BACKGROUND: The choice and mixture ratio of composite materials for bone tissue engineering scaffolds have a great influence on the osteoinductivity of scaffolds.
BACKGROUND: High-viscosity bone cement is modified on the basis of traditional polymethylmethacrylate with the long injection time, high-viscosity and low polymerized temperature feature and further improves the safety of percutaneous vertebroplasty.
RESULTS AND CONCLUSION: (1) The recovery rate of anterior height of the vertebra and local kyphosis angle improvement rate in group A were better than those in group B at the last follow-up (P < 0.05). (2) The visual analog scale scores and Oswestry dysfunction index scores in both A and B groups were significantly improved at the last follow-up compared to the baseline data (P < 0.05), but there was no significant difference between the two groups (P > 0.05). (3) The subgroups of degree I and II showed no significant difference in the recovery rate of anterior height of the vertebra and local kyphosis angle improvement rate at the last follow-up (P > 0.05). (4) There were nine patients with bone cement leakage, four patients with postoperative fever, two patients with low blood pressure in group A and eight patients with bone cement leakage, six patients with postoperative fever, two patients with high blood pressure, one patient with superficial skin infection in group B, but there was no significant difference in the postoperative complications between the two groups (P > 0.05). All the results suggest that percutaneous vertebroplasty with high-viscosity bone cement has positive efficacy in treating elderly women with single-segmental osteoporotic vertebral compression fracture. The better dispersion of bone cement in the fractured vertebrae indicates the better clinical effects. However, high-viscosity bone cement should be injected in an appropriate amount, as excessive dispersion will increase the risk of leakage.
BACKGROUND: Hydroxyapatite (HA)/polylactic acid (PLA) composite has good biocompatibility and osteoinductivity, but few studies have evaluated the feasibility of this composite used as a skull repair material.
BACKGROUND: With the development of tissue engineering technology, the use of natural biological materials as scaffolds can accelerate the formation of new cartilage tissue and facilitate the repair of cartilage defects.
RESULTS AND CONCLUSION: (1) Hematoxylin-eosin staining: The defect was basically not repaired at 3 months after implantation in the control group, with a small amount of fibrous tissue filling, sag in the defect area, matrix staining and poor integration of the bilateral interface; at 6 months after implantation, the defect area in the control group was still mainly filled with fibrous tissues and contained a small amount of fibrous cartilage, and there was still a clear boundary between the new tissue and surrounding normal tissue. At 3 months after implantation, the defect area of the experimental group was smaller than that of the control group, and the new tissue was a complex of fibrocartilage and hyaline cartilage. At 6 months after implantation, the proportion of tissue hyaline cartilage in the defect area of the experimental group increased, and the surface was relatively smooth, similar to the surrounding normal cartilage tissue, and well integrated. Enlarged cartilage lacunae were visible and the cells are arranged in order. (2) Safranine O-Fast Green staining: At 3 months after implantation, the defect area of the control group was basically free of proteoglycan red stain, while the defect area of the experimental group showed obvious proteoglycan coloring. At 6 months after implantation, the amount of proteoglycan-stained new tissue in the experimental group was significantly higher than that in the control group, and the proportion of hyaline cartilage in the new tissue was higher in the experimental group, similar to that of surrounding normal cartilage. (3) Biomechanical analysis: Six months after implantation, the average Young’s modulus of the experimental group was significantly higher than that of the control group (P < 0.05). All the findings reveal that the use of cartilage extracellular matrix-derived microparticles can promote the repair of cartilage defects.
BACKGROUND: In the treatment of osteoporotic vertebral compression fractures with percutaneous kyphoplasty, the choice of filling material has become an important factor for the surgical outcome.
BACKGROUND: Our previous findings indicate that the chemical composition and mechanical properties of gold-platinum (Au-Pt) ceramic alloy have no changes after repeated casting.
BACKGROUND: Current concerns are on how to maximize the reservation of tooth tissues after root canal treatment and to ensure the strength of the tooth after repair.
RESULTS AND CONCLUSION: Under different loading conditions, in the post-core crown group, the stress was concentrated in the edge of restoration, the shoulder of the preparation, the neck of the residual dentin, and the middle part of post-core crown in the post-core crown group. In the inlay group, the stress was concentrated in the load point of the enamel, and was transferred along the tooth enamel to the tooth neck; the stress concentration area also included the gingival wall and undersurface and transition site corresponding to the inlays and preparations. In the onlay group, the stress concentration occurred at the contact between the onlay and the enamel, at the gingival wall and undersurface of the preparation, and at the transition site. The stress was also concentrated and distributed evenly in the corresponding pulp cavity of the onlay. To conclude, the onlays have applicability and superiority in the repair of large-area defects of the maxillary molars.
