Fabrication Of Templates Research Articles

Self-sacrificing template fabrication of mesoporous CuO micro/nanoplates for photo-Fenton-like oxidation of sulfathiazole

In this study, we offer a simple self-sacrificial template-directed method to prepare mesoporous CuO micro/nanoplates by using copper hydroxide acetate (Cu2(OH)3(CH3COO)·H2O) plates as a template. The as-prepared material was structurally, morphologically, optically and texturally characterized and its excellent catalytic activity in the LED-driven photo-Fenton-like process of sulfathiazole oxidation was demonstrated. Within 90 min, 100 % sulfathiazole degradation and 87.3 % TOC removal were achieved in the presence of H2O2 and visible LED irradiation. Moreover, the degradation of sulfathiazole can still reach 96.1 % after five cycles, which indicates exceptional performance of the catalyst.

Enhancing craniofacial bone tissue engineering strategy: integrating rapid wet chemically synthesised bioactive glass with photopolymerized resins

BackgroundCraniofacial bone regeneration represents a dynamic area within tissue engineering and regenerative medicine. Central to this field, is the continual exploration of new methodologies for template fabrication, leveraging established bio ceramic materials, with the objective of restoring bone integrity and facilitating successful implant placements.MethodsPhotopolymerized templates were prepared using three distinct bio ceramic materials, specifically a wet chemically synthesized bioactive glass and two commercially sourced hydroxyapatite variants. These templates underwent comprehensive characterization to assess their physicochemical and mechanical attributes, employing techniques including Fourier transform infrared spectroscopy, scanning electron microscopy, and nano-computed tomography. Evaluation of their biocompatibility was conducted through interaction with primary human osteoblasts (hOB) and subsequent examination using scanning electron microscopy.ResultsThe results demonstrated that composite showed intramolecular hydrogen bonding interactions with the photopolymer, while computerized tomography unveiled the porous morphology and distribution within the templates. A relatively higher porosity percentage (31.55 ± 8.70%) and compressive strength (1.53 ± 0.11 MPa) was noted for bioactive glass templates. Human osteoblast cultured on bioactive glass showed higher viability compared to other specimens. Scanning micrographs of human osteoblast on templated showed cellular adhesion and the presence of filopodia and lamellipodia.ConclusionIn summary these templates have the potential to be used for alveolar bone regeneration in critical size defect. Photopolymerization of bioceramics may be an interesting technique for scaffolds fabrication for bone tissue engineering application but needs more optimization to overcome existing issues like the ideal ratio of the photopolymer to bioceramics.

Computer-Assisted Porcelain Laminate Veneer Preparation: A Scoping Review of Stereolithographic Template Design and Fabrication Workflows.

Computer-assisted preparation of porcelain laminate veneers (PLVs) using stereolithographic templates has been developed to enhance the accuracy of tooth preparation. However, the digital workflows involved in guided PLV preparation remain inconsistently defined across various practices. Therefore, this scoping review aimed to examine publications on computer-assisted PLV preparation to identify the key stage of digital workflows involved in designing and fabricating stereolithographic templates, as well as to highlight the limitations of various template designs. This scoping review aimed to identify publications on digital workflows for designing and fabricating stereolithographic templates in computer-assisted porcelain laminate veneer preparation. A systematic search on MEDLINE/PubMed, Web of Science and Scopus identified English-language articles published from 2014 to March 2024. Eligible articles focused on digitally designed and fabricated tooth reduction templates for porcelain laminate veneers, excluding conventional tooth preparation procedures for tooth reduction assessment. Seven clinical reports were included, demonstrating various 3D data acquisition techniques for virtual patient generation. All articles described virtual diagnostic wax-ups on digital casts, with two using a virtual articulator. Only five articles documented chair-side mock-ups with resin trial restorations to evaluate planned dental esthetics. Additionally, virtual tooth preparation prior to templates design was included in only four articles. The templates were designed using different software and ranged from simple designs with access windows to complex stacked templates with rotary instrument sleeved windows. Each template design had limitations affecting tooth reduction accuracy. All articles reported printing templates in clear acrylic resin using different technologies. In conclusion, the review highlights a lack of standardization in the digital workflow for designing stereolithographic templates for PLVs. Establishing a sound protocol for designing the tooth reduction templates is essential to ensure the accuracy and consistency of veneer preparation.

