Peng He

The effects of 4-phenylbutyrate (4-PBA) on particle-induced macrophage apoptosis in vitro have not been previously documented. This study aims to investigate the thera-peutic potential of 4-PBA in alleviating titanium nanoparticle (TiNP)-induced in-flammatory injury mediated by macrophages. Our findings demonstrate that TiNPs exhibit specific properties capable of inciting inflammatory injury to macrophages. Furthermore, the extent of inflammatory injury inflicted by TiNPs on macrophages progressively increases in correlation with both the concentration of particles and du-ration of exposure. Exposure to TiNPs significantly reduces macrophage viability, promotes apoptosis, enhances the expression of inflammatory cytokines, and exacer-bates the production of reactive oxygen species (ROS). Co-treatment with 4-PBA sig-nificantly alleviates the severity of particle-induced inflammatory injury while simul-taneously facilitating apoptosis in stressed macrophages. Pharmacological intervention with 4-PBA facilitates TiNP-induced macrophage apoptosis by increasing the expres-sion of pro-apoptotic proteins such as Caspase-3 and Bax, while decreasing the levels of anti-apoptotic protein Bcl-2. When used as an independent treatment, 4-PBA does not provoke a pronounced inflammatory response nor induce significant changes in mac-rophage apoptosis, underscoring its potential as a safe therapeutic option. These find-ings substantiate the hypothesis that employing a specific approach to facilitate mac-rophage apoptosis could serve as an effective therapeutic strategy for managing aseptic loosening. Significantly, this approach demonstrates a favorable safety profile, posi-tioning it as a promising avenue for future clinical applications in this domain.

A novel H-shaped miniplate (HSM) was specifically designed for restorative laminoplasties to restore patients’ posterior elements after laminectomies. A validated finite element (FE) model of L2/4 was utilized to create a laminectomy model, as well as three restorative laminoplasty models based on the fixation of different miniplates after a laminectomy (the RL-HSM model, the RL-LSM model, and the RL-THM model). The biomechanical effects of motion and displacement on a laminectomy and restorative laminoplasty with three different shapes for the fixation of miniplates were compared under the same mechanical conditions. This study aimed to validate the biomechanical stability, efficacy, and feasibility of a restorative laminoplasty with the fixation of miniplates post laminectomy. The laminectomy model demonstrated the greatest increase in motion and displacement, especially in axial rotation, followed by extension, flexion, and lateral bending. The restorative laminoplasty was exceptional in preserving the motion and displacement of surgical segments when compared to the intact state. This preservation was particularly evident in lateral bending and flexion/extension, with a slight maintenance efficacy observed in axial rotation. Compared to the laminectomy model, the restorative laminoplasties with the investigated miniplates demonstrated a motion-limiting effect for all directions and resulted in excellent stability levels under axial rotation and flexion/extension. The greatest reduction in motion and displacement was observed in the RL-HSM model, followed by the RL-LSM model and then the RL-THM model. When comparing the fixation of different miniplates in restorative laminoplasties, the HSMs were found to be superior to the LSMs and THMs in maintaining postoperative stability, particularly in axial rotation. The evidence suggests that a restorative laminoplasty with the fixation of miniplates is more effective than a conventional laminectomy due to the biomechanical effects of restoring posterior elements, which helps patients regain motion and limit load displacement responses in the spine after surgery, especially in axial rotation and flexion/extension. Additionally, our evaluation in this research study could benefit from further research and provide a methodological and modeling basis for the design and optimization of restorative laminoplasties.

To explore the effect of different functional groups on self-assembled monolayers on the biological characteristics of rabbit skeletal muscle cells in vitro. Rabbit skeletal muscle cells were cultured on self-assembled monolayers of gold on which different terminal chemical groups including methyl groups (-CH(3)), amino(-NH(2)), hydroxyl(-OH) and carboxyl (-COOH ) were anchored with self-assembled methods. Contact angle measurements and atomic force microscopy were employed to confirm the similar density of different functional groups occupation. Fluorescence microscopy, MTT assay, flow cytometry, and scanning electron microscopy (SEM) were used to analyze the morphological and biological alterations of the cells. SEM results revealed that the chemical groups on the surface of the monolayer modulated the structure of skeletal muscle cells and the cell morphology. Skeletal muscle cells cultured on the monolayer with -CH3 exhibited the smallest contact area with a spherical morphology, while the cells on the monolayers with -NH(2), -OH and -COOH showed much larger contact area and flatter morphology. The functional groups -NH(2) and -COOH obviously promoted cell adhesion and proliferation, while -CH(3) group produced significantly greater toxicity than -NH(2), -OH and -COOH groups to inhibit the cell growth and adhesion and promote cell death. Cell attachment and growth was enhanced, in the order the magnitude of the effect, by -NH(2)>-COOH>-OH>-CH(3), and the toxicity decreased in the order of -NH(2)>-COOH>-OH>-CH(3). The terminal chemical groups can obviously affect the phenotype of skeletal muscle cells in vitro, and this finding provides a theoretical basis for surface design of biomaterials.