中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程
BACKGROUND: As an emerging technology, chairside rapid sintering only makes sure that individual zirconia can achieve perfect performance, but there is no report on whether it is applicable for the other zirconia ceramics.
RESULTS AND CONCLUSION: The density value of TT, ST and inCoris ZI after sintering was (5.966±0.001), (6.060±0.001), and (6.031±0.001) g/cm3, respectively, and there were significant differences between groups (P < 0.05). The Vickers hardness of TT, ST and inCoris ZI after sintering was (12.02±0.04), (12.90±0.05) and (12.54±0.09) GPa, respectively, and significant differences appeared between groups (P < 0.05). The fracture toughness of TT, ST, and inCoris ZI after sintering was (4.87±0.07), (6.17±0.10), and (6.42±0.08) MPa·m1/2,respectively, and there were significant differences between groups (P < 0.05). The biaxial bending strength of TT, ST, and inCoris ZI after sintering was (624.41±92.01), (966.01±58.86), and (1 154.83±49.79) MPa, respectively. The biaxial bending strength of TT was significantly lower than that of ST and inCoris ZI (P < 0.05), but there was no significant difference between ST and inCoris ZI (P > 0.05). Therefore, the mechanical properties of ST and inCoris ZI under chairside rapid sintering can meet the clinical requirements, while TT needs to meet proper clinical indications.
BACKGROUND: Dental porcelain alloys hold different levels of cytotoxicity, which can lead to cell apoptosis. However, the in vitro researches on dental ceramic alloy causing apoptosis are mainly conducted, in which the oral environment cannot be simulated well.
BACKGROUND: Preliminary studies have shown that β-tricalcium phosphate loaded with advanced platelet-rich fibrin can induce bone formation and promote bone repair, which is better than β-tricalcium phosphate or advanced platelet-rich fibrin alone.
RESULTS AND CONCLUSION: Micro-CT findings revealed that the amount of newly formed bone in each group was increased with time, which was significantly higher in the combined group than the other two groups at 4 and 12 weeks after implantation (P < 0.05). Results from the push-out test of implants showed that as time went on, the maximum push strength of each group was increased, which was significantly higher in the combined group than in the other two groups at 4 and 12 weeks after implantation (P < 0.05). In summary, the combined strength of the implant-bone interface of β-tricalcium phosphate loaded with advanced platelet-rich fibrin is superior to that of advanced platelet-rich fibrin or β-tricalcium phosphate.
BACKGROUND: Preliminary studies have confirmed that vancomycin sustained-release microspheres exert satisfactory therapeutic effect on chronic osteomyelitis in rabbits. Nano-hydroxyapatite/chitosan (nHA/CS) has good biocompatibility, degradability and osteogenic induction. Autologous red bone marrow can be used as a seed cell source combined with nHA/CS scaffold to repair rabbit tibia bone defects. Therefore, the combined effects of the three materials in the repair of rabbit chronic osteomyelitis bone defects need a further investigation.
RESULTS AND CONCLUSION: The nHA/CS scaffolds carrying vancomycin/PLGA sustained-release microspheres held good biomechanical properties and drug sustained release. At 3 months after implantation, X-ray revealed that the defect region in the groups A and B had no obvious improvement, and there were still bone destruction and periosteal reaction. The group C showed the formation of the new bone, the defect area was slightly blurred, but the defect still existed. In the group D, new bone formed, the defect area became blurred, the density was slightly high, and the periosteum reaction disappeared. Hematoxylin-eosin staining showed the bone trabecular disorder and more damage in the groups A and B. The bone trabecula was neatly arranged and less damaged in the groups C and D, and especially the group D had thickened bone trabecula arranged regularly. These results indicate that nHA/CS scaffolds carrying vancomycin/PLGA sustained-release microspheres combined with autologous red bone marrow exhibit good outcomes in repairing the bone defect due to chronic osteomyelitis in rabbits.
BACKGROUND: After artificial joint replacement, daily activities lead to the production of a large number of titanium 6 aluminium 4 vanadium (Ti6Al4V), polymethylmethacrylate (PMMA), ultra-high-molecular-weight-polyethylene (UHMWPE) and chromium-cobalt alloy (Co-Cr) particles, activating monocytes to release a large number of inflammatory cytokines and chemokines, including a series of biological cascade reactions, such as inducing bone dissolution and forming pseudo-granuloma, and eventually leading to aseptic loosening of the prosthesis.
