Types Of Scaffolds Research Articles

Seq2Phase: language model-based accurate prediction of client proteins in liquid-liquid phase separation.

Liquid-liquid phase separation (LLPS) enables compartmentalization in cells without biological membranes. LLPS plays essential roles in membraneless organelles such as nucleoli and p-bodies, helps regulate cellular physiology, and is linked to amyloid formation. Two types of proteins, scaffolds and clients, are involved in LLPS. However, computational methods for predicting LLPS client proteins from amino-acid sequences remain underdeveloped. Here, we present Seq2Phase, an accurate predictor of LLPS client proteins. Information-rich features are extracted from amino-acid sequences by a deep-learning technique, Transformer, and fed into supervised machine learning. Predicted client proteins contained known LLPS regulators and showed localization enrichment into membraneless organelles, confirming the validity of the prediction. Feature analysis revealed that scaffolds and clients have different sequence properties and that textbook knowledge of LLPS-related proteins is biased and incomplete. Seq2Phase achieved high accuracies across human, mouse, yeast, and plant, showing that the method is not overfitted to specific species and has broad applicability. We predict that more than hundreds or thousands of LLPS client proteins remain undiscovered in each species and that Seq2Phase will advance our understanding of still enigmatic molecular and physiological bases of LLPS as well as its roles in disease. The software codes in Python underlying this article are available at https://github.com/IwasakiLab/Seq2Phase.

Scaffolds for Dentin-Pulp Complex Regeneration.

Background and Objectives: Regenerative dentistry aims to regenerate the pulp-dentin complex and restore those of its functions that have become compromised by pulp injury and/or inflammation. Scaffold-based techniques are a regeneration strategy that replicate a biological environment by utilizing a suitable scaffold, which is considered crucial for the successful regeneration of dental pulp. The aim of the present review is to address the main characteristics of the different scaffolds, as well as their application in dentin-pulp complex regeneration. Materials and Methods: A narrative review was conducted by two independent reviewers to answer the research question: What type of scaffolds can be used in dentin-pulp complex regeneration? An electronic search of PubMed, EMBASE and Cochrane library databases was undertaken. Keywords including "pulp-dentin regeneration scaffold" and "pulp-dentin complex regeneration" were used. To locate additional reports, reference mining of the identified papers was undertaken. Results: A wide variety of biomaterials is already available for tissue engineering and can be broadly categorized into two groups: (i) natural, and (ii) synthetic, scaffolds. Natural scaffolds often contain bioactive molecules, growth factors, and signaling cues that can positively influence cell behavior. These signaling molecules can promote specific cellular responses, such as cell proliferation and differentiation, crucial for effective tissue regeneration. Synthetic scaffolds offer flexibility in design and can be tailored to meet specific requirements, such as size, shape, and mechanical properties. Moreover, they can be functionalized with bioactive molecules, growth factors, or signaling cues to enhance their biological properties and the manufacturing process can be standardized, ensuring consistent quality for widespread clinical use. Conclusions: There is still a lack of evidence to determine the optimal scaffold composition that meets the specific requirements and complexities needed for effectively promoting dental pulp tissue engineering and achieving successful clinical outcomes.

Direct ink writing of hierarchical porous SiC ceramics as catalyst support for hydrogen production

Due to the tunable porosity at multiple scales, hierarchical porous ceramics feature large specific surface area and excellent heat and mass transfer performance, which can effectively improve the catalytic reaction performance. This paper presents a method to fabricate SiC scaffolds with regular and hierarchical pore structures by direct ink writing (DIW) combined with sacrificial template technology, which can be used as methanol steam reforming (MSR) microreactor catalyst supports. Through printing along a defined path, primary pores with a regular pore structure were created. After sintering, the sacrificial template was removed and secondary pores appeared. Four different types of hierarchical porous SiC scaffolds were successfully prepared and the pore structure, total porosity, linear shrinkage and compressive strength of these scaffolds were investigated. The catalyst coating was then loaded onto the scaffold, and the microstructure characterization showed that the pore structure would not be damaged and blocked. Finally, the hydrogen production experiments were carried out on the MSR microreactor, and the results showed that the support with larger and denser secondary pores had the best fluid flow and hydrogen production characteristics. At the temperature of 280 °C and the gas hourly space velocity (GHSV) of 30000 ml g−1 h−1, the methanol conversion and hydrogen production of the best support can reach 90.95 % and 44.96 ml/min, respectively.

