Engineered three-dimensional scaffolds for enhanced bone regeneration in osteonecrosis

For large segmental bone defects, porous titanium scaffolds have some advantages, however, they lack electrical activity which hinders their further use. In this study, a barium titanate (BaTiO 3 ) piezoelectric ceramic was used to modify the surface of a porous Ti6Al4V scaffold (pTi), which was characterized by scanning electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and roughness and water contact angle analyses. Low intensity pulsed ultrasound (LIPUS) was applied in vitro and in vivo study. The activity of bone marrow mesenchymal stem cells, including adhesion, proliferation, and gene expression, was significantly superior in the BaTiO 3 /pTi, pTi + LIPUS, and BaTiO 3 /pTi + LIPUS groups than in the pTi group. The activity was also higher in the BaTiO 3 /pTi + LIPUS group than in the BaTiO 3 /pTi and pTi + LIPUS groups. Additionally, micro-computed tomography, the mineral apposition rate, histomorphology, and the peak pull-out load showed that these scaffold conditions significantly enhanced osteogenesis and osseointegration 6 and 12 weeks after implantation in large segmental bone defects in the radius of rabbits compared with those resulting from the pTi condition. Consequently, the improved osteogenesis and osseointegration make the BaTiO 3 /pTi + LIPUS a promising method to promote bone regeneration in large segmental bone defects for clinical application.

Section: Discussionmentioning

confidence: 99%

Electroactive barium titanate coated titanium scaffold improves osteogenesis and osseointegration with low-intensity pulsed ultrasound for large segmental bone defects

Fan

Guo

et al. 2020

“…The interaction between scaffolds and surrounding tissue was initiated immediately upon implantation and influence the fate of the scaffolds throughout the entire healing process. Therefore, it is crucial to design an appropriate scaffold with proper surface attributes [ [165] , [166] , [167] ], aiming at modulating the host cell into a right phenotype at the host-scaffold interface.…”

Section: Harnessing the Power Of Macrophages For Enhanced Osteogenesimentioning

confidence: 99%

Modulating macrophage activities to promote endogenous bone regeneration: Biological mechanisms and engineering approaches

Niu

Wang

Shi

et al. 2021

108

109

A coordinated interaction between osteogenesis and osteoimmune microenvironment is essential for successful bone healing. In particular, macrophages play a central regulatory role in all stages of bone repair. Depending on the signals they sense, these highly plastic cells can mediate the host immune response against the exterior signals of molecular stimuli and implanted scaffolds, to exert regenerative potency to a varying extent. In this article, we first encapsulate the immunomodulatory functions of macrophages during bone regeneration into three aspects, as sweeper, mediator and instructor. We introduce the phagocytic role of macrophages in different bone healing periods (‘sweeper’) and overview a variety of paracrine cytokines released by macrophages either mediating cell mobilisation, vascularisation and matrix remodelling (‘mediator’), or directly driving the osteogenic differentiation of bone progenitors and bone repair (‘instructor’). Then, we systematically classify and discuss the emerging engineering strategies to recruit, activate and modulate the phenotype transition of macrophages, to exploit the power of endogenous macrophages to enhance the performance of engineered bone tissue.

“…However, the therapeutic efficacy is poor owing to its low mechanical strength and readily to be degraded by collagenase. Polymer-based artificial bone substitutes showing great potential in bone repair [ [47] , [48] , [49] , [50] , [51] , [52] , [53] , [54] , [55] , [56] , [57] ]. In comparison with previous materials, synthetic polymers have a range of advantages, such as controllable molecular mass and degradation time, excellent processability, and good mechanical properties.…”

Section: Introductionmentioning

confidence: 99%

Poly(lactic-co-glycolic acid)-based composite bone-substitute materials

Zhao

Zhu

et al. 2021

Self Cite

257

162

Research and development of the ideal artificial bone-substitute materials to replace autologous and allogeneic bones for repairing bone defects is still a challenge in clinical orthopedics. Recently, poly(lactic- co -glycolic acid) (PLGA)-based artificial bone-substitute materials are attracting increasing attention as the benefit of their suitable biocompatibility, degradability, mechanical properties, and capabilities to promote bone regeneration. In this article, we comprehensively review the artificial bone-substitute materials made from PLGA or the composites of PLGA and other organic and inorganic substances, elaborate on their applications for bone regeneration with or without bioactive factors, and prospect the challenges and opportunities in clinical bone regeneration.