Porous tantalum seeded with bone marrow mesenchymal stem cells attenuates steroid-associated osteonecrosis

Bone marrow mesenchymal stem cells (BMMSCs) have been widely applied in osteonecrosis. However, lack of biomechanical support limited application of BMMSCs. And porous tantalum (PTA) has been identified as a cell-friendly scaffold for bone regeneration. Herein, we aimed to investigate the efficacy of PTA seeded with BMMSCs in the treatment of osteonecrosis.

After the production of PTA seeded with BMMSCs, MTT and GFP were performed to identify the proliferation and adhesion of BMMSCs respectively, which was further examined by scanning electron microscopy (SEM). And real-time PCR was also used to determine mRNA level of osteogenic markers, including Alp, OCN, OPN, Col I and Runx-2 in BMMSCs. Nineteen adult rabbits were applied for building steroid-associated osteonecrosis (SAON) models. Bone formation rate (BFR) and mineral apposition rate (MAR) were determined. And Goldner Trichrome Staining was used in these SAON models, which further confirmed the efficacy of PTA seeded with BMMSCs in SAON.

PTA seeded with BMMSCs showed excellent biocompatibility. Additionally, SEM assay showed that BMMSCs adhered tightly and spread fully in the pores of PTA. Next, the expression of ALP and OPN mRNA in BMMSCs were significantly (p < 0.05) higher in the PTA-treated group compared to those in the PTA-untreated group. Furthermore, compared to those treated by only PTA, the dynamic bone formation in rabbits treated by PTA seeded with BMMSCs was significantly increased (p < 0.001) at both week 3rd and week 6th.

The product, PTA seeded with BMMSCs, was successfully produced, and was determined as high efficacy for treatment of steroid-associated osteonecrosis. PTA seeded with BMMSCs may afford a promising option for treating osteonecrosis.