Three-dimensional Titanium Research Articles

Preparation and optical characterization of 3D-TiO2 thin films with brilliant colors

In this paper, three-dimensional titanium dioxide (3D-TiO2) thin films with periodic structure were obtained by periodic pulse anodization of high-purity titanium wafers under specific alternating voltage (AV) using asymmetric sawtooth waveforms. The effect of voltage amplitude and electrolyte concentration on the structural color of the 3D-TiO2 thin films were investigated. It is shown that the nanotubes grown by asymmetric sawtooth wave at a specific AV have a “bamboo” shape, and the cycle length, as well as the inner and outer tube diameters of the nanotubes are closely related to the AV. The structural color of the samples was different at varying voltages and electrolyte concentrations for the same oxidation cycle time. The structural color of films grown under low voltage is analyzed to be related to the scattering and absorption of light on their surfaces. The thickness of the film grown under high voltage satisfies the conditions for light interference. The maximum reflected wavelength is red-shifted and then blue-shifted as the electrolyte concentration decreases. The study shows that the microstructure is the main influence on the color change of 3D-TiO2 thin films.

Nickel-cobalt alloy nanosheet-decorated three-dimensional titanium dioxide nanobelts electrodeposited on titanium meshes for boosting selective nitrate electroreduction to ammonia

Electrocatalytic nitrate reduction reaction presents a promising avenue for environmentally friendly ammonia (NH3) synthesis and wastewater treatment. An essential aspect to consider is the meticulous design of electrocatalysts. This study explores the utilization of a Ni-Co alloy nanosheet-decorated three-dimensional titanium dioxide (3D-TiO2) nanobelts electrodeposited on titanium meshes (NixCoy@TiO2/TM) for efficient electrocatalytic NH3 production. The optimized Ni1Co3@TiO2/TM electrode achieves a significant NH3 yield of 676.3 ± 27.1 umol h−1 cm−2 with an impressive Faradaic efficiency (FE) of 95.1 % ± 2.1 % in a 0.1 M KOH solution containing 0.1 M NO3− at −0.4 V versus the reversible hydrogen electrode. Additionally, the electrode demonstrates exceptional electrochemical activity for NH3 synthesis in simulated wastewater, delivering an outstanding NH3 yield of 751.6 ± 44.3 umol h−1 cm−2 with a FE of 96.8 % ± 0.4 % at the same potential of −0.4 V. Moreover, the electrode exhibits minimal variation in current density, NH3 yields and FEs throughout the 24-h stability test and the 20-cycle test, demonstrating its excellent stability and durability. This study offers a straightforward electrodeposited approach for the development of 3D-nanostructured alloys as catalysts for NH3 electrosynthesis from nitrates at room temperature.

Decompressive Bone Flap Replacement (Decompressive Cranioplasty): A Novel Technique for Intracranial Hypertension-Initial Experience and Outcome.

Intracranial hypertension is a life-threatening condition that can be treated by decompressive craniectomy (DC), which involves removing a part of the skull and intracranial lesions. However, DC has many complications and requires a second surgery to repair the skull. Decompressive bone flap replacement (DBFR) or decompressive cranioplasty is a novel technique that replaces the bone flap with a titanium mesh, providing both decompression and skull integrity. The materials and methods of DBFR are described in detail. A three-dimensional titanium mesh is fabricated based on the computed tomography (CT) data of previous DC patients. An appropriate titanium mesh is selected based on the preoperative and intraoperative assessments. After removing the intracranial lesions, the titanium mesh is fixed over the bone window. We successfully performed DBFR in three emergent cases. The postoperative CT scan showed adequate decompression in all cases. No reoperation for skull repair was needed, and there were no surgical complications. The cosmetic outcome was excellent. There were no relevant complications in the operative area. DBFR may be a safe and effective alternative to DC in a specific subgroup of patients, in whom complete removal of the bone flap is feasible. DBFR can reduce intracranial pressure while maintaining the integrity of the skull cavity, eliminating the need for additional surgery for skull repair. Possible improvements for DBFR in the future are suggested, such as using a greater curvature of the titanium mesh or a modified DBFR with a hinged titanium mesh.

