Abstract: BACKGROUND: Bone repair materials with biological functions have always been a research focus in biomedical engineering.
OBJECTIVE: To develop bionic bone matrix material with bionic space structure and bionic function based on the requirements of molecular structure biomimetic and biological function biomimetic. 
METHODS: Using amino-terminated polyethylene glycol and pyromellitic anhydride as reactants, four kinds of polyethylene glycol derivative hydrogels were obtained by adjusting the amount of butanediamine added (15, 30, 45, 60 µL). Bioactive substances based on polylactic acid and force growth factor (MGF-Ct24E-MPLA-EG-g-HAP) were added to the four hydrogels separately. The solvent method was used to prepare bioactive biomimetic bone matrix material (PAPI-BDA/MGF-Ct24E-MPLA-EG-g-HAP). The bioactive material loading rate, porosity, surface morphology, hydrophilic/hydrophobic properties, water absorption and microscopic morphology of the bioactive bionic bone matrix materials were characterized.
RESULTS AND CONCLUSION: (1) In the production process of the bionic bone matrix material, in PBS with pH=5.8, with the increased amount of butanediamine added, the loading of bioactive substances in the bionic bone matrix material first increased and then decreased. The loading of bioactive substances was the highest when the amount was 30 µL; in PBS with pH=3.5-7.4, the loading of bioactive substances in the biomimetic bone matrix material (the addition amount of butanediamine was 30 µL) showed a decreasing trend. When the pH value increased to 9.8, the loading of bioactive substances in the bionic bone matrix material remained basically stable. (2) In PBS with the same pH value, the porosity of the bionic bone matrix material decreased with the increase of the addition amount of butanediamine. When the addition amount of butanediamine was the same, with the increase of the pH value of PBS, the porosity of the bionic bone matrix material first decreased and then increased. (3) In PBS with pH=5.8, with the increase of the addition of butanediamine, the static contact angle of the bionic bone matrix material decreased and the water absorption increased. (4) It can be seen under the scanning electron microscope, the bionic bone matrix material has a continuous open pore structure, the pores are interconnected, the pore size distribution is 230-690 nm, and the pore size is inversely related to the amount of butanediamine added. The bionic bone matrix material prepared by adding butanediamine in an amount of 30 µL is similar to the structure of natural bone matrix.  

Key words: polyethylene glycol derivatives, butanediamine, hydrogel, polylactic acid, force growth factor E peptide, bionic bone matrix material