A new technique for Asian nasal tip shaping: "twin tower" folding ear cartilage transplantation.

Rhinoplasty focuses on the establishment of the structural support of nasal cartilage and the shaping of the nasal tip. The purpose of this study was to explore the application of "double tower" folding ear cartilage transplantation for nasal tip shaping in rhinoplasty.

3D printed poly(ε-caprolactone) scaffolds function with simvastatin-loaded poly(lactic-co-glycolic acid) microspheres to repair load-bearing segmental bone defects.

Repairing critical-sized bone defects has been a major challenge for orthopedic surgeons in the clinic. The generation of functioning bone tissue scaffolds using osteogenic induction factors is a promising method to facilitate bone healing. In the present study, three-dimensional (3D) printing of a poly(lactic-co-glycolic acid) (PLGA) scaffold with simvastatin (SIM) release functioning was generated by rapid prototyping, which was incorporated with collagen for surface activation, and was finally mixed with SIM-loaded PLGA microspheres. In vitro assays with bone marrow-derived mesenchymal stem cells were conducted. For the in vivo study, scaffolds were implanted into segmental defects created on the femurs of Sprague-Dawley rats. At 4 and 12 weeks following surgery, X-ray, micro-computed tomography and histological analysis were performed in order to evaluate bone regeneration. The results demonstrated that collagen functionalization of PLGA produced better cell adhesion, while the sustained release of SIM promoted greater cell proliferation with no significant cytotoxicity, compared with the blank PCL scaffold. Furthermore, in vivo experiments also confirmed that SIM-loaded scaffolds played a significant role in promoting bone regeneration. In conclusion, the present study successfully manufactured a 3D printing PLGA scaffold with sustained SIM release, which may meet the requirements for bone healing, including good mechanical strength and efficient osteoinduction ability. Thus, the results are indicative of a promising bone substitute to be used in the clinic.

Sustained curcumin release from PLGA microspheres improves bone formation under diabetic conditions by inhibiting the reactive oxygen species production.

BACKGROUND: Excessive reactive oxygen species production caused by type 2 diabetes conditions can disrupt normal bone metabolism and greatly impair bone regeneration. MATERIALS AND METHODS: In the present study, curcumin (Cur)-loaded microspheres were incorporated into a fish collagen nano-hydroxyapatite scaffold to promote bone repair under diabetic conditions by inhibiting the reactive oxygen species production. RESULTS: The drug release kinetic study showed that the Cur release from the composite scaffolds lasted up to 30 days. The sustained curcumin release from the scaffold significantly inhibited the overproduction of reactive oxygen species in mesenchymal stem cells caused by diabetic serum. Moreover, the Cur-loaded scaffold also remarkedly alleviated the negative effects of diabetic serum on the proliferation, migration, and osteogenic differentiation of mesenchymal stem cells. When implanted into bone defects in type 2 diabetic rats, the Cur-loaded scaffold also showed a greater bone formation capability compared to the pure scaffold. CONCLUSION: The results of this study suggested that the novel controlled Cur release system may provide a promising route to improve bone regeneration in type 2 diabetic patients.

Control-released Alpha-lipoic acid-loaded PLGA microspheres enhance bone formation in type 2 diabetic rat model.

Since diabetes lead to alterations in bone metabolism with reductions in bone mineral content and delayed bone formation, the most effective method for bone regeneration in diabetes remains to be determined. In this study, type 2 diabetes were successfully induced via a high-fat diet and low-dose streptozotocin intraperitoneal injection. Excess reactive oxygen species (ROS) has been implicated in diabetes mellitus. Overexpression of ROS can lead to oxidative stress and subsequently to H2O2-mediated impaired proliferation and delayed cellular differentiation. As a result, antioxidant alpha-lipoic acid (ALA)-loaded poly (lactic-co-glycolic acid) (PLGA) microspheres were fabricated using the emulsion solvent evaporation method, and a sustained and controlled release of ALA was observed up to 27 days. It was demonstrated that biodegradable PLGA microspheres loaded with ALA acted as ROS scavengers and partially recover the mesenchymal stem cell proliferation and differentiation. The bone formation of ALA loaded scaffolds in rat cranial bone defects were greater than the prime three-dimensional collagen scaffold. These results suggest the application of ALA loaded PLGA microsphere exhibit good bioactivity and bone forming ability in diabetes.