A molecular synergy of non-covalent interactions facilitated via theobromine modifying the self-assembly process of type I collagen

Type I Collagen is a multifunctional fibrous protein present significantly in the connective tissues. Generally, fibril formation process of an interstitial collagen begins with a triple helix alignment to form a pentafibril, which sequentially self-assembles into a microfibril. Typically, this sequential formation can be achieved under an in vitro condition as well by maintaining certain specific physiological parameters to mimic the interstitial microenvironment of collagen. The necessity to study such a kinetically driven process is due to its implications in template fabrication particularly as a scaffold to enhance the growth of specific stem cells or accelerating nanoparticle synthesis. Drawing inspiration from this, theobromine, a methylxanthine that contributes towards the hydrogen bond network via dimerization and stacking interaction was used as a small molecule in modifying the molecular level interactions of a self-assembled collagen. Initially, rheological studies revealed certain variations in the viscous properties of collagen on addition of theobromine. Turbidity assay showed an increase in the rate of fibril formation and its topographical changes were observed through the high-resolution scanning electron microscope. The stability and probable physico-chemical interactions between collagen and theobromine were comprehended from the vibrational frequency changes recorded using (FT-IR) (ATR) and conformational changes using Circular Dichroism (CD) studies. Our results show possible multibinding sites on theobromine, which would compete to bind with the polar and non-polar residues exposed over the monomeric surfaces of triple helix causing a local conformational fluctuation modifying protein-protein interaction.

Fabrication of high-quality Al-polar and N-polar AlN templates through self-forming tiny-pit layers and polarity inversion

Fabrication of high-quality Al-polar and N-polar AlN templates through self-forming tiny-pit layers and polarity inversion

Merging Mandibular Virtual Data Sets in Partially Edentulous Patients with a High-level of Scattering on Cone-beam CT Scans: A Technical Report.

Digital implant planning, utilizing the convergence of digital surface scanners, cone beam computer tomography (CBCT) scans, and advanced planning software, has transformed dental implantology. The merging of these data sets through triangulation of landmarks provides a detailed digital model of the jaws, facilitating precise implant positioning in edentulous areas. A critical step in this digital workflow is the accurate merging of DICOM files with STL/PLY/OBJ files, which underpins the design and fabrication of surgical templates for accurate implant placement. Errors in this phase can lead to implant mispositioning or damage to adjacent structures. Particularly in partial edentulism, the merging is based on the occlusal topography of the remaining teeth but scattering in the CBCT data-caused by interactions of radiation with radiodense materials-can complicate this process or even render it impossible. The manuscript presents a technique utilizing radiopaque markers to overcome scattering effects, ensuring accurate dataset superimposition in the mandible.

Three-dimensional anodic aluminum templates via a single-step pulsed potential method

Recent advances in the fabrication of three-dimensional Anodic Aluminum Oxide templates have opened novel opportunities in the generation of photonic structures and material nanostructuration. So far these structures have been produced from the standard two-step pulsed potential anodization and modulated current density anodization approaches. However, their fabrication is slow, with the two-step approach relying on intermediate oxide removal steps that often use toxic etchants. In this work, we report the fabrication of 3D Anodic Aluminum Oxide templates from a single-step pulsed potential method, completely removing the need for intermediate etching steps, and decreasing total fabrication times to less than 24 hours. Structural coloration was also successfully demonstrated and analyzed in these templates, for 99.999% and 99.5% Al precursors, presenting the same morphology and optical functionality as templates produced from two-step processes.

Monte Carlo simulation-guided design for size-tuned tumor spheroid formation in 3D printed microwells.