Three-dimensional titanium mesh-based flow electrode capacitive deionization for salt separation and enrichment in high salinity water

Flow electrode capacitive deionization (FCDI) is a highly promising desalination technique known for its exceptional electrosorption capacity, making it suitable for efficient salt separation in high salinity water. However, the unsatisfactory charge transfer process between the flow electrode and current collector severely curtails the salt separation and enrichment performance of the FCDI device. To address this issue, three-dimensional titanium mesh (3D-TM) was proposed as a novel current collector for FCDI device, which significantly amplifies the charge transfer area and exhibits excellent salt separation performance. The 3D-TM current collector promotes the electron transfer, charge percolation, and ion migration processes through the electroconvection generated by the turbulence effect on the flow electrode. In the specific case of the 20-mesh 3D-TM, which is composed of 12 stacking layers of titanium mesh, the remarkable average salt removal rate and charge efficiency were achieved 5.06 μmol cm−2 min−1 and 92.9 % under an appropriate applied voltage of 2.0 V, respectively. Dramatically, the desalination performance maintained above 76.4 % over 100 desalination cycles at 2.0 V, demonstrating the exceptional cyclic stability of the 3D-TM FCDI cell. In the seawater desalination, the 3D-TM FCDI cell exhibited an impressive salt removal efficiency of 97.5 % (from 34.2 g L−1 to 0.84 g L−1) for 1 L East China seawater at 2.0 V for 24 h. For lithium-ion enrichment, the FCDI continuous desalting system achieved an astonishing concentration of 17.3 g L−1 for Li+ ions enrichment from an initial concentration of 1.30 g L−1, obtaining the average salt treating rate of 23.6 g m−2h−1 and charge efficiency of 80.0 %. Moreover, the lithium-sodium ions and lithium-magnesium ions enrichments were both conducted, yielding an enriched concentration of 10.4 g L−1 and 7.30 g L−1 for Li+ ions, respectively. These findings highlight the enormous potential of FCDI technology in industrial engineering applications, further establishing it as a highly viable solution.

Numerical design of open-porous titanium scaffolds for Powder Bed Fusion using Laser Beam (PBF-LB)

The paper concerns the numerical design of novel three-dimensional titanium scaffolds with complex open-porous structures and desired mechanical properties for the Powder Bed Fusion using Laser Beam (PBF-LB). The 60 structures with a broad range of porosity (38–78%), strut diameters (0.70–1.15 mm), and coefficients of pore volume variation, CV(Vp), 0.35–5.35, were designed using the Laguerre-Voronoi tessellations (LVT). Their Young's moduli and Poisson's ratios were calculated using Finite Element Model (FEM) simulations.The experimental verification was performed on the representative designs additively manufactured (AM) from commercially pure titanium (CP Ti) which, after chemical polishing, were subjected to uniaxial compression tests. Scanning Electron Microscopy (SEM) observations and microtomography (μ-CT) confirmed the removal of the support structures and unmelted powder particles. PBF-LB structures after chemical polishing were in close agreement with the CAD models' dimensions having 4–12% more volume.The computational and experimental results show that elastic properties were predicted in very close agreement for the low CV(Vp), and with even 30–40% discrepancies for CV(Vp) higher than 4.0, mainly due to PBF-LB scaffold architecture drawbacks rather than CAD inaccuracy. Our research demonstrates the possibility of designing the open-porous scaffolds with pore volume diversity and tuning their elastic properties for biomedical applications.

Assessment of Response to Neoadjuvant Chemotherapy in Locally Advanced Breast Carcinoma Using Image-Guided Clip Placement.

