Synthesis of Amphiphilic and Hydrophilic Non-PAMAM Dendrimers Nanoparticles for Biomedical Applications and Realization of Water-soluble DDSs of two Triterpenoid Acids.

Carriers-mediated Drug Delivery emerged as a powerful strategy for the treatment of various pathologies. Many newly developed drugs are rejected by the pharmaceutical industry and will never benefit a patient because of poor bioavailability due to low water solubility and/or cell membrane permeability. Therefore, the development of new delivery technologies could help to overcome this challenge via the increase of specificity due to targeting of drugs to a particular tissue, cell or intracellular compartment, the control over release kinetics, the protection of the active agent or a combination of the above. For years, nanoparticles were proposed as drug carriers, and now are of eminent interest in biomedical applications mainly due to their stability and high drug-loading capabilities as well as permitting an easy control over their physicochemical properties. Among the various nanoparticles successfully tested as delivery tools systems dendrimers represent the most prospective drug delivery systems thanks to their inimitable characteristics including the exact molecular weight, the tree-like structure, poly-fuctionality, the spherical shapes as well as having a low index of polydispersion. The first part of this thesis focuses on the design, preparation and characterization of not cytotoxic amphiphilic polyester-based dendrimers obtained from the 2,2-bis(hydroxymethyl)propanoic acid and functionalized with positive charged amino acids as nanostructures for Drug Delivery applications. While the second part discusses the encapsulation of Ursolic and Oleanolic acids in hydrophilic arginine dendrimers.These acids are two triterpenoids acids from plants kingdom endowed with several pharmacological activities but unfortunately not exploitable because of restrictions such as very poor solubility and consequently low bioavailability.