Characterization Of Scaffolds Research Articles

Physicochemical and Biological Characterization of Gelatin/Alginate Scaffolds Reinforced with β-TCP, FDBA, and SrHA: Insights into Stem Cell Behavior and Osteogenic Differentiation.

Bone tissue engineering necessitates the development of scaffolds with optimal properties to provide a suitable microenvironment for cell adhesion, proliferation, and osteogenic differentiation. The selection of appropriate scaffold materials remains a critical challenge in this field. In this study, we aimed to address this challenge by evaluating and comparing the performance of hydrogel scaffolds reinforced with β-tricalcium phosphate (β-TCP), allograft, and a combination of allograft and strontium hydroxyapatite (SrHA). In this study, scaffolds containing the following compounds with a weight ratio of 75 : 25 : 50 were made using a 3D printer: group (1) alginate + gelatin + β-TCP (TCP), group (2) alginate + gelatin + allograft (Allo), and group (3) alginate + gelatin + allograft + strontium hydroxyapatite (Str). Stem cells extracted from rat bone marrow (rBMSCs) were cultured on scaffolds, and cell proliferation and differentiation tests were performed. Also, the physical and chemical properties of the scaffolds were investigated. The two/one-way analysis of variance (ANOVA) by Tukey's post hoc test was performed. There was no significant difference between scaffolds with pore size and porosity. TCP scaffolds' mechanical strength and degradation rate were significantly lower than the other two groups (P < 0.05). Also, the swelling ratio of Allo scaffolds was higher than in other samples. The amount of cell proliferation in the samples of the TCP group was lower than the other two, and the Allo samples had the best results in this concern (P < 0.01). However, the scaffolds containing strontium hydroxyapatite had significantly higher bone differentiation compared to the other two groups, and the lowest results were related to the scaffolds containing β-TCP. Hydrogel scaffolds reinforced with allograft or its combination with strontium showed better physicochemical and biological behavior compared to those reinforced with β-TCP. Besides, adding strontium had a limited impact on the physicochemical features of allograft-containing scaffolds while improving their potential to induce osteogenic differentiation.

Efficient three-dimensional (3D) human bone differentiation on quercetin-functionalized isotropic nano-architecture chitinous patterns of cockroach wings

Developing cost-effective, biocompatible scaffolds with nano-structured surface that truthfully replicate the physico-(bio)chemical and structural properties of bone tissue's extracellular matrix (ECM) is still challenging. In this regard, surface functionalization of natural scaffolds to enhance capability of mimicking 3D niches of the bone tissue has been suggested as a solution. In the current study, we aimed to investigate the potential of chitin-based cockroach wings (CW) as a natural scaffold for bone tissue engineering. To raise the osteogenic differentiation capacity of such a scaffold, a quercetin coating was also applied (hereafter this scaffold is referred as QCW). Moreover, the QCW scaffold exhibited effective antibacterial properties against gram-positive S. aureus bacteria. With respect to bone regeneration, the QCW scaffold optimally induced the differentiation of adipose-derived human mesenchymal stem cells (AD-hMSCs) into osteoblasts, as validated by mineralization assays, alkaline phosphatase (ALP) activity measurements, expression of pre-osteocyte marker genes, and immunocytochemical staining. Confirmation of the potent biocompatibility and physicochemical characteristics of the QCW scaffold through a series of in vitro and in vivo analysis revealed that surface modification had significant effect on multi-purpose features of obtained scaffold. Altogether, surface modification of QCW made it as an affordable bioinspired scaffold for bone tissue engineering.

Molecularly imprinted nanoparticles reveal regulatory scaffolding features in Pyk2 tyrosine kinase.

Pyk2 is a multi-domain non-receptor tyrosine kinase that serves dual roles as a signaling enzyme and scaffold. Pyk2 activation involves a multi-stage cascade of conformational rearrangements and protein interactions initiated by autophosphorylation of a linker site. Linker phosphorylation recruits Src kinase, and Src-mediated phosphorylation of the Pyk2 activation loop confers full activation. The regulation and accessibility of the initial Pyk2 autophosphorylation site remains unclear. We employed peptide-binding molecularly imprinted nanoparticles (MINPs) to probe the regulatory conformations controlling Pyk2 activation. MINPs differentiating local structure and phosphorylation state revealed that the Pyk2 autophosphorylation site is protected in the autoinhibited state. Activity profiling of Pyk2 variants implicated FERM and linker residues responsible for constraining the autophosphorylation site. MINPs targeting each Src docking site disrupt the higher-order kinase interactions critical for activation complex maturation. Ultimately, MINPs targeting key regulatory motifs establish a useful toolkit for probing successive activational stages in the higher-order Pyk2 signaling complex.