한국어 초급 읽기 수업을 위한 비계설정 전략

Objectives This study suggests the strategy of scaffolding for learners who are beginners in Korean language as a foreign language and aims to use meaningful teaching and learning strategies in Korean beginner’s reading classes in the future.
 Methods To this end, many prior studies related to reading strategy and scaffolding were first considered. Based on the fact that scaffolding strategy research in Korean reading education as a foreign language was not conducted, theoretical background was considered to present scaffolding strategies which are necessary and appropriate for Korean beginner reading classes.
 Results Based on Kim (2005)'s direct scaffolding structure and strategy, this study reconstructed four scaffolding types: explaining; demonstrating; giving hints; asking questions. Newly reorganized settings and examples were also presented based upon Choi (2003).
 Conclusions The contributions of this research are presented as follows: (1) the need for scaffolding in beginner Korean reading as a foreign language was mentioned; (2) the scaffolding type in beginner Korean reading as a foreign language was newly reconstructed and presented, unlike the existing scaffolding type in reading education.

Advances in the Application of Photothermal Composite Scaffolds for Osteosarcoma Ablation and Bone Regeneration.

Photothermal therapy is a promising approach to cancer treatment. The energy generated by the photothermal effect can effectively inhibit the growth of cancer cells without harming normal tissues, while the right amount of heat can also promote cell proliferation and accelerate tissue regeneration. Various nanomaterials have recently been used as photothermal agents (PTAs). The photothermal composite scaffolds can be obtained by introducing PTAs into bone tissue engineering (BTE) scaffolds, which produces a photothermal effect that can be used to ablate bone cancer with subsequent further use of the scaffold as a support to repair the bone defects created by ablation of osteosarcoma. Osteosarcoma is the most common among primary bone malignancies. However, a review of the efficacy of different types of photothermal composite scaffolds in osteosarcoma is lacking. This article first introduces the common PTAs, BTE materials, and preparation methods and then systematically summarizes the development of photothermal composite scaffolds. It would provide a useful reference for the combination of tumor therapy and tissue engineering in bone tumor-related diseases and complex diseases. It will also be valuable for advancing the clinical applications of photothermal composite scaffolds.

The Portfolio of Evidence for Lab-To-Clinic Innovative Product Bio-Printed Cartilage with Living Cells.

Bio-printed cartilage with living cells is a regenerative cartilage scaffold that has living cells 3D printing out for the treatment of osteoarthritis and other conditions that damage articular cartilage. It is a new type of scaffold that is biocompatible, biomimetic, regenerative, and long term in use. Currently, there is a clinical and market lack of products for the regeneration of therapeutic cartilage, so the need for such scaffolds is necessary. Bio-printed cartilage with living cells from concept to product development and non-clinical and clinical testing to market launch requires evaluation of the scaffold for safety, efficacy, and compliance with specific requirements of the medical directives regulation and combined advanced therapy medicinal products.

Impact of interstitial flow on cartilage matrix synthesis and NF-kB transcription factor mRNA expression in a novel perfusion bioreactor.

This work is focused on designing an easy-to-use novel perfusion system for articular cartilage (AC) tissue engineering and using it to elucidate the mechanism by which interstitial shear upregulates matrix synthesis by articular chondrocytes (AChs). Porous chitosan-agarose (CHAG) scaffolds were synthesized and compared to bulk agarose (AG) scaffolds. Both scaffolds were seeded with osteoarthritic human AChs and cultured in a novel perfusion system with a medium flow velocity of 0.33 mm/s corresponding to 0.4 mPa surfice shear and 40 mPa CHAG interstitial shear. While there were no statistical differences in cell viability for perfusion versus static cultures for either scaffold type, CHAG scaffolds exhibited a 3.3-fold higher (p < 0.005) cell viability compared to AG scaffold cultures. Effects of combined superficial and interstitial perfusion for CHAG showed 150- and 45-fold (p < 0.0001) increases in total collagen (COL) and 13- and 2.2-fold (p < 0.001) increases in glycosaminoglycans (GAGs) over AG non-perfusion and perfusion cultures, respectively, and a 1.5-fold and 3.6-fold (p < 0.005) increase over non-perfusion CHAG cultures. Contrasting CHAG perfusion and static cultures, chondrogenic gene comparisons showed a 3.5-fold increase in collagen type II/type I (COL2A1/COL1A1) mRNA ratio (p < 0.05), and a 1.3-fold increase in aggrecan mRNA. Observed effects are linked to NF-κB signal transduction pathway inhibition as confirmed by a 3.2-fold (p < 0.05) reduction of NF-κB mRNA expression upon exposure to perfusion. Our results demonstrate that pores play a critical role in improving cell viability and that interstitial flow caused by medium perfusion through the porous scaffolds enhances the expression of chondrogenic genes and extracellular matrix through downregulating NF-κB1.

