The synthesis and characterization of hydroxyapatite-β-alanine modified by grafting polymerization of γ-benzyl-L-glutamate-N-carboxyanhydride.
In this study, hydroxyapatite (HAP) was surface-modified by the addition of β-alanine (β-Ala), and the ring-opening polymerization of γ-benzyl-L-glutamate-N-carboxy-anhydride (BLG-NCA) was subsequently initiated. HAP containing surface poly-γ-benzyl-L-glutamates (PBLG) was successfully prepared in this way. With the increase of PBLG content in HAP-PBLG, the solubility of HAP-PBLG increased gradually and it was ultimately soluble in chloroform. HAP-PLGA with surface carboxyl groups was obtained by the catalytic hydrogenation of HAP-PBLG. In the process of HAP modification, the morphology changes from rod to sheet and from flake to needle. The effect of BLG-NCA concentration on the character of hydroxyapatite-β-alanine-poly(γ-benzyl-L-glutamate) (HAP-PBLG) was investigated. The existence of amino acids on the HAP surfaces was confirmed in the resulting Fourier transform infrared (FTIR) spectra. The resulting powder X-ray diffraction patterns indicated that the crystallinity of HAP decreased when the ratio of BLG-NCA/HAP-NH2 increased to 20/1. Transmission electron microscopy (TEM) indicated that the particle size of HAP-PBLG decreased significantly and that the resulting particles appeared less agglomerated relative to that of the HAP-NH₂ crystals. Furthermore, ¹H-NMR spectra and FTIR spectra revealed that hydroxyapatite-β-alanine-poly (L-glutamic acid) (HAP-PLGA) was able to successfully bear carboxylic acid groups on its side chains.
Engineering Research Center of Biopolymer Functional Materials of Yunnan, Yunnan University of Nationalities, Kunming 650500, China. yml@188.com.
Yukai
Y
Shan
Yuyue
Y
Qin
Yongming
Y
Chuan
Hongli
H
Li
Minglong
M
Yuan
D000812:Anhydrides / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D005971:Glutamates / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D046529:Microscopy, Electron, Transmission; D011099:Polyglutamic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D058105:Polymerization; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction; D015091:beta-Alanine / Q000737:chemistry*
D000812:Anhydrides; D005971:Glutamates; C568827:gamma-benzylglutamyl-N-carboxy anhydride; D015091:beta-Alanine; C003172:poly-gamma-benzyl-L-glutamate; D011099:Polyglutamic Acid; D017886:Durapatite