Tissue engineered cartilage from hTGF beta2 transduced human adipose derived stem cells seeded in PLGA/alginate compound in vitro and in vivo.

Abstract

Chondrogenic potential of human adipose derived stem cells (hASCs) makes them a possible source of seeding cells for cartilage tissue engineering. We aim to examine the chondrogenic differentiation of human transforming growth factor beta2 (hTGF beta2) transduced hASCs seeded in three-dimensional scaffold in vitro and in vivo. In this study, hASCs were isolated from human subcutaneous adipose tissue and transduced with a replication deficient adenovirus carrying hTGF beta2 (Ad5-hTGF beta2), and then the transduced cells were seeded and cultured in PLGA/alginate compounds. RT-PCR analysis revealed that Ad5-hTGF beta2 transduced hASCs produced aggrecan and collagen type II after 7-day induction in vitro and continued throughout the culture period; this was also demonstrated by the positive staining of Alcian blue and immunohistochemistry for collagen type II. For in vivo study, Ad5-hTGF beta2 transduced hASCs seeded in PLGA/alginate compounds were implanted in subcutaneous pockets of nude mice; after 12 weeks, the implants were harvested and examined by haematoxylin and eosin staining, AB-PAS staining, and immunohistochemical analysis, and the results demonstrated the formation of cartilage tissue. As a control, all these were not observed in the constructs with Ad5-EGFP transduced hASCs. In conclusion, our study demonstrates that adenovirus-mediated hTGF beta2 gene transfer is able to induce the hASCs into chondrogenic lineage both in vitro and in vivo. Ad5-hTGF beta2 transduced hASCs combined with three-dimensional PLGA/alginate compound may be a viable method in treating injuries of cartilage.