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Evaluation of titanium cranioplasty and polyetheretherketone cranioplasty after decompressive craniectomy for traumatic brain injury: A prospective, multicenter, non-randomized controlled trial.
Yang, J, Sun, T, Yuan, Y, Li, X, Yu, H, Guan, J
Medicine. 2020;(30):e21251
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Abstract
INTRODUCTION Cranioplasty following decompressive craniectomy is routinely performed to restore integrity of skull and improve neurological function. However, reconstructing the cranial defect brings many challenges to neurosurgeons and search for ideal implant materials is one of the most controversial issues. Although many studies have compared the outcomes of titanium and polyetheretherketone (PEEK) cranioplasty, yet no prospective study exists to guide the choice of titanium and PEEK materials. METHODS/DESIGN A non-randomized, partially blinded, prospective cohort study is described that comprehensively compares the long-term outcomes of titanium cranioplasty versus PEEK cranioplasty. One hundred forty-five patients for each group will be recruited. Eligible patients are those with cranial defect due to traumatic brain injury (≥ 16 years), defect size is over 25 cm and they must agree to participate in the trial. Each participant is evaluated before surgery, on discharge, 3, 6, and 12 months after cranioplasty. The primary outcome is the infection, implant failure and implant deformation requiring revision surgery within 12 months. Secondary outcomes include postoperative complication rate, neurological outcomes, motor function, and cosmetic outcome over a 6-month period. DISCUSSION Search for ideal implant materials is throughout the history of cranioplasty. This study will provide robust evidence for the choice of cranioplasty materials. TRIAL REGISTRATION NUMBER ChiCTR2000033406.
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Dopamine-Decorated TiO2 Nanoparticles in Water: A QM/MM vs an MM Description.
Siani, P, Motta, S, Ferraro, L, Dohn, AO, Di Valentin, C
Journal of chemical theory and computation. 2020;(10):6560-6574
Abstract
Nanoparticle functionalization is a modern strategy in nanotechnology to build up devices for several applications. Modeling fully decorated metal oxide nanoparticles of realistic size (few nanometers) in an aqueous environment is a challenging task. In this work, we present a case study relevant for solar-light exploitation and for biomedical applications, i.e., a dopamine-functionalized TiO2 nanoparticle (1700 atoms) in bulk water, for which we have performed an extensive comparative investigation with both MM and QM/MM approaches of the structural properties and of the conformational dynamics. We have used a combined multiscale protocol for a more efficient exploration of the complex conformational space. On the basis of the results of this study and of some QM and experimental data, we have defined strengths and limitations of the existing force field parameters. Our findings will be useful for an improved modeling and simulation of many other similar hybrid bioinorganic nanosystems in an aqueous environment that are pivotal in a broad range of nanotechnological applications.
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Synthesis and characterization of cellulose/TiO2 nanocomposite: Evaluation of in vitro antibacterial and in silico molecular docking studies.
M V, A, Harb, M, Sundaram, R
Carbohydrate polymers. 2020;:116868
Abstract
Cellulose/TiO2 nanocomposite was synthesized using coagulation in sodium hydroxide-thiourea-urea aqueous solution medium by precipitation method. This method was accomplished green and cost-effective for the fabrication of composite nanomaterials. Structure, morphology and optical properties of the nanocomposite were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, and ultraviolet diffuse reflectance spectra respectively. XRD results showed the anatase structure of TiO2 while FESEM micrograph showed evidence of particle size ranging from 20 to 40 nm for cellulose/TiO2 nanocomposite. The Fourier transfer infrared spectroscopy investigation reveals that the TiO2 is bound to hydroxyl groups to the cellulose by hydrogen bonding. The optical energy bandgap is found to be 2.71 eV for nanocomposite from the UV-DRS. The mechanical strength of the composites gently escalated with the addition of TiO2 nanoparticles into cellulose polymer matrix. Cellulose/TiO2 nanocomposite was screened for their in vitro antibacterial activity against Staphylococcus aureus and Escherichia coli bacteria have been investigated. Additionally, the results obtained from in silico molecular docking studies confirm the interaction of nanocomposite with proteins, were in good agreement with the experimental data. This finding provides a novel and simple method for the synthesis of cellulose/TiO2 nanocomposite as functional biomaterials.
