but also forming amphiphilic copolymers that can act like polymeric surfactants to stabilize the resultant particles therefore there are covalent linkages between the chitosan shell and the polymer core due to the grafting of poly vinyl chains onto chitosan backbone since amphiphilic graft copolymers formed initially self assemble into micelle like micro domain many small and uniform particles between 100 to 500 nm in diameter can be produced in a high solid content up to 30 such particles may be seen in fig1 further detail of the preferred embodiment is provided in the following examples and description the chitosan used in the present invention is poly u03b2 1 u2192 4 2 amono 2 deoxy d glucopyranose a deacetylated derivative of chitin other modified chitosans with various substituted groups and a part of the deacetylated amino groups can also been used such materials can have a wide range of molecular weights m w as well as deacetylation degrees dd generally the antibacterial activity of chitosan increases as the molecular weight and degree of deacetylation of chitosan increase and decreases over a certain high m w in the disclosed invention the m w of chitosan is higher than 10 000 and the dd is in the range of 10 to 100 it is desirable to have a medium m w of chitosan 50 000 to 100 000 with a relatively dd higher than 70 there is no particular restriction on the monomer of the core as long as it has a reactive vinyl group that can be polymerized by free radicals hydrophobic monomers with corresponding polymers having low glass transition temperatures tg are good for particles with soft cores hydrophilic monomers can also be used depending on the water solubility.