Platelet‐rich plasma loaded in situ‐formed hydrogel enhances hyaline cartilage regeneration by CB1 upregulation

Abstract

The efficacy of three‐dimensional (3D) culture on the proliferation and maturation of chondrocytes seeded into a hydrogel scaffold was assessed. Three types of hydrogel were prepared for the 3D culture of primary isolated chondrocytes. Chondrocyte proliferation was assessed using a live/dead viability/cytotoxicity assay and semiquantitative RT‐PCR after 3D culture in hydrogel. Cylindrical defects in the center of rat xyphoids were used for the implantation of platelet‐rich plasma (PRP)/hydrogel composites. Rats were killed at day 7 postoperatively and evaluated histochemically and immunohistologically. Xyphoid chondrocytes proliferated well with time in hydrogels. In the PRP‐containing hydrogels, xyphoid defects displayed early formation of chondroid matrix with massive peripheral infiltration of spindle cells. These results were consistent with Safranin‐O staining for proteoglycans and immunohistochemistry for type II collagen. Gene expression analyses in vitro revealed aggrecan, type II collagen, and ChM‐1 and CB1 upregulation by PRP/hydrogel. PRP/hydrogel provided a suitable environment for hyaline cartilaginous regeneration, leading to anti‐inflammation by significant increase of CB1 and inhibiting vascular ingrowth via considerable upregulation of ChM‐1. The results provide a valuable reference for the clinical application of hydrogel scaffolds for hyaline cartilage regeneration, as well as the use of autologous PRP to improve cellular proliferation and maturation of xyphoid repair. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A:3099–3107, 2012.

Three-Dimensional Culture Environment Increases the Efficacy of Platelet Rich Plasma Releasate in Prompting Skin Fibroblast Differentiation and Extracellular Matrix Formation

“…Previous studies showed that the mesenchymal stem cells (MSC) exhibited higher level of chondrogenic marker expression after the PRCR treatment of cells inside the scaffold environment compared to the 2D culture 21. Even mature chondrocyte when was seeded in the 3D systems showed high viability and efficacy in the proliferation and expression of chondrogenic gene markers after the treatment with PRCR 22. Another study showed opposite results, as the treatment of the ligament fibroblasts with high doses of PRCR in the scaffold culture system showed negative responses in terms of cells function.…”

Horseradish peroxidase-catalysedin situ-forming hydrogels for tissue-engineering applications

“…In vivo results demonstrated that PRP–GPT hydrogels could improve cartilage remodelling by upregulating SOX‐9, CB2, ChM‐1 and aggrecan after a 7 day incubation period. We have also attempted to regenerate non‐articular cartilage by the implantation of xyphoid chondrocytes encapsulated in PRP–GPT hydrogels (Lee et al ., ). A xyphoid defect rat model was used to show that the PRP–GPT hydrogels can induce proliferation and differentiation of chondrocytes in vitro and in vivo by inducing elevated levels of ChM‐1 and CB1.…”

Biology of platelet-rich plasma and its clinical application in cartilage repair

“…These results show that PRP had differential effects on chondrocytes; that is, promoting the synthesis of hyaline cartilage matrix while cellular progression to terminal hypertrophy is not facilitated or at least delayed. Another study further demonstrated that the chondrogenic differentiation and maturation induced by PRP treatment was related to the up-regulated expression of cannabinoid receptor 1 and 2 [36,37]. However, a few authors have argued that PRP treatment was unable to induce the deposition of typical cartilage matrix components [32,34], that there was no difference in the enhancement of extracellular matrix (ECM) production between the groups with PRP, PPP, whole blood or fibrin glue added into gelatin-based microcarriers [38], and that PRP treatment could in fact induce a dedifferentiation of chondrocytes towards a fibroblast-like phenotype [33].…”