Figures & data
Figure 1 Scanning electron microscopy images of hollow hydroxyapatite microspheres.
Notes: (A) External surface under low magnification. (B) Fractured section under high magnification.
![Figure 1 Scanning electron microscopy images of hollow hydroxyapatite microspheres.Notes: (A) External surface under low magnification. (B) Fractured section under high magnification.](/cms/asset/9aa8e71e-c025-41da-9477-25449b13fb59/dijn_a_74677_f0001_b.jpg)
Figure 2 Cumulative release of recombinant human bone morphogenetic protein 2 (rhBMP2) from hollow hydroxyapatite microspheres into phosphate-buffered saline.
Note: The insert graph shows an initial burst release within 48 hours.
![Figure 2 Cumulative release of recombinant human bone morphogenetic protein 2 (rhBMP2) from hollow hydroxyapatite microspheres into phosphate-buffered saline.Note: The insert graph shows an initial burst release within 48 hours.](/cms/asset/46e31065-2ccf-41ba-8f92-b85f83ef992b/dijn_a_74677_f0002_c.jpg)
Figure 3 Serum alkaline phosphatase level.
Notes: Group A: BMP2-loaded hollow HA microspheres; Group B: hollow HA microspheres without BMP2; Group C: soluble BMP2 without a carrier. Different symbols (&, #, and *) represent different serum alkaline phosphatase activities at each time point (P<0.05). N=4/group/time point.
Abbreviations: HA, hydroxyapatite; BMP2, bone morphogenetic protein 2; S-ALP, serum alkaline phosphatase.
![Figure 3 Serum alkaline phosphatase level.Notes: Group A: BMP2-loaded hollow HA microspheres; Group B: hollow HA microspheres without BMP2; Group C: soluble BMP2 without a carrier. Different symbols (&, #, and *) represent different serum alkaline phosphatase activities at each time point (P<0.05). N=4/group/time point.Abbreviations: HA, hydroxyapatite; BMP2, bone morphogenetic protein 2; S-ALP, serum alkaline phosphatase.](/cms/asset/16853173-420e-45c8-ba37-807791dd7c26/dijn_a_74677_f0003_c.jpg)
Figure 4 X-ray images of segmental radius at 4, 8, 12, and 16 weeks with different implants.
Notes: (A) BMP2-loaded hollow HA microspheres; (B) hollow HA microspheres without BMP2; (C) soluble BMP2 without a carrier. Arrows: defective and repairing sites.
Abbreviations: HA, hydroxyapatite; BMP2, bone morphogenetic protein 2.
![Figure 4 X-ray images of segmental radius at 4, 8, 12, and 16 weeks with different implants.Notes: (A) BMP2-loaded hollow HA microspheres; (B) hollow HA microspheres without BMP2; (C) soluble BMP2 without a carrier. Arrows: defective and repairing sites.Abbreviations: HA, hydroxyapatite; BMP2, bone morphogenetic protein 2.](/cms/asset/1de6c0e2-1abc-422e-a487-e8081b37c3a2/dijn_a_74677_f0004_b.jpg)
Table 1 Lane–Sandhu radiographical bone formation score (mean ± standard deviation)
Figure 5 Three-dimensional tomographic images of the segmental radius at 4 and 16 weeks.
Notes: (A) BMP2-loaded hollow HA microspheres; (B) hollow HA microspheres without BMP2; (C) soluble BMP2 without a carrier.
Abbreviations: HA, hydroxyapatite; BMP2, bone morphogenetic protein 2.
![Figure 5 Three-dimensional tomographic images of the segmental radius at 4 and 16 weeks.Notes: (A) BMP2-loaded hollow HA microspheres; (B) hollow HA microspheres without BMP2; (C) soluble BMP2 without a carrier.Abbreviations: HA, hydroxyapatite; BMP2, bone morphogenetic protein 2.](/cms/asset/d0b5417f-6d94-42e5-b33b-74af39b1d7f2/dijn_a_74677_f0005_c.jpg)
Table 2 Percentage of new bone formation (mean ± standard deviation)
Figure 6 Histological evaluation of three groups at 4, 8, 12, and 16 weeks.
Notes: (A) BMP2-loaded hollow HA microspheres; (B) hollow HA microspheres without BMP2; (C) soluble BMP2 without a carrier. Scale bars: 400 μm, 10× magnification; 100 μm, 40× magnification.
Abbreviations: BC, blood cells; BMP2, bone morphogenetic protein 2; CC, chondrocytes; FT, fibrous tissue; HA, hydroxyapatite; IC, inflammatory cells; Mat, material; NB, new bone; NLB, new lamellar bone; OB, osteoblasts; OC, osteocytes; OT, osteon; V, vessel.
![Figure 6 Histological evaluation of three groups at 4, 8, 12, and 16 weeks.Notes: (A) BMP2-loaded hollow HA microspheres; (B) hollow HA microspheres without BMP2; (C) soluble BMP2 without a carrier. Scale bars: 400 μm, 10× magnification; 100 μm, 40× magnification.Abbreviations: BC, blood cells; BMP2, bone morphogenetic protein 2; CC, chondrocytes; FT, fibrous tissue; HA, hydroxyapatite; IC, inflammatory cells; Mat, material; NB, new bone; NLB, new lamellar bone; OB, osteoblasts; OC, osteocytes; OT, osteon; V, vessel.](/cms/asset/a334b9fb-d6ce-4c8f-847c-2a5480c10e27/dijn_a_74677_f0006_c.jpg)
Figure 7 Counts from ROI at the fractured side.
Notes: (A) Blood pool phase; (B) static phase. Group A: BMP2-loaded hollow HA microspheres; Group B hollow HA microspheres without BMP2; Group C soluble BMP2 without a carrier. Different symbols (&, # and *) represent different ROI counts at each time point (P<0.05). N=4/group/time point.
Abbreviations: BMP2, bone morphogenetic protein 2; HA, hydroxyapatite; ROI, region of interest.
![Figure 7 Counts from ROI at the fractured side.Notes: (A) Blood pool phase; (B) static phase. Group A: BMP2-loaded hollow HA microspheres; Group B hollow HA microspheres without BMP2; Group C soluble BMP2 without a carrier. Different symbols (&, # and *) represent different ROI counts at each time point (P<0.05). N=4/group/time point.Abbreviations: BMP2, bone morphogenetic protein 2; HA, hydroxyapatite; ROI, region of interest.](/cms/asset/e40ffa86-f216-426c-965c-e5994369f0c6/dijn_a_74677_f0007_c.jpg)
Figure 8 Biomechanical test of defective radius.
Notes: (A) mechanical testing facility; (B) the maximum flexural strength of defective radius. Group A: BMP2-loaded hollow HA microspheres; Group B, hollow HA microspheres without BMP2. Different symbols (& and #) represent different biomechanical strengths at each time point (P<0.05). N=4/group/time point.
Abbreviations: BMP2, bone morphogenetic protein 2; HA, hydroxyapatite.
![Figure 8 Biomechanical test of defective radius.Notes: (A) mechanical testing facility; (B) the maximum flexural strength of defective radius. Group A: BMP2-loaded hollow HA microspheres; Group B, hollow HA microspheres without BMP2. Different symbols (& and #) represent different biomechanical strengths at each time point (P<0.05). N=4/group/time point.Abbreviations: BMP2, bone morphogenetic protein 2; HA, hydroxyapatite.](/cms/asset/df440c90-d4b8-4cf0-97e8-74ccdcbf7985/dijn_a_74677_f0008_c.jpg)