Teacher Scaffolding and Equity in Collaborative Knowledge Construction

This study examines teacher scaffolding and equity during collaborative small-group discussions in fifth-grade English language arts classrooms. Equity indicators analyzed include uptake, relational invitations, and conflicts for the floor (CFF). CFF indicates lower levels of participatory equity, while the others indicate higher relational equity. Three types of teacher scaffolding moves were included, and data were analyzed using statistical discourse analysis and repeated measures logistic regression. Teacher scaffolding was either negatively or not related to all equity indicators. Specifically, teacher scaffolding is associated with reduced indicators of relational equity, but also with reductions in CFF. The relationship with relational equity was stronger and more consistent than the relationship with CFF, suggesting that teachers’ largest influence on equity is on relational, rather than participatory, equity.

Discovery of potent chromone-based autotaxin inhibitors inspired by cannabinoids

Autotaxin (ATX) is an enzyme primarily known for the production of lysophosphatidic acid. Being involved in the development of major human diseases, such as cancer and neurodegenerative diseases, the enzyme has been featured in multiple studies as a pharmacological target. We previously found that the cannabinoid tetrahydrocannabinol (THC) could bind and act as an excellent inhibitor of ATX. This study aims to use the cannabinoid scaffold as a starting point to find cannabinoid-unrelated ATX inhibitors, following a funnel down approach in which large chemical libraries sharing chemical similarities with THC were screened to identify lead scaffold types for optimization. This approach allowed us to identify compounds bearing chromone and indole scaffolds as promising ATX inhibitors. Further optimization led to MEY-003, which is characterized by the direct linkage of an N-pentyl indole to the 5,7-dihydroxychromone moiety. This molecule has potent inhibitory activity towards ATX-β and ATX-ɣ as evidenced by enzymatic studies and its mode of action was rationalized by structural biology studies using macromolecular X-ray crystallography.

Optimal mechanical properties of Hydroxyapatite gradient Voronoi porous scaffolds for bone applications — A numerical study

Irregular Voronoi-based lattice (IVL) structures in tissue engineering (TE) have significant potential for bone regeneration. These scaffolds can mimic natural human bone interconnectivity by gradually altering strut thickness (ST) and seed point space (PS), which affects both mechanical and biological characteristics. This paper investigates the impact of design parameters, ST and PS, on Hydroxyapatite (HA) ILV structures’ mechanical properties (elastic modulus (E) and maximum compressive strength (MCS)) and geometrical characteristics (pore number, size, and distribution, surface area (SA), and surface area-to-volume ratio (SA/VR)). Four types of IVL scaffolds were designed; PC-TC (Constant PS-Constant ST), PC-TG (Constant PS-Gradient ST), PG-TC (Gradient PS-Constant ST), and PG-TG (Gradient PS-Gradient ST). The study, conducted through linear static structural finite element analysis (FEA) with maximum stress criteria, underscores the profound impact of irregularity and morphology on mechanical performance and geometrical features. Regarding SA and SA/VR, a comparison between PC-TC with other proposed scaffolds showed a minor improvement for PC-TG, while higher significant improvements were found for both PG-TG and PG-TC. In terms of pores distribution and number, no noticeable improvement was observed for the PC-TG scaffold compared to PC-TC. In contrast, PG-TC and PG-TG lattices demonstrated a variety of pore distributions and approximately doubled pore numbers. Studying mechanical properties, considering E and MCS, showcases substantial gains for PG-TC. It, however, revealed that for the rest of the scaffolds, no enhancement was observed regarding E. Based on these results, gradient PS proved to be more effective than gradient ST in enhancing mechanical performance and geometrical properties. Due to these improvements, this study holds promise for expediting bone regeneration and reducing postoperative complications in bone replacement applications.

