Surface bioactivation through the nanostructured layer on titanium modified by facile HPT treatment

AbstractFacile fabrication of nanostructured surface is of great importance for the use of titanium (Ti) implants in biomedical field. In this study, a low-cost and easy-to-operate method called HPT (hydrothermal &amp; pressure) here has been developed and used to fabricate the expected nanostructured surface on Ti substrates. The effects of experimental parameters on the morphology of Ti surface were investigated and characterized. The results indicated that by altering the hydrothermal pressure, NaOH concentration and treating time, surface nanostructure like nanopetals or nanoflakes could be formed on the surface of Ti substrates. The orthogonal experiments were conducted to demonstrate the optimized operation conditions. A formation mechanism of the nanostructured titanate layer was proposed, revealing that the nanostructured layer could be formed via a special upward and downward co-growth manner. In vitro cell culture showed that the HPT treated Ti substrates, especially the T-10 sample, could greatly enhance the cell-material interactions, i.e. the cell proliferation and differentiation, focal protein adhesion, and osteogenic factor expression. The HPT method paves a new way to modify the surface of Ti implants with better bioactivity and promising prospect for future biomedical applications.</jats:p

The accuracy of three-dimensional rapid prototyped surgical template guided anterior segmental osteotomy

Surgical guiding templates provided a reliable way to transfer the simulation to the actual operation. However, there was no template designed for anterior segmental osteotomy so far. The study aimed to introduce and evaluate a set of 3D rapid prototyping surgical templates used in anterior segmental osteotomy. From August 2015 to August 2017, 17 patients with bimaxillary protrusions were recruited and occlusal-based multi-sectional templates were applied in the surgeries. The cephalometric analysis and 3D superimposition were performed to evaluate the differences between the simulations and actual post-operative outcomes. The patients were followed-up for 12 months to evaluate the incidence rate of complications and relapse. Bimaxillary protrusion was corrected in all patients with no complication. In radiographic evaluations, there was no statistically significant difference between the actual operations and the computer-aided 3D simulations (p >0.05, the mean linear and angular differences were less than 1.32mm and 1.72° consequently, and 3D superimposition difference was less than 1.4mm). The Pearson intraclass correlation coefficient reliabilities were high (0.897), and the correlations were highly significant (P< 0.001). The 3D printed surgical template designed in this study can safely and accurately transfer the computer-aided 3D simulation into real practice

Application of digital technology in diagnosis and treatment of dentofacial deformities

Dento⁃maxillofacial deformity refers to an abnormal relationship of the volume or shape of the upper and lower jaw bones with the other bones of the craniofacial area. Its correction mainly involves hard tissues, such as the jaws and teeth. In recent years, digital techniques based on virtual surgery, real⁃time navigation, and 3D printing have developed rapidly in the area of craniomaxillofacial surgery. Digital technology has advantages for preoperative diagno⁃ sis, surgical plan formulation, surgical simulation, intraoperative navigation, effect prediction, doctor⁃patient communica⁃ tion, and young physician training. The Department of Orthognathic and TMJ Surgery of West China Hospital of Stoma⁃ tology, Sichuan University, has conducted digitized diagnosis and treatment of dento⁃facial deformities since 2008 and has established a digital center for the treatment of dentofacial deformities based on equipment such as spiral CT, den⁃ tal arch laser scanners, facial 3D cameras, virtual surgery software, 3D printers, and sleep⁃breathing monitoring. The re⁃ sult is a diagnostic and treatment protocol for dentofacial deformity specific to the characteristics of the population of West China. This article combines the latest domestic and foreign literature and comprehensively introduces the applica⁃ tion of digital technology for the diagnosis and treatment of dental and maxillofacial deformities

The Dual Role of Small Extracellular Vesicles in Joint Osteoarthritis: Their Global and Non-Coding Regulatory RNA Molecule-Based Pathogenic and Therapeutic Effects

OA is the most common joint disease that affects approximately 7% of the global population. Current treatment methods mainly relieve its symptoms with limited repairing effect on joint destructions, which ultimately contributes to the high morbidity rate of OA. Stem cell treatment is a potential regenerative medical therapy for joint repair in OA, but the uncertainty in differentiation direction and immunogenicity limits its clinical usage. Small extracellular vesicles (sEVs), the by-products secreted by stem cells, show similar efficacy levels but have safer regenerative repair effect without potential adverse outcomes, and have recently drawn attention from the broader research community. A series of research works and reviews have been performed in the last decade, providing references for the application of various exogenous therapeutic sEVs for treating OA. However, the clinical potential of target intervention involving endogenous pathogenic sEVs in the treatment of OA is still under-explored and under-discussed. In this review, and for the first time, we emphasize the dual role of sEVs in OA and explain the effects of sEVs on various joint tissues from both the pathogenic and therapeutic aspects. Our aim is to provide a reference for future research in the field