Tailoring hierarchical pore structures in carbon scaffolds for hydrogen storage of nanoconfined magnesium

Various carbon scaffolds have been developed for the nanoconfinement of Mg/MgH2 to achieve the synergistic effects of nanosizing-induced kinetic improvement, Mg-scaffold interaction-induced catalytic enhancement, and mechanical stress-driven thermodynamic stability tuning for advanced hydrogen storage. Yet, systematic studies linking the chemo-structural features of the carbon scaffolds and the hydrogen storage properties of Mg/MgH2 nanoparticles within the scaffolds remain largely unexplored. Here, we investigate the pore-dependent Mg nanoconfinement and its hydrogen storage behavior using hollow carbon nanospheres (HCNs) as scaffolds, dictated by their distinct pore properties. Contrary to the conventional wisdom of nanoconfinement, the Mg nanoparticles confined by the HCN with large mesopores exhibit faster hydrogen sorption kinetics and improved thermodynamic characteristics than those with small mesopores. The detailed analyses reveal that the interplay between reversible mechanical stress upon hydrogenation and nanosizing-induced facile kinetics leads to the observed experimental results. Ab initio computations further show that compressive stress retards bulk diffusion while at the same time enhances the surface hydrogen desorption, suggesting the need for stress optimization within the composite. Our study provides a design guideline for Mg strain engineering and the subsequent carbon scaffold structures for hydrogen storage, possibly leading to advanced hydrogen storage of confined Mg.

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.

Development of nanofibrous scaffolds containing polylactic acid modified with turmeric and hydroxyapatite/vivianite nanoparticles for wound dressing applications

Damaging the outer layer of the body (the skin) has been a common issue for decades. Fabrication of nanofibrous membranes via the electrospinning technique for the sake of making the wound healing process more facile has caught a lot of interest. For this purpose, a polymeric scaffold of polylactic acid (PLA) was doped with nanoparticles with different concentrations of turmeric/hydroxyapatite/vivianite/graphene oxide. The obtained membrane was tested by XRD, SEM, FTIR, and XPS. The surface topography of the scaffold has experienced changes upon adding different concentrations of the nanoparticles. The contact angle was measured by water droplets. It accentuated change in CA starting from 43.9o for pure condition of PLA to 67.7o for PLA/turmeric/vivianite. The thermogravimetric analysis (TGA) test stated that the PLA scaffold features are thermally stable in relatively high-temperature conditions initiating from room temperature to about 300 °C, meeting the maximum loss in mass of about 5 %. The cell viability was carried out in prepared vitro for the sample which contains PLA/turmeric/vivianite/GO, it was elucidated that the IC50 was around 3060 μg/ml.

A pedagogical approach for the development and optimization of a novel mix of biowastes-derived hydroxyapatite using the Box-Behnken experimental design

The current study details the creation of synthetic hydroxyapatite (HAp) using a combination of catfish and bovine bones (C&B). This is done to design the optimum processing parameters and consolidate instructional strategies to develop HAp scaffolds for biomedical engineering. The HAp produced from the novel mix of the biogenic materials (C&B) was through calcination and supported with the sol-gel technique, sintering, and low-cold compaction pressure. The ideal preparation conditions were identified with the aid of the Box-Behnken statistical design in response surface methodology. To understand the physicochemical and mechanical properties of the formulation, analytical studies on the synthesized HAp were carried out. To establish a substantial relation between the physicomechanical properties of the produced HAp scaffolds, three parameters— sintering temperature, compaction loads, and holding times were used. In the evaluation, the sintering temperature was found to have the greatest impact on the material's physicomechanical properties, with compressive strength (13 MPa), porosity (49.45 %), and elastic modulus (2.216 GPa) being the most enhanced properties in that order. The physicomechanical characteristics of the HAp scaffolds were at their optimal at 900 °C, 1 h 18 min of holding time, and 311.73 Pa of compaction pressure. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) results showed that powders with a dominant HAp phase were produced at all runs, including the optimum run. Therefore, using a computationally effective methodology that is helpful for novelties in biomedical engineering education, this study demonstrates the optimal process for the synthesis of a novel matrix bone-derived HAp, showing the most significant relations liable for manufacturing medically suitable HAp scaffolds from the mixture of bovine and catfish bones.

