Functional particle nuclei

The particle cores can consist of resistant or degradable materials. They are loaded with dye molecules, active ingredients or biomolecules.

Inorganic core

Nanoparticles with a polymer shell and magnetizable core (magnetite) that are attracted by a magnet (on the right).
Nanoparticles with a polymer shell and magnetizable core (magnetite) that are attracted by a magnet (on the right).

At Fraunhofer IGB we develop nano- and microparticles whose core consists of inorganic material. Metals, metal oxides or ceramic materials can be used. The shell, on the other hand, consists of an organic substance that exhibits certain physicochemical properties in the form of electrostatic charge or defined chemical groups. We develop biofunctional particles by conjugating biomolecules in their active form to particle surfaces.

Organic particles

Polymerisation techniques.
Polymerisation techniques and achievable particle sizes.

At Fraunhofer IGB we produce customized nano- and microparticles with cores of organic material. We use commercially available polymers or synthesize tailor-made materials and produce particles with diameters ranging from a few nanometers to several 100 micrometers using various polymerization techniques such as miniemulsion or dispersion polymerization. An overview of the available methods is given by the sketched scheme.

Among the nanoparticles with an organic core developed at the Fraunhofer IGB are

  • Surfmer nanoparticles
  • Biodegradable particles
  • Molecularly imprinted nanoparticles

Surfmer nanoparticles

Production of surfmer particles with binding of biomolecules.
Production of surfmer particles with binding of biomolecules.

At the Fraunhofer IGB we provide a class of molecules with modularly structured active ester surfmers (surfactant monomer), which provide three completely different reactivities in a single molecule and can thus be used for the simple synthesis of nanoparticles with binding sites for e.g. proteins:

  1. The function of a nanoparticle stabilizing emulsifier.
  2. The function of polymerizability by radical chain reaction.
  3. An active ester group that is stable against polymerization or storage, but can be used under easy-to-realize conditions for covalent anchoring of further components such as biomolecules.

With these surfmers, we can produce nanoparticles with controllably adjustable properties in one step by emulsion polymerization. Typical particle diameters of co-polystyrene or methyl methacrylate nanoparticles are in the range of 80 to 200 nanometers. The nanoparticles carry a defined number of anchor points for further chemical functionalization and conversions, for example for the immobilization of biomolecules.

Our surfmer-based technology enables the single-stage production of nanoparticles with tailor-made anchor sites for biomolecules. This enables the replacement of costly production processes with several different process steps that have been used in everyday technical applications up to now. Surfmer technology also enables particles to be produced that are many times smaller than the beads currently used for immobilizing biomolecules.