Biomineralization of the surface of PLGA-(ASP-PEG) modified with the K₁₆ and RGD-containing peptide

Abstract

K₁₆ and RGD-containing peptide was used to modify the surface of three-dimensional PLGA-(ASP-PEG) matrix, then the modified PLGA-(ASP-PEG) was incubated in modified simulated body fluid (SBF). The biomineralization of the modified PLGA-(ASP-PEG) was explored, and the peptide was synthesized with solid phase synthesis technology and linked covalently to PLGA-(ASP-PEG) through cross-linker (Sulfo-LC-SPDP), which was characterized with XPS. The modified PLGA-(ASP-PEG) (Experiment group, EG) and PLGA-(ASP-PEG) (Control group, CG) were all incubated into SBF for 10 d, and the growth of hydroxyapatite (HA) nanocrystals was confirmed with XRD, EDS and SEM. HPLC shows that peptide purity is 94.13%, while MS analysis shows that molecular value of peptide is 2741.26. Binding energy of the sulphur in EG was 164 eV is detected by XPS, and the ratio of carbon and sulphur is 99.746:0.1014. SEM analysis demonstrates the better growth of bonelike HA nanocrystals in EG than that in CG. The component of mineral in EG consisted mainly of hydroxyapatite containing low crystalline nanocrystals, and the Ca/P ratio is about 1.60, which is similar to that of natural bone, while the Ca/P ratio in CG is 1.52. PLGA-(ASP-PEG) modified with peptide provided enough functional groups for biomineralization, and possessed the bonelike structure.

Keywords

biomineralization / PLGA / hydroxyapatite (HA) / peptide

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