Advancements in scaffold for treating ligament injuries; in vitro evaluation.

Tendon/ligament (T/L) injuries are a worldwide health problem that affects millions of people annually. Due to the characteristics of tendons, the natural rehabilitation of their injuries is a very complex and lengthy process. Surgical treatment of a T/L injury frequently necessitates using autologous or allogeneic grafts or synthetic materials. Nonetheless, these alternatives have limitations in terms of mechanical properties and histocompatibility, and they do not permit the restoration of the original biological function of the tissue, which can negatively impact the patient's quality of life. It is crucial to find biological materials that possess the necessary properties for the successful surgical treatment of tissues and organs. In recent years, the in vitro regeneration of tissues and organs from stem cells has emerged as a promising approach for preparing autologous tissue and organs, and cell culture scaffolds play a critical role in this process. However, the biological traits and serviceability of different materials used for cell culture scaffolds vary significantly, which can impact the properties of the cultured tissues. Therefore, this review aims to analyze the differences in the biological properties and suitability of various materials based on scaffold characteristics such as cell compatibility, degradability, textile technologies, fiber arrangement, pore size, and porosity. This comprehensive analysis provides valuable insights to aid in the selection of appropriate scaffolds for in vitro tissue and organ culture.

Elastic 3D-Printed Nanofibers Composite Scaffold for Bone Tissue Engineering.

Loading nanoparticles into hydrogels has been a conventional approach to augment the printability of ink and the physicochemical characteristics of scaffolds in three-dimensional (3D) printing. However, the efficacy of this enhancement has often proven to be limited. We amalgamate electrospun nanofibers with 3D printing techniques to fabricate a composite scaffold reminiscent of a "reinforced concrete" structure, aimed at addressing bone defects. These supple silica nanofibers are synthesized through a dual-step process involving high-speed homogenization and low-temperature ball milling technology. The nanofibers are homogeneously blended with sodium alginate to create the printing ink. The resultant ink was extruded seamlessly, displaying commendable molding properties, thereby yielding scaffolds with favorable macroscopic morphology. In contrast to nanoparticle-reinforced scaffolds, composite scaffolds containing nanofibers exhibit superior mechanical attributes and bioactivity. These nanofiber composite scaffolds demonstrate enhanced osteoinductive properties in both in vitro and in vivo evaluations. To conclude, this research introduces a novel 3D printing approach where the fabricated nanofiber-infused 3D-printed scaffolds hold the potential to revolutionize the realm of 3D printing in the domain of bone tissue engineering.

Effects of Gamma Irradiation on the Properties of Hydroxyapatite-Collagen-Chitosan-Mg-ZnO Scaffolds for Bone Tissue Engineering

Bone tissue engineering aims to repair diseased or damaged bone that cannot be regenerated naturally. This study is designed to develop biodegradable porous scaffolds as bone substitutes and evaluate the effect of gamma irradiation on these scaffolds for the restoration of defected bone. Here, composite scaffolds (HA-COL-CS-Mg-ZnO) were prepared by the thermally induced phase separation (TIPS) technique using collagen (COL) and chitosan (CS), hydroxyapatite (HA), magnesium (Mg), and zinc oxide (ZnO) at different mass ratios. Thereafter, the scaffolds were subjected to 10 KGy γ-radiation for physical cross-linking and sterilization. The physicochemical and biological properties of the scaffolds were evaluated by Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR), field emission scanning electron microscopy (FESEM), physical stability (biodegradability, swelling rate, porosity, and density), mechanical properties, biocompatibility, cytotoxicity, and antimicrobial activity against Escherichia coli (ATCC-25922) and Staphylococcus aureus (ATCC-25923). We found that the irradiated scaffold showed enhanced tensile strength and antimicrobial activities which are desirable characteristics of bone-mimicking scaffolds. FESEM revealed that the average pore size decreased from 192.3 to 104.5 μm due to radiation. FTIR-ATR spectra showed that γ-radiation triggered cross-linking in the polymer matrix which improved mechanical strength (0.82 N/mm2 to 1.86 N/mm2) by increasing pore wall thickness. Moreover, the irradiated and nonirradiated scaffolds were biocompatible and noncytotoxic toward the Vero cell line which ensured their suitability for use in vivo. These results demonstrate that sterilization of HA-COL-CS-Mg-ZnO scaffolds with gamma-irradiation substantially improves the physicochemical and morphological features which aid bone tissue regeneration and could be supportive for new bone formation.

