Scaffold Group Research Articles

Negative Printing for the Reinforcement of In Situ Tissue-Engineered Cartilage.

In the realm of in situ cartilage engineering, the targeted delivery of both cells and hydrogel materials to the site of a defect serves to directly stimulate chondral repair. Although the in situ application of stem cell-laden soft hydrogels to tissue defects holds great promise for cartilage regeneration, a significant challenge lies in overcoming the inherent limitation of these soft hydrogels, which must attain mechanical properties akin to the native tissue to withstand physiological loading. We therefore developed a system where a gelatin methacryloyl hydrogel laden with human adipose-derived mesenchymal stem cells is combined with a secondary structure to provide bulk mechanical reinforcement. In this study, we used the negative embodied sacrificial template 3D printing technique to generate eight different lattice-based reinforcement structures made of polycaprolactone, which ranged in porosity from 80% to 90% with stiffnesses from 28 ± 5 kPa to 2853 ± 236 kPa. The most promising of these designs, the hex prism edge, was combined with the cellular hydrogel and retained a stable stiffness over 41 days of chondrogenic differentiation. There was no significant difference between the hydrogel-only and hydrogel scaffold group in the sulfated glycosaminoglycan production (340.46 ± 13.32 µg and 338.92 ± 47.33 µg, respectively) or Type II Collagen gene expression. As such, the use of negative printing represents a promising solution for the integration of bulk reinforcement without losing the ability to produce new chondrogenic matrix.

A Sociocultural Perspective on the Impact of Instructor Versus Peer Scaffolding Upon Lexical Digesting and Reading Perception

Based on a sociocultural theory and a plethora of experiential studies on the efficacy of scaffolding on foreign language learning, the goal of this research article is to examine the effectiveness of diverse types of scaffolding on university students’ lexical digesting and reading perception from a sociocultural standpoint. Using the Harvard Placement Test, 40 EFL students from a total of 70 were selected and divided into two experimental groups and a single control group. The first group (G1 Exp.) was given teaching with instructor scaffolding, the second group (G2 Exp.) received instruction with peer scaffolding, and the control group (G3 Cont.) received conventional instruction without any external enhancement. Pretests for lexical digesting and reading perception were administered to the three groups. Following the treatment, post-tests for lexical digesting and reading perception were administered. Descriptive statistics and inferential statistics were used to examine the collected data. The results showed a significant difference between instructor and peer scaffolding, with the peer scaffolding group outperforming the instructor scaffolding group. Both experimental groups outperformed the control group in lexical digesting and reading perception. Regarding various kinds of scaffolding, this study provided some advice for psycholinguists, curriculum designers, and language instructors.

Fibroblasts/three-dimensional scaffolds complexes promote wound healing in rats with skin defects

ABSTRACT We aim to construct a three-dimensional nano-skin scaffold material in vitro and study its promoting effect on wound healing in vivo. In this study, hybrid constructs of three-dimensional (3D) scaffolds were successfully fabricated by combination of type I collagen (COL-1) and polylactic-glycolic acid (PLGA). Fibroblasts and human umbilical cord mesenchymal stem cells (hUCMSCs) were used to implanted into 3D scaffolds and constructed into SD skin scaffolds in vitro. Finally, the fibroblasts/scaffolds complexes were inoculated on the surface of rat wound skin to study the promoting effect of the complex on wound healing. In our study, we successfully built a 3D scaffold, which had a certain porosity. Meanwhile, the content of COL-1 in the cell supernatant of fibroblast/scaffold complexes was increased. Furthermore, the expression of F-actin, CD105, integrin β, VEGF, and COL-1 was up-regulated in hUCMSC/scaffold complexes compared with the control group. In vivo, fibroblast/scaffold complexes promoted wound healing in rats. Our data suggested that the collagen Ⅳ and vimentin were elevated and collagen fibers were neatly arranged in the fibroblast/scaffold complex group was significantly higher than that in the scaffold group. Taken together, fibroblast/scaffold complexes were expected to be novel materials for treating skin defects.

Total meniscus replacement with a 3D printing of network hydrogel composite scaffold in a rabbit model.