Background The present study aims to evaluate the response of locally advanced breast carcinoma (LABC) to neoadjuvant chemotherapy (NACT) using image-guided clip placement based on Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria. Methods Thirty-four patients with LABC were included in the study. Consent for three-dimensional titanium clip placement (400/300/200 mm Liga clips) under local anesthesia with USG guidance was obtained. Serial sonographic/X-ray evaluations of tumor bed size were conducted before every cycle of NACT. All data were recorded in millimeters of concentric tumor regression/non-regression. Tumor regression in a concentric or Swiss cheese pattern and non-responders were evaluated. Assessment of the response to NACT was performed using RECIST criteria, dividing it into four categories. Tumor response was confirmed with computerized tomography (CT) conducted before and after the completion of NACT. Patients underwent surgical management, mostly modified radical mastectomy (MRM), as they had locally advanced breast carcinoma. Following MRM, the clips in the specimen guided the original site of the tumor for histopathological evaluation and response to chemotherapy. Results Tumor response was classified into four types: complete response (CR), partial response (PR), progressive disease (PD), and stable disease. RECIST 1.1 criteria were elaborated and defined. Data for all patients were entered into an Excel sheet (Microsoft Corporation, Redmond, Washington)to prepare a master chart, and the following observations were made and analyzed using SPSS software. The duration of chemotherapy for the study population ranged from 32 to 206 days, with a mean (±SD) of 111.82 (± 52.64) days and a median (IQR) of 81 (63, 158) days. The mean period between clip insertion and completion of NACT was 111.82 days. The baseline sum diameters and post-NACT diameters of the tumors were 70.50 (±13.60) mm before NACT and 17.75 (±17.20) mm after NACT. Hence, the mean size of the lump was statistically significantly lower after NACT, with a mean difference of 52.75 (p<0.05). The mean rate of reduction in tumor diameter was found to be 74.32% (±23.44%) based on RECIST 1.1 criteria. Pathological response was observed in all patients except for 8.8% of the patients. Clinical complete response was seen in 35.29% of patients, and partial response was observed in 52.92% of the patients based on RECIST 1.1 criteria. The study thus demonstrates the effectiveness of NACT in LABC, with a mean reduction in tumor diameter of 74.32%, assessed with the help of RECIST 1.1 criteria. Conclusion NACT for patients with LABC has shown a significant reduction in tumor size. NACT should be the initial mode of management for patients with LABC. RECIST 1.1 criteria are effective and can be used to assess tumor response to NACT. This has aided in the stratification of the response of NACT for further management through systemic therapy (adjuvant chemotherapy) after the surgical excision of the tumor.

Superior Capacity in Electric Double-Layer Capacitors Employing Three-Dimensional Titanium Foam Electrodes

Superior Capacity in Electric Double-Layer Capacitors Employing Three-Dimensional Titanium Foam Electrodes

Hydrogen production in a proton exchange membrane electrolysis cell (PEMEC) with titanium meshes as flow distributors

The proton exchange membrane electrolysis cell (PEMEC) is a green and efficient method for producing hydrogen. The flow field structure is a critical factor affecting the performance of electrolysis. However, conventional processing of flow channels is complex and expensive, a novel PEMEC structure utilizing three-dimensional titanium meshes as flow distributors instead of flow channels is proposed. It is found to exhibit higher current density, pressure, hydrogen concentration, and lower temperature than the traditional parallel flow fields. The current density is improved by 88.2 mA/cm2 and the energy consumption is reduced by 0.15 kW h N−1·m−3 at 1.9 V. Based on the uniformity index, the new structure is found to improve the current and temperature uniformity by 20.6% and 13.4%, respectively, when compared to the parallel flow field structure. Additionally, the physical properties of the mesh layers are studied in terms of their influence on electrolysis performance. The increase in porosity and decrease in thickness can enhance the performance of the cell. The results show that a structure with titanium meshes is more beneficial for improving the heat and mass transfer performance and optimizing uniform distribution than the parallel channels, which provides a new direction for the design of electrolysis cell structures.

