scholarly journals Influence of Materials Properties on Bio-Physical Features and Effectiveness of 3D-Scaffolds for Periodontal Regeneration

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1643
Author(s):  
Nicola d’Avanzo ◽  
Maria Chiara Bruno ◽  
Amerigo Giudice ◽  
Antonia Mancuso ◽  
Federica De Gaetano ◽  
...  
Keyword(s):  
Periodontal Diseases ◽  
Periodontal Regeneration ◽  
Three Dimensional ◽  
3D Scaffolds ◽  
Materials Properties ◽  
Severe Infections ◽  
Systemic Side Effects ◽  
Bad Breath ◽  
Multifactorial Disorders ◽  
Physical Features

Periodontal diseases are multifactorial disorders, mainly due to severe infections and inflammation which affect the tissues (i.e., gum and dental bone) that support and surround the teeth. These pathologies are characterized by bleeding gums, pain, bad breath and, in more severe forms, can lead to the detachment of gum from teeth, causing their loss. To date it is estimated that severe periodontal diseases affect around 10% of the population worldwide thus making necessary the development of effective treatments able to both reduce the infections and inflammation in injured sites and improve the regeneration of damaged tissues. In this scenario, the use of 3D scaffolds can play a pivotal role by providing an effective platform for drugs, nanosystems, growth factors, stem cells, etc., improving the effectiveness of therapies and reducing their systemic side effects. The aim of this review is to describe the recent progress in periodontal regeneration, highlighting the influence of materials’ properties used to realize three-dimensional (3D)-scaffolds, their bio-physical characteristics and their ability to provide a biocompatible platform able to embed nanosystems.

French RPV PTS Assessment: An Overview of EDF Research and Development in Progress on Thermalhydraulic, Materials and Mechanical Aspects

2003 ◽  
Author(s):  
Dominique Moinereau ◽  
Jean-Michel Frund ◽  
Henriette Churier-Bossennec ◽  
Georges Bezdikian ◽  
Alain Martin
Keyword(s):  
Structural Integrity ◽  
Three Dimensional ◽  
Crack Arrest ◽  
Pressure Vessels ◽  
Short Description ◽  
Constraint Effect ◽  
Materials Properties ◽  
Integrity Assessment ◽  
Pressurized Thermal Shock ◽  
Reactor Pressure

A significant extensive Research & Development work is conducted by Electricite´ de France (EDF) related to the structural integrity re-assessment of the French 900 and 1300 MWe reactor pressure vessels in order to increase their lifetime. Within the framework of this programme, numerous developments have been implemented or are in progress related to the methodology to assess flaws during a pressurized thermal shock (PTS) event. The paper contains three aspects: a short description of the specific French approach for RPV PTS assessment, a presentation of recent improvements on thermalhydraulic, materials and mechanical aspects, and finally an overview of the present R&D programme on thermalhydraulic, materials and mechanical aspects. Regarding the last aspect on present R&D programme, several projects in progress will be shortly described. This overview includes the redefinition of some significant thermalhydraulic transients based on some new three-dimensional CFD computations (focused at the present time on small break LOCA transient), the assessment of vessel materials properties, and the improvement of the RPV PTS structural integrity assessment including several themes such as warm pre-stress (WPS), crack arrest, constraint effect ....

scholarly journals “Three-Dimensional Printing” – A New Vista for Periodontal Regeneration: A Review

2017 ◽  
Vol 4 (3) ◽  
pp. 81-85
Author(s):  
Ravindra Babu Lakkaraju ◽  
Vikram Reddy Guntakandla ◽  
Jagadish Reddy Gooty ◽  
Raja Babu Palaparthy ◽  
Ravi Kiran Vundela ◽  
...  
Keyword(s):  
Periodontal Regeneration ◽  
Three Dimensional ◽  
Three Dimensional Printing ◽  
Dimensional Printing

scholarly journals Naturally Prefabricated Marine Biomaterials: Isolation and Applications of Flat Chitinous 3D Scaffolds from Ianthella labyrinthus (Demospongiae: Verongiida)

2019 ◽  
Vol 20 (20) ◽  
pp. 5105 ◽  
Author(s):  
Mario Schubert ◽  
Björn Binnewerg ◽  
Alona Voronkina ◽  
Lyubov Muzychka ◽  
Marcin Wysokowski ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Three Dimensional ◽  
Marine Sponges ◽  
Biologically Active ◽  
3D Scaffolds ◽  
Chemical Treatments ◽  
The Family ◽  
Unique Source ◽  
Induced Pluripotent ◽  
First Time