The aim of this study was to evaluate the role of a novel total meniscal implant in promoting meniscal regeneration and protecting articular cartilage in a rabbit model for 3 and 6 months. Thirty-six New Zealand rabbits were selected and divided into poly(ɛ-caprolactone) (PG-Pg) scaffold group, meniscectomy group and sham group. In this study, it was investigated whether PG-Pg scaffold can prevent articular cartilage degeneration and promote tissue degeneration, and its mechanical properties at 3 and 6 months after surgery were also explored. The degree of articular cartilage degeneration was significantly lower in the PG-Pg scaffold group than in the meniscectomy group. The number of chondrocytes increased in the PG-Pg scaffold at 3 and 6 months, while a gradual increase in the mechanical properties of the PG-Pg stent was observed from 6 months. The PG-Pg scaffold slows down the degeneration of articular cartilage, promotes tissue regeneration and improves biomechanical properties after meniscectomy. This novel meniscus scaffold holds promise for enhancing surgical strategies and delivering superior long-term results for individuals with severe meniscus tears. NA.

Discovery of Thiadiazoles as Human Dihydroorotate Dehydrogenase (hDHODH) Inhibitors by Combined Structure‐Based Modelling Methods

AbstractThis study involves the design of novel thiadiazole derivatives as hDHODH inhibitors using various structure‐based approaches such as pharmacophore modelling, high‐throughput virtual screening (HTVS), prediction of ADMET parameters, docking and molecular dynamics (MD) studies. We used the validated co‐crystal structure of hDHODH to create the six‐feature pharmacophore model ADHRRR, which was validated by the Güner‐Henry scoring (GH score=0.81) approach, enrichment calculations (enrichment factor=51), area under the curve (0.93), receiving operating characteristic (ROC) curve (0.89), and ROC′s Boltzmann‐enhanced discrimination, known as BEDROC (α=8) (0.859), (α=20) (0.828), (α=160) (0.912). Pharmacophore model as a 3D search query was used for the screening of zinc database followed by docking investigations and energy calculation (Prime/MMGBSA). For the design of novel compounds, we selected the thiadiazole moiety as the central scaffold and various functional groups based on pharmacophoric characters and binding interactions. In docking study, designed compounds showed favourable interactions with Gln47 and Arg136 at the active site of the hDHODH enzyme, and optimal drug likeness properties for ADMET prediction study. Stability of enzyme‐ligand complex was validated by MD simulation study with RMSD, RMSF and RoG calculations. These findings suggested that novel thiadiazoles are potential candidates as hDHODH inhibitors and anticancer agents.

Fibrochondrogenic Differentiation Potential of Human Adiposederived Mesenchymal Stem Cells in a Type I Collagen-based Meniscus Scaffold with Activated Platelet-Rich Plasma Stimulation In-vitro

Introduction: Despite efforts to use scaffolds to treat meniscus tears, minimal progress has been made in facilitating meniscus regeneration and return of function. Our research objective was to develop a meniscus repair and regeneration implant by applying a resorbable scaffold in combination with cells and growth factors. We report here the results of using Platelet-Rich Plasma (PRP) as a source of growth factors to induce fibrochondrogenic differentiation of human Adipose- Derived Mesenchymal Stem Cells (hADSC) in a three-dimensional (3D) Type I collagen-based scaffold in-vitro. Methods: Scaffold Preparation: Type I collagen scaffolds were prepared following a protocol previously published. Two different densities of scaffolds, High Density (HD) and Low Density (LD), were produced for in-vitro study. hADSC and PRP Preparation. hADSCs were cultured to the fifth passage to reach the desired number for experimentation. PRP was collected from human blood and activated. Cell Culture Procedure: Effects of PRP on hADSC proliferation and differentiation into fibrochondrogenic cells were examined in four scaffold groups: LD, HD, LD+PRP and HD+PRP. hADSCs were seeded onto scaffolds (n=5) at a concentration of 2 × 106 cells/scaffold. 1% of PRP was added to the experimental media. Cellular proliferation was assessed at 1, 7, 14 and 21 days. Differentiation was measured using qRT-PCR on Days 14 and 21. qRT- PCR analysis of gene expression was completed with primers for COLLAGEN 1 and AGGRECAN. Data Analysis: ANOVAs were conducted (two-tailed tests) at the .05 significance level. Results: Cellular proliferation of hADSCs seeded on each scaffold increased over time. Similar trend was observed for cells seeded on HD scaffolds with and without PRP. hADSC showed significant increase in cellular proliferation on the LD scaffolds at Days 1 and 7. At Day 21, PRP treatment and LD scaffold had a synergistic positive effect on Type I collagen gene expression. PRP did not elevate type I collagen gene in the HD group, the HD scaffold alone had the same level of type I collagen gene expression as LD+PRP. Aggrecan expression was elevated in the presence of PRP in both the HD and LD scaffold groups, indicating enhanced fibrochondrogenic differentiation of hADSCs. Effective cell infiltration was observed across both HD and LD scaffolds with and without PRP treatment. HD scaffolds displayed larger cell clusters and more extensive cell migration over time compared to LD scaffolds. However, LD scaffolds resulted a more uniform cellular distribution than HD scaffolds. Conclusion: Our study demonstrates that PRP can play an important role in directing hADSCs towards fibrochondrogenic differentiation in Type I collagen-based scaffolds in-vitro. Additionally, our study shows that collagen scaffold density can influence the spatial distribution and cellular behavior of infiltrated cells.