Tumor spheroid models have garnered significant attention in recent years as they can efficiently mimic in vivo models, and in addition, they offer a more controlled and reproducible environment for evaluating the efficacy of cancer drugs. In this study, we present the design and fabrication of a micromold template to form multicellular spheroids in a high-throughput and controlled-sized fashion. Briefly, polydimethylsiloxane-based micromolds at varying sizes and geometry were fabricated via soft lithography using 3D-printed molds as negative templates. The efficiency of spheroid formation was assessed using GFP-expressing human embryonic kidney 293 cells (HEK-293). After 7 days of culturing, circularity and cell viability of spheroids were >0.8 and 90%, respectively. At 1500 cells/microwell of cell seeding concentration, the spheroids were 454 ± 15 μm, 459 ± 7 μm, and 451 ± 18 μm when cultured in microwells with the diameters of 0.4, 0.6, and 0.8 μm, respectively. Moreover, the distance between each microwell and surfactant treatment before cell seeding notably impacted the uniform spheroid formation. The centrifugation was the key step to collect cells on the bottom of the microwells. Our findings were further verified using a commercial microplate. Furthermore, Monte Carlo simulation confirmed the seeding conditions where the spheroids could be formed. This study showed prominent steps in investigating spheroid formation, thereby leveraging the current know-how on the mechanism of tumor growth.

The Accuracy of Guided Implant Surgery With Different Fields of View of Cone-Beam Computerized Tomography.

Although a smaller size field of view (FOV) of cone-beam computerized tomography (CBCT) reduces radiation exposure, its effect on the accuracy of static computer-aided implant surgery (s-CAIS) remains unknown. This study aimed to evaluate the impact of the size of FOV on the accuracy of s-CAIS and to investigate if the arch affects this effect. A total of 32 implant sites on 8 identical scannable models (maxillae and mandibles) were randomly allocated to 2 FOV sizes: test (5 × 5 cm) and control (10 × 10 cm). All models were scanned with an intraoral scanner (IOS). With the registration of the surface scan and CBCT image, a prosthetic-driven implant position was planned. Following the fabrication of surgical templates, a single-blinded surgeon placed all implants with the fully guided s-CAIS protocol. IOS captured the implant positions with the scan body attached. Implant-planning software measured the angular deviation, 3-dimensional (3D) deviation at the crest, and 3D deviation at the apex between preplanned and actual implant positions. Two-way analysis of variance was used to analyze the effect of FOV and arch on the deviations. The size of FOV did not show a significant effect (P > .198) on angular deviation, 3D deviation at the crest, or 3D deviation at the apex. No significant difference was found when comparing the effect of the size of FOV between the maxillary and mandibular implants. In conclusion, the use of small FOV CBCT demonstrated comparable accuracy of s-CAIS to the use of medium FOV CBCT.

Evaluation of the accuracy of fully guided implant placement by undergraduate students and postgraduate dentists: a comparative prospective clinical study

PurposeThis study aimed to assess the accuracy of implant placement through three-dimensional planning and fully guided insertion, comparing outcomes between undergraduate and postgraduate surgeons.MethodsThirty-eight patients requiring 42 implants in posterior single-tooth gaps were enrolled from the University Clinic for Prosthodontics at the Martin Luther University Halle Wittenberg and the Department of Prosthodontics, Geriatric Dentistry, and Craniomandibular Disorders of Charité University Medicine, Berlin. Twenty-two implants were placed by undergraduate students (n = 18), while 20 implants were placed by trainee postgraduate dentists (n = 5). Pre-operative intraoral scans and cone beam computed tomography images were performed for implant planning and surgical template fabrication. Postoperative intraoral scans were superimposed onto the original scans to analyze implant accuracy in terms of apical, coronal, and angular deviations, as well as vertical discrepancies.ResultsIn the student group, two implant insertions were performed by the assistant dentist because of intraoperative complications and, thus, were excluded from further analysis. For the remaining implants, no statistically significant differences were observed between the dentist and student groups in terms of apical (p = 0.245), coronal (p = 0.745), or angular (p = 0.185) implant deviations, as well as vertical discrepancies (p = 0.433).ConclusionsThis study confirms the viability of fully guided implant placement by undergraduate students, with comparable accuracy to postgraduate dentists. Integration into dental education can prepare students for implant procedures, expanding access and potentially reducing costs in clinical practice. Collaboration is essential for safe implementation, and future research should explore long-term outcomes and patient perspectives, contributing to the advancement of dental education and practice.Trial registration: DRKS, DRKS00023024, Registered 8 September 2020—Retrospectively registered, https://drks.de/search/de/trial/DRKS00023024.

