From the beginning until present I obtained my Sc.B. degree in Chemistry from the Universitat Autònoma de Barcelona (UAB). I was a Spanish Government pre-doctoral fellow in the Biochemistry and Molecular Biology Department of the UAB. There I worked with Prof. F. X. Avilés to elucidate the activation mechanism of pancreatic zymogens where I earned my Ph. D. degree in Biochemistry. I was a post-doctoral fellow at the Institut de Biologia Fonamental (UAB) where I worked with Prof. C. M. Cuchillo who introduced me in the field of ribonucleases. In 1990, I joined the Department of Biology of the Faculty of Sciences at the Universitat de Girona where at present I'm Full Professor of Biochemistry and Molecular Biology. The research interests of the Protein Engineering Laboratory, where I work in collaboration with Dr. Marc Ribó and Dr. Antoni Benito, are focused on the development of antitumor proteins and characterization of the molecular basis of their cytotoxic action. In addition, we are interested in protein drug delivery systems to find an efficient way of arrival of drugs to the target tissues. Brief description of the Research lines Proteins belonging to the pancreatic ribonuclease family present some biological activities, such as antitumor, bactericidal or antiviral activity that have make them exceptional candidates as chemotherapeutics. On the other hand, the tumor selective killer protein, named apoptin, is another good candidate as antitumor agent. The mechanisms underlying the abilities of these proteins are not well known although are on the basis for the exploitation of these enzymes as therapeutic agents. On this basis, our research project intends to develop basic and applied studies according to the following research lines: Design, production and specific targeting of cytotoxic ribonucleases with antitumor activities. To study the molecular basis of the cytotoxic mechanism of the antitumor viral protein named apoptin. Design, production and characterization of a protein drug delivery nanoparticle based on the eukaryotic vault system.