The Effect of Incremental Scaffolds in Experimentation on Cognitive Load

Experimentation provides a suitable way for students to gain an understanding of scientific inquiry since it is one of its main methods to develop scientific knowledge. However, it is assumed that experimentation can lead to cognitive overload when students experience little support during experimentation, which, in turn, might hinder effective learning. Extraneous cognitive load describes the load caused by inefficient instructional designs such as unguided problem-solving or the way information is presented and thus can be influenced by appropriate instructions. In order to prevent students from cognitive overload and assist them during experimentation, they can be provided with incremental scaffolds, which are sequential written solution instructions. The present study investigates the extent to which the use of incremental scaffolds affects learners’ cognitive load during experimentation in biology classes. The students in the Incremental Scaffolds Group (IncrS; n = 54) used incremental scaffolds in two self-conducted experiments while students of the No-Incremental Scaffolds Group (No-IncrS; n = 74) experimented openly without such a support. Both groups were provided with a pre-structured researcher protocol including the steps of experimentation and received the same lessons. Extraneous cognitive load was assessed after both experiments using a self-developed questionnaire consisting of two items. These were designed to assess how cognitive load was affected by the learning materials. The findings only revealed a significant main effect of time between the two conducted experiments, but no significant interaction effect with the treatment. Consequently, the results show that repeated experimentation reduces cognitive load during experimentation, regardless of the provision of incremental scaffolds. The positive effects of incremental scaffolds, thus possibly also concerning cognitive load, are assumed to occur only after multiple applications; hence, they might need to be applied more frequently and regularly to really become practiced. Two sessions of experimenting with incremental scaffolds seem to be insufficient for providing learners with substantial support, as students may need more time to fully adjust to utilizing the incremental scaffolds. Furthermore, a brief reflection phase on the use of incremental scaffolds at the end of each lesson in which they were used appears to be helpful. If incremental scaffolds can free up working memory, it may also be useful to consider the relation between incremental scaffolds, cognitive load, and knowledge acquisition.

Application effect of a dual release system of androgen and its antagonist in the repair of full-thickness burn wounds in mice

Application effect of a dual release system of androgen and its antagonist in the repair of full-thickness burn wounds in mice

Mesenchymal stem cells in PRP and PRF containing poly(3-caprolactone)/gelatin Scaffold: a comparative in-vitro study.