Ti-doped Fe2O3 photoanodes on three-dimensional titanium microfiber felt substrate for photoelectrochemical oxygen evolution reaction

The macroporous structure of conductive substrates with large surface areas is crucial for fabricating semiconductor electrodes that offer better photoelectrochemical (PEC) performance in the water-splitting reaction. In this study, three-dimensional (3D) titanium microfiber felt (Ti felt) was used as a conductive substrate to prepare a Ti-doped Fe2O3 photoanode via a hydrothermal method with a two-step annealing treatment in air and argon atmospheres. Compared to conventional two-dimensional (2D) substrates, such as fluorine-doped tin oxide (FTO)-coated glass and Ti sheets, the loading amount of Fe2O3 on Ti felt was 2–5 times higher for a similar substrate geometric area. The thickness of Fe2O3 on the Ti felt (∼0.6 µm) was less than that on the 2D substrates. Ti-doped Fe2O3 on Ti felt (Ti-felt/Ti-Fe2O3) exhibits a higher photocurrent density than FTO/Ti-Fe2O3 and Ti-sheet/Ti-Fe2O3. Mott–Schottky analysis shows that the donor density of Ti-felt/Ti-Fe2O3 (8.58 × 1021 cm−3) was more than 10 times higher than that of FTO/Ti-Fe2O3 and Ti-sheet/Ti-Fe2O3. Analyses of the incident photon-to-current conversion efficiency (IPCE) and Faradaic efficiency indicated that Ti-felt/Ti-Fe2O3 showed higher PEC activity for the oxygen evolution reaction (OER) than FTO/Ti-Fe2O3. The enhanced PEC activity is ascribed to the higher donor density and moderate thickness of the Ti-doped Fe2O3 layer, which contribute to a short electron transport distance. Furthermore, the high loading of Fe2O3 on the Ti-felt substrate increased the photoabsorption in the UV and visible light regions and the photocurrent response at wavelengths near the band edge, even at low light intensities. This study provides new insights for preparing hematite photoanodes with higher PEC activity for the OER using a 3D porous substrate, rather than conventional 2D substrates.

20-year Results of a 3D Titanium Mesh Coating Stability of 31 Artificial Cups.

The aim of this work was to demonstrate the bony bond strength and resilience of a three-dimensional titanium mesh coating of an artificial acetabulum produced using the diffusion bonding technique. Under the extreme conditions ranging from abrasion-related osteolysis to acetabular perforation, the degree of residual bone and the integrity of the coating were determined. The remaining zones of the (still) stable bone connection are inevitably exposed to a greater load of the layer adhesion between the titanium mesh and the core shell. The investigation was intended to provide information about the stages of damage according to Paprosky in which it was still justifiable to leave the implant in place and simply change the inlay from the purely material-technical point of view of a stable coating. The bond between bone and implant was examined with regard to a possible retention of the implant for its adaptive remodeling up to 27 years. In a retrospective study, 31 explanted human acetabular cups of the Harris-Galante II type, with an average lifetime of 19.7 years (11-27 years), were examined by means of digital area measurement to determine both the bone areas remaining on the coating and the damaged areas of the titanium mesh. Periacetabular bone loss was recorded in a modified Paprosky (PAP) damage classification. Full hemispherical sections of 4 acetabular cups with a life time of 16, 20, 22 and 27 years were examined histopathologically using the diamond cut technique. The periacetabular bone loss resulted in damage class PAP I in 8 cases, PAP IIa in 7 cases, PAP IIb in 2 cases, PAP IIc in 9 cases, PAP IIIa in 3 cases and PAP IIIa in 2 cases PAP IIIb. The average amount of bone that was still firmly attached to the coating after explantation was 17% (0-70%) of the total cup surface. Paprosky I accounted for 44.1%, and PAP IIa and IIb stadiums together a total of 17.1%. The average bone fraction of the implants no longer anchored in the host bed at stages IIc, IIIa and IIIb was 2%. The average coating damage was 11% (0-100%) and was exclusively attributable to the unstable implants of stages IIc, IIIa and IIIb. The histopathological findings showed adaptive bone remodeling, that was detectable for up to 27 years through the titanium mesh down to the interface with the solid acetabular core. The titanium wire mesh was mostly surrounded by lamellar, mature bone. The results show that the connection between the Tivanium cup and the previously oldest and unchanged sintered coating - in the form of a three-dimensional titanium mesh applied in point and line contact - is very load-resistant even under the extreme loads of periacetabular osteolysis and cup perforations. Since there was no damage to the coating in periacetabular damage stages Paprosky I, IIa and IIb, it is justifiable in these damage stages to leave the implant in situ and to continue to use it with sole replacement of the inlay, but leaving the socket shell. The third-generation acetabular cup (Trilogy) with unchanged three-dimensional titanium mesh coating has been implanted in over 1.2 million cases for 26 years. After a long service life, an increasing number of wear and tear conditions can be expected in today's mostly elderly and vulnerable patient clientele. In view of the results presented here, the early detection of damage would make it possible to avoid costly and stressful explantation of the entire acetabular cup in favor of replacing the sole inlay in Paprosky stages I, IIa and IIb.

