Synthesis And Surface Characteristics Of Poly(γ-alkyl-α, L-glutamate)s

Polypeptides and their derivatives are attractive polymers with potential applications in various fields such as tissue engineering and pharmaceutical materials.In this work, Poly(γ-alkyl-α,L-glutamate)s(PALG) were synthesized by ring-opening polymerization (ROP) ofα-amino acid N-carboxyanhydrides(NCA).Dense films and electrospun mats were carefully fabricated and studied to evaluate the effect of surface chemical composition and morphology on the surface properties.Furthermore,novel metalloporphyrins were used to initiate theγ-stearyl-α,L-glutamate NCA(SLGNCA) to synthesize porphyrinated poly(γ-stearyl-α,L-glutamate)(PSLG) with high molecular weight.The main results of this work are listed as follows:Dense films and electrospun mats of PALG with four different alkyl groups were prepared by spin casting and electrospinning,respectively.The hydrophobicities of dense films increased with the increment of the alkyl chain length while the microfiber structure of electrospun mats could enhance the hydrophobicity/hydrophobicity of PALG.It was found that the blood biocompatibility of these PALG surfaces were determined by both their surface chemical composition and morphology.By electrospinning/electrospraying at different concentrations,PSLG mats with different morphologies were prepared.It was found that the surface composed of beads had higher hydrophobicity than that of microfibers.No matter for the electrosprayed mats or electrospun mats,the hydrophobicity increased with the decrease of the bead or microfiber diameters.Low adhesive superhydrophobic surface was prepared by electrospraying PSLG at concentration of 3 wt.%for 60 min.By electrospraying PSLG at concentration of 3 wt.%for 5 min or PDLG/PSLG mixtures with PSLG content of 20～50 wt.%for 60 min on aluminium,high adhesive superhydrophobic surfaces can be obtained.5-(4-Aminophenyl)-10,15,25-triphenylporphyrin(APTPP) and corresponding metal APTPP(MAPTPP) were firstly applied as initiators for the ROP of SLGNCA.PSLGs synthesized by the metalloporphyrins had higher molecular weight than that synthesized by APTPP,especially for CoAPTPE PSLG synthesized with APTPP and ZnAPTPP can be electrospun into discontinus fiber mats with strong fluorescence intensities while PSLG synthesized with CoAPTPP can be electrospun into well-define mats but with low fluorescence intensities.