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Negative pressure therapy stimulates healing of critical-size calvarial defects in rabbits.

Swain LD, Cornet DA, Manwaring ME, Collins B, Singh VK, Beniker D, Carnes DL - Bonekey Rep (2013)

Bottom Line: At 12 weeks after defect creation, NPT groups exhibited significantly greater defect bridging and bone within the scaffolds (P<0.01).Increasing duration of NPT did not result in a greater amount of bone within the scaffolds, but did increase the amount of bone distributed in the upper half of the scaffolds.An extracellular matrix densely populated with cells and capillaries, as well as larger vessels, infiltrated pores of NPT-treated scaffolds, while scattered spindle-shaped cells and sparse stroma are present within pores of control scaffolds.

View Article: PubMed Central - PubMed

Affiliation: Kinetic Concepts Inc. , San Antonio, TX, USA.

ABSTRACT
Negative pressure therapy (NPT) is the controlled application of subatmospheric pressure to wounds. It has been shown to stimulate healing across a broad spectrum of soft-tissue wounds, at least in part from the application of mechanical stress on cells and tissues in the wound environment. This study tests the hypothesis that application of NPT to cranial critical-size defects (CSD) in skeletally mature rabbits leads to osseous healing. NPT was delivered 1, 4, 6 or 10 days over CSD-containing calcium phosphate scaffolds placed in contact with intact dura. At 12 weeks after defect creation, NPT groups exhibited significantly greater defect bridging and bone within the scaffolds (P<0.01). Increasing duration of NPT did not result in a greater amount of bone within the scaffolds, but did increase the amount of bone distributed in the upper half of the scaffolds. Appearance of tissue within defects immediately following the removal of NPT at day 6 suggests alternating regions of dural compression and distention indicative of cell stretching. Dura and adjacent tissue were composed of multiple cell layers that extended up into the scaffolds, lining struts and populating pore spaces. An extracellular matrix densely populated with cells and capillaries, as well as larger vessels, infiltrated pores of NPT-treated scaffolds, while scattered spindle-shaped cells and sparse stroma are present within pores of control scaffolds. This rabbit model data suggest that NPT activates within mature dura a natural healing cascade that results in osseous tissue formation without the addition of exogenous factors or progenitor cells.

No MeSH data available.


Related in: MedlinePlus

Micrograph of the dura–scaffold interface. Undecalcified plastic-embedded section stained with Sanderson's rapid bone stain. The specimens were harvested immediately after 6 days of NPT to the CSD. Note the dense, multilayer morphology of the dura directly beneath the scaffold. Bone formation is present even at this early time point. Original magnification × 10.
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f5: Micrograph of the dura–scaffold interface. Undecalcified plastic-embedded section stained with Sanderson's rapid bone stain. The specimens were harvested immediately after 6 days of NPT to the CSD. Note the dense, multilayer morphology of the dura directly beneath the scaffold. Bone formation is present even at this early time point. Original magnification × 10.

Mentions: Greatly increased vascularity immediately after NPT compared with the 0 treatment group is also apparent (Figure 4). The pore space is populated not only with capillaries and microvessels but also with an abundance of larger vessels, suggesting that, in addition to angiogenesis, vascular invasion of the scaffold by pre-existing vessels has occurred. It is also apparent that there is a marked difference between the appearance of the cells and extracellular matrix populating the interstitial spaces throughout the thickness of scaffold in the NPT group compared with the untreated control group. A fibrous connective tissue with scattered spindle-shaped cells and sparse stroma was present within the pores of the control scaffold, while a mature extracellular matrix densely populated with cells and an abundance of capillaries, as well as larger vessels, had infiltrated the pores of the NPT-treated scaffold. In NPT-treated animals, the dura and immediately adjacent tissue were increased in thickness, being composed of multiple cell layers that extended up into the scaffold, lining the surface of the struts and populating the pore spaces (Figure 5). The presence of new bone even at this early 6-day time point suggests the migration of mesenchymal cells from the dura that differentiate to functional osteoblasts and osteocytes.


