The Research On Glycosylation Of Poly(γ-benzyl-L-glutamate) And Grafted Nano Hydroxyapatit/Polylactic Acid Composite Material

Poly(y-benzyl-L-glutamate)(PBLG) show excellent biocompatibility and biodegradable and secondary structure which is similar to protein, so it has a wide range of applications in drug delivery system, biosensor and tissue enginerring. The paper did the research in two aspects focusing on PBLG.1Polypeptide-glycopolymer amphiphilic tri-block compolymer has been synthesized by L-glutamic acid and β-D-glucose to prepare for evaluating the the potential application in tri-block compolymer in targeting drug delivery system.On one hand polysaccharides plays an important role in biological activity and especially can produce specific combination with protein which makes targeting drug delivery possible; on the other hand, poly(y-benzyl-L-glutamate) has a potential application in drug delivery system. We synthetized the polypeptide-glycopolymer tri-block copolymer by introducing the glycosyl into polypeptide chains. The copolymer can be self-assembly into micelle of gylcopolymer shell-polypeptide core structure in the water. The micelle can load hydrophobic drugs in the polypeptide core by physical embedding method, at the same time the specific identification of glycopolymer shell plays a role in targeting drug delivery.Amphiphilic tri-block polypeptide-glycopolymer copolymer was participated by the combination of ring-opening polymerization and atom transfer radical polymerization. Firstly, Poly(y-benzyl-L-glutamate)(PBLG) was synthesized Via ROP of BLG-NCA, and then PBLG was reacted with2-bromoisobutyl bromide, in then end, the functionalized PBLG was used as a macroinitiator to initatite ATRP of of2-(2’,3’,4’,6’-tetra-O-acetyl-β-glucosyloxy) ethyl methacrylate and the desired tri-block glycopolymer was synthesized. The structure of tri-block copolymer was characterized by FT-IR, H NMR.Hydroxyapatite (HA) is an kind of important material for bone regeneration as its excellent osteconduction and mechanical properties. But as its disadvantages of hydrophilicity, bad interfacial compatibility and aggregation, the applications of HA are limited. We prepared grafted HA by poly(y-benzyl-L-glutamate)(PBLG-g-HA). FT-IR and XPS exhibited that PBLG was grafted on the surface of HA successfully. TGA resulted that the quantities of grated PBLG are33.6%. The PBLG-g-HA/PLLA composite material was prepared via solvent composite method and its cytotoxicity was studied. The results show PBLG-g-HA/PLLA composite material exhibit good biocompatibility and can promote the proliferation of osteocyte.