PPAR-γ agonist pioglitazone alleviates inflammatory response induced by lipopolysaccharides in osteoblast cells.

Osteomyelitis is an acute or chronic inflammatory bone disease with a high disability rate. As an anti-inflammatory factor, peroxisome proliferator activated receptor-γ (PPAR-γ) is not only implicated in a variety of inflammatory responses but also regulates osteoblast differentiation and bone mass. However, the role of PPAR-γ in osteomyelitis is not fully understood. In the present study, we demonstrated that PPAR-γ showed a lower expression level in infected bone tissue of osteomyelitis patients as compared with uninfected bone tissue from nonosteomyelitis patients with fracture of the hip. We applied lipopolysaccharides (LPSs) in MC3T3-E1 osteoblast precursor cell line as an in vitro model for osteomyelitis. LPS treatment increased osteomyelitis-associated inflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), whereas PPAR-γ levels and cell viability in MC3T3-E1 cells were suppressed. PPAR-γ antagonist GW9662 further enhanced IL-6 and TNF-α levels, and decreased cell viability in the presence of LPS treatment. In contrast, PPAR-γ agonist pioglitazone antagonized the effect of LPS treatment in MC3T3-E1 cells. These findings suggest that PPAR-γ downregulation is associated with the inflammation and progression of osteomyelitis, and PPAR-γ agonist could serve as a therapeutic strategy to attenuate inflammatory responses. This study provides novel insights into the physiopathogenesis of osteomyelitis and future study is required to validate the findings in animal model and uncover the molecular mechanism of PPAR-γ-dependent anti-inflammation in osteoblasts.

Osteoblast Response to Copper-Doped Microporous Coatings on Titanium for Improved Bone Integration.

Due to their excellent mechanical properties and good biocompatibility, titanium alloys have become a popular research topic in the field of medical metal implants. However, the surface of the titanium alloy does not exhibit biological activity, which may cause poor integration between the interface of the titanium implant and the interface of the bone tissue and subsequently may cause the implant to fall off. Therefore, surface biological inertness is one of the problems that titanium alloys must overcome to become an ideal orthopedic implant material. Surface modification can improve the biological properties of titanium, thereby enhancing its osseointegration effect. Copper is an essential trace element for the human body, can promote bone formation and plays an important role in maintaining the physiological structure and function of bone and bone growth and development. In this study, a microporous copper-titanium dioxide coating was prepared on the surface of titanium by microarc oxidation. Based on the evaluation of its surface characteristics, the adhesion, proliferation and differentiation of MC3T3-E1 cells were observed. A titanium rod was implanted into the rabbit femoral condyle, and the integration of the coating and bone tissue was evaluated. Our research results show that the microporous copper-titanium dioxide coating has a nearly three-dimensional porous structure, and copper is incorporated into the coating without changing the structure of the coating. In vitro experiments found that the coating can promote the adhesion, proliferation and differentiation of MC3T3-E1 cells. In vivo experiments further confirmed that the titanium copper-titanium dioxide microporous coating can promote the osseointegration of titanium implants. In conclusion, copper-titanium dioxide microporous coatings can be prepared by microarc oxidation, which can improve the biological activity and biocompatibility of titanium, promote new bone formation and demonstrate good osteoinductive properties. Therefore, the use of this coating in orthopedics has potential clinical application.

Comparison of unilateral and bilateral puncture percutaneous kyphoplasty in the treatment of osteoporotic vertebral compression fractures.

OBJECTIVES: To compare the clinical efficacy of unilateral and bilateral puncture PKP in the treatment of OVCFs and explored whether there is a difference in the efficacy of unilateral and bilateral puncture PKP after surgery. METHODS: A total of 98 patients with OVCFs treated by PKP from August 2016 to June 2018 were selected. There were 62 cases in the unilateral puncture group and 36 cases in the bilateral puncture group. The operation time, the amount of bone cement injection, the height of the anterior edge of the vertebral body and the visual analog scale (Visual Analog Scale, VAS) scores before and after the operation were analyzed, and whether the differences between the 2 groups were statistically significant was analyzed. RESULTS: All patients were followed up completely. The operation time and the number of X-ray fluoroscopies of the unilateral puncture group were significantly reduced compared to those of the bilateral group, and the difference was statistically significant (p<0.05). In terms of the bone cement injection volume, the average injection volume of the bilateral group was greater than that of the unilateral group, and the difference was statistically significant (p<0.05); the postoperative VAS scores of the 2 groups of patients were significantly improved, and the difference was statistically significant compared with that before surgery (p<0.05) but that of the unilateral group was not statistically significant compared with that of the bilateral group (p>0.05). The height of the anterior edge of the vertebral body in both groups was significantly improved compared with that before the operation, and the difference was statistically significant (p<0.05). CONCLUSION: Unilateral and bilateral puncture PKP can achieve good clinical efficacy in the treatment of osteoporotic vertebral compression fractures, but unilateral PKP has the advantages of short operation time and low X-ray exposure.