The scaffold concept for alternative proteins

The present paper extends the tissue engineering (TE) scaffold concept to scaffolds for alternative proteins (AP). The textural characteristics of a food product, which is a key hurdle in increasing consumer acceptance for alternative proteins, can be addressed by using the scaffold as a template, which provides a degree of freedom for enhancement of its nutritional properties. Examples of tissue engineering and alternative protein scaffold types are first discussed to show how the scaffold concept can be applied to both. For both TE and AP, scaffold processes can be classified as adopting either top-down or bottom-up approaches, each associated with its own set of advantages and disadvantages. These scaffolds are meant for very different environments, thus the materials for their construction are often non-exchangeable. However, for the newer application of AP, the materials and methods for scaffold construction can be drawn from the substantial amount of work that has already been done on alternative proteins and meat analogues. The functionalities and applications of cultured meat (a special type of AP) scaffolds are compared to those of TE scaffolds. Applying and adapting the TE scaffold concept to the newer field of alternative proteins is foreseen to promote a more rapid development of the latter in terms of processing and productization.

Scaffolding Strategies for Training Anxiety-Stricken Novice Interpreters

Interpreting teaching and learning has long been a fret, particularly for novice undergraduate interpreters who suffer from higher levels of anxiety over their listening, note-taking, and production. This paper aims to ease this plight by offering various types of scaffolding, a method that has been maturely employed in language education. In this study, I use specific lecture examples to demonstrate how scaffolding can be used in each step of interpreting training for novices, including vocabulary building, active listening, discourse analysis, note-taking, production, shadow reading, and simultaneous interpreting. The present study may provide pedagogical implications for interpreter trainers and learning strategies for student or trainee interpreters.

Comparative evaluation of pH and Ca + ion release from MTA on interaction with platelet-rich fibrin and blood clot: an in vitro study.

Background: 'Regenerative endodontics' using host-derived scaffolds and biomaterials (MTA) is popular in the management of teeth with open apex. Alkaline pH and bioactivity contribute to tissue healing and remineralization. We assessed the influence of PRF and Blood Clot on the pH and Ca + ion release from MTA. Methods: A total of 15 single-rooted human extracted teeth were sectioned at the level of the cementoenamel junction. Based on the type of scaffolds used, samples were divided into three groups. Group 1 (MTA+ PRF), Group 2 (MTA + Blood Clot), Group 3 (control MTA). The prepared specimens were transferred to a fresh falcon tube containing 10mL of distilled water and the collected solutions were analysed for pH and Ca + ion release at 3h, seventh day and 14 th day. Results: It was observed that the mean pH and Ca + ion release were significantly lower in the experimental groups as compared to the control group. Though there was an increase in the pH recorded in Group 1 and 2 at all time periods, the difference was not significant. Ca + ion release peaked at Day 7 (Group3 > Group2 > Group1) and reduced significantly on the 14 th day for all groups. Conclusions: Within the limitations of the study, it can be concluded that PRF and blood clot influence the pH and Ca + ion release from MTA.

Nerve regeneration using decellularized tissues: challenges and opportunities.

In tissue engineering, the decellularization of organs and tissues as a biological scaffold plays a critical role in the repair of neurodegenerative diseases. Various protocols for cell removal can distinguish the effects of treatment ability, tissue structure, and extracellular matrix (ECM) ability. Despite considerable progress in nerve regeneration and functional recovery, the slow regeneration and recovery potential of the central nervous system (CNS) remains a challenge. The success of neural tissue engineering is primarily influenced by composition, microstructure, and mechanical properties. The primary objective of restorative techniques is to guide existing axons properly toward the distal end of the damaged nerve and the target organs. However, due to the limitations of nerve autografts, researchers are seeking alternative methods with high therapeutic efficiency and without the limitations of autograft transplantation. Decellularization scaffolds, due to their lack of immunogenicity and the preservation of essential factors in the ECM and high angiogenic ability, provide a suitable three-dimensional (3D) substrate for the adhesion and growth of axons being repaired toward the target organs. This study focuses on mentioning the types of scaffolds used in nerve regeneration, and the methods of tissue decellularization, and specifically explores the use of decellularized nerve tissues (DNT) for nerve transplantation.

