"During the last years an intense research has been done in pursuit of the development of highly active and stereoselective initiators for the ring opening polymerization of cyclic esters such as rac-lactide, e-caprolactone, etc. However, there is still a need to develop a new generation of catalyst which shows higher activities and stereoselectivity. Furthermore, one of the most important applications of these polyesters is for biomedical applications, and therefore the need of “benign” initiators is also very high, if the final polymer is intended to be used for these purposes. Thus, in the initial part of this project we will synthesized a new range of metal alkoxide initiators for the polymerization of cyclic esters, which will allow us to obtain a library of polyesters of varying properties by fine tuning the ligands in the first coordination sphere of the metal centers of the initiator. We will focus on the molecular weights, polydispersity, stereochemistry (i.e. atactic, stereotactic or isotactic), composition, block-lenghts, etc. of the new polymers in view of its posterior applications. Thus, in the second part of this project we will prepare new scaffolds for Tissue Engineering, based on the library of polymers previously synthesized. In this part of the project we will fabricate flat sheets and hollow fibers with the different polyesters and evaluate its applicability in cell culture (both attachment and proliferation) in order to improve the current scaffolds based in the commercial polymers. Apart from these research objectives, this proposal is expected that will help the applicant to reach a position of professional maturity by gain experience in the area of controlled polymerization, scaffold fabrication. Also is expected for the applicant a development of his experience in teaching, oral and written communication and networking by interaction with leading mentors in a top rank institution."