Nanosilver particles – Mechanisms of action and investigation of their possible interaction with tissues, cells and molecules. Definition of their relevant potential for intolerance
The objective of the project Nanosilver-Particles was to develop methods for the production of silver nanoparticles (AgNP) that can be safely introduced into a product whilst maintaining the intended. From different products consisting both of permanently embedded silver nanoparticles and of releasing, resorbable systems, detailed knowledge of the respective nanoparticles and nanomaterials was to be gained to exclude potential risks of application.
Different nanosilver-containing materials were developed to serve as model systems for three product types with silver nanoparticles:
- Organic base: Rapid short-term release of silver from e.g. collagen films
- Metallic base: Intermediate implants for osteosynthesis e.g. titanium screws or titanium plates
- Synthetic base: Permanent implants e.g. bone cement
Materials with different contents of silver nanoparticles were investigated to find the effective dose that enables a sufficient release and effectiveness of silver while having no toxic effect on the analysed cells. For that purpose, release profiles were analysed and the toxic effects on different cell types of the organism were determined. In addition to silver nanoparticles, conventional completely soluble silver salts were tested for comparison. Besides, the products’ antimicrobial efficiency was determined after simulated use to determine the possible duration of effect. Compatibility with the organism as well as a possible accumulation of the respective silver nanoparticles in organs were studied in limited animal experiments. No such accumulation was observed in the implants used.
The obtained results enable a better and more realistic assessment of the risk potential of silver nanoparticles and nanosilver-containing materials and allow safe assessment of the hazards when using these in medical products. According to the results, antimicrobially active nanosilver-containing medical products present a low risk to consumers while reducing the risk of implant-associated infections.
In the developed products, the silver nanoparticles show:
- a good bactericidal effect
- a good efficacy already at low dosages
- a good incorporation in the tested materials without reducing the materials’ performance
- no undesirable release during incorporation (this does not apply to resorbable products)
