RESUMO
BACKGROUND: 3D printing technology provides possibility for the preparation of an ideal bone tissue engineering scaffold with high individualization, precise regulation of the porosity, pore size and inter-aperture connectivity. OBJECTIVE: To study the physical properties and biocompatibility of allogeneic bone microparticle/poly (lactic-co-glycolic acid) composite absorbable scaffolds fabricated via fused deposition modeling 3D printing. METHODS: 3D printed bone microparticle/poly (lactic-co-glycolic acid) composite absorbable scaffolds were fabricated via fused deposition modeling. The porosity, water absorption, water contact angle and in vitro degradation rate of the scaffold were measured. (1) Cytotoxicity test: Rabbit adipose-derived mesenchymal stem cells were cultured in normal medium (negative control group) and composite scaffold extract (experimental group) for 1, 3, 5, 7 days, and cell counting kit-8 was then used to detect cell proliferation. (2) Hemolysis test: Rabbit anti-clotting was added to physiological saline, distilled water and composite scaffold extract, and the hemolysis rate was detected after 50 minutes. (3) Acute toxicity test: The physiological saline and composite scaffold extracts were intraperitoneally injected into the rabbits respectively to observe the general condition of rabbits and the pathological changes of important organs. RESULTS AND CONCLUSION: (1) The porosity, water absorption and water contact angle of the composite scaffold were (60.86±2.88) ％, (53.98±2.04) ％ and (76.27±0.34) °, respectively. (2) After in vitro immersion in PBS for 4 weeks, the absorbable composite scaffold degraded relatively slowly, and the scaffold morphology remained stable, while the degradation rate accelerated after 4 weeks. The scaffold was almost completely absorbed at about 11 weeks, and it is a relatively ideal absorbable scaffold material. (3) There was no difference in cell proliferation between the experimental group and the negative control group at different time points (P> 0.05) . The cytotoxicity of the absorbable composite scaffold was grade 1. (4) The hemolysis rate of the absorbable composite scaffold was 3.8％, which met the hemolytic requirement of biomedical materials (the hemolysis rate of less than 5％) . (5) Within 72 hours after injection of absorbable scaffold extract, the rabbits showed no acute toxic reaction, as well as no pathological changes in the liver, heart and kidney were observed after 7 days of injection. (6) To conclude, the 3D printed allogeneic bone microparticle/poly (lactic-co-glycolic acid) fabricated via fused deposition modeling 3D printing has preferable physical properties and biocompatibility.
