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In Vivo Osteogenic Potential of Biomimetic Hydroxyapatite/Collagen Microspheres: Comparison with Injectable Cement Pastes.

Cuzmar E, Perez RA, Manzanares MC, Ginebra MP, Franch J - PLoS ONE (2015)

Bottom Line: The osteogenic capacity of biomimetic calcium deficient hydroxyapatite microspheres with and without collagen obtained by emulsification of a calcium phosphate cement paste has been evaluated in an in vivo model, and compared with an injectable calcium phosphate cement with the same composition.Consequently, bone ingrowth was enhanced by the microspheres, with a tenfold increase compared to the cement, which was associated to the higher accessibility for the cells provided by the macroporous network between the microspheres, and the larger surface area available for osteoconduction.No significant differences were found in terms of bone formation associated with the presence of collagen in the materials, although a more extensive erosion of the collagen-containing microspheres was observed.

View Article: PubMed Central - PubMed

Affiliation: Medicine and Animal Surgery Department, Autonomous University of Barcelona (UAB), V Building, 08193 Bellaterra, Spain; Veterinarian Clinical Science Institute, Universidad Austral de Chile. Fundo Teja Norte, Valdivia, Chile.

ABSTRACT
The osteogenic capacity of biomimetic calcium deficient hydroxyapatite microspheres with and without collagen obtained by emulsification of a calcium phosphate cement paste has been evaluated in an in vivo model, and compared with an injectable calcium phosphate cement with the same composition. The materials were implanted into a 5 mm defect in the femur condyle of rabbits, and bone formation was assessed after 1 and 3 months. The histological analysis revealed that the cements presented cellular activity only in the margins of the material, whereas each one of the individual microspheres was covered with osteogenic cells. Consequently, bone ingrowth was enhanced by the microspheres, with a tenfold increase compared to the cement, which was associated to the higher accessibility for the cells provided by the macroporous network between the microspheres, and the larger surface area available for osteoconduction. No significant differences were found in terms of bone formation associated with the presence of collagen in the materials, although a more extensive erosion of the collagen-containing microspheres was observed.

No MeSH data available.


Related in: MedlinePlus

Backscattered electron micrographs of undecalcified section of the cements (A,B) and the microspheres (C,D) after 1 month implantation, in the absence (A,C) and presence (B,D) of collagen.Trabeculae constituted mostly by calcified chondroid tissue are visible in the periphery of the cements (A, B), whereas denser trabeculae with new bone covering the initial chondroid tissue were able to grow both on the surface of the microspheres and in the pores between them (C, D).
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pone.0131188.g005: Backscattered electron micrographs of undecalcified section of the cements (A,B) and the microspheres (C,D) after 1 month implantation, in the absence (A,C) and presence (B,D) of collagen.Trabeculae constituted mostly by calcified chondroid tissue are visible in the periphery of the cements (A, B), whereas denser trabeculae with new bone covering the initial chondroid tissue were able to grow both on the surface of the microspheres and in the pores between them (C, D).

Mentions: SEM images after one and three months implantation are shown in Figs 5 and 6 respectively. New bone was observed growing on the periphery of the cements, in direct contact with its surface (Figs 5A and 5B and 6A and 6B), but the small-sized porosity hindered the penetration of new tissue within the material. A completely different result was observed for the microspheres (Figs 5C and 5D and 6C and 6D). The larger surface available and the open macroporosity generated between the individual microspheres enhanced cell penetration and bone ingrowth within the defect. The microspheres guided the formation of the new trabecular structure, becoming integrated in the new bone trabeculae. Calcified chondroid tissue was the principal component of the initial trabeculae surrounding all the biomaterials (Fig 5), but the coll-MS were covered by denser trabeculae, with a clear lamellar deposition (Fig 5D). At 3 months (Fig 6), the trabeculae around the biomaterial were consistently formed by lamellar bone, with only sparse remnants of the initial chondroid tissue (Fig 6B and 6C). Interestingly, some resorption was observed, more pronounced in the case of the MS and coll-MS (Fig 6C and 6D) with numerous Howship’s lacunae eroding both the biomaterial and the surrounding osseous tissues.


