Table 1.
Primer sequences of osteoblast-related genes used for real-time quantitative PCR.
Fig 1.
XRD patterns of the 5%β-TCP/Mg-3%Zn composites of different porosity.
Fig 2.
Surface morphologies (a-c) and elemental analysis (d-g) of the 5%β-TCP/Mg-3%Zn composites.
Table 2.
Porosity and mechanical properties of porous 5%β-TCP /Mg-3%Zn composites in comparison with porous Mg-6Zn and natural bone.
Fig 3.
SEM images of the surface morphology of coated composites along with a cross-sectional view of the dopamine/gelatin/rhBMP-2 coating.
(a) Gelatin surface; (b) BMP-2–loaded gelatin microparticles; (c) dopamine layer; and (d) the total composite coating. Elemental analysis of the (e) gelatin layer, (f) dopamine layer, and (g) substrate.
Fig 4.
Anti-corrosion properties of dopamine/gelatin/rhBMP-2–coated 5%β-TCP/Mg-3%Zn composites.
(a) Potentiodynamic polarization curves for the bare and coated 5%β-TCP/Mg-3%Zn specimens in Hank’s solution. (b) Variation in pH value of Hank’s solution with immersion time. (c) Volume of hydrogen produced during immersion. (d) Variation in weight of the immersed specimens.
Table 3.
Corrosion potential (Ecorr) and corrosion current density (icorr) of all 5%β-TCP/Mg-3%Zn specimens in Hank’s solution.
Fig 5.
SEM images showing the surface morphologies of bare 5%β-TCP/Mg-3%Zn composites after immersion in Hank’s solution for 72 h: (a) 6% porosity; (b) 13% porosity; and (c) 18% porosity. SEM images showing the surface morphologies of dopamine/gelatin/rhBMP-2–coated 5%β-TCP/Mg-3%Zn composites after immersion in Hank’s solution for 5 h (d), 9 h (e) and 72 h (f). EDS analysis of the bare (g) and coated (h) specimen surfaces after immersion for 72 h.
Fig 6.
Cell viability of rBMSCs cultured with extracts from bare or coated 5%β-TCP/Mg-3%Zn composites over 4 days.
*p<0.05.
Fig 7.
Osteogenic differentiation of rBMSCs cultured in solutions of extracts from bare or coated 5%β-TCP/Mg-3%Zn composites.
(a) ALP staining after culture for 7 and 14 days; (b) quantitative ALP activity; (c-e) qPCR analysis of COL I, OCN, and OPN gene expression on days 7 and 14. *p<0.05.
Fig 8.
Serum concentrations of Mg2+ (a), Zn2+ (b), and Ca2+ (c) ions as well as ALT (d), AST (e), BUN (f) and Cr (g) in the experimental rabbits (n = 6) before and after implantation.
Normal reference values for metal ions: Mg2+: 0.82–2.22 mmol/L, Zn2+:75.5–170 μmol/L, and Ca2+:3.1–5.2 mmol/L.
Fig 9.
H&E staining of heart (a, d), liver (b, e) and kidney (c, f) tissue obtained from rabbits of the implantation and control groups at 1 month post-surgery.
Fig 10.
Radiographic evaluation of the implant site in the femur of New Zealand rabbits: (a-c) anteroposterior view of femurs in the experimental group; (e-g) lateral view of femurs in the experimental group; (d, h) anteroposterior and lateral view of femurs in the control group.
Yellow arrows: periosteal reaction/callus; green arrows: hydrogen bubble; blue arrows: residual implant.
Fig 11.
Representative images of H&E staining of decalcifying bone tissues around the implanted coated composite specimens at the indicated time points post-implantation.
(a-c): Experimental group, 200×; (e-g): experimental group, 400×; (d, h) control group, 200× and 400×. Yellow arrows: newly formed trabeculae; blue arrows: multinucleated giant cells; green arrows: osteoblasts; yellow squares: new capillaries; red arrows: osteoclasts; yellow stars: osteocytes; green ellipses: lamellar bone matrix.