During the past decade Prof. Margel research group have pioneered in the development of Polymeric Nanoparticles ranging in size from a few nanometers to a few microns. These particles having very narrow size distribution, spherical shape and high surface area. They may also contain different dyes and variety of surface functional groups (i.e. aldehydes, hydroxyls, carboxylate, amines and thiols), and may provide a unique solution to a variety of basic and practical problems in materials science and biotechnology.

During the past ten years six major types of uniform functional monodispersed nanoparticles have been prepared in the laboratory:

1) Solid nanoparticles suspended in aqueous and/or organic solvents microencapsulated with different dye compounds and/or magnetic properties. These nanoparticles were prepared from a variety of functional polymeric materials, e.g. polyacrolein, polyglutaraldehyde, polymethyl -(hydroxymethyl)acrylate, polychloromethylstyrene, polyvinyl  -amino acids, cellulose and silica;

2) Core-shell particles composed of cores from micron-sized monodispersed polystyrene particles and shells from different metals or inorganic materials (e.g. gold, silica, titania and magnetite).

3) Non-magnetic and magnetic silica hollow micron-sized particles composed of sintered silica nanoparticles.

4. Supported nanoparticles prepared by covalent binding in a monolayer structure of functional

nanoparticles, i.e. polyacrolein, onto solid substrates such as glass and polystyrene.

5) Template nanoparticles based on polystyrene have been used for preparation of other uniform functional nanoparticles, e.g. PMMA, polyvinyl alcohol, etc, and for in situ surface modification with functional vinylic monomers such as polyacrylic acid, polyacryl amide, etc. This technology is also used for encapsulating into the template particles different materials such as a variety of fluorescent dyes.

6) Biodegradable, non-toxic, magnetite (Fe₃O₄) nanoparticles of very narrow size distribution in sizes ranging from approximately 20 nm up to 0.1 µm. The process for preparation of these monodispersed magnetic nanoparticles is simple and the yield of the particles is almost 100%. These particles are superparamagnetic, i.e. they magnetized in the presence of a magnetic field, but no remanence is observed in the absence of a magnetic field.

The functional groups of the particles have been used for covalent binding, via different activation procedures, of ligands such as drugs, proteins, enzymes, antigens and antibodies to the nanoparticle surfaces. The non-conjugated and the conjugated particles were then used for applications such as imaging, catalysis, biocatalysis, specific cell labeling and cell separation, diagnostics, affinity chromatography, specific blood filtration by hemoperfusion, heavy metal ions detoxification and carriers for oligonucleotide synthesis and various bio-chemical reactions.