Abstract

BackgroundThere has been increased interest in one-step cell-free procedures to avoid the problems related to cell manipulation and its inherent disadvantages. We have studied the chondrogenic induction ability of a PAMPS/PDMAAm double-network (DN) gel and found it to induce chondrogenesis in animal osteochondral defect models. The purpose of this study was to investigate whether the healing process and the degree of cartilage regeneration induced by the cell-free method using DN gel are influenced by the size of osteochondral defects.MethodsA total of 63 mature female Japanese white rabbits were used in this study, randomly divided into 3 groups of 21 rabbits each. A 2.5-mm diameter osteochondral defect was created in the femoral trochlea of the patellofemoral joint of bilateral knees in Group I, a 4.3-mm osteochondral defect in Group II, and a 5.8-mm osteochondral defect in Group III. In the right knee of each animal, a DN gel plug was implanted so that a vacant space of 2-mm depth was left above the plug. In the left knee, we did not conduct any treatment to obtain control data. Animals were sacrificed at 2, 4, and 12 weeks after surgery, and gross and histological evaluations were made.ResultsThe present study demonstrated that all sizes of the DN gel implanted defects as well as the 2.5mm untreated defects showed cartilage regeneration at 4 and 12 weeks. The 4.3-mm and 5.8-mm untreated defects did not show cartilage regeneration during the 12-week period. The quantitative score reported by O’Driscoll et al. was significantly higher in the 4.3-mm and 5.8-mm DN gel-implanted defects than the untreated defects at 4 and 12 weeks (p < 0.05). The 2.5-mm and 4.3-mm DN gel implanted defects maintained relatively high macroscopic and histological scores for the 12-week implantation period, while the histological score of the 5.8-mm DN gel implanted defect had decreased somewhat but statistically significantly at 12 weeks (p = 0.0057).ConclusionsThe DN gel induced cartilage regeneration in defects between 2.5 and 5.8 mm, offering a promising device to establish a cell-free cartilage regeneration therapy and applicable to various sizes of osteochondral defects.

Highlights

  • There has been increased interest in one-step cell-free procedures to avoid the problems related to cell manipulation and its inherent disadvantages

  • In the search for a useful material to develop a cellfree method for cartilage repair, we have studied the chondrogenic induction ability of a PAMPS/PDMAAm double-network (DN) gel composed of poly-(2-Acrylamido-2-methylpropanesulfonic acid) (PAMPS) and poly(N,N’-dimethyl acrylamide) (PDMAAm) and found it to be a promising candidate

  • The PAMPS/PDMAAm DN gel was immersed in 0.9% NaCl solution for 1 week with the water changed twice daily to remove any un-reacted materials From a 5.0 mm thick PAMPS/PDMAAm DN gel block, we punched out 2.7 mm, 4.5 mm, and 6.0 mm diameter plugs from the gel block

Read more

Summary

Introduction

There has been increased interest in one-step cell-free procedures to avoid the problems related to cell manipulation and its inherent disadvantages. Our previous studies have demonstrated that this DN gel has the potential to induce chondrogenesis in vitro, and that cartilage regeneration is induced in vivo in animal osteochondral defect models [16,17,18,19,20,21,22]. We have established that DN gel with a thickness of only 1.0 mm can induce a hyaline cartilage regeneration similar to that of a 5.0 mm thick DN gel plug [19], which will make less invasive surgery possible Using this method, the repair of larger defects has not been systematically studied yet. The purpose of this study was to investigate whether the healing process and the degree of cartilage regeneration induced by the cell-free method using DN gel are influenced by the size of osteochondral defects

Objectives
Methods
Results
Discussion
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call