Size control of self-assembly polymeric nanospheres for biomedical applications

The control of nanospheres properties and the understanding of their influence on biological environments not only improve the drug delivery system outcome but also facilitates its clinical translation. Nanospheres size, for instance, has substantial impact on biological responses and have a direct effect on the particle performance after administration. This thesis presents a new method to tune the size of TyroSpheres and evaluates the copolymer structure-property relationship in the biomedical field. TyroSpheres are dynamic core-shell nanospheres constituted of a tyrosine-derived amphiphilic copolymer. The TyroSpheres hydrophobic core allows encapsulation of hydrophobic drugs at levels that surpass its aqueous solubility. On the other hand, its shell, composed of poly(ethylene glycol) (PEG) promotes particle stabilization. Even though the TyroSpheres were extensively studied with success for many different biomedical applications in the past, its size was never controlled. Here size control was achieved through precise synthesis and characterization of block copolymers (diblock (A-B) and triblock (A-B-A)) and of its respective tyrosine-derived monomeric units. In addition, the tyrosine-derived block copolymers were synthetically modified to optimize the copolymers performance as fusogenic agents for nerve repair. The work presented here promotes a deeper understanding of polymeric nanospheres, which could be expanded for other polymeric nano-delivery systems and also adds a novel property for the previously established TyroSpheres.Ph.D.Includes bibliographical reference