Nanoimprint lithography guiding templates for advanced magnetic media fabrication

Nanoimprint lithography presents unique opportunities for advanced magnetic storage media with ordered bit arrangements such as bit patterned media or heated dot magnetic recording. Providing sub-10 nm resolution and full disk imprinting capability, UV-nanoimprint lithography based on rigid quartz templates bears the entitlement for patterned recording media manufacturing with high throughput at low cost. However, a key challenge is the fabrication of the high-resolution template that can transfer the desired pattern onto the disk with high fidelity and low line edge roughness. In this article, we present fabrication routes and overcome challenges to the fabrication of quartz templates suitable for self-alignment and guiding purposes to be used for template replication toward full disk imprints. Guiding patterns down to 40 nm pitch are prepared using a rotary electron beam lithography tool. We compare three different process approaches to fabricate an etching mask for patterning the quartz. Two methods target chromium patterning, one with traditional lift-off and another by dry etching, both using an e-beam resist mask. The third approach is based on the development of a carbon-based Tri-layer hard mask. The template pattern profile is optimized for imprint-suitable sidewall angles using dry etching in a CF4/O2 chemistry. The templates were characterized using scanning electron microscopy and atomic force microscopy to evaluate the quality of the transferred pattern as well as line edge roughness. Our results show that the Tri-layer process using carbon resulted in the lowest line edge roughness of ≈0.65 nm at the imprinted disk level. In addition, we show that Tri-layer masking allowed for the use of conventional ZEP e-beam resist and fast writing speeds, while gaining high selectivity during quartz patterning.

Unidirectional Freezing of Polymer Solution Droplets.

Ice templating provides a means of generating textures with a well-defined topography. Recent applications involve the freezing of water droplets, with or without colloids, on flat or textured surfaces. An interesting feature of water droplets freezing on a substrate is the formation of a pointy tip at a constant angle, regardless of the substrate temperature, surface energy, or droplet volume. Here, by adding the polymer to water, we demonstrate how to manipulate and even prevent the formation of such an icy tip. We find that the sharpness of the tip decreases with increasing polymer concentration until completely disappearing above the overlap concentration, while the total freezing time increases concomitantly. Building on these observations, we combined simple geometrical arguments with heat flux measurements to model and connect the spatial and temporal evolution of polymer droplets under unidirectional freezing. Together our results provide new ways to control the shape of frozen droplets for ice templating or microstructure fabrication, with applications in tissue engineering, separation membranes, and soft robotics.

Nanoparticle Assembly: From Self-Organization to Controlled Micropatterning for Enhanced Functionalities.

Nanoparticles form long-range micropatterns via self-assembly or directed self-assembly with superior mechanical, electrical, optical, magnetic, chemical, and other functional properties for broad applications, such as structural supports, thermal exchangers, optoelectronics, microelectronics, and robotics. The precisely defined particle assembly at the nanoscale with simultaneously scalable patterning at the microscale is indispensable for enabling functionality and improving the performance of devices. This article provides a comprehensive review of nanoparticle assembly formed primarily via the balance of forces at the nanoscale (e.g., van der Waals, colloidal, capillary, convection, and chemical forces) and nanoparticle-template interactions (e.g., physical confinement, chemical functionalization, additive layer-upon-layer). The review commences with a general overview of nanoparticle self-assembly, with the state-of-the-art literature review and motivation. It subsequently reviews the recent progress in nanoparticle assembly without the presence of surface templates. Manufacturing techniques for surface template fabrication and their influence on nanoparticle assembly efficiency and effectiveness are then explored. The primary focus is the spatial organization and orientational preference of nanoparticles on non-templated and pre-templated surfaces in a controlled manner. Moreover, the article discusses broad applications of micropatterned surfaces, encompassing various fields. Finally, the review concludes with a summary of manufacturing methods, their limitations, and future trends in nanoparticle assembly.

