Icariin（ICA） is one of the main active ingredients in the Berberidaceae family Epimedium. It makes a variety of biological activities, such as promoting bone formation, antibacterial and anti-inflammatory, and regulating immunity. Periodontitis is a chronic inflammatory disease that is present in the soft and hard tissues of the periodontium. The ultimate goals of its treatment are the reconstruction of periodontal tissues and bone defect repairing. At present, conventional treatment of periodontitis fails to achieve the ideal periodontal tissue regeneration. In recent years, the rapid development of tissue engineering technology has brought new ideas for the treatment of periodontal disease and bone defect repairing. Because of its anti-inflammatory and osteogenic effects, ICA has great potential for the treatments of periodontitis and bone defect repairing. This paper summarizes the effect and the molecular mechanism of ICA in the treatment of periodontitis and bone defect repairing, and discusses its application prospect as a drug for periodontal adjuvant therapy. This paper aims to provide a theoretical basis for the research and application of ICA in periodontitis treatment and bone defect repairing.
ObjectiveTo investigate the feasibility of tissue engineered periosteum (TEP) constructed by porcine small intestinal submucosa (SIS) and bone marrow mesenchymal stem cells (BMSCs) of rabbit to repair the large irregular bone defects in allogenic rabbits. MethodsThe BMSCs were cultivated from the bone marrow of New Zealand white rabbits (aged, 2 weeks-1 month). SIS was fabricated by porcine proximal jejunum. The TEP constructed by SIS scaffold and BMSCs was prepared in vitro. Eighteen 6-month-old New Zealand white rabbits whose scapula was incompletely resected to establish one side large irregular bone defects (3 cm×3 cm) model. The bone defects were repaired with TEP (experimental group,n=9) and SIS (control group,n=9), respectively. At 8 weeks after operation, the rabbits were sacrificed, and the implants were harvested. The general condition of the rabbits was observed; X-ray radiography and score according to Lane-Sandhu criteria, and histological examination (HE staining and Masson staining) were performed. ResultsAfter operation, all animals had normal behavior and diet; the incision healed normally. The X-ray results showed new bone formation with normal bone density in the defect area of experimental group; but no bone formation was observed in control group. The X-ray score was 6.67±0.32 in experimental group and was 0.32±0.04 in control group, showing significant difference (t=19.871,P=0.001). The general observation of the specimens showed bone healing at both ends of the defect, and the defect was filled by new bone in experimental group; no new bone formed in the control group. The histological staining showed new bone tissue where there were a lot of new vessels and medullary cavity, and no macrophages or lymphocytes infiltration was observed in the defect area of experimental group; only some connective tissue was found in the control group. ConclusionTEP constructed by porcine SIS and BMSCs of rabbit can form new bone in allogenic rabbit and has the feasibility to repair the large irregular bone defects.
ObjectiveTo review the methods of improving the mechanical properties of hydrogels and the research progress in bone tissue engineering. MethodsThe recent domestic and foreign literature on hydrogels in bone tissue engineering was reviewed, and the methods of improving the mechanical properties of hydrogels and the effect of bone repair in vivo and in vitro were summarized. ResultsHydrogels are widely used in bone tissue engineering, but their mechanical properties are poor. Improving the mechanical properties of hydrogels can enhance bone repair. The methods of improving the mechanical properties of hydrogels include the construction of dual network structures, inorganic nanoparticle composites, introduction of conductive materials, and fiber network reinforcement. These methods can improve the mechanical properties of hydrogels to various degrees while also demonstrating a significant bone repair impact. ConclusionThe mechanical properties of hydrogels can be effectively improved by modifying the system, components, and fiber structure, and bone repair can be effectively promoted.
Objective To explore the effect of short-term low-frequency electrical stimulation (SLES) during operation on nerve regeneration in delayed peripheral nerve injury with long gap. Methods Thirty female adult Sprague Dawley rats, weighing 160-180 g, were used to prepare 13-mm defect model by trimming the nerve stumps. Then all rats were randomly divided into 2 groups, 15 rats in each group. After nerve defect was bridged by the contralateral normal sciatic nerve, SLES was applied in the experimental group, but was not in the control group. The spinal cords and dorsal root ganglions (DRGs) were harvested to carry out immunofluorescence histochemistry double staining for growth-associated proteins 43 (GAP-43) and brain-derived neurotrophic factor (BDNF) at 1, 2, and 7 days after repair. Fluorogold (FG) retrograde tracing was performed at 3 months after repair. The mid-portion regenerated segments were harvested to perform Meyer’s trichrome staining, immunofluorescence double staining for neurofilament (NF) and soluble protein 100 (S-100) on the transversely or longitudinal sections at 3 months after repair. The segment of the distal sciatic nerve trunk was harvested for electron microscopy and morphometric analyses to measure the diameter of the myelinated axons, thickness of myelin sheaths, the G ratio, and the density of the myelinated nerve fibers. The gastrocnemius muscles of the operated sides were harvested to measure the relative wet weight ratios. Karnovsky-Root cholinesterase staining of the motor endplate was carried out. Results In the experimental group, the expressions of GAP-43 and BDNF were higher than those in the control group at 1 and 2 days after repair. The number of labeled neurons in the anterior horn of gray matter in the spinal cord and DRGs at the operated side from the experimental group was more than that from the control group. Meyer’s trichrome staining, immunofluorescence double staining, and the electron microscopy observation showed that the regenerated nerves were observed to develop better in the experimental group than the control group. The relative wet weight ratio of experimental group was significantly higher than that of the control group (t=4.633,P=0.000). The size and the shape of the motor endplates in the experimental group were better than those in the control group. Conclusion SLES can promote the regeneration ability of the short-term (1 month) delayed nerve injury with long gap to a certain extent.