Scaffold design is one of the three most essential parts of tissue engineering. Platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) have been used in clinics and regenerative medicine for years. However, the temporal release of their growth factors limits their efficacy in tissue engineering. In the present study, we planned to synthesize nanofibrous scaffolds with the incorporation of PRP and PRF by electrospinning method to evaluate the effect of the release of PRP and PRF growth factors on osteogenic gene expression, calcification, proliferation, and cell adhesion of human bone marrow mesenchymal stem cell (h-BMSC) as they are part of scaffold structures. Therefore, we combined PRP/PRF, derived from the centrifugation of whole blood, with gelatin and Polycaprolactone (PCL) and produced nanofibrous electrospun PCL/Gel/PRP and PCL/Gel/PRF scaffolds. Three groups of scaffolds were fabricated, and h-BMSCs were seeded on them: (1) PCL/Gel; (2) PCL/Gel/PRP; (3) PCL/Gel/PRF. MTS assay was performed to assess cell proliferation and adhesion, and alizarin red staining confirmed the formation of bone minerals during the experiment. The result indicated that PCL/Gel did not have any better outcomes than the PRP and PRF group in any study variants after the first day of the experiment. PCL/gelatin/PRF was more successful regarding cell proliferation and adhesion. Although PCL/gelatin/PRP showed more promising results on the last day of the experiment in mineralization and osteogenic gene expression, except RUNX2, in which the difference with PCL/gelatin/PRF group was not significant.

Impact of Using Processed Urinary Bladder Submucosa and Hydrogel Fabricated from Tendon on Skin Healing Process in Rabbits.

This study was intended to evaluate the healing of skin injury by using decellularized urinary bladder submucosa scaffolds and tendon-derived hydrogel. Thirty-six adult local breeds of both sex rabbits, with an average weight of 2.0-2.5 kg, were divided randomly into three groups (12 animals for each group). All groups were subjected to an induced injury (2 cm) in diameter at the right side of the abdominal skin, the rabbits of the 1st group (A) were sutured without the application of any substance as a control group, the rabbits of the 2nd group (B) were sutured and treated with the application of decellularized urinary bladder submucosa scaffolds, and in the 3rd group (C), they were sutured and treated with the application of tendon-derived hydrogel. Postoperative care following had been done for all groups throughout the study period. Specimens from the injured skin were taken for the histopathological study on the postinjury day, 8th, 14th, 21st, and 24th. The study showed a clear effect of materials used in the treatment of wounds through a clear progression in the healing stages with a noticed superiority of the submucosa scaffold group.

Dual delivery gene-activated scaffold directs fibroblast activity and keratinocyte epithelization.

Fibroblasts are the most abundant cell type in dermal skin and keratinocytes are the most abundant cell type in the epidermis; both play a crucial role in wound remodeling and maturation. We aim to assess the functionality of a novel dual gene activated scaffold (GAS) on human adult dermal fibroblasts (hDFs) and see how the secretome produced could affect human dermal microvascular endothelial cells (HDMVECs) and human epidermal keratinocyte (hEKs) growth and epithelization. Our GAS is a collagen chondroitin sulfate scaffold loaded with pro-angiogenic stromal derived factor (SDF-1α) and/or an anti-aging β-Klotho plasmids. hDFs were grown on GAS for two weeks and compared to gene-free scaffolds. GAS produced a significantly better healing outcome in the fibroblasts than in the gene-free scaffold group. Among the GAS groups, the dual GAS induced the most potent pro-regenerative maturation in fibroblasts with a downregulation in proliferation (twofold, p < 0.05), fibrotic remodeling regulators TGF-β1 (1.43-fold, p < 0.01) and CTGF (1.4-fold, p < 0.05), fibrotic cellular protein α-SMA (twofold, p < 0.05), and fibronectin matrix deposition (twofold, p < 0.05). The dual GAS secretome also showed enhancements of paracrine keratinocyte pro-epithelializing ability (1.3-fold, p < 0.05); basement membrane regeneration through laminin (6.4-fold, p < 0.005) and collagen IV (8.7-fold, p < 0.005) deposition. Our findings demonstrate enhanced responses in dual GAS containing hDFs by proangiogenic SDF-1α and β-Klotho anti-fibrotic rejuvenating activities. This was demonstrated by activating hDFs on dual GAS to become anti-fibrotic in nature while eliciting wound repair basement membrane proteins; enhancing a proangiogenic HDMVECs paracrine signaling and greater epithelisation of hEKs.

