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Evaluation of a biodegradable graft substitute in rabbit bone defect model.

Yang X, Li Y, Huang Q, Yang J, Shen B, Pei F - Indian J Orthop (2012)

Bottom Line: There was no significant difference between groups A and B.These findings demonstrated that the novel biodegradable copolymers can repair large areas of cancellous bone defects.With its controllable degradation rate, it suggests that CS/PAA may be a series of useful therapeutic substitute for bone defects.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedics, West China Hospital, Sichuan University, Chengdu, China.

ABSTRACT

Objective: To evaluate a new biodegradable copolymer calcium sulfate/poly amino acid (CS/PAA) as a graft substitute for the repair of the surgically created cancellous bone defects in rabbits and its biological properties in vivo.

Materials and methods: Cancellous bone defects were created by drilling holes in the unilateral lateral aspect of the femoral condyle of New Zealand white rabbits. Three groups were assigned: Group A rabbits were grafted with 80% CS/PAA and group B rabbits were grafted with 95% CS/PAA as two treatment groups; group C was sham-operation control group. To study the osteogenic capability in vivo, specimens were harvested at 4, 8, 12, and 16 weeks after implantation and were evaluated by gross assessment, X-ray, histological examination, and histomorphometry. In order to identify the molecular mechanism of bone defect repair, the expression of bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF) was detected using Western blot at 4 weeks.

Results: Group A and group B showed more vigorous and rapid repair leading to regeneration of cancellous bone than sham-operation control group on gross observation, radiology, and histomorphometry. There was no significant difference between groups A and B. Morphological observation and histological examination showed that the copolymers degraded in sync with the new bone formation process. The expression of BMP-2 and VEGF in implantation groups was higher than that in control group by western blot.

Conclusion: These findings demonstrated that the novel biodegradable copolymers can repair large areas of cancellous bone defects. With its controllable degradation rate, it suggests that CS/PAA may be a series of useful therapeutic substitute for bone defects.

No MeSH data available.


Related in: MedlinePlus

The materials and rabbit model with bone defect: (a) materials; (b) model of rabbit femoral condyle bone defect; (c) defects were grafted by CS/PAA
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Figure 1: The materials and rabbit model with bone defect: (a) materials; (b) model of rabbit femoral condyle bone defect; (c) defects were grafted by CS/PAA

Mentions: CS/PAA was provided by the Sichuan National Nano Technology Co. Ltd., Province Chengdu, Sichuan. Two specifications of materials included 80% CS/PAA and 95% CS/PAA according to the proportion of calcium sulfate. The poly amino acid was composed of 6 g alanine, 7 g benzene alanine, 1 g glycine, 108 g 6-aminocaproic acid, 6 g proline, and 2 g lysine. Raw materials [appropriate proportion of calcium sulfate and poly amino acid] were dissolved together in water and were dehydrated at 150°C–160°C temperature. Using inert gas for protection, the raw materials were processed with a pre-polymerization reaction at 220°C in a molten state for 3 hours and then polymerization reaction at 230°C for 3 hours. By in situ polymer composite technology, poly amino acid and calcium sulfate were used as the composite materials without any catalyst and other additives. The composite materials were ground into powder less than 120 mesh after cooling down by nitrogen, reconciled into a paste with water (1:1), and then processed into granules (d=2.5 mm, h=2.5 mm) [Figure 1a]. The materials were sterilized by radiation for reserve at last.


Evaluation of a biodegradable graft substitute in rabbit bone defect model.

Yang X, Li Y, Huang Q, Yang J, Shen B, Pei F - Indian J Orthop (2012)

The materials and rabbit model with bone defect: (a) materials; (b) model of rabbit femoral condyle bone defect; (c) defects were grafted by CS/PAA
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3377135&req=5

Figure 1: The materials and rabbit model with bone defect: (a) materials; (b) model of rabbit femoral condyle bone defect; (c) defects were grafted by CS/PAA
Mentions: CS/PAA was provided by the Sichuan National Nano Technology Co. Ltd., Province Chengdu, Sichuan. Two specifications of materials included 80% CS/PAA and 95% CS/PAA according to the proportion of calcium sulfate. The poly amino acid was composed of 6 g alanine, 7 g benzene alanine, 1 g glycine, 108 g 6-aminocaproic acid, 6 g proline, and 2 g lysine. Raw materials [appropriate proportion of calcium sulfate and poly amino acid] were dissolved together in water and were dehydrated at 150°C–160°C temperature. Using inert gas for protection, the raw materials were processed with a pre-polymerization reaction at 220°C in a molten state for 3 hours and then polymerization reaction at 230°C for 3 hours. By in situ polymer composite technology, poly amino acid and calcium sulfate were used as the composite materials without any catalyst and other additives. The composite materials were ground into powder less than 120 mesh after cooling down by nitrogen, reconciled into a paste with water (1:1), and then processed into granules (d=2.5 mm, h=2.5 mm) [Figure 1a]. The materials were sterilized by radiation for reserve at last.

Bottom Line: There was no significant difference between groups A and B.These findings demonstrated that the novel biodegradable copolymers can repair large areas of cancellous bone defects.With its controllable degradation rate, it suggests that CS/PAA may be a series of useful therapeutic substitute for bone defects.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedics, West China Hospital, Sichuan University, Chengdu, China.

ABSTRACT

Objective: To evaluate a new biodegradable copolymer calcium sulfate/poly amino acid (CS/PAA) as a graft substitute for the repair of the surgically created cancellous bone defects in rabbits and its biological properties in vivo.

Materials and methods: Cancellous bone defects were created by drilling holes in the unilateral lateral aspect of the femoral condyle of New Zealand white rabbits. Three groups were assigned: Group A rabbits were grafted with 80% CS/PAA and group B rabbits were grafted with 95% CS/PAA as two treatment groups; group C was sham-operation control group. To study the osteogenic capability in vivo, specimens were harvested at 4, 8, 12, and 16 weeks after implantation and were evaluated by gross assessment, X-ray, histological examination, and histomorphometry. In order to identify the molecular mechanism of bone defect repair, the expression of bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF) was detected using Western blot at 4 weeks.

Results: Group A and group B showed more vigorous and rapid repair leading to regeneration of cancellous bone than sham-operation control group on gross observation, radiology, and histomorphometry. There was no significant difference between groups A and B. Morphological observation and histological examination showed that the copolymers degraded in sync with the new bone formation process. The expression of BMP-2 and VEGF in implantation groups was higher than that in control group by western blot.

Conclusion: These findings demonstrated that the novel biodegradable copolymers can repair large areas of cancellous bone defects. With its controllable degradation rate, it suggests that CS/PAA may be a series of useful therapeutic substitute for bone defects.

No MeSH data available.


Related in: MedlinePlus