Electrospun aligned tacrolimus-loaded polycaprolactone biomaterials for peripheral nerve repair.

Background: Efficacious repair of peripheral nerve injury is an unmet clinical need. The implantation of biomaterials containing neurotrophic drugs at the injury site could promote nerve regeneration and improve outcomes for patients. Materials & methods: Random and aligned electrospun poly-ε-caprolactone scaffolds containing encapsulated tacrolimus were fabricated, and the gene expression profile of Schwann cells (SCs) cultured on the surface was elucidated. On aligned fibers, the morphology of SCs and primary rat neurons was investigated. Results: Both scaffold types exhibited sustained release of drug, and the gene expression of SCs was modulated by both nanofibrous topography and thepresence of tacrolimus. Aligned fibers promoted the alignment of SCs and orientated outgrowth from neurons. Conclusion: Electrospun PCL scaffolds with tacrolimus hold promise for the repair of peripheral nerve injury.

Porous biomaterial scaffolds for skeletal muscle tissue engineering.

Volumetric muscle loss is a traumatic injury which overwhelms the innate repair mechanisms of skeletal muscle and results in significant loss of muscle functionality. Tissue engineering seeks to regenerate these injuries through implantation of biomaterial scaffolds to encourage endogenous tissue formation and to restore mechanical function. Many types of scaffolds are currently being researched for this purpose. Scaffolds are typically made from either natural, synthetic, or conductive polymers, or any combination therein. A major criterion for the use of scaffolds for skeletal muscle is their porosity, which is essential for myoblast infiltration and myofiber ingrowth. In this review, we summarize the various methods of fabricating porous biomaterial scaffolds for skeletal muscle regeneration, as well as the various types of materials used to make these scaffolds. We provide guidelines for the fabrication of scaffolds based on functional requirements of skeletal muscle tissue, and discuss the general state of the field for skeletal muscle tissue engineering.

Microporous Polylactic Acid Scaffolds Enable Fluorescence-Based Perfusion Imaging of Intrinsic In Vivo Vascularization.

In vivo tissue engineering (TE) techniques like the AV loop model provide an isolated and well-defined microenvironment to study angiogenesis-related cell interactions. Functional visualization of the microvascular network within these artificial tissue constructs is crucial for the fundamental understanding of vessel network formation and to identify the underlying key regulatory mechanisms. To facilitate microvascular tracking advanced fluorescence imaging techniques are required. We studied the suitability of microporous polylactic acid (PLA) scaffolds with known low autofluorescence to form axial vascularized tissue constructs in the AV loop model and to validate these scaffolds for fluorescence-based perfusion imaging. Compared to commonly used collagen elastin (CE) scaffolds, the total number of vessels and cells in PLA scaffolds was lower. In detail, CE-based constructs exhibited significantly higher vessel numbers on day 14 and 28 (d14: 316 ± 53; d28: 610 ± 74) compared to the respective time points in PLA-based constructs (d14: 144 ± 18; d28: 327 ± 34; each p < 0.05). Analogously, cell counts in CE scaffolds were higher compared to corresponding PLA constructs (d14: 7661.25 ± 505.93 and 5804.04 ± 716.59; d28: 11211.75 + 1278.97 and 6045.71 ± 572.72, p < 0.05). CE scaffolds showed significantly higher vessel densities in proximity to the main vessel axis compared to PLA scaffolds (200-400 µm and 600-800 µm on day 14; 400-1000 µm and 1400-1600 µm on day 28). CE scaffolds had significantly higher cell counts on day 14 at distances from 800 to 2000 µm and at distances from 400 to 1600 µm on day 28. While the total number of vessels and cells in PLA scaffolds were lower, both scaffold types were ideally suited for axial vascularization techniques. The intravascular perfusion of PLA-based constructs with fluorescence dye MHI148-PEI demonstrated dye specificity against vascular walls of low- and high-order branches as well as capillaries and facilitated the fluorescence-based visualization of microcirculatory networks. Fluorophore tracking may contribute to the development of automated quantification methods after 3D reconstruction and image segmentation. These technologies may facilitate the characterization of key regulators within specific subdomains and add to the current understanding of vessel formation in axially vascularized tissue constructs.