Evaluation of secretomes derived from human dermal and adipose tissue mesenchymal stem/stromal cells for skin wound healing: not as effective as cells

BackgroundAlthough the paracrine effects of mesenchymal stem/stromal cells (MSCs) have been recognized as crucial mediators of their regenerative effects on tissue repair, the potential of MSC secretomes as effective substitutes for cellular therapies remains underexplored.MethodsIn this study, we compared MSCs from the human dermis (DSCs) and adipose tissue (ASCs) with their secretomes regarding their efficacy for skin wound healing using a translationally relevant murine model.ResultsProteomic analysis revealed that while there was a substantial overlap in protein composition between DSC and ASC secretomes, specific proteins associated with wound healing and angiogenesis were differentially expressed. Despite a similar angiogenic potential in vivo, DSC and ASC secretomes were found to be less effective than cells in accelerating wound closure and promoting tissue remodeling.ConclusionsOverall, secretome-treated groups showed intermediary results between cells- and control-treated (empty scaffold) groups. These findings highlight that although secretomes possess therapeutic potential, their efficacy might be limited compared to cellular therapies. This study contributes to the growing understanding of MSC secretomes, emphasizes the need for further protocol optimization, and offers insights into their potential applications in regenerative medicine.

Effectiveness of Bilayer Scaffold Containing Chitosan/Gelatin/Diclofenac and Bovine Hydroxyapatite on Cartilage/Subchondral Regeneration in Rabbit Joint Defect Models.

Subchondral defects are often caused by trauma involving cartilage damage, leading to subsequent damage to the underlying bone, specifically the subchondral region. Bilayer scaffolds made from biomaterials, such as bovine hydroxyapatite, possess biocompatible and biodegradable properties that mimic the natural environmental conditions of target tissues so that they can support the formation of new tissues. On the other side, diclofenac as an anti-inflammatory drug potentiates to inhibit the inflammatory excess regarding the damage. This study aims to study the effectiveness of diclofenac scaffold to rabbit joint defect model. The scaffold was implanted in the rabbit femoral trochlear bone hole, which had a diameter of 5 mm and a depth of 4 mm. After 28 days of intervention, the animals were examined using macroscopic evaluation, hematoxylin-eosin (HE) staining, and immunohistochemistry (IHC) for type I collagen and type II collagen. Subsequently, the cartilage was evaluated using the International Cartilage Repair Society (ICRS) scoring system. The macroscopic ICRS scores were significantly higher (p < 0.05) in the bilayer scaffold implantation group compared to the monolayer scaffold and control groups. Histological ICRS scores were also significantly higher (p < 0.05) in the bilayer scaffold group compared to the control group. Type II collagen expression was higher (p < 0.05) in the bilayer scaffold group compared to the monolayer scaffold and control groups, although type I collagen expression was lower in comparison. In conclusion, this research suggests that the diclofenac-loaded bilayer scaffold effectively enhances cartilage and subchondral bone regeneration.

Space Adventure Game-Based Learning: How Games and Scaffolds Affect Eighth Graders' Physics Learning and Game Immersion

Game-based learning (GBL) has long been recognized as an effective way to engage students in learning through games, but little emphasis has been placed on scaffolding support for students, which hinders their learning. Therefore, our design of Space Adventure GBL ties games closely to scaffolds at every stage and investigates what role games and scaffolds play and whether greater exposure to games and scaffolds can boost learning. Six classes of 152 8th graders were randomly assigned to unlimited gaming and scaffolding group, limited scaffolding group, and limited gaming group. Students' learning outcomes in physics are optimized when they have unlimited access to GBL's gaming and scaffolding. All three groups perceived similar levels of engagement, engrossment and total immersion. According to regression, time spent mastering the scaffolds on their first attempt is the most determinant predictor of physics concept learning and engagement, whereas winning the games for the first-time predicts mental model construction, engrossment and total immersion the most. This study sheds light on future GBL studies that closely tying scaffolds and games challenges could motivate and facilitate students to master scaffolds and win games on their first attempts, resulting in better physics learning performance and more game immersion.

Evaluation of osteoconductive effect of polycaprolactone (PCL) scaffold treated with fibronectin on adipose-derived mesenchymal stem cells (AD-MSCs).