1D 2D and 3D anatase TiO2 sensitized with BNQDs for sensitive acetone detection

In this study, one-dimensional titanium dioxide nanorods (TiO2NRs), two-dimensional titanium dioxide nanoplates (TiO2NPs) and three-dimensional titanium dioxide nanospheres (TiO2NSs) sensitized by boron nitride quantum dots (BNQDs) were successfully synthesized via hydrothermal method. The crystal phase, microstructure and chemical bonding states of the samples were characterized by XRD, SEM, TEM and XPS. The results showed that the crystal phase of the three kinds of TiO2 nano materials were all anatase phase. The gas-sensing performances of TiO2-based sensors were also systematically investigated. The testing results displayed that the BNQDs/TiO2NRs, BNQDs/TiO2NPs and BNQDs/TiO2NSs sensors exhibited significant enhancement of gas sensing performance to acetone at 320 ℃. Among them, the response of BNQDs/TiO2NRs to acetone was 7.76 times that of the pristine TiO2NRs. In addition, all sensors were of fast response time, excellent stability, low detection limit and good selectivity to acetone. The excellent sensing performance of TiO2 sensitized by BNQDs can be ascribed to the synergistic effect of the small size and edge defects of BNQDs, which resulted in the formation of abundant active centers and promoted the generation of more oxygen-active species.

World experience in use of three-dimensional titanium implants in veterinary practice

Additive technologies have been actively developing in recent decades. Their introduction into medicine provides new opportunities for reconstructive treatment, including animal patients.One of the most popular materials for 3D printing is titanium and titanium alloys. Their demand is explained by the properties of mechanical biocompatibility, strength and elasticity comparable to bone.The purpose of this review was to summarize data on the use of 3D printed titanium implants for the treatment of animals with bone defects. The search for information was carried out in the databases of scientific data of domestic and foreign literature and medical resources.The conducted studies have shown that the use of 3D printing technology makes it possible to design and create individual implants and endoprostheses based on images of each patient, exactly corresponding to the area of the defect. This approach reduces the time of surgical intervention, reduces the time of postoperative recovery.Possibility of obtaining the necessary specified porosity and surface roughness, which leads to a decrease in the micromovement of the boneimplant structure and promotes good osseointegration. These properties are the advantages of 3D printing implants made of titanium and titanium alloys.The given practical examples of the use of individual three-dimensional titanium implants show the possibilities of using additive technology for veterinary medicine.

Physicochemical and Photocatalytic Properties of 3D-Printed TiO2/Chitin/Cellulose Composite with Ordered Porous Structures.

In this study, we printed three-dimensional (3D) titanium dioxide (TiO2)/chitin/cellulose composite photocatalysts with ordered interconnected porous structures. Chitin microparticles were mixed with cellulose in the N-methylmorpholine-N-oxide (NMMO) solution to prepare the printing "ink". TiO2 nanoparticles were embedded on the chitin/cellulose composite in the NMMO removal process by water before the freeze-drying process to build the 3D cellulosic photocatalysts with well-defined porous structures. The 3D-printed TiO2/chitin/cellulose composites were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Energy Disperse Spectroscopy (EDS). The XRD and FTIR analyses showed that chitin had an interference effect on the crystal regeneration of cellulose and resulted in a large amount of amorphous phase. The SEM images show that the printed cellulosic strands had a hollow structure, and the EDS analysis showed that TiO2 nanoparticles were embedded on the chitin/cellulose composite surfaces. In the photocatalytic degradation process of methylene blue (MB) dye in an aqueous solution, the TiO2/chitin/cellulose 3D composite photocatalysts demonstrated efficient MB degradation activities with excellent reusability and stability, in which the chitin content performed the function of adjusting the MB degradation efficiency.