The role of embodied scaffolding in revealing "enactive potentialities" in intergenerational science exploration.

Although adults are known to play an important role in young children's development, little work has focused on the enactive features of scaffolding in informal learning settings, and the embodied dynamics of intergenerational interaction. To address this gap, this paper undertakes a microinteractional analysis to examine intergenerational collaborative interaction in a science museum setting. The paper presents a fine-grained moment-by-moment analysis of video-recorded interaction of children and their adult carers around science-themed objects. Taking an enactive cognition perspective, the analysis enables access to subtle shifts in interactants' perception, action, gesture, and movement to examine how young children engage with exhibits, and the role adult action plays in supporting young children's engagement with exhibits and developing ideas about science. Our findings demonstrate that intergenerational "embodied scaffolding" is instrumental in making "enactive potentialities" in the environment more accessible for children, thus deepening and enriching children's engagement with science. Adult action is central to revealing scientific dimensions of objects' interaction and relationships in ways that expose novel types of perception and action opportunities in shaping science experiences and meaning making. This has implications for science education practices since it foregrounds not only "doing" science, through active hands-on activities, but also speaks to the interconnectedness between senses and the role of the body in thinking. Drawing on the findings, this paper also offers design implications for informal science learning environments.

In vitro and in vivo efficacy of naturally derived scaffolds for cartilage repair and regeneration.

Intrinsically present bioactive cues allow naturally derived materials to mimic important characteristics of cartilage while also facilitating cellular recruitment, infiltration, and differentiation. Such traits are often what tissue engineers desire when they fabricate scaffolds, and yet, literature from the past decade is replete with examples of how most natural constructs with native biomolecules have only offered sub-optimal results in the treatment of cartilage defects. This paper provides an in-depth investigation of the performance of such scaffolds through a review of a collection of natural materials that have been used so far in repairing/regenerating articular cartilage. Although in vivo and clinical studies are the best indicators of scaffold efficacy, it was, however, observed that a large number of natural constructs had very promising scaffold characteristics to begin with, and would often show good in vitro/in vivo results. Finally, an examination of the biochemistry and biomechanics of repair tissues in studies that reported positive outcomes showed that these attributes often approached target cartilage values. The paper concludes with an outline of current trends as well as future directions for the field. STATEMENT OF SIGNIFICANCE: This review offers an exclusive focus on natural scaffold materials for cartilage repair and regeneration and provides a quantitative and qualitative analysis of their performance under a variety of in vitro and in vivo conditions. Readers can learn about environments where natural scaffolds have had the most success and tailor strategies to optimize their own work. Furthermore, given how the glycosaminoglycan (GAG) to hydroxyproline (HYP) ratio and moduli are fundamental attributes of hyaline cartilage, this paper adds to the body of knowledge by exploring how these characteristics reflect in preclinical outcomes. Such perspectives can greatly aid researchers better utilize natural materials for Cartilage Tissue Engineering (CTE).