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The Titanium-coated PEEK Cage Maintains Better Bone Fusion With the Endplate Than the PEEK Cage 6 Months After PLIF Surgery: A Multicenter, Prospective, Randomized Study.
Hasegawa, T, Ushirozako, H, Shigeto, E, Ohba, T, Oba, H, Mukaiyama, K, Shimizu, S, Yamato, Y, Ide, K, Shibata, Y, et al
Spine. 2020;(15):E892-E902
Abstract
STUDY DESIGN A multicenter, randomized, open-label, parallel-group trial. OBJECTIVE To investigate interbody bone fusion rates in titanium-coated polyetheretherketone (TiPEEK) and polyetheretherketone (PEEK) cages after posterior lumbar interbody fusion (PLIF) surgery. SUMMARY OF BACKGROUND DATA Previous clinical studies have not revealed any significant difference in bone fusion rates between TiPEEK and PEEK cages. METHODS During one-level PLIF surgery, 149 patients (84 men, 65 women, mean age 67 yr) were randomly allocated to use either a TiPEEK cage (n = 69) or PEEK cage (n = 80). Blinded radiographic evaluations were performed using computed tomography and assessed by modified intention-to-treat analysis in 149 cases and per-protocol analysis in 143 cases who were followed for 12 months. Clinical outcomes were assessed using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire and the Oswestry Disability Index. RESULTS The interbody union rate at 12 months after surgery was 45% owing to a very strict definition of bone fusion. The rates of bone fusion were significantly higher at 4 and 6 months after surgery in the TiPEEK group than in the PEEK group in the unadjusted modified intention-to-treat analysis and were significantly higher at 6 months in the unadjusted per-protocol analysis. Binary logistic regression analysis adjusted for sex, age, body mass index, bone mineral density, and surgical level showed that using a TiPEEK cage (odds ratio, 2.27; 95% confidence interval: 1.09-4.74; P = 0.03) was independently associated with bone fusion at 6 months after surgery. Japanese Orthopaedic Association Back Pain Evaluation Questionnaire and Oswestry Disability Index results improved postoperatively in both groups. CONCLUSION Using the TiPEEK cage for PLIF enabled the maintenance of better bone fusion to the endplate than using the PEEK cage at 6 months after the surgery. Our findings suggest the possibility of an earlier return to rigorous work or sports by the use of TiPEEK cage. LEVEL OF EVIDENCE 1.
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Comparative analysis of corrosion resistance between beta titanium and Ti-6Al-4V alloys: A systematic review.
Dias Corpa Tardelli, J, Bolfarini, C, Cândido Dos Reis, A
Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS). 2020;:126618
Abstract
BACKGROUND The knowledge of the electrochemical property (corrosion resistance) of beta titanium alloys compared to Ti-6Al-4 V for implants is relevant because of the potential cytotoxic effects that the released ions could cause to long-term health. OBJECTIVES The objective of this systematic review was to seek information on the electrochemical properties (corrosion resistance) of beta titanium alloys compared to Ti-6Al-4 V since the awareness of the electrochemical behavior of the implant surface in the medium is essential for the best indication of the alloys or compositional changes, which may promote benefits to bone-implant interaction in all areas that this procedure is required. METHODS The PubMed, LILACS, COCHRANE Library, and Science Direct databases were electronically searched for the terms: dental implants AND beta-titanium AND Ti-6Al-4 V AND electrochemical technics. The inclusion criteria were research articles that studied beta-titanium compared to Ti-6Al-4 V using electrochemical techniques in electrolytes of chemical composition similar to body fluid, published in English, between 2000 and 2020. Articles that did not compare the corrosion resistance of these alloys in electrolytes similar to body fluids were excluded. RESULTS A total of 189 articles were restored and selected by title and/or abstract according to the inclusion and exclusion criteria, which resulted in 15 articles that were reduced to 8 after read in full. The studies in vitro evaluated the corrosion resistance in electrolytes Hank, Ringer, SBF, and 0.9 % NaCl, between beta titanium alloys, obtained by arc fusion or bars stock, and Ti-6Al-4 V, for dental or biomedical implants submitted to surface treatments by heat treatment, plasma electrolytic oxidation (PEO), alkaline treatment, and thermomechanical. CONCLUSION The evaluated literature allowed to determine that 1) The oxides Nb2O 5, Ta2O 5, and ZrO2 have higher stability and protection quality than that of TiO2 modified by the oxides of Al and V; 2) A higher modulus of elasticity of the Ti-6Al-4 V alloy favors protection against corrosion by maintaining a thicker and more firmly adhered oxide layer; 3) The increase in the thickness of the Ti alloys superficial layer contributes to the improvement of the corrosion resistance.