In vitro application of drug-loaded hydrogel combined with 3D-printed porous scaffolds

Titanium mesh and three-dimensional titanium alloy scaffolds play a key role in addressing oral and maxillofacial bone defects, which can provide a specific environment and structure for bone growth and development. The two main causes of implant surgery failure are aseptic loosening and bacterial-induced implant-associated infections. To make bone defect implants effective for a long time, the ideal scaffold should take into account the two functions of osseointegration and anti-infection. Therefore, on the basis of the low-elastic-modulus Ti-10Ta-2Nb-2Zr (TTNZ) alloys developed by the research group in the early stage, this study intends to combine the vancomycin-loaded hydrogel with the 3D-printed through-hole porous titanium alloy scaffold to endow 3D-printed TTNZ scaffolds with antibacterial properties. The antibacterial properties of the complex were investigated by the zone of inhibition test and the adhesion/free antibacterial test. The effects of the composite system on osseointegration were investigated from the aspects of cell adhesion, cell proliferation and osteogenesis-related gene expression. The results showed that loading 2.5 wt.% and 5 wt.% vancomycin did not affect the structure of chitosan–hyaluronic acid hydrogel. The properties of the hydrogels were examined by scanning electron microscopy, Fourier-transform infrared, degradation experiment in vitro and vancomycin release experiment in vitro. When combined with porous scaffolds, the drug-loaded hydrogels exhibited slower drug release rates and longer release times. In addition, in vitro studies found that the TTNZ scaffolds loaded with 5 wt.% vancomycin had a certain effect on the expression of osteogenesis-related genes in cells, but the antibacterial effect was the best. The porous scaffolds loaded with 2.5 wt.% vancomycin hydrogel TTNZ scaffolds did not inhibit cell proliferation, adhesion, alkaline phosphatase activity, and osteogenesis-related gene ex-pression, but the antibacterial effect on free bacteria was not as good as that of TTNZ scaffolds loaded with 5 wt.% vancomycin. This study, complementing the advantages of the two and controlling the local release rate of vancomycin, provides a new idea for future 3D printing of titanium alloy stents for anti-infection.

Evaluating Different TiO2 Nanoflower-Based Composites for Humidity Detection.

Unique three-dimensional (3D) titanium dioxide (TiO2) nanoflowers (TFNA) have shown great potential for humidity sensing applications, due to their large surface area-to-volume ratio and high hydrophilicity. The formation of a composite with other materials could further enhance the performance of this material. In this work, the effect of different types of composites on the performance of a TNFA-based humidity sensor was examined. NiO, ZnO, rGO, and PVDF have been explored as possible composite pairing candidates with TiO2 nanoflowers, which were prepared via a modified solution immersion method. The properties of the composites were examined using field emission electron spectroscopy (FESEM), X-ray diffractometry (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), current-voltage (I-V) analysis, Hall effect measurement, and contact angle measurement. The performance of the humidity sensor was assessed using a humidity sensor measurement system inside a humidity-controlled chamber. Based on the result, the combination of TiO2 with rGO produced the highest sensor response at 39,590%. The achievement is attributed to the increase in the electrical conductivity, hydrophilicity, and specific surface area of the composite.

