Novel osteogenic growth peptide C-terminal pentapeptide grafted poly(d,l-lactic acid) improves the proliferation and differentiation of osteoblasts: The potential bone regenerative biomaterial

Abstract

Poly(d,l-lactic acid) (PDLLA) is widely used for bone regenerative engineering, because of its proven biocompatibility and biodegradability. However, the major limitation of PDLLA is its cell recognition and low hydrophilicity. The objective of this study was to develop a novel bioactive poly(d,l-lactic acid) tethered with osteogenic growth peptide (OGP), which has been confirmed as one of the important growth factors related to bone repair/regeneration. The biomimetic material modification methods were utilized that maleic anhydride-modified poly(d,l-lactic acid) (MPLA) as raw material, the active C-terminal pentapeptide OGP(10–14) were covalently grafted onto the side chain of MPLA through amide reaction using 1‑ethyl‑3‑(3‑dimethyl aminopropyl) carbodiimide hydrochloride (EDC) and N‑hydroxysuccinimide (NHS) as the condensing agent to produce a new biopolymer (OGP(10–14)-MPLA). The OGP(10–14)-MPLA were further characterized with the Fourier transform infrared spectrometry, amino acid analyzer, elementary analysis, X-ray photoelectron spectroscopy. The results revealed that OGP(10–14) was successfully modified MPLA and its coupling efficiency was 12.40%. The data from both contact angle and water absorption showed the better hydrophilicity of OGP(10–14)-MPLA, compared with MPLA. Also, we found that OGP(10–14)-MPLA could improve the proliferation, differentiation, and mineralization of osteoblasts, indicating that the novel OGP(10–14)-MPLA has the better biocompatibility and is more osteoinductive. In conclusion, the OGP(10–14) modified MPLA have the potential for bone regenerative engineering.