Objective To explore the application effect of 3D printed heart models in the training of young cardiac surgeons, and evaluate their application value in surgical simulation and skill improvement. MethodsEight young cardiac surgeons were selected form West China Hospital as the trainees. Before training, the Hands-On Surgical Training-Congenital Heart Surgery (HOST-CHS) operation scores of the 8 cardiac surgeons were obtained after operating on 2 pig heart models of ventricular septal defect (VSD). Subsequently, simulation training was conducted on a 3D printed peri-membrane VSD heart model for 6 weeks, once a week. After the training, all trainees completed 2 pig heart VSD repair surgeries. The improvement of doctors’ skills was evaluated through survey questionnaires, HOST-CHS scores, and operation time after training. ResultsBefore the training, the average HOST-CHS score of the 8 trainees was 52.2±6.3 points, and the average time for VSD repair was 54.7±7.1 min. During the 6-week simulation training using 3D printed models, the total score of HOST-CHS for the 8 trainees gradually increased (P<0.001), and the time required to complete VSD repair was shortened (P<0.001). The trainees had the most significant improvement in scores of surgical cognition and protective awareness. The survey results showed that trainees were generally very satisfied with the effectiveness of 3D model simulation training. Conclusion The 3D printed VSD model demonstrates significant application advantages in the training of young cardiac surgeons. By providing highly realistic anatomical structures, 3D models can effectively enhance surgeons’ surgical skills. It is suggested to further promote the application of 3D printing technology in medical education, providing strong support for cultivating high-quality cardiac surgeons.
Aiming at the problem of scaffold degradation in bone tissue engineering, we studied the feasibility that controlls bone defect repair effect with the inhomogeneous structure of scaffold. The prediction model of bone defect repair which contains governing equations for bone formation and scaffold degradation was constructed on the basis of analyzing the process and main influence factors of bone repair in bone tissue engineering. The process of bone defect repair and bone structure after repairing can be predicted by combining the model with finite element method (FEM). Bone defect repair effects with homogenous and inhomogeneous scaffold were simulated respectively by using the above method. The simulation results illustrated that repair effect could be impacted by scaffold structure obviously and it can also be controlled via the inhomogeneous structure of scaffold with some feasibility.
Objective To construct a new type of self-assembling peptide nanofiber scaffolds—RGDmx, and to study the cell compatibility of the new scaffolds and the proliferation and chondrogenic differentiation of precartilaginous stem cells(PSCs) in scaffolds. Methods PSCs were separated and purified from newborn Sprague Dawley rats by magnetic activated cell sorting and indentified by immunohistochemistry and immunofluorescent staining. The RGDmx were constructed by mixing KLD-12 and KLD-12-PRG at volume ratio of 1 ∶ 1. PSCs at passage 3 were seeded into the KLD-12 scaffold (control group) and RGDmx scaffold (experimental group). The proliferation of PSCs in 2 groups were observed with the method of cell counting kit (CCK) -8 after 1, 3, 7, and 14 days after culture. The RGDmx were constructed by mixing KLD-12-PRG and KLD-12 at different volume ratios of 0, 20%, 40%, 60%, 80%, and 100% and the prol iferation of PSCs was also observed. The complete chondrogenic medium (CCM) was used to induce chondrogenic differentiation of PSCs in different scaffolds. The differentiation of PSCs was observed by toluidine blue staining and RT-PCR assay. Results PSCs were separated and purified successfully, which were identified by immunohistochemistry and immunofluorescent staining methods. The results of CCK-8 showed that the absorbance (A) value in the experimental group increased gradually and reached the highest at 7 days; the A value in the experimental group was significantly higher than that in the control group at 7 days and 14 days (P lt; 0.05). Meanwhile, the A value in the RGDmx scaffold with a volume ratio of 40% was significantly higher than those in others (P lt; 0.05). After 14 days of induction culture with CCM, the toluidine blue staining results were positive in 2 groups; the results of RT-PCR showedthat the expression levels of collagen type II and the aggrecan in the experimental group were significantly higher than those in the control group (P lt; 0.05). Conclusion The self-assembling peptide nanofiber scaffold—RGDmx is an ideal scaffold for tissue engineer because it has good cell compatibility and more effective properties of promoting the differentiation of PSCs to chondrocytes.
