RESUMO
Nanomaterial-based drug sustainable release systems have been tentatively applied to bone regeneration. They, however, still face disadvantages of high toxicity, low biocompatibility, and low drug-load capacity. In view of the low toxicity and high biocompatibility of polymer nanomaterials and the excellent load capacity of hollow nanomaterials with high specific surface area, we evaluated the hollow polydopamine nanoparticles (HPDA NPs), in order to find an optimal system to effectively deliver the osteogenic drugs to improve treatment of bone defect. Data demonstrated that the HPDA NPs synthesized herein could efficiently load four types of osteogenic drugs and the drugs can effectively release from the HPDA NPs for a relatively longer time in vitro and in vivo with low toxicity and high biocompatibility. Results of qRT-PCR, ALP, and alizarin red S staining showed that drugs released from the HPDA NPs could promote osteogenic differentiation and proliferation of rat bone marrow mesenchymal stem cells (rBMSCs) in vitro. Image data from micro-CT and H&E staining showed that all four osteogenic drugs released from the HPDA NPs effectively promoted bone regeneration in the defect of tooth extraction fossa in vivo, especially tacrolimus. These results suggest that the HPDA NPs, the biodegradable hollow polymer nanoparticles with high drug load rate and sustainable release ability, have good prospect to treat the bone defect in future clinical practice.
Assuntos
Animais , Ratos , Regeneração Óssea , Indóis , Nanopartículas , Osteogênese , Preparações Farmacêuticas , PolímerosRESUMO
At the present day, curettage and periodontal surgery comprise the main strategy for the treatment of periodontitis, however, these methods are limited in regenerating cementum. It has been found that some biological factors such asenamel matrix derivative (EMD), transforming growth factor-β (TGF-β) and insulin-like growth factor (IGF) could promote cementum regeneration. In the cementum regenerationstudies, there has been a lack of criteria to distinguish cementum from alveolar bone and other types of cementum. Therefore, this article will briefly review the biological factors that affect the cementum regeneration and the molecular markers used to judge the regenerating cementum.
RESUMO
Objective To observe the effect of transplantation of telomerase immortalized human neural progenitor cells to acute injured canine spinal cord by using MR diffusion tensor imaging (DTI).Methods Telomerase immortalized human neural progenitor cells with expression of green fluorescent protein were prepared for transplantation. Eight adult canines with left spinal cord hemisection at the level of T13 were examined by MR diffusion tensor imaging four times sequentially: prior to injury, one week after injury, one week after transplantation (two weeks after injury), and four weeks after transplantation. Results The ADC values of the injured spinal cord were (1.00?0.15)?10 -3 mm2/s, (1.65?0.45)?10 -3 mm2/s, (1.44?0.48)?10 -3 mm2/s, and (1.43?0.26) ?10 -3 mm2/s, respectively. There was statistically significant difference between the data obtained at different times (F=6.038, P=0.005). The FA values of the injured spinal cord were 0.59?0.11, 0.30?0.17, 0.36?0.25, and 0.34?0.11, respectively. There was also statistically significant difference between the data obtained at different times ( F=5.221,P=0.009). The ADC values of the intact spinal cord were (1.01?0.17)?10 -3 mm2/s, (1.32?0.06)?10 -3 mm2/s, (1.10?0.24)?10 -3 mm2/s, and (1.14?0.22) ?10 -3 mm2/s, respectively. There was no statistically significant difference between the data obtained at different times ( F=1.303,P=0.306). The FA values of the intact spinal cord were 0.60?0.09, 0.38?0.25, 0.46?0.15, and 0.50?0.21, respectively. There was also no statistically significant difference between the data obtained at different times (F=2.797,P=0.072).Conclusion DTI can provide useful information for spinal cord injury and regeneration in experimental spinal cord injury.