Macroscopic and microscopic features of pancreatic scaffold generated by SDS-based decellularization using multiple needle injections

Background: Pancreatic tissue engineering requires a scaffold in addition to cells and signaling. An adequate scaffold no longer contains cells but retains its extracellular matrix. Biological scaffolds from organ or tissue decellularization are widely used because they can retain the extracellular matrix essential for cell proliferation and differentiation. Pancreatic scaffolds were developed for pancreatic tissue engineering through various decellularization techniques. Available decellularization techniques have advantages and disadvantages, and the development of new techniques is necessary. This study aims to characterize pancreatic scaffold generated by SDS-based decellularization using multiple needle injections. Method: The rat pancreas was isolated and injected with multiple SDS with graded concentration (0,1-1%) using a 1 cc syringe. Scaffold characterization was performed using hematoxylin-eosin (H&amp;E) staining. Results: The results obtained were the loss of cells in the pancreatic scaffold with intact extracellular matrix. Macroscopic appearance after decellularization showed a translucent, white, and flabby pancreas. Microscopic image after decellularization showed pancreatic tissue with cell loss but visible extracellular matrix. Conclusion: This study can produce an SDS-based decellularized pancreatic scaffold using multiple needle injections with adequate macroscopic and microscopic characteristics.

Bone repair potential of collagen-poly(3-hydroxybutyrate)-carbon nanotubes scaffold loaded with mesenchymal stem cells for the reconstruction of critical-sized mandibular defects

The poor structural stability of collagen (COL) upon hydration poses a significant challenge in tissue engineering (TE). To overcome this limitation, the incorporation of hydrophobic polymers such as poly(3-hydroxybutyrate) (PHB), and nanomaterials such as carbon nanotubes (CNTs) has been explored. In this study, we investigated the physical, chemical, and biological characteristics of COL-based scaffolds modified with PHB and CNTs for bone tissue engineering (BTE) applications. The tensile strength analysis revealed a substantial improvement in the ultimate tensile strength with the addition of 10 % PHB and 4 % CNTs. Scanning electron microscopy (SEM) images depicted a denser and more compact structure resulting from the presence of PHB and CNTs, enhancing the scaffold's mechanical properties. Fourier-transform infrared spectroscopy (FTIR) confirmed the successful incorporation of PHB and CNTs into the composite scaffold, maintaining the chemical integrity of COL. Stereological studies also conducted in a rat model with induced critical-sized bone defects in the mandibular bone further emphasize the substantial increase in bone formation and reduction in defect volume achieved by the scaffold loaded with stem cells. These findings underscore the promising approach to enhance bone healing, using COL-based scaffolds loaded with stem cells, and the favorable results obtained in this study can contribute to the advancement of BTE strategies.

Research progress in influence of microstructure on performance of triply-periodic minimal surface bone scaffolds

To summarize the influence of microstructure on performance of triply-periodic minimal surface (TPMS) bone scaffolds. The relevant literature on the microstructure of TPMS bone scaffolds both domestically and internationally in recent years was widely reviewed, and the research progress in the imfluence of microstructure on the performance of bone scaffolds was summarized. The microstructure characteristics of TPMS bone scaffolds, such as pore shape, porosity, pore size, curvature, specific surface area, and tortuosity, exert a profound influence on bone scaffold performance. By finely adjusting the above parameters, it becomes feasible to substantially optimize the structural mechanical characteristics of the scaffold, thereby effectively preempting the occurrence of stress shielding phenomena. Concurrently, the manipulation of these parameters can also optimize the scaffold's biological performance, facilitating cell adhesion, proliferation, and growth, while facilitating the ingrowth and permeation of bone tissue. Ultimately, the ideal bone fusion results will obtain. The microstructure significantly and substantially influences the performance of TPMS bone scaffolds. By deeply exploring the characteristics of these microstructure effects on the performance of bone scaffolds, the design of bone scaffolds can be further optimized to better match specific implantation regions.

Physical stimuli-emitting scaffolds: The role of piezoelectricity in tissue regeneration.

The imbalance between life expectancy and quality of life is increasing due to the raising prevalence of chronic diseases. Musculoskeletal disorders and chronic wounds affect a growing percentage of people and demand more efficient tools for regenerative medicine. Scaffolds that can better mimic the natural physical stimuli that tissues receive under healthy conditions and during healing may significantly aid the regeneration process. Shape, mechanical properties, pore size and interconnectivity have already been demonstrated to be relevant scaffold features that can determine cell adhesion and differentiation. Much less attention has been paid to scaffolds that can deliver more dynamic physical stimuli, such as electrical signals. Recent developments in the precise measurement of electrical fields in vivo have revealed their key role in cell movement (galvanotaxis), growth, activation of secondary cascades, and differentiation to different lineages in a variety of tissues, not just neural. Piezoelectric scaffolds can mimic the natural bioelectric potentials and gradients in an autonomous way by generating the electric stimuli themselves when subjected to mechanical loads or, if the patient or the tissue lacks mobility, ultrasound irradiation. This review provides an analysis on endogenous bioelectrical signals, recent developments on piezoelectric scaffolds for bone, cartilage, tendon and nerve regeneration, and their main outcomes in vivo. Wound healing with piezoelectric dressings is addressed in the last section with relevant examples of performance in animal models. Results evidence that a fine adjustment of material composition and processing (electrospinning, corona poling, 3D printing, annealing) provides scaffolds that act as true emitters of electrical stimuli that activate endogenous signaling pathways for more efficient and long-term tissue repair.

