Angiogenic Potential of Human Bone Marrow-Derived Mesenchymal Stem Cells in Chondrocyte Brick-Enriched Constructs Promoted Stable Regeneration of Craniofacial Cartilage

Abstract

Craniofacial deformities caused by congenital defects or trauma remain challenges for clinicians, whereas current surgical interventions present limited therapeutic outcomes. Injection of bone marrow‐derived mesenchymal stem cells (BMSCs) into the defect is highly desirable because such a procedure is microinvasive and grafts are more flexible to fill the lesions. However, preventing hypertrophic transition and morphological contraction remain significant challenges. We have developed an “all host derived” cell transplantation system composed of chondrocyte brick (CB)‐enriched platelet‐rich plasma (P) gel and BMSCs (B). Without exogenous biomaterials or growth factors, such grafts regenerate cartilage efficiently and present great clinical promise. In immunodeficient mice, we compared performance of BMSCs and BMSCs lacking angiogenic potential in CB‐B‐P constructs and followed the cartilage maturation process by histology, immunostaining, micro‐computed tomography, and protein analysis. We determined that angiogenesis occurred quickly inside rudimentary cartilage derived from CB‐B‐P constructs after implantation, which improved tissue survival, tissue growth, and production of chondrogenic signals from chondrocytes. In contrast, silencing angiogenic potential of BMSCs led to poor chondrogenesis accompanied by necrosis. Chondrocyte bricks merged rapidly with angiogenesis, which constituted an enclosed chondrogenic niche and effectively inhibited runt‐related transcription factor‐2‐dependent hypertrophic transition of BMSCs as well as endochondral ossification; progressive chondrogenic differentiation of BMSCs resulted in vascularization regression, thus favoring persistent chondrogenesis and effectively augmenting nasal cartilage. In conclusion, these findings provided a novel, efficient approach to regenerating cartilage tissues in vivo. Chondrocyte bricks mixed with P provide transient vascularization and a persistently chondrogenic microenvironment for BMSCs; this provides a mini‐invasive approach for craniofacial cartilage reconstruction. Stem Cells Translational Medicine 2017;6:601–612

Exosomes derived from mature chondrocytes facilitate subcutaneous stable ectopic chondrogenesis of cartilage progenitor cells

“…Currently, exosomes have been identified as the principal agent in mediating the therapeutic efficacy of the cell-based regenerative medicine approach [ 20 , 21 , 57 , 58 ], and BMSC-Exos have been reported for promoting in situ cartilage defect repair [ 21 , 26 ]. However, the therapeutic outcome for subcutaneous cartilage defect repair is still limited because of the lack of a suitable pro-chondrogenic environment [ 17 , 40 , 59 ]. Meanwhile, previous studies have also shown that chondrocytes could steer the chondrogenesis of stem cells in vitro and in vivo through paracrine effects [ 1 , 7 , 60 ].…”

“…However, after the addition of BMSC-Exos, expression of SDF-1 and VEGF is upregulated, which promotes cell homing and angiogenesis. This is beneficial for cartilage engineering during the early stage of implantation [ 40 ], which may account for the better neo-cartilage formation in the BMSC-Exos, as reported [ 21 , 26 ]. However, it also has a disadvantage as evidenced by promoting associated ectopic cartilage hypertrophy.…”

“…The protocol and procedure for Western blot were performed as described in previous reports [ 40 ]. For each sample, the 30 μg extracted total protein was loaded onto a 10–15% SDS/PAGE gel.…”

Evaluation of the effects of dimethylsulphoxide on morphology, cellular viability, mRNA, and protein expression of stem cells culture in growth media

“…Stem cells may be obtained from various tissues, including bone marrow and fat ( 9 ). Bone marrow-derived stem cells are widely used in medical fields in applications including the regeneration of cartilage tissue ( 9 , 10 ). Adipose tissue is suggested to be an abundant and accessible source of adult mesenchymal stem cells ( 11 ).…”

Potential and recent advances of microcarriers in repairing cartilage defects

“…BMSCs have been extensively studied [ [39] , [40] , [41] , [42] ], and a number of scholars are committed to their application in cartilage regeneration. BMSCs have been demonstrated to have immunomodulatory properties, multilineage potential [ 43 ] and tissue homing properties.…”