Design of Tailor-Made Biopolymer-Based Capsules for Biological Application by Combining Porous Particles and Polysaccharide Assembly.

Various approaches have been described in the literature to demonstrate the possibility of designing biopolymer particles with well-defined characteristics, such as size, chemical composition or mechanical properties. From a biological point of view, the properties of particle have been related to their biodistribution and bioavailability. Among the reported core-shell nanoparticles, biopolymer-based capsules can be used as a versatile platform for drug delivery purposes. Among the known biopolymers, the present review focuses on polysaccharide-based capsules. We only report on biopolyelectrolyte capsules fabricated by combining porous particles as a template and using the layer-by-layer technique. The review focuses on the major steps of the capsule design, i.e., the fabrication and subsequent use of the sacrificial porous template, multilayer coating with polysaccharides, the removal of the porous template to obtain the capsules, capsule characterisation and the application of capsules in the biomedical field. In the last part, selected examples are presented to evidence the major benefits of using polysaccharide-based capsules for biological purposes.

Reconfigurable pH-Responsive DNA Origami Lattices.

DNA nanotechnology enables straightforward fabrication of user-defined and nanometer-precise templates for a cornucopia of different uses. To date, most of these DNA assemblies have been static, but dynamic structures are increasingly coming into view. The programmability of DNA not only allows for encoding of the DNA object shape but also it may be equally used in defining the mechanism of action and the type of stimuli-responsiveness of the dynamic structures. However, these "robotic" features of DNA nanostructures are usually demonstrated for only small, discrete, and device-like objects rather than for collectively behaving higher-order systems. Here, we show how a large-scale, two-dimensional (2D) and pH-responsive DNA origami-based lattice can be assembled into two different configurations ("open" and "closed" states) on a mica substrate and further switched from one to the other distinct state upon a pH change of the surrounding solution. The control over these two configurations is achieved by equipping the arms of the lattice-forming DNA origami units with "pH-latches" that form Hoogsteen-type triplexes at low pH. In short, we demonstrate how the electrostatic control over the adhesion and mobility of the DNA origami units on the surface can be used both in the large lattice formation (with the help of directed polymerization) and in the conformational switching of the whole lattice. To further emphasize the feasibility of the method, we also demonstrate the formation of pH-responsive 2D gold nanoparticle lattices. We believe this work can bridge the nanometer-precise DNA origami templates and higher-order large-scale systems with the stimuli-induced dynamicity.

Performance of Ultraviolet‐B Laser Diodes on AlGaN Templates Prepared Using Different Fabrication Methods

Herein, the differences in the characteristics of ultraviolet‐B (UV‐B) laser diodes (LDs) are investigated and fabricated on AlGaN templates prepared using two types of fabrication methods: 1) spontaneous nucleation in which AlGaN is grown 3D from spontaneously generated AlN crystal nuclei and 2) AlN nanopillar in which AlGaN is grown on AlN nanopillars. The LD formed on the AlGaN fabricated using the AlN nanopillar method of slope efficiency and maximum peak light output power is improved four and six times, respectively, which are significantly better compared with the spontaneous nucleation method. The analysis also confirms the differences in injection efficiency and internal loss in the semiconductor crystal. Furthermore, detailed analysis of the current–voltage characteristics shows that the AlN nanopillar method has lower reverse leakage current and n‐value than the spontaneous nucleation method. Comparison of these differences with crystallographic properties suggests that these differences in device properties are manifested by differences in V‐shaped pits and dislocation density. The reduction of dislocations and V‐shaped pit density in an AlGaN template is important to realize high‐performance UV‐B LDs, and the AlN nanopillar method is found to be useful for the fabrication of a suitable AlGaN template.

Introduction of temporomandibular joint and skull base combined reconstruction by autogenous bone graft.

