Modification of poly(l-lactic acid) electrospun fibers and films with poly(propylene imine) dendrimer

Poly( l -lactic acid) (PLLA) electrospun fibers and films were modified with the second generation of poly(propylene imine) dendrimer (PPI-G 2 ) by three different approaches, namely, sodium hydroxide hydrolysis, plasma treatment and direct application of PPI-G 2 . For the first and the second approaches, PLLA was modified by sodium hydroxide hydrolysis or plasma treatment to produce carboxylic acid groups. Then, the carboxylic acid groups were activated by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC) and N,N′-dicyclohexyl carbodiimide (DCC) as a hetero bi-functional cross-linker. The cross-linkers promoted the grafting of carboxylic acid groups on the modified PLLA with NH 2 groups of PPI-G 2 . In the third approach, the PPI-G 2 dendrimer was directly used as an aminolysis agent for the functionalization of PLLA in a one step process. FTIR analysis confirmed the presence of NH 2 groups of PPI-G 2 on the modified PLLA samples, resulting from each one of the three modification methods. Studies by SEM shows bead free electrospun fibers. Also, FE-SEM shows nano-cracks on the surface of films after modification. Contact angle, drug release tests, antibacterial effects and the dying results confirmed that these functionalization methods increased hydrophilicity and reactive side-chains of PLLA in the wet chemical process resulted in providing host–guest properties on the PLLA surface for adsorbing various kinds of guest molecules.