BACKGROUND: A proper scaffold is the basis for construction of tissue-engineered small diameter blood vessels. Preliminary study has shown non-ionic detergents with limited effects of decellularization, and combined application of ionic detergents exhibits more effective decellularization.
RESULTS AND CONCLUSION: Hematoxylin-eosin staining and Movat’s staining revealed that the cellular components were completely removed in the groups B and C; however, cellular residues were visualized in the groups D and E. Under the scanning electron microscope collagen and elastin fiber bundles were well preserved in the decellularization groups; however, the morphology and size of porous structure in the group B were superior to those in the groups C, D and E. Immunohistochemistry staining showed that the xenogeneic antigen, α-1,3-Gal, expressed in the decellularization groups; however, the expression of α-1,3-Gal was lower in the group B than the other groups. Biomechanical test indicated that burst pressure, suture-holding capacity and suture-holding strength were significantly decreased in the decellularization groups compared with group A (P < 0.05). However, there was no significant difference in the compliance, longitudinal elongation at brake, circumferential ultimate tensile stress, circumferential elongation at break and circumferential Young’s modulus compared with control group (P > 0.05). Decellularization caused a significant decrease in the longitudinal ultimate tensile stress and longitudinal Young’s modulus in the decellularization groups (P < 0.05). Furthermore, the longitudinal ultimate tensile stress and longitudinal Young’s modulus in the groups B and C were significantly lower than those in the groups D and E (P < 0.05). Our results suggest that the novel decellularization method based on 1% sodium dodecyl sulfate and 1% sodium deoxycholate optimizes the extracellular matrix scaffold for the construction of tissue-engineered small-diameter blood vessel.
BACKGROUND: Recombinant collagen has good hydrophilicity and biocompatibility, but it has the disadvantages of strong solubility and low mechanical strength. Chemical crosslinking can significantly improve the toughness, mechanical strength and degradation resistance of the material.
BACKGROUND: Previous studies have shown that fibrinogen can serve as tissue engineering scaffold material. Therefore, the reuse of fibrinogen in the autologous blood can make the scaffold material which has non-immunogenicity and good biocompatibility.
RESULTS AND CONCLUSION: (1) Under the scanning electron microscope, fiber structure with uneven fiber thickness was observed, and a lot of droplet-like structures were also visible in the group A; the ordered multi-layer fiber structure with similar fiber diameter and pore size was observed in the group B, and only a small amount of droplet-like structures were detected; in the group C, there was no fiber structure, but the droplet-like structures of different sizes. (2) The contact angle of the scaffold material was (82±3)o in the group A, (67±5)o in the group B, and (80±3)o in the group C. (3) After 7 days of co-culture, the bone marrow mesenchymal stem cells adhered to the scaffold materials in the three groups. The cells on the surface of group B were evenly distributed, which were adherent to the fiber surface and had relative regular nuclei. Only a small amount of cells grew onto the scaffolds in the groups A and C, especially in the group C, in which the cells had irregular nuclei and no fiber structure was observed. (4) The cells in the group B exhibited an increasing proliferation tendency as shown by the results of Alamar Blue experiment, and the cell growth was in good status. All these findings indicate that it is feasible to prepare the blood fibrinogen biofilm with good biocompatibility using the electrospinning technology.
BACKGROUND: Absorbable silk fibroin film holds good mechanical strength, degradability, tissue affinity, and excellent barrier effect.
BACKGROUND: Previous studies by the research team found that 5% silver nanoparticle-doped β-tricalcium phosphate material has antibacterial properties and good biocompatibility.
RESULTS AND CONCLUSION: (1) There was no difference in cell proliferation between the TCP group, normal culture group and 10% SNPs-TCP group at different time points (P < 0.05). (2) The concentration of silver ions in the blood, heart, liver, spleen, lung and kidney of the experimental and control groups was less than 0.1×10-6, which was less than the highest concentration of silver ions (0.5×10-6)in the human body specified by the WHO. (3) There were no obvious pathological changes in the heart, liver, spleen, lung and kidney sections of the experimental and control groups. (4) The contours of the implantation materials in the experimental and control groups could be distinguished. New bone tissues stained with red were around the materials. A large amount of red-stained new bone tissues were visible inside the porous structure of the materials. There was no significant difference in the distribution of new bone tissue in the porous structure of the two groups of materials. To conclude, the 10% SNPs-TCP has no obvious cytotoxicity and toxicity in animals, and has good biocompatibility.