Negative pressure therapy stimulates healing of critical-size calvarial defects in rabbits.

Swain LD, Cornet DA, Manwaring ME, Collins B, Singh VK, Beniker D, Carnes DL - Bonekey Rep (2013)

Micrograph of the dura–scaffold interface. Undecalcified plastic-embedded section stained with Sanderson's rapid bone stain. The specimens were harvested immediately after 6 days of NPT to the CSD. Note the dense, multilayer morphology of the dura directly beneath the scaffold. Bone formation is present even at this early time point. Original magnification × 10.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3722738&req=5

f5: Micrograph of the dura–scaffold interface. Undecalcified plastic-embedded section stained with Sanderson's rapid bone stain. The specimens were harvested immediately after 6 days of NPT to the CSD. Note the dense, multilayer morphology of the dura directly beneath the scaffold. Bone formation is present even at this early time point. Original magnification × 10.
Mentions: Greatly increased vascularity immediately after NPT compared with the 0 treatment group is also apparent (Figure 4). The pore space is populated not only with capillaries and microvessels but also with an abundance of larger vessels, suggesting that, in addition to angiogenesis, vascular invasion of the scaffold by pre-existing vessels has occurred. It is also apparent that there is a marked difference between the appearance of the cells and extracellular matrix populating the interstitial spaces throughout the thickness of scaffold in the NPT group compared with the untreated control group. A fibrous connective tissue with scattered spindle-shaped cells and sparse stroma was present within the pores of the control scaffold, while a mature extracellular matrix densely populated with cells and an abundance of capillaries, as well as larger vessels, had infiltrated the pores of the NPT-treated scaffold. In NPT-treated animals, the dura and immediately adjacent tissue were increased in thickness, being composed of multiple cell layers that extended up into the scaffold, lining the surface of the struts and populating the pore spaces (Figure 5). The presence of new bone even at this early 6-day time point suggests the migration of mesenchymal cells from the dura that differentiate to functional osteoblasts and osteocytes.

Bottom Line: At 12 weeks after defect creation, NPT groups exhibited significantly greater defect bridging and bone within the scaffolds (P<0.01).Increasing duration of NPT did not result in a greater amount of bone within the scaffolds, but did increase the amount of bone distributed in the upper half of the scaffolds.An extracellular matrix densely populated with cells and capillaries, as well as larger vessels, infiltrated pores of NPT-treated scaffolds, while scattered spindle-shaped cells and sparse stroma are present within pores of control scaffolds.

View Article: PubMed Central - PubMed

Affiliation: Kinetic Concepts Inc. , San Antonio, TX, USA.

ABSTRACT
Negative pressure therapy (NPT) is the controlled application of subatmospheric pressure to wounds. It has been shown to stimulate healing across a broad spectrum of soft-tissue wounds, at least in part from the application of mechanical stress on cells and tissues in the wound environment. This study tests the hypothesis that application of NPT to cranial critical-size defects (CSD) in skeletally mature rabbits leads to osseous healing. NPT was delivered 1, 4, 6 or 10 days over CSD-containing calcium phosphate scaffolds placed in contact with intact dura. At 12 weeks after defect creation, NPT groups exhibited significantly greater defect bridging and bone within the scaffolds (P<0.01). Increasing duration of NPT did not result in a greater amount of bone within the scaffolds, but did increase the amount of bone distributed in the upper half of the scaffolds. Appearance of tissue within defects immediately following the removal of NPT at day 6 suggests alternating regions of dural compression and distention indicative of cell stretching. Dura and adjacent tissue were composed of multiple cell layers that extended up into the scaffolds, lining struts and populating pore spaces. An extracellular matrix densely populated with cells and capillaries, as well as larger vessels, infiltrated pores of NPT-treated scaffolds, while scattered spindle-shaped cells and sparse stroma are present within pores of control scaffolds. This rabbit model data suggest that NPT activates within mature dura a natural healing cascade that results in osseous tissue formation without the addition of exogenous factors or progenitor cells.

No MeSH data available.


Related in: MedlinePlus