Variation of Mesenchymal Cells in Polylactic Acid Scaffold in an Osteochondral Repair Model

Abstract

Objective: To achieve osteochondral regeneration utilizing transplantation of cartilage-lineage cells and adequate scaffolds, it is essential to characterize the behavior of transplanted cells in the repair process. The objectives of this study were to elucidate the survival of mesenchymal cells (MCs). In a polylactic acid (PLA) scaffold and assess the possibility of MC=PLA constructs for osteochondral repair. Design: Bone marrow from mature male rabbits was cultured for 2 weeks, and fibroblast-like MCs, which contain mesenchymal stem cells (MSCs), were obtained. A cell=scaffold construct was prepared with one million MCs and a biodegradable PLA core using a rotator device. One week after culturing, the construct was transplanted into an osteochondral defect in the medial femoral condyle of female rabbits and the healing process examined histologically. To examine the survivability of transplanted MCs, the male-derived sex-determining region Y (SRY) gene was assessed as a marker of MCs in the defect by polymerase chain reaction (PCR). Results: In the groups of defects without any treatment, and the transplantation of PLA without cells, the defects were not repaired with hyaline cartilage. The cartilaginous matrix by safranin O staining and type II collagen by immunohistochemical staining were recognized, however the PLA matrix was still present in the defects at 24 weeks after transplantation of the construct. During the time passage, transplanted MCs numbers decreased from 7.8Â105 at 1 week, to 3.5Â105 at 4 weeks, and to 3.8Â104 at 12 weeks. Transplanted MCs were not detectable at 24 weeks. Conclusions: MCs contribute to the osteochondral repair expressing the cartilaginous matrix, however the number of MCs were decreasing with time (i.e. 24 weeks). These results could be essential for achieving cartilage regeneration by cell transplantation strategies with growth factors and=or gene therapy.

Oligo[poly(ethylene glycol)fumarate] Hydrogel Enhances Osteochondral Repair in Porcine Femoral Condyle Defects

“…Complete integration was noted between neotissue and host cartilage and subchondral bone, similar to osteochondral repair reported in other publications [41,61]. However, despite the cartilage healing observed, regeneration of trabecular subchondral bone did not occur even at 4 months.…”

“…This is contrary to OPF hydrogel implantation in a rabbit model, where the osteochondral defect was fully packed with repair tissue at 3 months postoperatively [13]. More than 90% tissue filling was also noted in 2.4-mm [63] and 3.7-mm [41] defects of the rabbit model, which were left untreated for 2 and 3 months, respectively. However, osteochondral defects implanted with hydrogel scaffolds generally have incomplete filling in large animals [14,48].…”

Development and characterisation of a decellularised bovine osteochondral biomaterial for cartilage repair

“…Due to the limitation of current interventions, the repair of cartilage lesions using tissue engineered approaches is being explored. Synthetic biomaterials such as polycaprolactone (PCL) [ 10 ] and polylactic acid [ 11 ] are easily manufactured with precise material properties; however achieving satisfactory biological integration is often a challenge. Biological materials such as fibrin [ 12 ] and gelatin [ 13 ] are biodegradable and biocompatible, however there remain concerns over scaffold integration.…”

An anti-inflammatory cell-free collagen/resveratrol scaffold for repairing osteochondral defects in rabbits

“…The transplanted BMSCs numbers decreased from 7.8 Â 10 5 at 1 week, to 3.5 Â 10 5 at 4 weeks, to 3.8 Â 10 4 at 12 weeks, and were not detectable at 24 weeks. The results indicate that endogenous cells participated in the reparative process, and the cells in the neo-tissue were the host cells instead of the transplanted cells [34]. In addition, cell delivery has encountered crucial barriers in therapeutic translation, including immune rejection, pathogen transmission, potential tumorigenesis, issues with packaging, storage and shipping and difficulties in clinical adoption and regulatory approval [35].…”