Few-layered nitrogen-doped graphene wrapped three-dimensional titanium oxide flower as a robust support for Pt nanoparticles in catalyzing oxygen reduction reaction

• Few-layered nitrogen-doped graphene wrapped 3D flower-like TiO 2 is synthesized. • The anti-corrosion support has a high surface area and electronic conductivity. • Pt-TiO 2 @N-Gr-800 exhibits superior ORR activity, stability, and CO tolerance. • Pt-TiO 2 @N-Gr-800 shows a strong metal and support interaction. Carbon materials are commonly used as electrocatalyst supports in fuel cells. Nevertheless, carbon corrosion is a severe concern under strong acidic and oxidizing environments. Hence, developing a robust catalyst support is critical to ensuring fuel cells stability. Herein, we report a unique support of few-layered nitrogen-doped graphene wrapped three-dimensional (3D) flower-like anatase TiO 2 (TiO 2 @N-Gr) via in-situ polymerizing dopamine on the surface of a 3D-TiO 2 flower precursor, followed by pyrolysis. After loading Pt nanoparticles, Pt-TiO 2 @N-Gr-800 exhibits comparable ORR activity to the commercial Pt/C catalyst (E 1/2 = 0.91 V RHE ), superior stability in a 30 K cycling stability test and strong CO resistance capability. The outstanding performance of the Pt-TiO 2 @N-Gr-800 catalyst is attributed to the strong anti-corrosion property and high electronic conductivity of the nanocomposite support, as well as a strong metal and support interaction. The unique flower-like scaffold is also of great advantage for mass transfer. This work provides a facile strategy to synthesize robust nanocomposite supports for fuel cells.

Simultaneous Closure Of Bilateral Cranial Defects Using Custom-Made 3D Titanium Implants- A Single Institution Series.

Closure of bilateral cranial defects using custom-made implants is challenging for neurosurgeons due to enlarging defect areas and challenges in developing materials or techniques such as mirror imaging. This study presents the outcomes of the simultaneous closure of bilateral cranial defects using custom-made three-dimensional (3D) titanium implants. Demographic data of 26 patients with bilateral cranial defects who underwent cranioplasty using the 3D custom-made titanium implants in our clinic between 2017 and 2022 were retrospectively reviewed. Data on the area of cranium defect, the time interval between last cranial surgery and cranioplasty, postoperative complications, etiology of the cranium defect, and hospitalization of the patient were statistically evaluated. The incidence of bilateral cranioplasty was 19.11%. The gender distribution of patients was 4 (15.4%) female and 22 (84.6%) male, with a mean age of 29.08 ± 14.65 years. The mean defect area was 35.0 ± 19.03 and 29.24 ± 22.51 cm2 on the right and left sides, respectively. The etiology of the cranium defect was gunshot wounds in 12 patients, and 14 patients had a history of trauma-related injuries such as falls and vehicle accidents. Eight patients had a history of failed cranioplasty with autologous bone. Postoperative complications were wound dehiscence in two patients and diffuse cerebral edema in one patient. No mortality was recorded. The custom-made cranioplasty is feasible for simultaneous closure of bilateral cranial defects. Many complications can be prevented by careful preoperative evaluation before surgery and an appropriate implant selection for the patient.

A Novel Titanium Cranioplasty Technique of Marking the Coronal and Squamosoparietal Sutures in Three-Dimensional Titanium Mesh as Anatomical Positioning Markers to Increase the Surgical Accuracy and Reduce Postoperative Complications.

Objective: The objective of this research is to modify the titanium cranioplasty (Ti-CP) technique to increase the surgical accuracy and preliminarily verify the effectiveness and safety of this improvement.Methods: We developed a novel technique of marking the coronal and squamosoparietal sutures in three-dimensional (3D) titanium mesh as anatomical positioning markers and designed a prospective trial in patients with a unilateral frontotemporoparietal skull defect. Patients were randomly divided into two groups by the presence or absence of the anatomical positioning markers, and the therapeutic effects of these two groups were compared.Results: Forty-four patients were included in this study, including 28 (64%) males and 16 (36%) females. The mean age was 44.8 ± 15.2 years (range, 13–75 years). Overall postoperative complication rate of the intervention group (18%) was significantly (P = 0.03) lower than the control group (50%). Surgical accuracy of the intervention group (97.8%) was significantly (P < 0.001) higher than the control group (94%). Visual analog scale for cosmesis (VASC) of the intervention group (8.4) was significantly (P < 0.001) higher than the control group (7). The overall postoperative complication rate was 34%. Multivariate analyses showed that surgical accuracy <95.8% (OR = 19.20, 95% CI = 3.17–116.45, P = 0.001) was significantly associated with overall postoperative complications. Independent predictor of overall postoperative complications was surgical accuracy (OR = 0.57, 95% CI = 0.40–0.82, P = 0.002).Conclusions: This novel technique for repairing frontotemporoparietal skull defects increases surgical accuracy, improves cosmetic prognosis, and reduces postoperative complications. Therefore, it is a safe and effective improvement for Ti-CP.

