Small, but Powerful Antimicrobial Particles

Remarkably efficient antimicrobial alginate micropaticles with integrated silver nanoparticles were developed at the Faculty of Technology and Metallurgy, University of Belgrade. These particles can be used as biocompatible scaffolds and/or efficient carriers with controlled release of silver nanoparticles for applications in biomedicine, pharmacy, catalysis, optics.

Since the discovery of penicillin, antibiotics have belonged to a group of drugs that are most frequently used in therapy, because of the strong antibacterial effects they manifest. However, microorganisms are prone to developing resistance to this type of medications, reducing their efficiency, so that the modern medicine requires fresh, innovative ideas.

When it comes to topical applications, the solution lies in using silver nanoparticles as a supstitute for antibiotics, since they manifest strong antimicrobial effect and, therefore, successfully act against different bacteria, fungi and viruses. It is also proven that silver nanoparticles are more effective than silver ions. This fact has encouraged scientists to develop new methods for obtaining silver nanoparticles and their incorporation in different materials which act as scaffolds.

One of the problems that arise during the production of nanoparticles is their tendency to agglomerate, which reduces their applicability. An attractive solution to this problem originated at the Faculty of Technology and Metallurgy (FTM), University of Belgrade, within a team of young and talented researchers, led by Professors Bojana Obradović and Vesna Mišković-Stanković. This team has prevented nanoparticle agglomeration by applying a novel electrochemical method accompanied with the careful selection of the scaffold material. Silver nanoparticles were successfully produced and incorporated in alginate hydrogel (which is in the form of microparticles), by using this innovative method, which has brought a number of outstanding advantages, all of which are embodied in the product NanoAktiv.

PhD students Jasmina Stojkovska and Željka Jovanović have contributed to the development of NanoAktiv by devoted work and innovative ideas. They strongly believe that this product has high commercialization potential: “NanoAktiv is not cytotoxic and it provides prolonged release and antimicrobial effects. In addition, it’s a known fact that silver is used as a catalyst in many chemical reactions and therefore, we consider that this product can be applied not only in biomedicine and pharmacy,  but also in the fields of catalysis and optics”.

The patented product from FTM laboratories participated in the 31st International Exibition of Inventions, New Technologies and Design, organized by the Belgrade Association of Inventors, where more than 120 papers and 180 authors from 10 countries took part. At this International Exhibition, held in May of 2011, NanoAktiv won the golden medal. This award is an additional confirmation of the product’s innovative significance. Meanwhile the team from FTM is pursuing further development of this invention, by using other polymer materials as scaffolds, which will open a range of new application opportunities.

The secret of antimicrobial microparticles

In any potential product, it is necessary to stabilize silver nanoparticles, as it was already mentioned, due to the problem of agglomeration. With this aim, the most commonly stabilization materials used are polymer solutions or polymer hydrogels. Polymer hydrogels are more suitable for achieving high concentrations of nanoparticles and their controlled release, which is of great importance for systems used in pharmacy and medicine. Keeping this in mind NanoAktiv was developed at the FTM.  NanoAktiv is composed of silver nanoparticles incorporated in pure alginate microparticles. Since alginate is a biocompatible natural hydrogel, it is completely safe for medical use. Additionally, the new electrochemical method uses very few chemicals, so that the risk of side efects of the product is reduced. In contrast, solvents and other chemicals, that are used in other procedures for obtaining hydrogels and nanoparticles, can be potentially toxic, even in very small amounts.

This new and unique technique for obtaining alginate microparticles with silver nanoparticles is simple, and not only does it use fewer chemicals (e.g. there are no additional solvents except water), it also provides better gelation control, compared to the techniques used so far. All this leads to a final product that has high concentration and uniform distribution of nanoparticles. These features enable efficient and continuous release of silver nanoparticles from alginate microparticles, which can significantly increase the activity of the product.

Prof. Dr Bojana Obradović points out the possible application opportunities and the advantages provided by NanoAktiv, in regards to other similar products with silver nanoparticles: “NanoAktiv can be used as a hydrogel, but also in dehydrated form and as such it would be a beneficial component of antibacterial patches, which are placed on wounds after surgeries and injuries. Along with antimicrobial effects of silver, dehydrated alginate would successfully absorb liquids excreted from wounds. Therefore, it would speed up the healing process. A more advanced application of our patented product could be as a part of soft tissue implants, since it is biodegradable and decreases the risk of infections after surgery. In addition, our invention can be used in tissue engineering as a scaffold. Alginate is already used for such purposes, but now the incorporated silver nanoparticles exhibit the antibacterial effect and additionally protect cells. These are just some examples of potential applications of NanoAktiv and therefore we are continuing our research with a belief that we will develop soon a commercial product.”


Source: www.inovacionifond.rs