BACKGROUND: Synthesis of ropivacaine-loaded poly(lactid-co-glycolide) copolymer microsphere and its pharmacokinetics have been studied preliminarily, and we have confirmed its effectiveness. However, its large size and tissue simulation limit its application.
BACKGROUND: Nano-hydroxyapatite/polyamide 66 (nHA/PA66) composite materials possess high bionic properties and exert biological activity by directly combining with host bone, but it lacks sufficient mechanical strength.
BACKGROUND: Poly(trimethylene carbonate) has great potential in clinical applications due to the excellent biocompatibility and biodegradability. Little is reported on the factors influencing the in vitro enzymatic degradation of poly(trimethylene carbonate) and the underlying mechanism.
RESULTS AND CONCLUSION: The molecular mass and shape as well as molar ratio played important roles on the in vitro enzymatic degradation behavior of poly(trimethylene carbonate). As the molecular mass increased from 135 to 256 kDa, the degradation rate constant of poly(trimethylene carbonate) homopolymer increased from 1.46% to 3.81%, indicating that the higher the molecular mass, the higher degradation rate of poly(trimethylene carbonate). The poly(trimethylene carbonate) film presented with higher degradation rate than the cylinder one with the same molecular weight, and the degradation rate constant increased from 3.81% to 9.16% as the shape of poly(trimethylene carbonate) with a molecular weight of 256 kDa changed from rods to films. The introduction of polycaprolactone segment accelerated the degradation rate of poly(trimethylene carbonate). The degradation rate constant increased from 3.81% to14.49% as the 50 mol% caprolactone content was introduced into the structure of poly(trimethylene carbonate) (256 kDa). In summary, the order of factors influencing the degradation rate of poly(trimethylene carbonate) is as follows: copolymer composition > shape > molecular mass.
BACKGROUND: The acellular vascular scaffold has excellent properties, but its biomechanical properties have been reduced to varying degrees during preparation.
BACKGROUND: Curcumin has good anticancer and anti-inflammatory effects, but which is limited for the low solubility.
RESULTS AND CONCLUSION: The solubility of curcumin hydroxypropyl-β-cyclodextrin in water was increased by 33.68 times compared with that of curcumin. The absorption rate constant (Ka) of curcumin hydroxypropyl-β-cyclodextrin was ranked as follows: duodenum > ileum > jejunum > colon, and the effective permeability (Papp) was ranked as follows: colon > duodenum > ileum > jejunum, and the absorption in the intestines was significantly higher than that of curcumin (P < 0.05). In summary, curcumin hydroxypropyl-β-cyclodextrin can obviously improve the absorption of curcumin in the intestines of rats.
BACKGROUND: With the advancement of bio-printing technology and chemical synthesis technology, the incorporation of these technologies into tissue engineering scaffolds for promoting bone regeneration has become a hot topic in current research.
RESULTS AND CONCLUSION: Bioactive scaffolds mainly include metal composite scaffolds, bioceramic composite scaffolds and polymer composite scaffolds, which have been used in bone tissue engineering. Several examples of successful bone and cartilage construction with clinical transformation have been developed, in which bioceramic and polymer composites may be the most successful due to their similar tissue composition and good biocompatibility with natural bone. And if combined with existing bioactive materials, growth factors, functionalization techniques and biomimetic scaffold designs, the potential for creating complex bone tissue engineering scaffolds for patient-specific applications in the future is enormous. This also provides hope for the treatment of a variety of challenging diseases, including bone tumor, osteoporosis and severe bone defects.
BACKGROUND: Insufficient bone mass in the posterior maxilla region often increases the difficulty of dental implantation. The application of maxillary sinus floor elevation successfully solves this problem. In the surgery, bone grafting can be used to obtain sufficient bone mass. However, nonuse of graft materials can shorten the cycle of patient’s treatment and reduce trauma and cost.
RESULTS AND CONCLUSION: Ideal results can be achieved in the maxillary sinus floor elevation with or without simultaneous bone grafting. In addition, the nonuse of grafting materials have the advantages of simplifying surgical procedures, shortening treatment cycles, reducing trauma and pain, reducing treatment costs, reducing complications and failure rates, thus gaining the favor of doctors and patients. Therefore, the maxillary sinus floor elevation without simultaneous bone grafting will be the primary choice of the doctors engaged in dental implantation in the future.
BACKGROUND: Drug-eluting stents, which combine the mechanical properties of metal stents with the specificity of an anti-proliferative drug, can effectively reduce the incidence of stent injury, restenosis and thrombosis, and reduce the risk of late adverse events.