This study introduces the application of autogenous bone graft for the reconstruction of temporomandibular joint (TMJ) and skull base combined defects. Patients treated with autogenous bone grafts for reconstruction of the TMJ and skull base were reviewed. All patients underwent virtual surgical design to confirm the osteotomies of the combined lesion and the selections of autogenous bone graft, fabrication of surgical templates to transfer the plan to actual operation, and reconstruction of autogenous bone graft for the TMJ and/or skull base. Surgical outcomes were assessed by clinical examinations and radiological data. Twenty-two patients were involved in this study. Ten patients underwent reconstruction of the skull base by a free iliac or temporal bone graft and preservation of the TMJ. Twelve patients underwent skull base reconstruction by the same methods and total reconstruction of the TMJ by half sternoclavicular joint flap or costochondral bone graft. No severe complications occurred after surgery. The occlusion relationship was stable and similar to that of the preoperative state. The pain and maximal interincisal opening were significantly improved by the 101.2-month follow-up. Autogenous bone graft is a good alternative for repairing the TMJ and the skull base structure and function. The study introduced the application of autogenous bone graft for the reconstruction of temporomandibular joint and skull base combined defect, which is a good way to repair the defect and restore the function.

An innovative digital workfl ow for the fabrication of a prosthetic ear: A case report

The aim of maxillofacial rehabilitation is to provide suitable prostheses for patients with oro-facial defects, and enable them to resume their roles in society. Recent advances in bionics and prosthetics have combined different techniques to help in the production of aesthetic and functional prostheses. Technology can now supplement the freehand sculpting skills of the clinician by capturing accurate images of the soft tissues from both the defect and non-defect areas, and using these to digitally recreate the desired templates. This case report describes the digital steps used to capture necessary data for the design and fabrication of an auricular template, and fi nal ear prosthesis. Results from this case study suggested that the digital method is: 1) more accurate; 2) less time-consuming than traditional methods; and 3) less invasive, and thus more accepted by patients.

Use of polyvinyl siloxane to maintain peri-implant submucosal contours on removal of screw-retained implant-supported restorations

When submucosal screw-retained implant-supported restorations are removed for a short period, the soft-tissue contours collapse, which can affect treatment expediency and patient comfort when restorations are reinserted. This technique involves the fabrication of a polyvinyl siloxane submucosal template to help mitigate the soft-tissue collapse and its potential sequelae. This method of maintaining peri-implant soft-tissue contours is achieved through a quick succession of steps: removing the screw-retained implant prosthesis, drying the soft tissue thoroughly, injecting light-bodied fast-set polyvinyl siloxane directly into the implant fixture of the internal connection implants and the screw channel for external connection implants together with the remaining submucosal areas, allowing the polyvinyl siloxane submucosal template to polymerize undisturbed, and removing it when ready to replace the prosthesis.

Block copolymer interfaces investigated by means of NMR, atomic force microscopy and dielectric spectroscopy

Self-assembly of block copolymers (BC) is a key feature for bottom-up patterning that is applied in the fabrication of templates for nanostructured membranes, photonic nanodevices, or solar cells. The wide range of possible BC applications is because the dissimilar blocks can be appropriately selected to form distinct domains with controllable dimensions and functionalities. An important representative of these materials is polystyrene-b-poly(ethylene oxide) (PS-b-PEO) diblock copolymer. This copolymer is of considerable academic interest and therefore it is examined by a plethora of experimental techniques to elucidate its structure and molecular dynamics. Particularly worth investigating is the interphase, consisting of polymer chains located at the interface of crystallite-amorphous and inter-domain regions, which codetermines the properties of such a system. It is shown that below the melting point of the PEO, the majority of the amorphous PEO are occupying interfacial sites and are represented by the rigid amorphous fraction (RAF) which can be monitored by dielectric and nuclear magnetic resonance spectroscopies. Moreover, two independent NMR spin-diffusion experiments reveal the asymmetrical nature of PS-PEO interface indicating a significant fraction of the PEO phase under the influence of stiff, adjacent polystyrene. An analysis of complementary thermal calorimetry and X-ray scattering data confirms the presence of microphase-separated morphology as well as the semicrystalline nature of PEO component. Lamelar domain architecture was confirmed by atomic force microscopy data acquired in the case of thin copolymer film.