Regenerative Effect of Adipose‐Derived Mesenchymal Stem Cells on Pain in a Rat Model of Osteochondral Defect

Abstract

In recent years, a lot of attention has been focused on using adipose‐derived mesenchymal stem cells obtained from infrapatellar fat pad (IPFP‐ASCs) for the articular cartilage regeneration. IPFP‐ASCs constructs were previously characterized and demonstrated chondrogenic differentiation potential to produce hyaline like‐cartilage in vitro. However, little is known about the relationship of its regeneration potential and pain associated with osteochondral defect. This study aimed to investigate the effect of implantation of the 3‐Dimensional (3D) cartilage construct of IPFP‐ASCs on the restoration of an articular hyaline cartilage as well as attenuation of pain associated with the cartilage defect in an osteochondral defect rat model. The chondrogenic differentiation potential of the 3D cartilage construct derived from IPFP‐ASCs was determined prior to implantation and at 4, 8 and 12 weeks post‐implantation by gene expression and immunochemistry analysis. Pain‐related behavior was examined weekly up to 8 weeks post‐implantation by using weight‐bearing test. A significant pain‐associated with osteochondral defect was observed in this model in all groups post‐induction; however, this pain can spontaneously resolve within three weeks post‐implantation regardless of implantation of IPFP‐ASCs constructs. The existences of mature chondrocytes as well as a significant (p<0.05) positively immunostained for type II collagen and aggrecan were identified in the implanted site for up to 12 weeks compared to untreated group, indicating the hyaline cartilage regeneration. Overall, this study reported the successful outcome of osteochondral regeneration with scaffold‐free IPFP‐ASCs constructs in an osteochondral defect rat model. Although the implantation of the cartilage construct could not attenuate pain associated with the cartilage defect, it provides novel and interesting insights into the current hypothesis that 3D construct IPFP‐ASCs may have potential benefits as an alternative approach to repair bone and cartilage defect.