Replacing damaged organs or tissues and repairing damage by tissue engineering are attracting great interest today. A potentially effective method for bone remodeling involves combining nanofiber scaffolds with extracellular matrix (ECM), and growth factors. Today, electrospun PCL-based scaffolds are widely used for tissue engineering applications. In this study, we used an electrospun polycaprolactone (PCL) scaffold coated with fibronectin (Fn), a ubiquitous ECM glycoprotein, to investigate the induction potential of this scaffold in osteogenesis with adipose-derived mesenchymal stem cells (AD-MSCs). Scanning electron microscopy (SEM) analysis showed that fibronectin, by binding to the membrane receptors of mesenchymal stem cells (MSCs), leads to their attachment and proliferation on the PCL scaffold and provides a suitable environment for osteogenesis. In addition, biochemical tests showed that fibronectin leads to increased calcium deposition. The results also showed that alkaline phosphatase activity was significantly higher in the PCL scaffold coated with fibronectin than in the control groups (PCL scaffold group and tissue culture polystyrene (TCPS) group) (P<0.05). Also, the analysis of quantitative reverse transcription PCR (qRT-PCR) data showed that the relative expression of bone marker genes such as osteonectin (ON), osteocalcin (OC), RUNX family transcription factor 2 (RUNX2), and collagen type I alpha 1 (COL1) was much higher in the cells seeded on the PCL/Fn scaffold than in the other groups (P<0.05). The results show that fibronectin has an increasing effect in accelerating bone formation and promising potential for use in bone tissue engineering.

Cytotoxicity and mechanical properties of biphasic calcium phosphate scaffold from Tegilarca granosa due to its composition

Background: Biphasic calcium phosphate (BCP) is graft material contained HA and TCP. Tegilarca granosa shell is a natural source that may converted into BCP. This study aims to determine the composition and cytotoxicity of BCP synthesized from Tegilarca granosa shell used various hydrothermal hours and to evaluate the mechanical properties of BCP scaffold. Methods: Tegilarca granosa shell was converted into BCP using hydrothermal method at 200˚C for 6h (Group 1); 9h (Group 2); and 12h (Group 3). The composition was determined by XRD and the cell viability were evaluated using MTT Assays. Each group was added with 20% gelatin ratio 50:50 (w/v) and freeze-dried to form scaffold. Scaffolds (Ø6mm x 4mm) were prepared for diametral tensile strength (DTS) test (n=6) and scaffolds (Ø7mm x 11mm) were used for compressive strength (CS) test (n=6). All data were analyzed using Kruskall-Wallis followed by Mann-Whitney test. Results: The composition of BCP (HA/ TCP) at Group 1, Group 2, and Group 3 were 81.80%/14,10%; 87%/6%; and 72%/21%. The cell viabilities were good for all groups. The DTS and CS test showed there was a significant difference between Group 1 and Group 3 scaffold, meanwhile there was no significant differences between Group 2 and Group 3 scaffold. Group 3 scaffold showed the highest DTS and CS, 6.921 MPa and 1,233 MPa. Conclusion: The BCP composition were depent on hydrothermal hours. Although all scaffold groups were non-toxic, but BCP scaffold synthesized from Tegilarca granosa shell using hydrothermal for 12 hours showed the highest mechanical properties.

A parathyroid hormone related supramolecular peptide for multi-functionalized osteoregeneration

Supramolecular peptide nanofiber hydrogels are emerging biomaterials for tissue engineering, but it is difficult to fabricate multi-functional systems by simply mixing several short-motif-modified supramolecular peptides because relatively abundant motifs generally hinder nanofiber cross-linking or the formation of long nanofiber. Coupling bioactive factors to the assembling backbone is an ideal strategy to design multi-functional supramolecular peptides in spite of challenging synthesis and purification. Herein, a multi-functional supramolecular peptide, P1R16, is developed by coupling a bioactive factor, parathyroid hormone related peptide 1 (PTHrP-1), to the basic supramolecular peptide RADA16-Ⅰ via solid-phase synthesis. It is found that P1R16 self-assembles into long nanofibers and co-assembles with RADA16-Ⅰ to form nanofiber hydrogels, thus coupling PTHrP-1 to hydrogel matrix. P1R16 nanofiber retains osteoinductive activity in a dose-dependent manner, and P1R16/RADA16-Ⅰ nanofiber hydrogels promote osteogenesis, angiogenesis and osteoclastogenesis in vitro and induce multi-functionalized osteoregeneration by intramembranous ossification and bone remodeling in vivo when loaded to collagen (Col) scaffolds. Abundant red blood marrow formation, ideal osteointegration and adapted degradation are observed in the 50% P1R16/Col scaffold group. Therefore, this study provides a promising strategy to develop multi-functional supramolecular peptides and a new method to topically administrate parathyroid hormone or parathyroid hormone related peptides for non-healing bone defects.

