Tissue Eng Regen Med.  2019 Apr;16(2):177-189. 10.1007/s13770-018-0171-5.

D-RADA16-RGD-Reinforced Nano-Hydroxyapatite/Polyamide 66 Ternary Biomaterial for Bone Formation

• Zhao W
• He B
• Zhou A
• Li Y
• Chen X
• Yang Q
• Chen B
• Qiao B
• Jiang D

• KMID: 2449248
• DOI: http://doi.org/10.1007/s13770-018-0171-5

Abstract

BACKGROUND
Nano-hydroxyapatite/polyamide 66 (nHA/PA66) is a composite used widely in the repair of bone defects. However, this material is insufficient bioactivity. In contrast, D-RADA16-RGD self-assembling peptide (D-RADA16-RGD sequence containing all D-amino acids is Ac-RADARADARADARADARGDS-CONH2) shows admirable bioactivity for both cell culture and bone regeneration. Here, we describe the fabrication of a favorable biomaterial material (nHA/PA66/D-RADA16-RGD).
METHODS
Proteinase K and circular dichroism spectroscopy were employed to test the stability and secondary structural properties of peptide D-RADA16-RGD respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the surface of these materials. Confocal laser scanning (CLS), cell counting kit-8 tests (CCK-8), alizarin red S staining, cell immunofluorescence analysis and Western blotting were involved in vitro. Also biosafety and bioactivity of them have been evaluated in vivo.
RESULTS
Proteinase K and circular dichroism spectroscopy demonstrated that D-RADA16-RGD in nHA/PA66 was able to form stable-sheet secondary structure. SEM and TEM showed that the D-RADA16-RGD material was 7-33 nm in width and 130-600 nm in length, and the interwoven pore size ranged from 40 to 200 nm. CLS suggests that cells in nHA/PA66/D-RADA16-RGD group were linked to adjacent cells with more actin filaments. CCK-8 analysis showed that nHA/PA66/D-RADA16-RGD revealed good biocompatibility. The results of Alizarin-red S staining and Western blotting as well as vivo osteogenesis suggest nHA/PA66/D-RADA16-RGD exhibits better bioactivity.
CONCLUSION
This study demonstrates that our nHA/PA66/D-RADA16-RGD composite exhibits reasonable mechanical properties, biocompatibility and bioactivity with promotion of bone formation.

Keyword

nHA/PA66/D-RADA16-RGD; Bone defect; Bone regeneration; Peptide hydrogel

MeSH Terms

Actin Cytoskeleton
Blotting, Western
Bone Regeneration
Cell Count
Cell Culture Techniques
Circular Dichroism
Endopeptidase K
Fluorescent Antibody Technique
In Vitro Techniques
Microscopy, Electron, Scanning
Microscopy, Electron, Transmission
Osteogenesis*
Sincalide
Spectrum Analysis
Endopeptidase K
Sincalide