Objective To investigate the effect of simvastatin on inducing endothel ial progenitor cells (EPCs) homing and promoting bone defect repair, and to explore the mechanism of local implanting simvastatin in promoting bone formation. Methods Simvastatin (50 mg) compounded with polylactic acid (PLA, 200 mg) or only PLA (200 mg) was dissolved in acetone (1 mL) to prepare implanted materials (Simvastatin-PLA material, PLA material). EPCs were harvested from bone marrow of 2 male rabbits and cultured with M199; after identified by immunohistochemistry, the cell suspension of EPCs at the 3rd generation (2 × 106 cells/mL) was prepared and transplanted into 12 female rabbits through auricular veins(2 mL). After 3 days, the models of cranial defect with 15 cm diameter were made in the 12 female rabbits. And the defects were repaired with Simvastatin-PLA materials (experimental group, n=6) and PLA materials (control group, n=6), respectively. The bone repair was observed after 8 weeks of operation by gross appearance, X-ray film, and histology; gelatin-ink perfusion and HE staining were used to show the new vessels formation in the defect. Fluorescence in situ hybridization (FISH) was performed to show the EPCs homing at the defect site. Results All experimental animals of 2 groups survived to the end of the experiment. After 8 weeks in experimental group, new bone formation was observed in the bone defect by gross and histology, and an irregular, hyperdense shadow by X-ray film; no similar changes were observed in control group. FISH showed that the male EPC containing Y chromosome was found in the wall of new vessels in the defect of experimental group, while no male EPC containing Y chromosome was found in control group. The percentage of new bone formation in defect area was 91.63% ± 4.07% in experimental group and 59.45% ± 5.43% in control group, showing significant difference (P lt; 0.05). Conclusion Simvastatin can promote bone defect repair, and its mechanism is probably associated with inducing EPCs homing and enhancing vasculogenesis.
Objective To discuss the role of heparan sulfate (HS) in bone formation and bone remodeling and summarize the research progress in the osteogenic mechanism of HS. Methods The domestic and abroad related literature about HS acting on osteoblast cell line in vitro, HS and HS composite scaffold materials acting on the ani-mal bone defect models, and the effect of HS proteoglycans on bone development were summarized and analyzed. Results Many growth factors involved in fracture healing especially heparin-binding growth factors, such as fibroblast growth factors, bone morphogenetic protein, and transforming growth factor β, are connected noncovalently with long HS chains. HS proteoglycans protect these proteins from protease degradation and are directly involved in the regulation of growth factors signaling and bone cell function. HS can promote the differentiation of stem cells into osteoblasts and enhance the differentiation of osteoblasts. In bone matrix, HS plays a significant role in promoting the formation, maintaining the stability, and accelerating the mineralization. Conclusion The osteogenesis of HS is pronounced. HS is likely to become the clinical treatment measures of fracture nonunion or delayed union, and is expected to provide more choices for bone tissue engineering with identification of its long-term safety.
ObjectiveTo observe the short-term therapeutic outcomes of atrial septal defects (ASD) repair using on-pump beating-heart technique assisted by robotic surgery system (Da Vinci Si) or thoracoscopy.MethodsClinical data of 50 patients undergoing ASD repair at the First Affiliated Hospital of Anhui Medical University from January 2015 to December 2018 were retrospectively analyzed. According to the different surgical methods, patients were divided into a robot group and a total thoracoscopy group. In the robot group, there were 35 patients including 11 males and 24 females, at an average age of 42.1±16.8 years, and in the total thoracoscopy group there were 15 patients including 8 males and 7 females at an average age of 38.4±10.9 years. During follow-up, the left ventricular ejection fraction, left and right atrial diameter, and right ventricular end-diastolic diameter in the cardiac Doppler echocardiography were recorded. The operation time, extracorporeal circulation time, ventilation time, postoperative ICU stay, postoperative hospital stay, perioperative pleural drainage and early complications were compared between the two groups.ResultsIn the perioperative period, the robot group had less operation time (3.8±0.3 h vs. 6.1±1.4 h), extracorporeal circulation time (72.3 ± 10.4 min vs. 139.1 ± 32.8 min), ventilation time (5.5±1.2 h vs. 9.5 ± 2.1 h), postoperative hospital stay (6.7±0.5 d vs. 9.8 ± 0.6 d) and thoracic drainage (253.4±26.8 mL vs. 289.3 ± 29.5 mL) than the total thoracoscopy group (P<0.05), while the postoperative complications were not statistically significant between the two groups (P>0.05). All patients were reviewed by color Doppler ultrasound at 1 month after operation. The postoperative dilated right atrium, right ventricle and left atrium were smaller than those before surgery.ConclusionFor patients undergoing ASD repair, robot-assisted and total thoracoscopy can achieve good results, but the robot group has more advantages in terms of operation time, extracorporeal circulation time, ventilation time, postoperative hospital stay and thoracic drainage.