Vertical Grammatical Variability in Writing

The present study aimed to investigate the effects of scaffolding techniques on eliminating the grammatical variability in IELTS. 120 IELTS candidates were selected randomly and placed in a control, and three experimental groups. Prior to the course, the candidates and teachers were interviewed regarding the effectiveness of scaffolding techniques. The teachers were also asked to keep a diary and report every session. On the first, 10th, 20th, and 30th sessions, three essay writing topics were given to all the candidates, and their grammatical accuracy and variability were rated by official IELTS Mock examiners to check their vertical grammatical variability. The results were analyzed using SPANOVA procedure. The qualitative data were also content analyzed, coded, and compared with the quantitative results. The findings showed that the distributed scaffolding group was relatively more successful. The qualitative results showed gaps between teachers’ and candidates’ conceptions. The theoretical and pedagogical implications are also discussed.

In Vitro and In Vivo Evaluation of 3D Printed Poly(Ethylene Glycol) Dimethacrylate-Based Photocurable Hydrogel Platform for Bone Tissue Engineering.

This study focuses to develop a unique hybrid hydrogel bioink formulation that incorporates poly(ethylene glycol) dimethacrylate (PEGDMA), gelatin (Gel), and methylcellulose (MC). This formulation achieves the necessary viscosity for extrusion-based three-dimensional (3D) printing of scaffolds intended for bone regeneration. After thorough optimization of the hybrid bioink system with Gel, three distinct scaffold groups are investigated in vitro: 0%, 3%, and 6% (w/v) Gel. These scaffold groups are examined for their morphology, mechanical strength, biodegradation, in vitro cell proliferation and differentiation, and in vivo bone formation using a rat cranial defect model. Among these scaffold compositions, the 3% Gel scaffold exhibits the most favorable characteristics, prompting further evaluation as a rat mesenchymal stem cell (rMSC) carrier in a critical-size cranial defect within a Lewis rat model. The compressive strength of all three scaffold groups range between 1 and 2MPa. Notably, the inclusion of Gel in the scaffolds leads to enhanced bioactivity and cell adhesion. The Gel-containing scaffolds notably amplify osteogenic differentiation, as evidenced by alkaline phosphatase (ALP) and Western blot analyses. The in vivo results, as depicted by microcomputed tomography, showcase augmented osteogenesis within cell-seeded scaffolds, thus validating this innovative PEGDMA-based scaffold system as a promising candidate for cranial bone defect healing.

N-Substituted 2-(Benzenosulfonyl)-1-Carbotioamide Derivatives Exert Antimicrobial and Cytotoxic Effects via Aldehyde Dehydrogenase Pathway: Synthesis, In Silico and In Vitro Studies.

A series of N-Substituted 2-(benzenosulfonyl)-1-carbotioamide derivatives (WZ1-WZ4) were synthesized and characterized using spectral methods. A comprehensive activity study was performed for each compound. All compounds were tested for antibacterial activity. Moreover, in silico studies were carried out to determine the anticancer potential of the designed WZ1-WZ4 ligands. Based on molecular docking, aldehyde dehydrogenase was selected as a molecular target. The obtained data were compared with experimental data in vitro tests. Novel hybrids of the thiosemicarbazide scaffold and sulfonyl groups may have promising anticancer activity via the aldehyde dehydrogenase pathway. The best candidate for further studies appears to be WZ2, due to its superior selectivity in comparison to the other tested compounds.