Limits...
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

Gross observation after surgery: (a and b) group A (80% CS/PAA) and group B (95% CS/PAA), 7 days after implantation; (c) specimen of group C (control group) at 16 weeks; (d) specimen of group B (95% CS/PAA) at 16 weeks; (e and f) specimen of group A (80% CS/PAA) at 16 weeks
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3377135&req=5

Figure 3: Gross observation after surgery: (a and b) group A (80% CS/PAA) and group B (95% CS/PAA), 7 days after implantation; (c) specimen of group C (control group) at 16 weeks; (d) specimen of group B (95% CS/PAA) at 16 weeks; (e and f) specimen of group A (80% CS/PAA) at 16 weeks

Mentions: None of the animals died during the study. The specimens did not show any evidence of tissue infection and inflammation on gross observation [Figures 3a and b]. The materials got incorporated intimately with the surrounding host bone. The boundary between the materials and adjacent host bone became indistinct with time. In the control group, the specimens did not totally heal at the end of the experiment. At the early stage of bone repair, the area of defect was filled by blood clot (4 weeks after operation) and fibrous soft tissue (8 weeks after operation). At later stage of bone repair, partial new bone was observed and most of the defect was still filled by fibrous soft tissue [Figure 3c]. In the implantation groups, defects and materials were no longer visible on macroscopic examination at 16 weeks after the operation. Biomaterials were partly degraded at 4 weeks after operation. Half of 6 in group B (95% CS/PAA) and 1of 6 in group A (80% CS/PAA) were totally degraded at 12 weeks after operation. Specimens in the implantation groups revealed a substantial fill of repair tissue in bone defect regions with only a slight depression at the defect site visible at 12 weeks after the operation, while one specimen (1/6) in both the implantation groups got absolutely repaired. All the specimens in both the implantation groups showed complete repair of bone defect at 16 weeks after the operation [Figure 3d–f].


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)

Gross observation after surgery: (a and b) group A (80% CS/PAA) and group B (95% CS/PAA), 7 days after implantation; (c) specimen of group C (control group) at 16 weeks; (d) specimen of group B (95% CS/PAA) at 16 weeks; (e and f) specimen of group A (80% CS/PAA) at 16 weeks
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 3: Gross observation after surgery: (a and b) group A (80% CS/PAA) and group B (95% CS/PAA), 7 days after implantation; (c) specimen of group C (control group) at 16 weeks; (d) specimen of group B (95% CS/PAA) at 16 weeks; (e and f) specimen of group A (80% CS/PAA) at 16 weeks
Mentions: None of the animals died during the study. The specimens did not show any evidence of tissue infection and inflammation on gross observation [Figures 3a and b]. The materials got incorporated intimately with the surrounding host bone. The boundary between the materials and adjacent host bone became indistinct with time. In the control group, the specimens did not totally heal at the end of the experiment. At the early stage of bone repair, the area of defect was filled by blood clot (4 weeks after operation) and fibrous soft tissue (8 weeks after operation). At later stage of bone repair, partial new bone was observed and most of the defect was still filled by fibrous soft tissue [Figure 3c]. In the implantation groups, defects and materials were no longer visible on macroscopic examination at 16 weeks after the operation. Biomaterials were partly degraded at 4 weeks after operation. Half of 6 in group B (95% CS/PAA) and 1of 6 in group A (80% CS/PAA) were totally degraded at 12 weeks after operation. Specimens in the implantation groups revealed a substantial fill of repair tissue in bone defect regions with only a slight depression at the defect site visible at 12 weeks after the operation, while one specimen (1/6) in both the implantation groups got absolutely repaired. All the specimens in both the implantation groups showed complete repair of bone defect at 16 weeks after the operation [Figure 3d–f].

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