RESUMEN
Biomimetic bone tissue engineering strategies partially recapitulate development. We recently showed functional restoration of femoral defects using scaffold-free human mesenchymal stem cell (hMSC) condensates featuring localized morphogen presentation with delayed in vivo mechanical loading. Possible effects of construct geometry on healing outcome remain unclear. Here, we hypothesized that localized presentation of transforming growth factor (TGF)-ß1 and bone morphogenetic protein (BMP)-2 to engineered hMSC tubes mimicking femoral diaphyses induces endochondral ossification, and that TGF-ß1 + BMP-2-presenting hMSC tubes enhance defect healing with delayed in vivo loading vs. loosely packed hMSC sheets. Localized morphogen presentation stimulated chondrogenic priming/endochondral differentiation in vitro. Subcutaneously, hMSC tubes formed cartilage templates that underwent bony remodeling. Orthotopically, hMSC tubes stimulated more robust endochondral defect healing vs. hMSC sheets. Tissue resembling normal growth plate was observed with negligible ectopic bone. This study demonstrates interactions between hMSC condensation geometry, morphogen bioavailability, and mechanical cues to recapitulate development for biomimetic bone tissue engineering.
Asunto(s)
Huesos/metabolismo , Materiales Biocompatibles , Proteína Morfogenética Ósea 2/metabolismo , Regeneración Ósea/fisiología , Diferenciación Celular , Células Cultivadas , Condrogénesis/efectos de los fármacos , Colágeno/metabolismo , Humanos , Células Madre Mesenquimatosas/efectos de los fármacos , Células Madre Mesenquimatosas/metabolismo , Osteogénesis/fisiología , Ingeniería de Tejidos , Factor de Crecimiento Transformador beta1/metabolismo , Cicatrización de Heridas/efectos de los fármacosRESUMEN
Despite great progress in biomaterial design strategies for replacing damaged articular cartilage, prevention of stem cell-derived chondrocyte hypertrophy and resulting inferior tissue formation is still a critical challenge. Here, by using engineered biomaterials and a high-throughput system for screening of combinatorial cues in cartilage microenvironments, we demonstrate that biomaterial cross-linking density that regulates matrix degradation and stiffness-together with defined presentation of growth factors, mechanical stimulation, and arginine-glycine-aspartic acid (RGD) peptides-can guide human mesenchymal stem cell (hMSC) differentiation into articular or hypertrophic cartilage phenotypes. Faster-degrading, soft matrices promoted articular cartilage tissue formation of hMSCs by inducing their proliferation and maturation, while slower-degrading, stiff matrices promoted cells to differentiate into hypertrophic chondrocytes through Yes-associated protein (YAP)-dependent mechanotransduction. in vitro and in vivo chondrogenesis studies also suggest that down-regulation of the Wingless and INT-1 (WNT) signaling pathway is required for better quality articular cartilage-like tissue production.
Asunto(s)
Cartílago Articular , Células Madre Mesenquimatosas , Materiales Biocompatibles/metabolismo , Cartílago Articular/metabolismo , Diferenciación Celular , Mecanotransducción Celular/fisiología , Células Madre Mesenquimatosas/metabolismo , Fenotipo , Células Madre , Ingeniería de Tejidos/métodosRESUMEN
Three-dimensional (3D) gradients of biochemical and physical signals in macroscale degradable hydrogels are engineered that can regulate photoencapsulated human mesenchymal stem cell (hMSC) behavior. This simple, cytocompatible, and versatile gradient system may be a valuable tool for researchers in biomaterials science to control stem cell fate in 3D and guide tissue regeneration.