Marine sponges remain representative of a unique source of renewable biological materials. The demosponges of the family Ianthellidae possess chitin-based skeletons with high biomimetic potential. These three-dimensional (3D) constructs can potentially be used in tissue engineering and regenerative medicine. In this study, we focus our attention, for the first time, on the marine sponge Ianthella labyrinthus Bergquist & Kelly-Borges, 1995 (Demospongiae: Verongida: Ianthellidae) as a novel potential source of naturally prestructured bandage-like 3D scaffolds which can be isolated simultaneously with biologically active bromotyrosines. Specifically, translucent and elastic flat chitinous scaffolds have been obtained after bromotyrosine extraction and chemical treatments of the sponge skeleton with alternate alkaline and acidic solutions. For the first time, cardiomyocytes differentiated from human induced pluripotent stem cells (iPSC-CMs) have been used to test the suitability of I. labyrinthus chitinous skeleton as ready-to-use scaffold for their cell culture. Results reveal a comparable attachment and growth on isolated chitin-skeleton, compared to scaffolds coated with extracellular matrix mimetic Geltrex®. Thus, the natural, unmodified I. labyrinthus cleaned sponge skeleton can be used to culture iPSC-CMs and 3D tissue engineering. In addition, I. labyrinthus chitin-based scaffolds demonstrate strong and efficient capability to absorb blood deep into the microtubes due to their excellent capillary effect. These findings are suggestive of the future development of new sponge chitin-based absorbable hemostats as alternatives to already well recognized cellulose-based fabrics.

scholarly journals Quantitative Research and Characterization of the Loess Microstructure in the Bai Lu Tableland, Shaanxi Province, China

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Longsheng Deng ◽  
Wen Fan ◽  
Shaopeng Liu ◽  
Yupeng Chang ◽  
Yan Dai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Quantitative Research ◽  
Three Dimensional ◽  
Channel Length ◽  
Shaanxi Province ◽  
Third Order ◽  
Axis Ratio ◽  
Loess Particles ◽  
Serial Samples ◽  
Physical Features

Loess is a special geotechnical material with strong structural properties, and the microstructural characteristics of loess significantly influence its macroscopic physical features, mechanical properties, and catastrophic behavior. In this paper, serial samples were extracted from the continuous loess and paleosol strata of the Bai Lu tableland; with these samples, the optical microscopy-based serial sectioning method was adopted to study the quantitative characterization and variation in the loess microstructure. Three-dimensional characteristics and quantitative parameters of the particles, pores, and throats of the loess were obtained. The results indicate that the volume, Eq-Radius, and major-minor axis ratio of the loess particles satisfy third-order, third-order, and second-order Gaussian distributions, respectively. The Eq-Radius of the loess pores and throats satisfies a first-order Gaussian distribution, and the throat channel length satisfies a gamma distribution. With increasing stratum depth, the particles become more flattened, the throat radii become larger and the pore channels become slenderer. The variation in fitting parameters and the correlations between the macrophysical and mechanical properties of loess were then explored. The study of the microstructure of loess contributes to a better understanding of the catastrophic behavior of loess and the physical mechanism of geologic hazards in this area.

Three-Dimensional Microfabrication System for Scaffolds in Tissue Engineering

2006 ◽  
Vol 326-328 ◽  
pp. 723-726 ◽  
Author(s):  
Seung Jae Lee ◽  
Byung Kim ◽  
Jin Sang Lee ◽  
Sung Won Kim ◽  
Min Soo Kim ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Complex Environments ◽  
Key Factors ◽  
3D Scaffolds ◽  
Fundamental Limitations ◽  
Adhesion Behavior ◽  
Basic Biology ◽  
Geometrical Factors ◽  
Human Nasal Septum ◽  
Near Future

Understanding chondrocyte behavior inside complex, three-dimensional environments with controlled patterning of geometrical factors would provide significant insights into the basic biology of tissue regenerations. One of the fundamental limitations in studying such behavior has been the inability to fabricate controlled 3D structures. To overcome this problem, we have developed a three-dimensional microfabrication system. This system allows fabrication of predesigned internal architectures and pore size by stacking up the photopolymerized materials. Photopolymer SL5180 was used as the 3D microfabricated scaffolds. The results demonstrate that controllable and reproducible inner-architecture can be fabricated. Chondrocytes from human nasal septum were cultured in 3D scaffolds for cell adhesion behavior. Such 3D scaffolds might provide effective key factors to study cell behavior in complex environments and could eventually lead to optimum design of scaffolds in various tissue regenerations such as cartilage, bone, etc. in a near future.

scholarly journals Freeze-dried multiscale porous nanofibrous three dimensional scaffolds for bone regenerations

Bioimpacts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 73-85 ◽  
Author(s):  
Maryam Sadat Khoramgah ◽  
Javad Ranjbari ◽  
Hojjat-Allah Abbaszadeh ◽  
Fatemeh Sadat Tabatabaei Mirakabad ◽  
Shadie Hatami ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Freeze Drying ◽  
Three Dimensional ◽  
Cross Linking ◽  
Drying Methods ◽  
3D Scaffolds ◽  
Hierarchical Porous ◽  
Physicochemical Features

