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A Macroporous Bioreactor Super Activated by the Recombinant Human Transforming Growth Factor-β(3).

Ripamonti U, Teare J, Ferretti C - Front Physiol (2012)

Bottom Line: Bone formation was assessed on decalcified paraffin-embedded sections by measuring the fractional volume of newly formed bone.On day 30 and 90, single phase HA implants showed greater amounts of bone when compared to biphasic specimens; 5 and 13% HA/CC pre-loaded with 125 and 250 μg hTGF-β(3) showed substantial induction of bone formation; 250 μg hTGF-β(3) induced as yet unreported massive induction of bone formation as early as 20 days prominently outside the profile of the macroporous constructs.The unprecedented tissue induction by single doses of 250 μg hTGF-β(3) resulting in rapid bone morphogenesis of vast mineralized ossicles with multiple trabeculations surfaced by contiguous secreting osteoblasts is the novel molecular and morphological frontier for the induction of bone formation in clinical contexts.

View Article: PubMed Central - PubMed

Affiliation: Bone Research Unit, Faculty of Health Sciences, School of Physiology, Medical Research Council/University of the Witwatersrand Johannesburg, South Africa.

ABSTRACT
Macroporous single phase hydroxyapatite (HA) and biphasic HA/β-tricalcium phosphate with 33% post-sinter hydroxyapatite (HA/β-TCP) were combined with 25 or 125 μg recombinant human transforming growth factor-β3 (hTGF-β(3)) to engineer a super activated bioreactor implanted in orthotopic calvarial and heterotopic rectus abdominis muscle sites and harvested on day 30 and 90. Coral-derived calcium carbonate fully converted (100%) and partially converted to 5 and 13% hydroxyapatite/calcium carbonate (5 and 13% HA/CC) pre-loaded with 125 and 250 μg hTGF-β(3), and 1:5 and 5:1 binary applications of hTGF-β(3): hOP-1 by weight, were implanted in the rectus abdominis and harvested on day 20 and 30, respectively, to monitor spatial/temporal morphogenesis by high doses of hTGF-β(3). Bone formation was assessed on decalcified paraffin-embedded sections by measuring the fractional volume of newly formed bone. On day 30 and 90, single phase HA implants showed greater amounts of bone when compared to biphasic specimens; 5 and 13% HA/CC pre-loaded with 125 and 250 μg hTGF-β(3) showed substantial induction of bone formation; 250 μg hTGF-β(3) induced as yet unreported massive induction of bone formation as early as 20 days prominently outside the profile of the macroporous constructs. The induction of bone formation is controlled by the implanted ratio of the recombinant morphogens, i.e., the 1:5 hTGF-β(3):hOP-1 ratio by weight was greater than the inverse ratio. The unprecedented tissue induction by single doses of 250 μg hTGF-β(3) resulting in rapid bone morphogenesis of vast mineralized ossicles with multiple trabeculations surfaced by contiguous secreting osteoblasts is the novel molecular and morphological frontier for the induction of bone formation in clinical contexts.

No MeSH data available.


Related in: MedlinePlus

Orthotopic single phase hydroxyapatite constructs harvested on day 30 and the induction of bone differentiation by 25 and 125 μg recombinant human transforming growth factor-β3 (hTGF-β3). (A,B) Low and high power views of the induction of bone formation within concavities of the macroporous spaces (blue arrow) as initiated by 25 μg hTGF-β3 on day 30.(C) Induction of bone formation (white arrows) by 125 μg hTGF-β3 within the macroporous spaces of a single phase HA construct. (D) Hypercellular osteoblastic activity of the newly formed bone (white arrow) tightly attached to the single phase HA substratum.
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Figure 2: Orthotopic single phase hydroxyapatite constructs harvested on day 30 and the induction of bone differentiation by 25 and 125 μg recombinant human transforming growth factor-β3 (hTGF-β3). (A,B) Low and high power views of the induction of bone formation within concavities of the macroporous spaces (blue arrow) as initiated by 25 μg hTGF-β3 on day 30.(C) Induction of bone formation (white arrows) by 125 μg hTGF-β3 within the macroporous spaces of a single phase HA construct. (D) Hypercellular osteoblastic activity of the newly formed bone (white arrow) tightly attached to the single phase HA substratum.

Mentions: Untreated single phase HA orthotopic specimens showed lack of bone formation with minimal bone by conduction at the calvarial interfaces (<2%). Specimens treated with 25 and 125 μg hTGF-β3 showed limited induction of bone formation by day 30 (Figures 2 and 3); the induction of bone, though minimal on day 30, had occurred along concavities of the macroporous spaces (Figure 2). By day 90, control specimens showed the induction of bone formation across the macroporous constructs (21.66 ± 0.60%) though preferentially endocranially with minimal bone formation pericranially below the temporalis muscle (Figures 4A,B). On day 90, single phase HA pre-loaded with 25 and 125 μg hTGF-β3 resulted in a dose-dependent increase of bone induction (46.29 ± 6.3 vs. 74.40 ± 3.4%), respectively (Figures 4 and 5). A significant difference (p < 0.01), as detected by Dunnet’s multiple comparison test, was noted for control vs. single phase HA pre-loaded with 125 μg hTGF-β3 (Figure 5). Newly induced bone by the hTGF-β3 isoform was characterized by numerous contiguous rows of well rounded osteoblasts surfacing the newly induced bone within the macroporous spaces of the implanted substrata (Figures 4E,F).