초등영어 학습중심평가를 위한 AI 챗봇의 스캐폴딩 유형화 연구

The purpose of this study is to explore the types of scaffolding that AI chatbots can&#x0D; provide through systematic feedback based on learners' individual utterances during&#x0D; elementary English learning-oriented assessment. For the study, the researcher designed&#x0D; an English speaking task and implemented an learning-oriented speaking assessment&#x0D; using an AI chatbot for 25 learners in the 6th grade. Subsequently, individual interviews&#x0D; were conducted to analyze the learners' responses to the scaffolding. By analyzing&#x0D; learner responses and transcripts of conversations between learners and chatbots, the&#x0D; researcher categorized the types of scaffolding that AI chatbots can provide during&#x0D; the learning-oriented assessment. As a result, first, the scaffolding can be categorized&#x0D; into three areas: linguistic, cognitive, and affective. Linguistically, the chatbots&#x0D; provided scaffolding for conveying meaning, language forms, and pronunciation&#x0D; aspects. In the cognitive aspect, the scaffolding assisted learners in their thinking&#x0D; processes, while in the affective aspect, it helped regulate frustration. Second, through&#x0D; scaffolding using various strategies, learners demonstrated the ability to self-correct&#x0D; erroneous utterances and gradually complete sentences on their own. In addition,&#x0D; cognitive scaffolding helped learners solve challenging tasks at their current cognitive&#x0D; level, and affective scaffolding contributed to improving confidence in speaking&#x0D; English. The study offers implications and recommendations based on the findings.

Exploring In-Game Scaffolds for Higher-Order Learning in a Case-Based RPG Learning Game

As active learning tools, digital games often focus on including interface and design features to scaffold progression. However, little emphasis on the use of such in-game scaffolds for higher-order learning exists in the literature. We focused this study on the second interaction of a working prototype game called Stories of a GeoFarmer. The study evaluates the importance of in-game scaffolds for engaging learners in higher-order thinking in undergraduate Geography education. Stories of a GeoFarmer is a case-based role-playing game where players take on the role of a farmer in different countries. The game utilizes documented case studies of different environmental issues relating to cultural geography to place players into the role of the individuals impacted by the various situations. The situations are ill-structured presenting interesting arguments for no-win situations meant to engage more thinking about geographic implications. We incorporated several in-game scaffold types that connected to the learning objectives including metacognitive, conceptual, and procedural. We use a mixed methods exploratory design approach consisting of thematic analysis and correlation of post-game survey responses. Our research question asks how does in-game scaffolding in the geography game Stories of GeoFarmer affect the adult learners' experience? Results from 63 undergraduates indicate that students can regularly recall and extrapolate how their in-game actions affect the environment. However, fewer students are able to evaluate why no singular solution exists to the game’s problem despite all the provided in-game scaffolds. Metacognitive scaffolds play the largest role in prompting students to recognize cause and effect but also highlight the necessity of making multiple scaffold types more prominent in order to reach higher-order thinking. This study holds implications for serious game designers to consider how in-game scaffolds can be presented to support high-order learning in adults.

Application of seaweed polysaccharide in bone tissue regeneration

Regeneration is a complex process influenced by many independent or combined factors, including inflammation, proliferation, and tissue remodeling. The ocean, the most extensive resource on Earth, is rich in Seaweed. With increasing research in recent years, researchers have discovered that seaweed polysaccharides have various pharmacological effects, including a particular efficacy in promoting bone tissue regeneration. However, the application of this material in the field of bone tissue engineering is very limited. However, there are few studies on the polysaccharide at home and abroad, and little is known about its potential application value in bone repair. In addition, the bioavailability of the seaweed polysaccharide is also low, and there are still many problems to be solved. For example, the ease of solubility of fucoidan in water is a key issue that restricts its practical application. In this review, we summarize the applications and mechanisms of seaweed polysaccharides in bone healing. We also propose to combine seaweed polysaccharides with novel technologies through different types of preparations, hydrogels, scaffolds, and 3D printing to improve their use in tissue healing and regeneration.