Introduction: Simulating hydrophobic-hydrophilic composite face with hierarchical porous and fibrous architectures of bone extracellular matrix (ECM) is a key aspect in bone tissue engineering. This study focused on the fabrication of new three-dimensional (3D) scaffolds containing polytetrafluoroethylene (PTFE), and polyvinyl alcohol (PVA), with and without graphene oxide (GO) nanoparticles using the chemical cross-linking and freeze-drying methods for bone tissue application. The effects of GO on physicochemical features and osteoinduction properties of the scaffolds were evaluated through an in vitro study. Methods: After synthesizing the GO nanoparticles, two types of 3D scaffolds, PTFE/PVA (PP) and PTFE/PVA/GO (PPG), were developed by cross-linking and freeze-drying methods. The physicochemical features of scaffolds were assessed and the interaction of the 3D scaffold types with human adipose mesenchymal stem cells (hADSCs) including attachment, proliferation, and differentiation to osteogenic like cells were investigated. Results: GO nanoparticles were successfully synthesized with no agglomeration. The blending of PTFE as a hydrophobic polymer with PVA polymer and GO nanoparticles (hydrophilic compartments) were successful. Two types of 3D scaffolds had nano topographical structures, good porosities, hydrophilic surfaces, thermal stabilities, good stiffness, as well as supporting the cell attachments, proliferation, and osteogenic differentiation. Notably, GO incorporating scaffolds provided a better milieu for cell behaviors. Conclusion: Novel multiscale porous nanofibrous 3D scaffolds made from PTFE/ PVA polymers with and without GO nanoparticles could be an ideal candidate for bone tissue engineering as a 3D template.

scholarly journals SARS-CoV-2 Restructures the Host Chromatin Architecture

2021 ◽  
Author(s):  
Ruoyu Wang ◽  
Joo-Hyung Lee ◽  
Feng Xiong ◽  
Jieun Kim ◽  
Lana Al Hasani ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Host Cells ◽  
Interferon Response ◽  
Genome Architecture ◽  
3D Genome ◽  
Chromatin Architecture ◽  
Severe Infections ◽  
Global Reduction ◽  
Host Chromatin

SARS-CoV-2 has made >190-million infections worldwide, thus it is pivotal to understand the viral impacts on host cells. Many viruses can significantly alter host chromatin, but such roles of SARS-CoV-2 are largely unknown. Here, we characterized the three-dimensional (3D) genome architecture and epigenome landscapes in human cells after SARS-CoV-2 infection, revealing remarkable restructuring of host chromatin architecture. High-resolution Hi-C 3.0 uncovered widespread A compartmental weakening and A-B mixing, together with a global reduction of intra-TAD chromatin contacts. The cohesin complex, a central organizer of the 3D genome, was significantly depleted from intra-TAD regions, supporting that SARS-CoV-2 disrupts cohesin loop extrusion. Calibrated ChIP-Seq verified chromatin restructuring by SARS-CoV-2 that is particularly manifested by a pervasive reduction of euchromatin modifications. Built on the rewired 3D genome/epigenome maps, a modified activity-by-contact model highlights the transcriptional weakening of antiviral interferon response genes or virus sensors (e.g., DDX58) incurred by SARS-CoV-2. In contrast, pro-inflammatory genes (e.g. IL-6) high in severe infections were uniquely regulated by augmented H3K4me3 at their promoters. These findings illustrate how SARS-CoV-2 rewires host chromatin architecture to confer immunological gene deregulation, laying a foundation to characterize the long-term epigenomic impacts of this virus.

Qualitative Assessment of Four Types of Three-Dimensional Printed Anatomical Tibial Bone Models Compared to Commercially Available Models

2020 ◽  
Vol 33 (04) ◽  
pp. 267-273
Author(s):  
Sarah Malek ◽  
Cassandra D. Foster ◽  
Davin H. Huston
Keyword(s):  
Model Development ◽  
Three Dimensional ◽  
Acrylonitrile Butadiene Styrene ◽  
Cost Effective ◽  
Qualitative Assessment ◽  
Tibial Bone ◽  
Cost Effective Alternative ◽  
Polylactide Acid ◽  
Physical Features

Abstract Objective The aim of this study was to compare technical and physical features of four three-dimensional printed bone models used for teaching purposes to commercial models. Study Design A canine tibia was imaged using computed tomography and used for model development. Tibial models were printed using Resin, polylactide acid (PLA), acrylonitrile butadiene styrene (ABS) and high-impact polystyrene (HIPS). They were compared with two commercial models (SAWBONES 2117 and 2108). Models were drilled in three locations and then cut transversely. Subjective quality of models, time and cost of production were compared. Results Print time was approximately 3 hours for Resin and 4 hours for each of the PLA, ABS and HIPS models. Unlike the Resin and SAWBONES, the PLA, HIPS and ABS had higher heat generation during both drilling and cutting with mild construct deformation at cut surfaces in ABS and PLA models. Characteristics of real bone during drilling and cutting were best simulated in decreasing order by Resin, PLA, ABS and HIPS followed by SAWBONES 2117 and 2108 models. Material costs were $14.6 (Resin), $0.48 (PLA/ABS), $1.52 (HIPS), $23.50 and $17.50 for SAWBONES 2117 and 2108 per model, respectively. Resin performed best and had the closest subjective tactile properties to real bone. Conclusion The three-dimensional printed tibial bone models provide a cost-effective alternative to commercially available bone models in veterinary medicine as teaching models.

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