A Macroporous Bioreactor Super Activated by the Recombinant Human Transforming Growth Factor-β(3).

Ripamonti U, Teare J, Ferretti C - Front Physiol (2012)

Orthotopic single phase hydroxyapatite constructs harvested on day 30 and the induction of bone differentiation by 25 and 125 μg recombinant human transforming growth factor-β3 (hTGF-β3). (A,B) Low and high power views of the induction of bone formation within concavities of the macroporous spaces (blue arrow) as initiated by 25 μg hTGF-β3 on day 30.(C) Induction of bone formation (white arrows) by 125 μg hTGF-β3 within the macroporous spaces of a single phase HA construct. (D) Hypercellular osteoblastic activity of the newly formed bone (white arrow) tightly attached to the single phase HA substratum.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3369251&req=5

Figure 2: Orthotopic single phase hydroxyapatite constructs harvested on day 30 and the induction of bone differentiation by 25 and 125 μg recombinant human transforming growth factor-β3 (hTGF-β3). (A,B) Low and high power views of the induction of bone formation within concavities of the macroporous spaces (blue arrow) as initiated by 25 μg hTGF-β3 on day 30.(C) Induction of bone formation (white arrows) by 125 μg hTGF-β3 within the macroporous spaces of a single phase HA construct. (D) Hypercellular osteoblastic activity of the newly formed bone (white arrow) tightly attached to the single phase HA substratum.
Mentions: Untreated single phase HA orthotopic specimens showed lack of bone formation with minimal bone by conduction at the calvarial interfaces (<2%). Specimens treated with 25 and 125 μg hTGF-β3 showed limited induction of bone formation by day 30 (Figures 2 and 3); the induction of bone, though minimal on day 30, had occurred along concavities of the macroporous spaces (Figure 2). By day 90, control specimens showed the induction of bone formation across the macroporous constructs (21.66 ± 0.60%) though preferentially endocranially with minimal bone formation pericranially below the temporalis muscle (Figures 4A,B). On day 90, single phase HA pre-loaded with 25 and 125 μg hTGF-β3 resulted in a dose-dependent increase of bone induction (46.29 ± 6.3 vs. 74.40 ± 3.4%), respectively (Figures 4 and 5). A significant difference (p < 0.01), as detected by Dunnet’s multiple comparison test, was noted for control vs. single phase HA pre-loaded with 125 μg hTGF-β3 (Figure 5). Newly induced bone by the hTGF-β3 isoform was characterized by numerous contiguous rows of well rounded osteoblasts surfacing the newly induced bone within the macroporous spaces of the implanted substrata (Figures 4E,F).

Bottom Line: Bone formation was assessed on decalcified paraffin-embedded sections by measuring the fractional volume of newly formed bone.On day 30 and 90, single phase HA implants showed greater amounts of bone when compared to biphasic specimens; 5 and 13% HA/CC pre-loaded with 125 and 250 μg hTGF-β(3) showed substantial induction of bone formation; 250 μg hTGF-β(3) induced as yet unreported massive induction of bone formation as early as 20 days prominently outside the profile of the macroporous constructs.The unprecedented tissue induction by single doses of 250 μg hTGF-β(3) resulting in rapid bone morphogenesis of vast mineralized ossicles with multiple trabeculations surfaced by contiguous secreting osteoblasts is the novel molecular and morphological frontier for the induction of bone formation in clinical contexts.

View Article: PubMed Central - PubMed

Affiliation: Bone Research Unit, Faculty of Health Sciences, School of Physiology, Medical Research Council/University of the Witwatersrand Johannesburg, South Africa.

ABSTRACT
Macroporous single phase hydroxyapatite (HA) and biphasic HA/β-tricalcium phosphate with 33% post-sinter hydroxyapatite (HA/β-TCP) were combined with 25 or 125 μg recombinant human transforming growth factor-β3 (hTGF-β(3)) to engineer a super activated bioreactor implanted in orthotopic calvarial and heterotopic rectus abdominis muscle sites and harvested on day 30 and 90. Coral-derived calcium carbonate fully converted (100%) and partially converted to 5 and 13% hydroxyapatite/calcium carbonate (5 and 13% HA/CC) pre-loaded with 125 and 250 μg hTGF-β(3), and 1:5 and 5:1 binary applications of hTGF-β(3): hOP-1 by weight, were implanted in the rectus abdominis and harvested on day 20 and 30, respectively, to monitor spatial/temporal morphogenesis by high doses of hTGF-β(3). Bone formation was assessed on decalcified paraffin-embedded sections by measuring the fractional volume of newly formed bone. On day 30 and 90, single phase HA implants showed greater amounts of bone when compared to biphasic specimens; 5 and 13% HA/CC pre-loaded with 125 and 250 μg hTGF-β(3) showed substantial induction of bone formation; 250 μg hTGF-β(3) induced as yet unreported massive induction of bone formation as early as 20 days prominently outside the profile of the macroporous constructs. The induction of bone formation is controlled by the implanted ratio of the recombinant morphogens, i.e., the 1:5 hTGF-β(3):hOP-1 ratio by weight was greater than the inverse ratio. The unprecedented tissue induction by single doses of 250 μg hTGF-β(3) resulting in rapid bone morphogenesis of vast mineralized ossicles with multiple trabeculations surfaced by contiguous secreting osteoblasts is the novel molecular and morphological frontier for the induction of bone formation in clinical contexts.

No MeSH data available.


Related in: MedlinePlus