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Canonical, deprotonated, or zwitterionic? II. A computational study on amino acid interaction with the TiO2(110) rutile surface: comparison with the anatase (101) surface.
Pantaleone, S, Rimola, A, Sodupe, M
Physical chemistry chemical physics : PCCP. 2020;(29):16862-16876
Abstract
The adsorption of 11 amino acids (Gly, Leu, Met, Phe, Ser, Cys, Glu, Gln, Arg, Lys, and His) on the TiO2(110) rutile surface is investigated adopting a theoretical approach, using the PBE-D2* functional as implemented in the periodic VASP code. The adsorption of the amino acids is considered in their canonical, deprotonated and zwitterionic forms. For all cases, the most stable adsorption mode adopts a bidentate (O,O) binding with surface undercoordinated Ti atoms, in agreement with previous experimental and computational studies using glycine as a test case. Such a binding mode is possible due to the surface morphology, because the Ti-Ti distances match very well with the carboxylic O-O distance. The most stable adsorption states are the deprotonated and the zwitterionic ones, the canonical one lying significantly above in energy. The relative stability between the deprotonated and the zwitterionic states results in a delicate trade-off among dative interactions (O, N, and S atoms of the amino acids with Ti atoms of the surface), H-bond interactions, dispersive forces and, to a lesser extent, steric hindrance of the amino acidic lateral chains. Finally, the difference in the amino acid adsorption between the (110) rutile and the (101) anatase surfaces is discussed both from the energetic and surface morphological standpoints, highlighting the larger reactivity of the rutile polymorph in adsorbing and deprotonating the amino acids compared with the anatase one.
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PEEK versus metal cages in posterior lumbar interbody fusion: a clinical and radiological comparative study.
Cuzzocrea, F, Ivone, A, Jannelli, E, Fioruzzi, A, Ferranti, E, Vanelli, R, Benazzo, F
Musculoskeletal surgery. 2019;(3):237-241
Abstract
BACKGROUND Low back pain and sciatica represent a common disabling condition with a significant impact on the social, working and economic lives of patients. Transforaminal lumbar interbody fusion (TLIF) is a surgical procedure used in degenerative spine conditions. Several types of cages were used in the TLIF procedure. PURPOSE To determine whether there is a difference in terms of symptomatology improvement, return to daily activities and fusion rate between metal cages and polyetheretherketone (PEEK) cages. METHODS We have retrospectively reviewed 40 patients who have undergone TLIF from October 2015 to May 2016. All patients were clinically evaluated with questionnaires and were assessed with CT scan and standing X-ray films of the full-length spine. RESULTS We found no significant functional differences in the two groups. At 1-year follow-up, osteolysis was present in 50% of cases of the PEEK cages and in 10% cases of the metal cages. The degree of fusion at 1 year was evaluated as complete in 40% cases of the metal cages and 15% cases of the PEEK cages. CONCLUSIONS We have found a better fusion rate and prevalence of fusion in the group treated with metal cages, reflecting the well-known osteoinductive properties of titanium and tantalum.
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Solid-State NMR and MD Study of the Structure of the Statherin Mutant SNa15 on Mineral Surfaces.
