetic molecules. This presentation outlines recent advances in nanocarriers.

Prof. Raymond Jagessar obtained his BSc (Distinction) in Chemistry/Biology from the University of Guyana (1992) and his PhD from the UK (1995). He was Assistant Lecturer at the University of Guyana, 1991-1992. He held three Post Doctoral Research Fellowships (PDF) at the University of South Carolina, Columbia (USA), Wichita State University, Kansas (USA) and the University of the West Indies during the period, 1996 1999. He is also accredited with a distinction in DiPEd (higher education) at the University of Guyana in 2022. He has several international awards, amongst them are Chartered Chemist, CChem, Fellow of the Royal Society of Chemistry, FRSC, UK, Research Grants etc. He is an awardee of the Guyana Innovation Prize and a Fellow of the Caribbean Academy of Sciences. His research interests are broad, covering the spectrum of Pure and Applied Chemistry, Chemical Biology and Pharmaceutical Chemistry. He has published over one hundred (100) research articles, five book chapters, one book, three e-books and presented at over 100 conferences locally, regionally and internationally. He has given keynote presentations at several conferences at the international forum. He is a member of several editorial boards and reviewer to several journals. He is currently Professor of Chemistry at the University of Guyana (South America), former President of the Caribbean Academy of Sciences (2020-2023) and currently, Foreign Secretary of the Caribbean Academy of Sciences.