A Bioactive Cartilage Graft of IGF1-Transduced Adipose Mesenchymal Stem Cells Embedded in an Alginate/Bovine Cartilage Matrix Tridimensional Scaffold

Abstract

Articular cartilage injuries remain as a therapeutic challenge due to the limited regeneration potential of this tissue. Cartilage engineering grafts combining chondrogenic cells, scaffold materials, and microenvironmental factors are emerging as promissory alternatives. The design of an adequate scaffold resembling the physicochemical features of natural cartilage and able to support chondrogenesis in the implants is a crucial topic to solve. This study reports the development of an implant constructed with IGF1-transduced adipose-derived mesenchymal stem cells (immunophenotypes: CD105+, CD90+, CD73+, CD14-, and CD34-) embedded in a scaffold composed of a mix of alginate/milled bovine decellularized knee material which was cultivated in vitro for 28 days (3CI). Histological analyses demonstrated the distribution into isogenous groups of chondrocytes surrounded by a de novo dense extracellular matrix with balanced proportions of collagens II and I and high amounts of sulfated proteoglycans which also evidenced adequate cell proliferation and differentiation. This graft also shoved mechanical properties resembling the natural knee cartilage. A modified Bern/O’Driscoll scale showed that the 3CI implants had a significantly higher score than the 2CI implants lacking cells transduced with IGF1 (16/18 vs. 14/18), representing high-quality engineering cartilage suitable for in vivo tests. This study suggests that this graft resembles several features of typical hyaline cartilage and will be promissory for preclinical studies for cartilage regeneration.

A Cellularized Biphasic Implant Based on a Bioactive Silk Fibroin Promotes Integration and Tissue Organization during Osteochondral Defect Repair in a Porcine Model

“…To overcome mechanical tissue demands, a strategy used by our group [16] and others has been to incorporate decellularized ECM processed in the form of micronized particles.…”

“…In this sense, biofunctionalization with an ECM derived from several tissues and decellularized organs has become more attractive and is used for the regeneration of tissues, such as skeletal muscle [12], blood vessels [13], nerves [14], and cartilage [15,16]. The ECM provides informative signals and a unique composition that mimics the natural tissue environment and leads to proper tissue regeneration.…”

Sequential growth factor exposure of human Ad‑MSCs improves chondrogenic differentiation in an osteochondral biphasic implant

“…To isolate Ad-MSCs, a modified version of the isolation protocol described in Moncada-Saucedo et al ( 19 ) was followed ( 20 ). To achieve this, lipoaspirate was centrifuged for 10 min at 1,000 x g in a 4˚C refrigerated centrifuge (5804R; Eppendorf), the aqueous phase was discarded and the adipose tissue was washed with PBS (pH 7.4).…”

Biological perspectives and current biofabrication strategies in osteochondral tissue engineering

“…IGF-1 has been reported showing high anabolic effects and decrease in catabolic responses in articular cartilage metabolism in vitro [167,168]. Other studies have reported using different growth factors which were successful in producing several features that resembled typical articular cartilage [169][170][171]. Despite the capacity to promote cartilage matrix formation, growth factors have shown some drawbacks with IGF-1 associated with a loss of chondrocyte phenotype and extracellular matrix breakdown [168].…”

“…Despite the capacity to promote cartilage matrix formation, growth factors have shown some drawbacks with IGF-1 associated with a loss of chondrocyte phenotype and extracellular matrix breakdown [168]. Furthermore, IGF-1 in human MSCs inhibited collagen II expression and overexpression can induce hypertrophic differentiation and mineralisation [172].…”