Activating the healing process: three-dimensional culture of stem cells in Matrigel for tissue repair.

BACKGROUND: To establish a strategy for stem cell-related tissue regeneration therapy, human gingival mesenchymal stem cells (hGMSCs) were loaded with three-dimensional (3D) bioengineered Matrigel matrix scaffolds in high-cell density microtissues to promote local tissue restoration. METHODS: The biological performance and stemness of hGMSCs under 3D culture conditions were investigated by viability and multidirectional differentiation analyses. A Sprague‒Dawley (SD) rat full-thickness buccal mucosa wound model was established, and hGMSCs/Matrigel were injected into the submucosa of the wound. Autologous stem cell proliferation and wound repair in local tissue were assessed by histomorphometry and immunohistochemical staining. RESULTS: Three-dimensional suspension culture can provide a more natural environment for extensions and contacts between hGMSCs, and the viability and adipogenic differentiation capacity of hGMSCs were significantly enhanced. An animal study showed that hGMSCs/Matrigel significantly accelerated soft tissue repair by promoting autologous stem cell proliferation and enhancing the generation of collagen fibers in local tissue. CONCLUSION: Three-dimensional cell culture with hydrogel scaffolds, such as Matrigel, can effectively improve the biological function and maintain the stemness of stem cells. The therapeutic efficacy of hGMSCs/Matrigel was confirmed, as these cells could effectively stimulate soft tissue repair to promote the healing process by activating the host microenvironment and autologous stem cells.

Synergistic effects of graphene microgrooves and electrical stimulation on M2 macrophage polarization.

Macrophages play a crucial role in host response and wound healing, with M2 polarization contributing to the reduction of foreign-body reactions induced by the implantation of biomaterials and promoting tissue regeneration. Electrical stimulation (ES) and micropatterned substrates have a significant impact on the macrophage polarization. However, there is currently a lack of well-established cell culture platforms for studying the synergistic effects of these two factors. In this study, we prepared a graphene free-standing substrate with 20 µm microgrooves using capillary forces induced by water evaporation. Subsequently, we established an ES cell culture platform for macrophage cultivation by integrating a self-designed multi-well chamber cell culture device. We observed that graphene microgrooves, in combination with ES, significantly reduce cell spreading area and circularity. Results from immunofluorescence, ELISA, and flow cytometry demonstrate that the synergistic effect of graphene microgrooves and ES effectively promotes macrophage M2 phenotypic polarization. Finally, RNA sequencing results reveal that the synergistic effects of ES and graphene microgrooves inhibit the macrophage actin polymerization and the downstream PI3K signaling pathway, thereby influencing the phenotypic transition. Our results demonstrate the potential of graphene-based microgrooves and ES to synergistically modulate macrophage polarization, offering promising applications in regenerative medicine.

Big Data Value Calculation Method Based on Particle Swarm Optimization Algorithm.

SI is a relatively recent technology that was inspired by observations of natural social insects and artificial systems. This system comprises multiple individual agents who rely on collective behavior in decentralized and self-organized networks. One of the biggest difficulties for existing computer techniques is learning from such large datasets, which is addressed utilizing big data. Big data-based categorization refers to the challenge of determining which set of classifications a new discovery belongs to. This classification is based on a training set of data that comprises observations that have been assigned to a certain category. In this paper, CIN-big data value calculation based on particle swarm optimization (BD-PSO) algorithm is proposed by operating in local optima and to improve the operating efficiency. The convergence speed of the particle swarm optimization (PSO), which operates in the local optima, is improved by big data-based particle swarm optimization (BD-PSO). It improves computing efficiency by improving the method, resulting in a reduction in calculation time. The performance of the BD-PSO is tested on four benchmark dataset, which is taken from the UCI. The datasets used for evaluation are wine, iris, blood transfusion, and zoo. SVM and CG-CNB are the two existing methods used for the comparison of BD-PSO. It achieves 92% of accuracy, 92% of precision, 92% of recall, and 1.34 of F1 measure, and time taken for execution is 149 ms, which in turn outperforms the existing approaches. It achieves robust solutions and identifies appropriate intelligent technique related to the optimization problem.

Changes of the condylar cartilage and subchondral bone in the temporomandibular joints of rats under unilateral mastication and expression of Insulin-like Growth Factor-1.

OBJECTIVES: This study aimed to define changes in the rat condylar cartilage and subchondral bone using the unilateral mastication model. MATERIALS AND METHODS: In this study, forty 4-week-old Wistar rats were randomly divided into experimental (n = 20) and control group (n = 20). In the experimental group, unilateral dental splints were placed on the occlusal surface of left maxillary molars. The rats were sacrificed at 1, 2, 3, and 4 weeks after placement of the splint. Micro-CT scanning and histological staining were performed to observe the changes in the mandibular condylar cartilage and subchondral bone. Levels of insulin-like growth factor-1 (IGF-1) were determined via immunohistochemistry to analyse the occurrence of osteogenic changes. RESULTS: Micro-CT scanning findings demonstrated the occurrence of asymmetric growth of condyle in the experimental group. The condylar cartilage and subchondral bone exhibited degradation on the chewing side of the experimental group and showed decreased bone mineral density, thinner cartilage thickness, and increased degree of degeneration and osteoclast activity. Compared with the control group, the expression of IGF-1 was remarkably higher on the non-chewing side. CONCLUSION: Long-term unilateral mastication can lead to the occurrence of degenerative changes in the condylar cartilage and subchondral bone during growth and development. IGF-1 may play a role in promoting the process of osteogenesis.

