During the last years, our research team has studied collagen and chitosan based membranes, with and without silver, proving their effect in enhancing antibacterial activity. The bactericidal action was most evident in Escherichia coli. The experimental study continued with collagen and chitosan based membranes with alkaline phosphatase (ALP) immobilisation, the haemolytic properties and cell viability in their case being better than those recorded on simple collagen or chitosan membranes. On the basis of our published results, this project represents a continuation of the biotechnological process for the development of new immobilised protein membranes, which will be materialised as TRL3 experimental demonstrator. We intend to find a suitable technique to improve the enzymatic activity of chitosan-based membranes for tissue engineering by adding different metal ions. The structural and morphological characteristics, mechanical properties, degree of adsorption and contact angle of the membranes will be studied in order to find the appropriate formulation for use in therapy. The determination of the optimal concentration of Mg+ 2 to activate or inhibit ALP activity and its influence on cell adhesion and proliferation on the obtained membranes will be investigated. In vitro biodegradation, using bacterial collagenase (Clostridium histolyticum) and haemocompatibility of the obtained membranes will be tested. Taking into account that the incorporation of metal ions, such as Cu+ 2, Zn+ 2 or Ag + can improve the antimicrobial property, we intend to find a specific metal ion to increase the antimicrobial activity while maintaining a high biocompatibility. At the end of this project we plan to submit a patent application.