Objective To investigate the effect of solid lipid nanoparticles (SLNs) on enhancing the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in vitro by resveratrol (Res), and provide a method for the treatment of bone homeostasis disorders. MethodsRes-SLNs were prepared by high-temperature emulsification and low-temperature solidification method, and then the 2nd-3rd generation BMSCs from Sprague Dawley rat were co-cultured with different concentrations (0, 0.1, 1, 5, 10, 20 μmol/L) of Res and Res-SLNs. The effects of Res and Res-SLNs on the cell viability of BMSCs were detected by cell counting kit 8 (CCK-8) and live/dead cell staining; the effects of Res and Res-SLNs on the osteogenic differentiation of BMSCs were detected by alkaline phosphatase (ALP) staining and alizarin red S (ARS) staining after osteogenic differentiation induction, and the optimal concentration of Res-SLNs for gene detection was determined. Anti-osteocalcin (OCN) immunofluorescence staining and real-time fluorescent quantitative PCR (RT-qPCR) were used to detect the effect of Res and Res-SLNs on osteoblast-related genes (ALP and OCN) of BMSCs. ResultsLive/dead cell staining showed that there was no significant difference in the number of dead cells between Res and Res-SLNs groups; CCK-8 detection showed that the activity of BMSCs in Res group was significantly reduced at the concentration of 20 μmol/L (P<0.05), while Res-SLNs activity was not affected by Res concentration (P>0.05). After osteogenic differentiation, the staining intensity of ALP and ARS in both groups was dose-dependent. The percentage of ALP positive staining area and the percentage of mineralized nodule area in Res group and Res-SLNs group reached the maximum at the concentrations of 10 μmol/L and 1 μmol/L, respectively (P<0.05), and then decreased gradually; the most effective concentration of Res-SLNs was 1 μmol/L. The expression of OCN and the relative expression of ALP and OCN mRNA in Res-SLNs group were significantly higher than those in Res group (P<0.05). ConclusionEncapsulation of SLNs can improve the effect of Res on promoting osteogenesis, and achieve the best effect of osteogenic differentiation of BMSCs at a lower concentration, which is expected to be used in the treatment of bone homeostasis imbalance diseases.
ObjectiveTo investigate the effectiveness of modified tibial transverse bone transport technique combined with vancomycin calcium phosphate bone cement local filling and covering in the treatment of diabetic foot (DF). MethodsThe clinical data of 22 DF patients treated with modified tibial transverse bone transport technique combined with vancomycin calcium phosphate bone cement local filling and covering between October 2019 and December 2021 were retrospectively analyzed. There were 13 males and 9 females with an average age of 61.3 years (range, 41-74 years). The duration of diabetes mellitus was 8-30 years, with an average of 12.5 years, and the duration of DF was 10-42 days, with an average of 28.2 days. There were 2 cases of grade 3 and 20 cases of grade 4 according to Wagner classification. CT angiography was performed on both lower extremities of the patients, and the blood vessels of the affected extremities were narrowed to varying degrees and the blood supply was poor. The preoperative skin temperature of affected foot was (28.27±0.91)°C, the ankle brachial index (ABI) was 0.42±0.11, and the visual analogue scale (VAS) score was 7.7±0.6. Preoperative size of DF ulcer ranged from 2.5 cm×2.0 cm to 3.5 cm×3.0 cm. The skin temperature of affected foot, ABI, VAS score, and skin wound healing of the affected foot were recorded and compared between before operation and at 3 months after operation. ResultsAll patients were followed up 3-18 months, with an average of 10.5 months. The infection of 1 patient with Wagner grade 4 did not improve significantly after operation, and there was a trend of further deterioration, and the amputation of the left leg was finally performed at 22 days after operation.The remaining 21 patients recovered well after operation, the external fixator was removed at 1 month after operation, the wound healed at 3 months after operation, and there was no recurrence of ulcer in situ or other sites during follow-up. At 3 months after operation, the skin temperature of affected foot was (31.76±0.34)°C, the ABI was 0.94±0.08, and the VAS score was 2.1±0.3, which significantly improved when compared with those before operation (t=25.060, P<0.001; t=32.412, P<0.001; t=–51.746, P<0.001). ConclusionModified tibial transverse bone transport technique combined with vancomycin calcium phosphate bone cement local filling and covering for DF patients can effectively improve the blood supply of the affected limb, promote wound healing, and improve effectiveness.