Oxygen Tension-Controlled Matrices with Osteogenic and Vasculogenic Cells for Vascularized Bone Regeneration In Vivo.

Despite recent progress, segmental bone defect repair is still a significant challenge in orthopedic surgery. While bone tissue engineering approaches using biodegradable matrices along with bone/blood vessel forming cells offered improved possibilities, current regenerative strategies lack the ability to achieve vascularized bone regeneration in critical-sized/segmental bone defects. In this study, we introduced and evaluated a two-pronged approach for vascularized bone regeneration in vivo.

Functionalized carbon nanotube reinforced scaffolds for bone regenerative engineering: fabrication, in vitro and in vivo evaluation.

Designing biodegradable scaffolds with bone-compatible mechanical properties has been a significant challenge in the field of bone tissue engineering and regenerative engineering. The objective of this work is to improve the polymeric scaffold's mechanical strength by compositing it with mechanically superior carbon nanotubes. Poly(lactide-co-glycolide) (PLGA) microsphere scaffolds exhibit mechanical properties in the range of human cancellous bone.

Bone tissue engineering: recent advances and challenges.

The worldwide incidence of bone disorders and conditions has trended steeply upward and is expected to double by 2020, especially in populations where aging is coupled with increased obesity and poor physical activity. Engineered bone tissue has been viewed as a potential alternative to the conventional use of bone grafts, due to their limitless supply and no disease transmission. However, bone tissue engineering practices have not proceeded to clinical practice due to several limitations or challenges.

Optimally porous and biomechanically compatible scaffolds for large-area bone regeneration.

Large-area or critical-sized bone defects pose a serious challenge in orthopedic surgery, as all current treatment options present with shortcomings. Bone tissue engineering offers a more promising alternative treatment strategy. However, this approach requires mechanically stable scaffolds that support homogenous bone formation throughout the scaffold thickness.

Differential analysis of peripheral blood- and bone marrow-derived endothelial progenitor cells for enhanced vascularization in bone tissue engineering.

For tissue engineering applications, effective bone regeneration requires rapid neo-vascularization of implanted grafts to ensure the survival of cells in the early post-implantation phase. Incorporation of autologous endothelial progenitor cells (EPCs) for the promotion of primitive vascular network formation ex vivo has offered great promise for improved graft survival, enhanced rate of vascularization and bone regeneration in vivo. For clinical usage, identification of an optimal EPC isolation source from the patient is critical.

Optimal scaffold design and effective progenitor cell identification for the regeneration of vascularized bone.

Bone tissue engineering offers perhaps the most attractive treatment option for bone repair/regeneration as it eliminates complications of other bone grafting options (i.e., availability and immunogenicity issues of autografts and allografts, respectively).

Short-term and long-term effects of orthopedic biodegradable implants.

Presently, orthopedic and oral/maxillofacial implants represent a combined $2.8 billion market, a figure expected to experience significant and continued growth. Although traditional permanent implants have been proved clinically efficacious, they are also associated with several drawbacks, including secondary revision and removal surgeries.

Insulin-like growth factor-1 (IGF-1) inversely regulates atrophy-induced genes via the phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway.

Skeletal muscle size is regulated by anabolic (hypertrophic) and catabolic (atrophic) processes. We first characterized molecular markers of both hypertrophy and atrophy and identified a small subset of genes that are inversely regulated in these two settings (e.g.