In Vivo Osteogenic Potential of Biomimetic Hydroxyapatite/Collagen Microspheres: Comparison with Injectable Cement Pastes.

Cuzmar E, Perez RA, Manzanares MC, Ginebra MP, Franch J - PLoS ONE (2015)

Backscattered electron micrographs of undecalcified section of the cements (A,B) and the microspheres (C,D) after 1 month implantation, in the absence (A,C) and presence (B,D) of collagen.Trabeculae constituted mostly by calcified chondroid tissue are visible in the periphery of the cements (A, B), whereas denser trabeculae with new bone covering the initial chondroid tissue were able to grow both on the surface of the microspheres and in the pores between them (C, D).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4488499&req=5

pone.0131188.g005: Backscattered electron micrographs of undecalcified section of the cements (A,B) and the microspheres (C,D) after 1 month implantation, in the absence (A,C) and presence (B,D) of collagen.Trabeculae constituted mostly by calcified chondroid tissue are visible in the periphery of the cements (A, B), whereas denser trabeculae with new bone covering the initial chondroid tissue were able to grow both on the surface of the microspheres and in the pores between them (C, D).
Mentions: SEM images after one and three months implantation are shown in Figs 5 and 6 respectively. New bone was observed growing on the periphery of the cements, in direct contact with its surface (Figs 5A and 5B and 6A and 6B), but the small-sized porosity hindered the penetration of new tissue within the material. A completely different result was observed for the microspheres (Figs 5C and 5D and 6C and 6D). The larger surface available and the open macroporosity generated between the individual microspheres enhanced cell penetration and bone ingrowth within the defect. The microspheres guided the formation of the new trabecular structure, becoming integrated in the new bone trabeculae. Calcified chondroid tissue was the principal component of the initial trabeculae surrounding all the biomaterials (Fig 5), but the coll-MS were covered by denser trabeculae, with a clear lamellar deposition (Fig 5D). At 3 months (Fig 6), the trabeculae around the biomaterial were consistently formed by lamellar bone, with only sparse remnants of the initial chondroid tissue (Fig 6B and 6C). Interestingly, some resorption was observed, more pronounced in the case of the MS and coll-MS (Fig 6C and 6D) with numerous Howship’s lacunae eroding both the biomaterial and the surrounding osseous tissues.

Bottom Line: The osteogenic capacity of biomimetic calcium deficient hydroxyapatite microspheres with and without collagen obtained by emulsification of a calcium phosphate cement paste has been evaluated in an in vivo model, and compared with an injectable calcium phosphate cement with the same composition.Consequently, bone ingrowth was enhanced by the microspheres, with a tenfold increase compared to the cement, which was associated to the higher accessibility for the cells provided by the macroporous network between the microspheres, and the larger surface area available for osteoconduction.No significant differences were found in terms of bone formation associated with the presence of collagen in the materials, although a more extensive erosion of the collagen-containing microspheres was observed.

View Article: PubMed Central - PubMed

Affiliation: Medicine and Animal Surgery Department, Autonomous University of Barcelona (UAB), V Building, 08193 Bellaterra, Spain; Veterinarian Clinical Science Institute, Universidad Austral de Chile. Fundo Teja Norte, Valdivia, Chile.

ABSTRACT
The osteogenic capacity of biomimetic calcium deficient hydroxyapatite microspheres with and without collagen obtained by emulsification of a calcium phosphate cement paste has been evaluated in an in vivo model, and compared with an injectable calcium phosphate cement with the same composition. The materials were implanted into a 5 mm defect in the femur condyle of rabbits, and bone formation was assessed after 1 and 3 months. The histological analysis revealed that the cements presented cellular activity only in the margins of the material, whereas each one of the individual microspheres was covered with osteogenic cells. Consequently, bone ingrowth was enhanced by the microspheres, with a tenfold increase compared to the cement, which was associated to the higher accessibility for the cells provided by the macroporous network between the microspheres, and the larger surface area available for osteoconduction. No significant differences were found in terms of bone formation associated with the presence of collagen in the materials, although a more extensive erosion of the collagen-containing microspheres was observed.

No MeSH data available.


Related in: MedlinePlus