3D-printed titanium cages without bone graft outperform PEEK cages with autograft in an animal model

BACKGROUND CONTEXTModernization of 3D printing has allowed for the production of porous titanium interbody cages (3D-pTi) which purportedly optimize implant characteristics and increase osseointegration; however, this remains largely unstudied in vivo. PURPOSETo compare osseointegration of three-dimensional (3D) titanium cages without bone graft and Polyether-ether-ketone (PEEK) interbody cages with autologous iliac crest bone graft (AICBG). STUDY DESIGNAnimal study utilizing an ovine in vivo model of lumbar fusion. METHODSInterbody cages of PEEK or 3D-pTi supplied by Spineart SA (Geneva, Switzerland) were implanted in seven living sheep at L2-L3 and L4-L5, leaving the intervening disc space untreated. Both implant materials were used in each sheep and randomized to the aforementioned disc spaces. Computed tomography (CT) was obtained at 4 weeks and 8 weeks. MicroCT and histological sections were obtained to evaluate osseointegration. RESULTSMicroCT demonstrated osseous in-growth of native cancellous bone in the trabecular architecture of the 3D-pTi interbody cages and no interaction between the PEEK cages with the surrounding native bone. Qualitative histology revealed robust osseointegration in 3D-pTi implants and negligible osseointegration with localized fibrosis in PEEK implants. Evidence of intramembranous and endochondral ossification was apparent with the 3D-pTi cages. Quantitative histometric bone implant contact demonstrated significantly more contact in the 3D-pTi implants versus PEEK (p<.001); region of interest calculations also demonstrated significantly greater osseous and cartilaginous interdigitation at the implant-native bone interface with the 3D-pTi cages (p=.008 and p=.015, respectively). CONCLUSIONS3D-pTi interbody cages without bone graft outperform PEEK interbody cages with AICBG in terms of osseointegration at 4 and 8 weeks postoperatively in an ovine lumbar fusion model. CLINICAL SIGNIFICANCE3D-pTi interbody cages demonstrated early and robust osseointegration without any bone graft or additive osteoinductive agents. This may yield early stability in anterior lumbar arthrodesis and potentially bolster the rate of successful fusion. This could be of particular advantage in patients with spinal neoplasms needing post-ablative arthrodesis, where local autograft use would be ill advised.

Low Intensity Pulsed Ultrasound for Bone Tissue Engineering.

As explained by Wolff’s law and the mechanostat hypothesis, mechanical stimulation can be used to promote bone formation. Low intensity pulsed ultrasound (LIPUS) is a source of mechanical stimulation that can activate the integrin/phosphatidylinositol 3-OH kinase/Akt pathway and upregulate osteogenic proteins through the production of cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2). This paper analyzes the results of in vitro and in vivo studies that have evaluated the effects of LIPUS on cell behavior within three-dimensional (3D) titanium, ceramic, and hydrogel scaffolds. We focus specifically on cell morphology and attachment, cell proliferation and viability, osteogenic differentiation, mineralization, bone volume, and osseointegration. As shown by upregulated levels of alkaline phosphatase and osteocalcin, increased mineral deposition, improved cell ingrowth, greater scaffold pore occupancy by bone tissue, and superior vascularization, LIPUS generally has a positive effect and promotes bone formation within engineered scaffolds. Additionally, LIPUS can have synergistic effects by producing the piezoelectric effect and enhancing the benefits of 3D hydrogel encapsulation, growth factor delivery, and scaffold modification. Additional research should be conducted to optimize the ultrasound parameters and evaluate the effects of LIPUS with other types of scaffold materials and cell types.