Jiaoxia Sun

Synthesis, characterization, and biocompatibility of a novel biomimetic material based on MGF-Ct24E modified poly(D, L-lactic acid).

Mechano-growth factor (MGF) is an alternative splicing variant of Insulin-like growth factor I. MGF and its 24 amino acid peptide analog corresponding to the unique C-terminal E-domain (MGF-Ct24E) are the positive regulator for tissue regenesis in bone. A novel biomimetic poly(D, L-lactic acid) (PDLLA) modification was designed and synthesized based on MGF-Ct24E grafted maleic anhydride modified PDLLA (MPLA). MGF-Ct24Es were grafted into the side chain of MPLA via a stable covalent amide bond using 1-ethyl-3-(3-dimethyllaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide as the condensing agent to produce biomimetic MPLA materials (MGF-Ct24E-MPLA). Fourier transform infrared spectrometry, amino acid analyzer, and elementary analysis were used to characterize the MGF-Ct24E-MPLA. The hydrophilicity of MGF-Ct24E-MPLA was evaluated by means of the water-uptake ratios and static water contact angle. Data revealed that the grafting efficiency of MGF-Ct24E was about 29.9%. MGF-Ct24E-MPLA had better hydrophilicity than PDLLA and MPLA. The osteoblasts behavior of proliferation, differentiation, and mineralization on PDLLA, MPLA, and MGF-Ct24E-MPLA films was investigated and the results indicated that the introduction of MGF-Ct24E could improve osteoblasts proliferation, mineralization, and delay differentiation. The MGF-Ct24E modified MPLA with higher bioactivity may have potential application for bone tissue engineering.

In vitro cytocompatibility evaluation of MGF-Ct24E chemically grafted and physically blended with maleic anhydride modified poly(D, L-lactic acid)

As a growth repair factor, mechano-growth factor (MGF) and its 24 amino acid peptide analogs corresponding to the unique C-terminal E-domain (MGF-Ct24E) positively regulate bone regeneration. MGF-Ct24E was introduced into the poly(D, L-lactic acid) (PDLLA) to improve bone regeneration in our previous study. MGF-Ct24E-grafted PDLLA was chemically characterized and showed potential as a biofunctional polymer. In this study, we evaluated the cytocompatibility of MGF-Ct24E chemically grafted and physically blended with maleic anhydride modified PDLLA, relative to maleic anhydride modified PDLLA (MPLA) as the control. The surface properties of these three polymer films were characterized with scanning electron microscopy and X-ray photoelectron spectroscopy. Rat calvarial osteoblasts were seeded on the three polymer films, and cell adhesion, spreading, and proliferation were assessed with an inverted microscope, laser scanning confocal microscope, and a cell counting kit-8, respectively. The alkaline phosphatase activity and extracellular calcium production were exploited to characterize the differentiation and mineralization of rat calvarial osteoblasts on various polymer films. The results revealed that compared with MPLA, MGF-Ct24E-MPLA, and MGF-Ct24E/MPLA blends promoted adhesion, spreading, proliferation, and the later differentiation and mineralization process of rat calvarial osteoblasts. In addition, the positive effect of MGF-Ct24E-MPLA on rat calvarial osteoblasts was maintained longer than the MGF-Ct24E/MPLA blends. In conclusion, MGF-Ct24E-MPLA synthesized chemically might be a promising biomaterial for bone tissue engineering.