| As a good biocompatibility and biodegradable material, polylactic acid(PLA) has broad application prospect in the field of biomedical engineering. However, some defects, such as poor hydrophilicity and bioactivity, limit its application in biomedical engineering. The bionic modification is a way to overcome these drawbacks by enhancing biocompatibility and bioactivity. The advantage of modified PLA compared with original PLA, leads to its more significant role in bionic bone repair of tissue engineering. The aim of this study is to produce a novel biomimetic material(OGP(10-14)-MPLA), which can promote the osteogenic activity, by grafting Osteogenesis Growth Peptide(OGP(10-14)) into the side chain of the maleic anhydride modified PDLLA(MPLA). The characterization of the biomimetic biomaterials was conducted by means of Fourier transform infrared spectrometry(FTIR), Amino acid analyzer(AAA), Elementary analysis(EA), X-ray photoelectron spectroscopy(XPS) and Differential scanning calorimeter(DSC), aiming to evaluate the structure and properties of the biomimetic biomaterials. Further, the hydrophilicity/hydrophobicity and in vitro biodegradation of the synthetic biomaterials were investigated. At last, the cytocompatibility of synthetic biomaterials was systemically evaluated. The main works and conclusions are listed as follows:①Preparation and characterization of OGP(10-14)-MPLAThe OGP(10-14) was grafted into the side chain of MPLA via a stable covalent amide bond, which is created by amide reaction between amidogen on OGP(10-14) and anhydride on MPLA by using 1-ethyl-3-(3-dimethyllaminopropyl) carbodiimide hydrochloride(EDC) and N-Hydroxysuccinimide(NHS) as the condensing agent. The FTIR, AAA, EA, XPS and DSC analyses revealed that OGP(10-14) was successfully modified into the side chain of MPLA. The average content of OGP(10-14) in OGP(10-14)-MPLA materials was 2.46 μmol/g and the coupling efficiency was 12.40%. The DSC results showed that the glass transition temperature of OGP(10-14)-MPLA was 68.50℃, and the glass transition temperature of OGP(10-14)-MPLA was higher than the glass transition temperature of MPLA.②Basic physical and chemical properties of OGP(10-14)-MPLAThe basic physical and chemical properties of MPLA and OGP(10-14)-MPLA materials were characterized by detecting the water absorption rate and static water contact angle. The experiment results revealed that the static water contact angle of OGP(10-14)-MPLA was smaller than MPLA, and the water absorption rate of OGP(10-14)-MPLA was higher than MPLA, so the hydrophilicity of modified polylactic acid materials was enhanced. Results about the p H of degradation medium in vitro hydrolytic degradation of OGP(10-14) –MPLA and MPLA indicated that the p H of degradation medium of OGP(10-14)-MPLA was higher and the acid induced auto-catalysis of OGP(10-14)-MPLA was weaker, as compared to MPLA materials. Due to the OGP(10-14) was grafted into the MPLA, the degradation system of material was changed, and in vitro degradation stability of OGP(10-14)-MPLA was controlled.③ Cytocompatibility evaluation of OGP(10-14)-MPLARat calvarial osteoblasts were seeded on the polymer films of OGP(10-14)-MPLA and MPLA materials in vitro culture. The cell adhesion, spreading, proliferation, differentiation and mineralization were detected to evlaute the cytocompatibility of OGP(10-14)-MPLA and MPLA. Compared with MPLA material, all obtained results indicated that OGP(10-14)-MPLA had significantly promoted osteoblasts adhesion, proliferation, differentiation and mineralization. The OGP(10-14) was grafted into MPLA, which promote the osteogenic bioactivity of materials.To summarize, the peptide OGP(10-14) can be grafted into the PLA material with higher coupling efficiency through amide reaction based on maleic anhydride modified PLA. The obtained new material has improved hydrophilicity and degradation feature compared to original material. The cytocompatibility evaluation in vitro showed that the bioactivity of OGP(10-14) have kept and promoted adhesion, proliferation and differentiation of osteoblasts seeded on the new material. The results reveal that the novel material may make contribution to bone repair. |
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