Hi Class! This week, Prof. Zhou talked about the importance of drug delivery in medical sciences and biomaterials used for drug delivery with a focus on polymers and polymeric nanoparticles. This blog post will look at another excellent material candidate for drug delivery, which is metallic nanoparticle/nano-device.
First, here is a brief introduction of the topic as well as a recap from the lectures. Drug delivery is one of the most important research directions in biomedical sciences. The increase of the drug efficacy and the reduction of the side effects are among the goals of the research in the field. Researchers have been working on the development of metallic nanoparticles which target the infected cells without doing harm to other neighbor cells. Metallic nanoparticles such as gold nanoparticles, silver nanoparticles, iron nanoparticles and copper nanoparticles are being extensively researched which show high potential in site-specific drug delivery. These nanoparticles have unique physical and chemical properties such as, plasmatic resonance, fluorescent enhancement, and catalytic activity enhancement which make them very fascinating materials in drug delivery applications. [1]
Figure 1. A schematic of gold nanoparticles for drug delivery to cells [1]
From the lectures, we learned that the performance of nanoparticles inside the human body is controlled by complex factors such as their shape, density, size distribution and surface characteristics. All these factors control the flow properties of nanoparticles, bifurcation in the vascular compartment, modulation of circulation time, and mode of entry into the cell.
Take gold nanoparticles as an example, they can bind with a wide range of organic molecules due to their surface properties so they have been used as therapeutic agents or vaccine carriers into the specific cells. Gold nanoparticles having small size and diameter about 1 nm are able to cross the cell membrane and nucleus to interact with DNA. Therefore by using gene gun, gold nanoparticles have been extensively used for epidermal delivery of DNA vaccines and this method is one of the best methods to deliver DNA vaccine. Another application is that coated walls of gold nano-cages with temperature-sensitive polymer were used as drug carrier which releases their effectors with interaction of near-infrared irradiations. [2]
Figure 2. A schematic of gold nanoparticles for different applications [3]
Compared to traditional drug delivery methods, some advantages of gold nanoparticles are summarized as follows :
- Gold nanoparticles have unique optical, physical and chemical properties due to their size and shape
- Gold nanoparticles have high surface area which provide dense drug loading;
- These particles are biocompatible and are readily available for conjugation with small biomolecules such as proteins, enzymes, carboxylic acid, DNA, and amino acids;
- Due to small size and uniform dispersion they can easily reach to the targeted site with blood flow;
- They are non-cytotoxic to the normal cells;
- Gold nanoparticles are easily synthesized by various methods.
As pointed out in a review article [4], recent advances in the field of metallic nanoparticles offer the promise of better diagnostic and therapeutic options. Metallic nanoparticles are attracting attention in drug delivery because of their superb properties for targeted delivery in imaging and drug delivery to the desired site. We will continue to see breakthroughs in research and technology of drug delivery based on metallic nanotechnology in the future and these fascinating nanoparticles will indeed provide a new approach to effective and precise drug delivery.
References:
- [1] Website: http://nanoparticles.org
- [2] Khan, A. K., et al. “Gold nanoparticles: synthesis and applications in drug delivery.” Tropical Journal of Pharmaceutical Research 13.7 (2014): 1169-1177.
- [3] Hussain, Kashif, and Touseef Hussain. “Gold nanoparticles: a boon to drug delivery system.” South Indian Journal of Biological Sciences 1.3 (2015): 128-133.
- [4] Ahmad, Mohammad Zaki, et al. “Metallic nanoparticles: technology overview & drug delivery applications in oncology.” Expert opinion on drug delivery 7.8 (2010): 927-942.