The Effectiveness of Photobiomodulation on Accelerating Tooth Movement in Orthodontics: A Systematic Review and Meta-Analysis.

Objective: This meta-analysis evaluated the effectiveness of photobiomodulation therapy (PBMT) on accelerating orthodontic tooth movement (OTM) in clinical practice. Methods: Data from bilingual journals across seven different databases were compiled and analyzed. Randomized controlled trials (RCTs) and quasi-RCTs regarding the effect of PBMT on OTM in cases with four first premolar extractions in split-mouth design were selected. This study was conducted after approval from the IRB. The outcome variables were the cumulative tooth movement distances in 1, 2, and 3 months. Data extraction was performed by two authors independently and in duplicate. Risk of bias was assessed. Results: Eight RCTs and one quasi-RCT were ultimately included and analyzed in meta-analysis. This study revealed that the pooled mean difference (MD) among these trials was 0.30 [95% confidence interval (CI): -0.02 to 0.62], 0.69 (95% CI: 0.08 to 1.29), and 0.64 (95% CI: -0.01 to 1.29) for 1, 2, and 3 months, respectively. The results remained consistent after sensitivity analysis assessment. Conclusions: There is insufficient evidence to support that photobiomodulation accelerates tooth movement in orthodontic treatments. Our results suggest that the optimal parameters of PBMT on OTM in human might be about 20 mW, 5-8 J/cm2, 0.5 W/cm2, 0.2 J/point, and 2-10 J/tooth. More large-sample multicenter clinical trials carried out in similar settings are required to confirm and pinpoint treatment efficiency and optimal parameters. Registration: The review protocol was not registered prior to the study.

A Comparative Study on Functional Recovery, Complications, and Changes in Inflammatory Factors in Patients with Thoracolumbar Spinal Fracture Complicated with Nerve Injury Treated by Anterior and Posterior Decompression.

BACKGROUND The aim of this study was to evaluate 2 methods to treat patients with thoracic lumbar spine fracture with merging spinal cord injury, including complications of surgery and the influence of inflammatory factors. MATERIAL AND METHODS Eighty patients were randomly divided into an anterior decompression group (study group) or a posterior decompression group (control group) to observe perioperative complications, evaluate preoperative and postoperative nerve function, and evaluate the 6-month injured vertebral height and Cobb angle of the vertebral bodies. The expression level of TGF-ß2 on day 1, day 7, day 15, and day 30 after treatment was detected by enzyme-linked immunosorbent assay (ELISA). RESULTS The nerve function sensation score, the height of the vertebral body, and the recovery of Cobb angle were better for the anterior decompression group than the posterior decompression group and the effect was significant (P<0.05). The complication rate for the posterior decompression group was lower than the anterior decompression group. The level of TGF-ß2 in the anterior decompression group was higher than in the posterior decompression group for the same times: after day 1, day 7, day 15, and day 30 after treatment (P<0.05). CONCLUSIONS Patients who had thoracic lumbar spine fracture with merging spinal cord injury and who had anterior fixation achieved a good fixation effect; their neurologic and vertebral injury recovery was better. However, this relatively complex and traumatic surgery must consider the clinical manifestations and fractures of the patients and select the appropriate surgical approach.

Effects of a mandibular advancement device on genioglossus in obstructive sleep apnoea hypopnea syndrome.

OBJECTIVE: To investigate effects of mandibular advancement device (MAD) therapy for obstructive sleep apnoea hypopnea syndrome (OSAHS) on the genioglossus contractile properties and fibre-type distribution. MATERIALS AND METHODS: Thirty 6-month old male New Zealand white rabbits were randomised into three groups: OSAHS, MAD, and controls. Rabbits in Group OSAHS and Group MAD were established as OSAHS models by injection, at a dose of 2 ml hydrophilic polyacrylamide gel, via the submucous muscular layer of soft palate. Spiral computed tomography (CT) showed a significant reduced retropalatal upper airway, and apnoeas happened with an increase of Apnea Hypopnea Index (AHI) and a decrease of blood oxygen saturation during polysomnography (PSG), which indicated the OSAHS model developed successfully. OSAHS rabbits in Group MAD were fitted with a MAD made from self-curing composite resin, at 30 degrees to the upper incisors, and the mandible was guided forward 3 to 4mm. Further, spiral CT and PSG suggested MAD was effective. Rabbits in 3 groups were induced to sleep for 4-6 hours per day for 8 weeks, after which the genioglossus was removed, mounted in a tissue bath, and stimulated through platinum electrodes; maximal twitch tension, contraction time, half-relaxation time, force-frequency relationship, and fatigability were recorded. The percentage of Type I and Type II fibres was quantified. RESULTS: The fatigability and percentage of Type II fibres of genioglossus increased in Group OSAHS compared with controls; this abnormality was corrected by MAD. CONCLUSION: MAD therapy for OSAHS could prevent genioglossus fatigue and abnormal fibre-type distribution of genioglossus in OSAHS.