An Investigation of Structure-Activity Relationships and Cell Death Mechanisms of the Marine Alkaloids Discorhabdins in Merkel Cell Carcinoma Cells.

A library of naturally occurring and semi-synthetic discorhabdins was assessed for their effects on Merkel cell carcinoma (MCC) cell viability. The set included five new natural products and semi-synthetic compounds whose structures were elucidated with NMR, HRMS, and ECD techniques. Several discorhabdins averaged sub-micromolar potency against the MCC cell lines tested and most of the active compounds showed selectivity towards virus-positive MCC cell lines. An investigation of structure-activity relationships resulted in an expanded understanding of the crucial structural features of the discorhabdin scaffold. Mechanistic cell death assays suggested that discorhabdins, unlike many other MCC-active small molecules, do not induce apoptosis, as shown by the lack of caspase activation, annexin V staining, and response to caspase inhibition. Similarly, discorhabdin treatment failed to increase MCC intracellular calcium and ROS levels. In contrast, the rapid loss of cellular reducing potential and mitochondrial membrane potential suggested that discorhabdins induce mitochondrial dysfunction leading to non-apoptotic cell death.

Peripheral Nerve Regeneration at 1 Year: Biodegradable Polybutylene Succinate Artificial Scaffold vs. Conventional Epineurial Sutures.

The utilization of a planar poly(1,4-butylene succinate) (PBS) scaffold has been demonstrated as an effective approach for preserving nerve continuity and facilitating nerve regeneration. In this study, we assessed the characteristics of a microfibrous tubular scaffold specifically designed and fabricated through electrospinning, utilizing PBS as a biocompatible and biodegradable material. These scaffolds were evaluated as nerve guide conduits in a rat model of sciatic nerve neurotmesis, demonstrating both their biodegradability and efficacy in enhancing the reconstruction process over a long-term period (1-year follow-up). Histological assay and electrophysiological evaluation were performed to compare the long-term outcomes following sutureless repair with the microfibrillar wrap to outcomes obtained using traditional suture repair.

DESIGNED-IN SCAFFOLDING: SUPPORTING EFL YOUNG LEARNERS IN CREATING MULTIMODAL TEXTS

The research explored the designed-in scaffolding features implemented by the teacher in the English as a foreign language (EFL) young learner classroom to support young learners in creating multimodal texts. The research used scaffolding theory proposed by Hammond and Gibbons (2005) which categorized scaffolding into two fragments: designed-in and interactional scaffolding. The research was conducted in one of the elementary schools in Bandung. It involved one teacher who taught 18 students in 4th grade. The data were gained from classroom observation and teacher’s lesson plans. The findings revealed that the features of designed-in scaffolding were employed by the teacher in planning and implementing the lesson in the classroom. This research also found that following the designed-in scaffolding features could lead the teacher to structure and provide activities, tasks, and multimodal exposures for the students to be familiar with the multimodal texts. Hence, this research resulted in the pedagogical implication to encourage the teacher to be aware of scaffolding. If the teacher could provide an appropriate scaffolding, the students could gain the assistances, supports, and multimodal exposure for young learners to learn and create multimodal texts.

Optical Coherence Tomography Characteristics of the Novel Resorbable Magnesium Scaffold at 6 Months: An Intravascular Imaging Analysis of the First-in-Human Trial on DREAMS 3G

Optical Coherence Tomography Characteristics of the Novel Resorbable Magnesium Scaffold at 6 Months: An Intravascular Imaging Analysis of the First-in-Human Trial on DREAMS 3G