Application of induced pluripotent stem cells for cartilage regeneration in CLAWN miniature pig osteochondral replacement model

Abstract

IntroductionPluripotent stem cells have an advantage that they can proliferate without reduction of the quality, while they have risk of tumorigenesis. It is desirable that pluripotent stem cells can be utilized safely with minimal effort in cartilage regenerative medicine. To accomplish this, we examined the potential usefulness of induced pluripotent stem cells (iPS cells) after minimal treatment via cell isolation and hydrogel embedding for cartilage regeneration using a large animal model.MethodsPorcine iPS-like cells were established from the CLAWN miniature pig. In vitro differentiation was examined for porcine iPS-like cells with minimal treatment. For the osteochondral replacement model, osteochondral defect was made in the quarters of the anteromedial sides of the proximal tibias in pigs. Porcine iPS-like cells and human iPS cells with minimal treatment were seeded on scaffold made of thermo-compression-bonded beta-TCP and poly-L-lactic acid and transplanted to the defect, and cartilage regeneration and tumorigenesis were evaluated.ResultsThe in vitro analysis indicated that the minimal treatment was sufficient to weaken the pluripotency of the porcine iPS-like cells, while chondrogenic differentiation did not occur in vitro. When porcine iPS-like cells were transplanted into osteochondral replacement model after minimal treatment in vitro, cartilage regeneration was observed without tumor formation. Additionally, fluorescent in situ hybridization (FISH) indicated that the chondrocytes in the regenerative cartilage originated from transplanted porcine iPS-like cells. Transplantation of human iPS cells also showed the regeneration of cartilage in miniature pigs under immunosuppressive treatment.ConclusionMinimally-treated iPS cells will be a useful cell source for cartilage regenerative medicine.

Versatility of Induced Pluripotent Stem Cells (iPSCs) for Improving the Knowledge on Musculoskeletal Diseases

“…MSCs derived from iPSCs were found to be comparable to adult MSCs in terms of multipotency even when derived using different protocols [ 134 , 138 , 145 ]. Osteochondral and bone defects treated with iPSCs or differentiated iPSCs on scaffolds did not show differences when compared with adult MSCs transplanted using the same procedures [ 44 , 137 , 142 ]. Jungbluth et al [ 142 ] derived MSCs from iPSCs and combined them with calcium phosphate granules to treat critical bone size defects in minipigs.…”

“…Differentiation of iPSCs into chondrocytes showed better repair capacity of osteochondral lesions than iPSCs or iPSC-MSCs in independent studies [ 136 , 138 ]. Uto et al [ 137 ] cultured iPSCs in chondrogenic media and embedded them in atelocollagen before soaking them in beta-tricalcium phosphate (TCP)/poly-L-lactic acid (PLLA) scaffolds and implanted them in osteochondral defects in miniature pigs. After eight weeks, the formed neo-tissue was similar to the one formed by adult MSCs and both were better than TCP scaffolds alone.…”

“…Nevertheless, low differentiation efficiencies are hampering the translational application of iPSC-based basic research findings, because the presence of undifferentiated cells can contaminate the final, fully differentiated cell population, thus representing a safety issue due to the risk of teratoma formation [ 42 , 164 ]. Even when no teratomas were found in several in vivo studies using different types of animals [ 60 , 137 , 139 , 140 , 145 , 165 ], there is still some concern [ 166 ]. Some studies reported absence of teratomas when iPSCs were transplanted in vivo as differentiated MSCs [ 139 , 142 , 145 ], lineage-differentiated cells [ 60 , 140 , 143 , 165 ] or even iPSCs seeded on scaffolds [ 137 ].…”

“…Even when no teratomas were found in several in vivo studies using different types of animals [ 60 , 137 , 139 , 140 , 145 , 165 ], there is still some concern [ 166 ]. Some studies reported absence of teratomas when iPSCs were transplanted in vivo as differentiated MSCs [ 139 , 142 , 145 ], lineage-differentiated cells [ 60 , 140 , 143 , 165 ] or even iPSCs seeded on scaffolds [ 137 ]. However, other studies have shown teratoma formation in some animals after treatment with iPSCs seeded on collagen and implanted in osteochondral defects in rats [ 167 ] or after one week of differentiation before implantation in mice [ 164 ].…”

Protection of human induced pluripotent stem cells against shear stress in suspension culture by Bingham plastic fluid

“…Pluripotent stem cells (PSCs) are one of the most promising cell sources for regenerative therapy [1][2][3] and drug screening 3,4 owing to their special characteristics, such as extensive growth and the potential to differentiate into any type of body cell. For the industrial production of PSCs, stable mass production systems are necessary to establish a cell bank and to regenerate large organs such as the liver, heart, and pancreas.…”