In vivo bioluminescence imaging of magnetically targeted bone marrow‐derived mesenchymal stem cells in skeletal muscle injury model

The purpose of this study is to clarify the kinetics of transplanted mesenchymal stem cells (MSCs) in rat skeletal muscle injury model and the contribution of the magnetic cell delivery system to muscle injury repair. A magnetic field generator was used to apply an external magnetic force to the injury site of the tibia anterior muscle, and 1 × 10⁶ MSCs labeled with ferucarbotran–protamine complexes, which were isolated from luciferase transgenic rats, were injected into the injury site. MSCs were injected with and without an external magnetic force (MSC M+ and MSC M? groups, respectively), and phosphate‐buffered saline was injected into injury sites as a control. In vivo bioluminescence imaging was performed immediately after the transplantation and, at 12, 24, and 72 h, and 1 and 4 weeks post‐transplantation. Also, muscle regeneration and function were histologically and electromechanically evaluated. In vivo bioluminescence imaging showed that the photon of the MSC M+ group was significantly higher than that of the MSC M? group throughout the observation period. In addition, muscle regeneration and function in the MSC M+ group was histologically and functionally better than that of the MSC M? group. The results of our study indicated that magnetic cell delivery system may be of use in directing the transplanted MSCs to the injury site to promote skeletal muscle regeneration. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 754–759, 2013     

Gene delivery system of pDNA using the blood glycoprotein fetuin

Fetuin is a biocompatible plasma protein and strongly enhances phagocytosis of bacteria, DNA and apoptotic cells by peripheral blood cells such as monocytes, macrophages and dendritic cells. We developed a novel gene delivery system: ternary complexes constructed with pDNA, polyethylenimine (PEI) and fetuin. Without covalent binding, fetuin was able to coat pDNA–PEI complexes, and stable anionic nanoparticles formed at a weight ratio greater than 30. Optimised pDNA–PEI–fetuin complexes significantly decreased the cytotoxicity of pDNA–PEI complexes in the melanoma cell line B16F10. Furthermore, the pDNA–PEI–fetuin complexes had higher transgene efficiency compared to that of commercial lipofectin previously reported in B16F10 cells despite an anionic surface. The pDNA–PEI–fetuin complexes did not agglutinate with erythrocytes. The pDNA–PEI–fetuin complexes had high gene expression in the spleen after intravenous administration in mice. Thus, the pDNA–PEI–fetuin complexes were a useful in vivo gene delivery system with tropism for the spleen.     

Acceptable parameters for alignment of distal radius fracture with conservative treatment in elderly patients

BackgroundThere is a conflict in the treatment of distal radius fractures in elderly patients, because fracture reduction does not appear to be as strongly associated with functional outcomes as in younger patients. The purpose of this study was to evaluate radiographic findings of acceptable reduction without leading to wrist dysfunction and poor outcomes.MethodsFifty-two active and healthy elderly patients with conservatively managed distal radius fractures were included in the study. They consisted of 7 men and 45 women, all 60 years or older. Radiographic assessment included volar tilt, radial inclination and ulnar variance, and outcome evaluation included the Mayo wrist score and DASH score. As a control group, the preoperative radiographic and clinical outcomes were examined as well for 19 patients older than 60 with malunion, for whom corrective osteotomy was performed because of wrist dysfunction. The radiographic parameters and clinical outcomes were compared between the two groups in a statistical manner. Correlation coefficients of the radiographic parameters with Mayo wrist score and DASH score were analyzed by multiple regression.ResultsVolar tilt (mean —1.2°) and ulnar variance (mean 2.5 mm), as well as Mayo wrist score (mean 80.0 points) and DASH score (mean 8.6 points) in the objective group were significantly superior to those in the control group when comparing radiographic parameters and clinical outcomes. There was no significant difference between the two groups in regard to RI (mean 14.9°). Multiple regression analysis revealed that volar tilt and ulnar variance were significantly correlated with the clinical outcomes in the objective.ConclusionThe parameters of volar tilt and ulnar variance had a significant correlation with clinical outcomes. Clinical outcomes significantly worsened when those parameters exceeded a tolerable range. In elderly patients, it is important to determine an appropriate therapeutic modality for a distal radius fracture when considering the acceptable parameters for alignment.     

Optimization of secondary drying condition for desired residual water content in a lyophilized product using a novel simulation program for pharmaceutical lyophilization

The aim of this study was to optimize the shelf temperature and the drying time, mainly dependent on the residual water content of a lyophilized product using a novel simulation program for the secondary drying of lyophilization. The simulation program was developed based upon heat transfer formulas, two empirical formulas, and a modified Fick’s second law. When a preliminary lyophilization run of secondary drying was carried out, the equilibrium product temperature at the end of secondary drying under various shelf temperatures was accurately predicted by the heat transfer formulas. The apparent diffusion coefficient of water, D_eff, and the apparent equilibrium residual water content, W_e, under the predicted equilibrium product temperature were estimated by two empirical formulas. These estimated D_eff and W_e allow the modified Fick’s second law to predict the residual water content in the lyophilized product. Using the developed simulation program, it was verified that the secondary drying condition to achieve the desired residual water content in the lyophilized product was successfully predicted. Therefore, the simulation program can be used to effectively design the secondary drying condition of lyophilization cycles without a trial and error approach.