Studies on Chemical Constituents of Radix Angelicae pubescentis

Backgound:Angelicae pubescentis is the root of Angelica pubescens Maxim. f. biserrata Shan et Yuan. The main active ingredients are coumarin and volatile oil, and it has a variety of pharmacological activities such as antibacterial, antioxidant and anti-inflammatory. In this paper, the active components of the CO2 supercritical extract of Angelicae pubescentis were studied. The results of this study will provide a scientific basis for the study of the chemical composition of Angelicae pubescentis. Purpose: To study the chemical constituents of supercritical extract of Radix Angelicae pubescentis. Method: The supercritical extract of Radix Angelicae pubescentis was separated by silica gel column chromatography to obtain monomers. The structures were identified based on physicochemical properties and spectroscopic data. Result: Eight compounds were separated from the supercritical extract of Radix Angelicae pubescentis, six of which were identified.They are Osthol, Columbianedin, Columbianetin, Columbianetin Acetate, Xanthotoxin and Bergapten. Conclusion: Xanthotoxin and Bergapten were isolated, which structure were similar. The standard substance of Osthol and Columbianedin were producted in order to offer the good material base for quality evaluation and pharmacodynamic study of Radix Angelicae pubescentis. Their purification were more than 99%. The results of this study are of great significance for exploring the effective material basis and medicinal value of the supercritical extract of Radix Angelicae pubescentis

(3,5-Dimethyl-1H-pyrrol-2-yl)(phenyl)methanone

In the title molecule, C13H13NO, the dihedral angle between phenyl and pyrrole rings is 57.2 (1)°. In the crystal, N—H...O hydrogen bonds link the molecules, forming chains propagating along the b axis

Nonlinear Creep Damage Constitutive Model of Concrete Based on Fractional Calculus Theory

Concrete creep has become one of the major problems that threatens concrete structural development and construction. However, a reasonable and accurate calculation model for numerical analysis is the key to control and solve the creep deformation of concrete. To better describe the concrete nonlinear creep damage evolution rule, the visco-elasticity Plasticity Rheological Theory, Riemann Liouville Theory and Combined Model Theory are quoted, and the Able dashpot is used to reconstruct fractional-order soft-body composite elements to propose the expression of the stress-strain relationship of the elastomer, visco-elasticity plasticity body, and Viscoplasticity body, considering the evolution of the concrete compression damage process. A nonlinear creep damage constitutive model of concrete, based on fractional calculus theory, is conducted, and the parameters of the specific calculation method of the model are given. The influence of stress level &#963;, fractional order n and material parameter &#945; on the concrete creep process is determined by a sensitivity analysis of the model parameters. The creep process and deformation amount of concrete in practical engineering can be effectively controlled by the results of the proposed sensitivity analysis. The research results can be used to provide guidance and reference for the safe construction of concrete engineering in actual practice

Graphene Reinforced Polyether Ether Ketone Nanocomposites for Bone Repair Applications

To improve the performance of polyether ether ketone matrix (PEEK) in hard tissue repair and replacement applications, we fabricated graphene (G) reinforced PEEK with graded G concentrations (0.1%-5%) through injection molding. The mechanical properties, surface morphology, chemical composition and thermal stability of the composites have been characterized through universal mechanical testing, scanning electron microscopy, contact-angle measurement, transmission electron microscope, X-ray photoelectron spectroscopy, X-ray diffraction and thermal analysis system. The biocompatibility has been assessed in vitro and the bone repair function of the composite implant have been assessed in vivo using a rabbit mandibular bone defect model. Mechanical testing results suggest that the composite samples have compressive moduli similar to that of the natural bone. Although addition of G into PEEK does not significantly influence the composite tensile, flexural or compressive moduli, it can significantly enhance the ductility and toughness of the material. On the other hand, all G-reinforced PEEK implants demonstrated enhanced adhesion and differentiation of rat bone marrow stromal cells (BMSCs), with 5% G-PEEK showing the highest bioactivity among all samples. The in vivo osseointegration data further revealed that 5% G-PEEK has the best effect in promoting osseointegration and bone regeneration, in both early stage and late stage bone re-growth. Study shows that our G-reinforced PEEK-based implants provides a promising strategy for enhancing the performance of future regenerative bone implants.<br /