Enterprise Europe Network

Stable aqueous dispersion of silver nanoparticles

Country of origin:
External Id: 
Last update
Expiration date


Partner keyword: 
Inorganic Substances
Other Processes
Micro- and Nanotechnology
Micro- and Nanotechnology related to Biological sciences
Therapeutic services
Other speciality materials
Other research and experimental development on natural sciences and engineering


A Bulgarian research organization with R&D experience in the field of polymer chemistry and materials science has developed an innovative method for synthesis and preparation of highly concentrated dispersion of silver nano particles with high antibacterial activity.The team is looking to reach commercial agreements with technical assistance with interested companies for the implementation of the technology, license or technical cooperation agreements.



An academic research institution from Bulgaria with strong background in polymer and materials science and interdisciplinary research has developed innovative laboratory scale method for synthesis of hybrid silver nanoparticles dispersion, surface stabilized by water-soluble derivatives of calixarenes.

The method avoids the use of the traditionally used silver nitrate salt precursor, thus avoiding residual traces of the unreduced ion precursor and significantly simplifying the isolation and purification of the resulting colloidal dispersion. High concentrations (up to 400 ppm) of colloidal dispersion of AgNPs is achieved, which are stable over time and easily re-dispersed after drying, including in physiological aqueous saline solutions, which extends storage and possible biomedical (both human and veterinary) applications of the preparations. The biological tests of the synthesized preparations showed strongly pronounced antibacterial activity against strains of Gram-positive and Gram-negative bacteria, as well as pronounced in vitro selective cytotoxicity against tumor cell lines (bladder cancer and leukemia) at low blood plasma levels of elemental silver.
The team is looking for international partners to conclude the following types of agreements in order to disseminate and/or improve the developed technology:
- commercial agreements with technical assistance are sought under which acquisition (transfer) of the method for synthesis of hybrid silver nanoparticles dispersion is envisaged, supported by technical consultancy by the research team for its efficient use;
- in the case of licensing implementation of the supplement in the industry is expected against payment of license fee or royalties;
- under technical cooperation a further scale-up the method of production to be realized is envisaged;
- it is also possible to conclude other types of contracts depending on the wish of the potential partner and the negotiations, research cooperation agreement for further deep R&D of the obtained dispersion, including pre-clinical / clinical testing.

Advantages & innovations

Cooperation plus value: 
The obtained series of concentrated silver nanoparticles aqueous dispersions have the following advantages: - The colloidal dispersions are inherently stable and do not get agglomerated for at least 2 years storage in refrigerator at 4°C. - The synthesis and purification of the silver nanoparticles dispersions is easy and affordable, following green chemistry approach with the use of cheap and available reagents at mild reaction conditions. - The method avoids the use of silver nitrate as a traditional AgNPs precursor which automatically rejects the availability of unreacted/remaining excessive silver and nitrate ions in the final dispersions as well as the generation of undesirable toxic/cancerogenic and polymer-degrading NOx gases and nitrous acid during the synthesis. - The as obtained sterically stabilized AgNPs could be obtained in dried/lyophilized form, from which could be easily fully re-dispersed in both aqueous/ biological solutions as well as in organic media, which further increases their shelf life and the possible biopharmaceutical use.

Stage of development

Cooperation stage dev stage: 
Available for demonstration

Partner sought

Cooperation area: 
Type and role of partners sought: industry; partners with expertise in biomedical / pharmaceutical field. R&D organisations or universities for further joint project(s) aiming development of new ideas for the implementation of the dispersion. Type of partnership sought: the partner is expected to: acquire the know-how accompanied by offering him the necessary technical support for its efficient use (in case of commercial agreement with technical assistance), implement the new method in the production and pay a license fee or royalty as a reward (in case of license agreement), continue the technological development based on his specific existing technological capacity (in case of technical cooperation).

Type and size

Cooperation task: 
SME 11-50,>500 MNE,251-500,SME 51-250,>500