Buckle, EL, Prakash, A, Bonomi, M, Sampath, J, Pfaendtner, J, Drobny, GP
Journal of the American Chemical Society. 2019;(5):1998-2011
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Abstract
Elucidation of the structure and interactions of proteins at native mineral interfaces is key to understanding how biological systems regulate the formation of hard tissue structures. In addition, understanding how these same proteins interact with non-native mineral surfaces has important implications for the design of medical and dental implants, chromatographic supports, diagnostic tools, and a host of other applications. Here, we combine solid-state NMR spectroscopy, isotherm measurements, and molecular dynamics simulations to study how SNa15, a peptide derived from the hydroxyapatite (HAP) recognition domain of the biomineralization protein statherin, interacts with HAP, silica (SiO2), and titania (TiO2) mineral surfaces. Adsorption isotherms are used to characterize the binding affinity of SNa15 to HAP, SiO2, and TiO2. We also apply 1D 13C CP MAS, 1D 15N CP MAS, and 2D 13C-13C DARR experiments to SNa15 samples with uniformly 13C- and 15N-enriched residues to determine backbone and side-chain chemical shifts. Different computational tools, namely TALOS-N and molecular dynamics simulations, are used to deduce secondary structure from backbone and side-chain chemical shift data. Our results show that SNa15 adopts an α-helical conformation when adsorbed to HAP and TiO2, but the helix largely unravels upon adsorption to SiO2. Interactions with HAP are mediated in general by acidic and some basic amino acids, although the specific amino acids involved in direct surface interaction vary with surface. The integrated experimental and computational approach used in this study is able to provide high-resolution insights into adsorption of proteins on interfaces.
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Elastic, electronic, chemical bonding and thermodynamic properties of the ternary nitride Ca4TiN4: Ab initio predictions.
Boucenna, S, Haddadi, K, Bouhemadou, A, Louail, L, Soyalp, F, Khenata, R
Journal of molecular graphics & modelling. 2019;:74-85
Abstract
In order to shed light on the unexplored properties of the ternary nitride Ca4TiN4, we report for the first time the results of an ab initio study of its structural, electronic, elastic, chemical bonding and thermodynamic properties. Calculated equilibrium structural parameters are in excellent concordance with available experimental data. Electronic properties were explored through the calculation of the energy band dispersions and density of states. It is found that Ca4TiN4 has an indirect band gap (Z-Γ) of 1.625 (1.701) eV using LDA (GGA). Nature of the chemical bonding was studied via Mulliken population analysis and charge density distribution map. It is found that the Ca-N bond is dominantly ionic, whereas the Ti-N one is dominantly covalent. Elastic properties of both single-crystal and polycrystalline phases of the title compound were explored in details using the stain-stress approach. Analysis of the calculated elastic moduli reveals that the title compound is mechanically stable, ductile and elastically anisotropic. Temperature and pressure dependencies of the unit-cell volume, bulk modulus, heat capacities, volume thermal expansion coefficient, Grüneisen parameter and Debye temperature were investigated based on the quasiharmonic Debye model.
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Photodegradation using TiO2-activated borosilicate tubes.
Khalaf, S, Shoqeir, JH, Scrano, L, Karaman, R, Bufo, SA
Environmental science and pollution research international. 2019;(19):19025-19034
Abstract
This study examines the photocatalytic activity of titanium dioxide (TiO2) semiconductor supported on borosilicate tubes (cut-off 290 nm) towards removal of a mix of persistent organic pollutants (POPs) from water. For this purpose, two widely used analgesic and anti-inflammatory drugs (NSAIDs), ibuprofen (IBU) and mefenamic acid, along with MCPA sodium monohydrate, which is a common herbicide frequently used in the agricultural activities, were selected as a case study. Borosilicate tubes were coated with titanium oxide through two different approaches: sol-gel dip-coating and a hybrid nanoparticle dip-coating and plasma-enhanced chemical vapour deposition (PECVD) process. The photochemical reactor that hosts the titania-coated tubes was designed to permit continuous throughput of liquid feed stream. The photodegradation experiments were performed in laboratory conditions under artificial irradiation simulating solar light. The efficiency of direct photolysis and heterogeneous photocatalysis (TiO2) was investigated, and the performance of each coating method was evaluated. Kinetic studies for each experiment were accomplished, the overall results showed poor efficiency and insufficient removal for NSAIDs through direct photolysis, whereas applying heterogeneous photacatalysis with TiO2 coated on borosilicate tubes was found to accelerate their degradation rate with complete decomposition. Concomitantly, kinetic experimental results showed a critical difference of performance for the two coating methods used; in particular, the degradation rates of pollutants by the sol-gel-coated tubes were much faster than the degradation by the nanoparticle/PECVD-coated tubes. Using TiO2 supported on borosilicate tubes appears to be a promising alternative to conventional TiO2 suspension and avoid post-separation stages. The results achieved in this study can be used to optimise large-scale applications, and expanding the study to cover a wide range of pollutants will lead to achieve more representative results.