Innovation of the product The present invention is directed to a nanocomposite providing sustained release of bioactive proteins which comprises: • a charge-carrying, bioactive protein core, precipitated reversibly in an ionic mechanism and • polyelectrolyte shell around the said core consisting of two oppositely charged polyelectrolytes, forming 3 to 5 layers, where one of the polyelectrolytes has pH-dependent charges while the other polyelectrolyte has permanent, pH-independent charge. Further, the present invention is directed to a procedure for the preparation of said nanocomposite wherein: • a biocative protein or a protein mixture containing at least one bioactive protein, • the precipitated protein of positive charge or of negative charge is separated by centrifugation, • a solution of a first polyelectrolyte that is oppositely charged relative to the protein is added to the above protein sediment while mixing at a pH adjusted by a buffer to the pH of the precipitated protein, • the polyelectrolyte-coated nanocomposite particles charged oppositely relative to the precipitated protein core are separated by centrifugation and optionally washed with buffer solution, • a solution of a second polyelectrolyte, charged oppositely relative to the first polyelectrolyte is added to the sediment at the same pH adjusted by buffer, • the two-polyelectrolyte-coated nanocomposite particles having similar charge as the protein core are separated by centrifugation and optionally washed with buffer, • sediment of the core-shell nanocomposite containing 3 to 5 coating layers as desired on the primary protein nanoparticle is freeze-dried. In further aspects the present invention is directed: • to a sustained release drug formulation which comprises a nanocomposite according to the invention and optionally other bioactive agent(s) and pharmaceutically acceptable inert carrier(s) and/or other excipient(s), • to the use of said nanocomposite in the preparation of a sustained release drug formulation. Further informations about the presented technology The technology have been developing with interferon as core protein and regarding the mentioned type of core protein the next step is to increase the level of the technology to industrial size. If the inquiring partner would like to use different type of molecule as core protein our partner, a Hungarian University (the inventor of the technology) possesses a well equipped lab and a well qualified expert team to help them optimize the technology for the requirements.

File Number: MED-LC-015-TO