Poly(amidoamine)s of biotechnological interest

Abstract: Poly(amidoamine)s (PAAs) represent a promising material for drug delivery applications. They are synthetic functional polymers endowed with a combination of properties making them suitable for a variety of biomedical applications mostly related to drug delivery systems. PAAs can be obtained by stepwise polyaddition of primary or secondary aliphatic amines to bisacrylamides. The synthesis is carried out in water or protic solvent, with a mild base and at room temperature. In the first section of this thesis, a group of novel amphoteric PAAs homo- and copolymers containing secondary and tertiary amine groups in their main chain and different structures in the bisacrylamide segments were synthesized and evaluated as magnetic nanoparticles coating agents. In the second section of this thesis, a general method for preparing linear high polymers of peptides was investigated. Polymers with an average molecular weight included in the range 3000 – 40000 were obtained by Michael polyaddition reaction between 2,2-bisacrylamidoacetic acid or N,N’-bisacryloylpiperazine and glutathione (reduced and oxidised) or the RGD peptide. In preliminary biological tests these polymers showed a good values of zeta potential and negligible values of cytotoxicity and haemolytic activity. Further in vitro tests are in progress to investigate the biological properties of these polymers in comparison with the parent peptides. In the third section of this thesis, gene delivery properties of new hyperbranched PAAs, containing disulfide linkages in the main chain, were investigated in comparison with the relevant linear polymers. Structural characterization of the polymers synthesized and the reactivity of the monomers utilized were also determined. The results shown by these polymers in DNA transfection are very promising and encourage further studies in vitro with these biodegradable hyperbranched PAAs to test the effect, on transfection efficiency, of different terminal groups.