Scaffolds

El andamio como herramienta arquitectónica tiene una larga historia vinculada
a la producción arquitectónica. En este artículo, se subvierte su rol instrumental
para explorar sus posibilidades como elemento de soporte a la construcción, pero
también como elemento arquitectónico integrado a la obra. Para esto, se lleva a
cabo un estudio de caso de dos obras desarrolladas por el colectivo República
Portátil, en las cuales los andamios dejan de lado su función netamente operativa y
se constituyen como obras. Se aplica un método de investigación por acción y las
conclusiones ofrecen un conjunto de reflexiones teóricas sobre el andamio como
modelo teórico espacial donde la reticulación de soluciones permite una amplia
versatilidad productiva.



The scaffolding, as an architectural tool has a long history linked to architectural
production. In this article, its instrumental role is subverted to explore its
possibilities as a support element for construction, but also as an architectural
element integrated into the work. For this, a case study of two works developed
by the Chilean collective named República Portátil is carried out, in which the
scaffolding neglects its purely operational function and is constituted as an architecture
itself. An action research method is applied, and the conclusions offer
a set of theoretical reflections on the scaffolding as a theoretical spatial model
where the cross-linking of solutions allows a wide productive versatility.

As today's classrooms become more and more diverse, there is a growing need to explore the intersection between English Learners (ELs) and students with learning disabilities (LD) in the content-specific instruction of mathematics problem solving. The aim of this study was to determine which types of instructional scaffolds may be used by math teachers to effectively support ELs with LD learning multiplicative reasoning. To this end, we employed an exploratory case study based on a frequency count analysis of four scaffold types used by the students and the teacher in their sessions. The results showed that kinesthetic and linguistic scaffolds were the most beneficial for helping ELs with LD to cultivate mathematical thinking with both concrete and abstract units, while also helping to increase the sophistication of their mathematical content-language usage. In combination with small-group interactions, these scaffolds provide an effective instructional method for improving multiplicative reasoning among ELs with LD.

La fabricación por manufactura aditiva (MA) ha sido investigada y desarrollada desde los últimos 20 años. Esto ha conllevado también al avance de otras áreas como la ingeniería de tejidos. La novedad y la ventaja de estas técnicas recaen en el hecho de que en lugar de fundamentar el proceso en la eliminación de material, ésta crea piezas tridimensionales capa por capa y con mucha precisión directamente de modelos CAD (Computer Aided Design), con altas complejidades geométricas y usando materiales que no podrían ser producidos a través de procesos de fabricación tradicionales. Durante estas últimas dos décadas, se ha hecho un progreso significativo en el desarrollo y comercialización de nuevos e innovadores procesos de MA y prototipado rápido (PR), así como de numerosas aplicaciones con muchos avances en la industria aeroespacial, automotriz, biomédica, biomecánica, farmacológica y otros campos.

The present research was carried out to investigate the effect of scaffolding and self-regulation on the reading comprehension of ESP students. For this purpose, one hundred and thirty ESP students who had passed prerequisite general English courses and who were about to take the professional English course were chosen. Further, through the PET test they were homogenized. Besides, the participants were non-randomly assigned to two experimental groups and one control group. Therefore, a quasi-experimental design was adopted to test the effect of scaffolding instruction and self-regulated learning on ESP learners' reading comprehension. This study had a pretest before the treatment and a posttest at the end. Then, in order to find whether, scaffolding or self-regulation could be more effective on ESP students " reading comprehension, the pretest scores were compared with the posttest scores. The statistical measure of MANOVA was used to test the group scores and compare them against each other. The analysis of the data revealed that the experimental group in relation to scaffolding effect on reading comprehension outperformed the control group. In addition, it was found that the scaffolding group significantly outperformed the self-regulation learning group on the posttest of reading comprehension. This study has implications for students and teachers.

The objectives of this study were i) to investigate whether a novel biphasic collagen scaffold supports meniscal repair in an ovine meniscal defect model in vivo, ii) to investigate meniscal cell ingrowth and ECM production in an ex-vivo model and iii) to investigate the effect platelet rich plasma (PRP) on the response of meniscal elements to the scaffold.A novel biphasic scaffold (collagen sponge with 300 mm open pores, reinforced with bands of 150 mm internal strengthening fibres) was implanted into a circular defect in the meniscus of adult sheep with and without PRP. Healing in vivo was monitored by longitudinal gait analysis.  At 2 and 26 weeks post surgery durometry, histology and immunohistochemistry was performed on recovered menisci. In vitro, ex vivo ovine meniscus/scaffold models were constructed and the effects of PRP on cell migration and extracellular matrix production monitored by cell tracking, protein extraction and Western blotting.In this study we have demonstrated that a novel biphasic collagen scaffold can support meniscal defect repair in an in vivo model and support the ingrowth of meniscal fibrochondrocyte (MFC) in an ex vivo model.  In addition we have demonstrated that the addition of PRP significantly enhances MFC migration and ECM production in vitro and promotes rapid defect healing in vivo. This novel biphasic scaffold supports meniscal healing, which is increased in the presence of PRP, likely due to increased MFC migration.

Bone defects are difficult to heal when large part of tissue is lost. Mesenchymal stem cells (MSCs) are used for in vitro studies showing they can differentiate into osteoblasts, thus being able to contribute to bone-like structures formation when seeded on scaffolds. Purpose of our study was to show that demineralized bone can be used as biological scaffold together with different cellular types inducing rapid healing of defects. Femoral bones were obtained from rats sacrificed during other experiments and submitted to demineralization protocol, being further used as scaffolds. Experimental group consisted of 10 female Wistar rats, 6-8 weeks old. Rat bone marrow was harvested from iliac bone and cultured in adherent plates. Part of bone marrow-derived MSCs was maintained in culture for multiple passages. Rests of the cells were differentiated into osteoblasts. Bone defects of 0.25 cm 3 were induced on both femoral bones of each rat and biologic scaffolds combined with MSCs and oste...

Biomaterials capable of controlling the release of multiple growth factors (GFs) could potentially
promote the integration of co-transplanted neural progenitor cells (NPCs) and stimulate the plasticity
and regenerability of the lesioned spinal cord. As a first step towards the employment of such a
vehicle for cell therapy, this study examined the capability of an alginate–sulphate/alginate scaffold,
able to capture and rigorously control the release of GFs, to promote the expansion and lineage
differentiation of NPCs in vitro. Epidermal growth factor (EGF) and fibroblast growth factor-2 (bFGF)
were affinity-bound to alginate–sulphate (200 ng/scaffold) and the bioconjugates were mixed with
partially calcium-crosslinked alginate. NPCs isolated from 18 day-old rat embryo brains and seeded
into the scaffold during preparation were found to proliferate and differentiate within the vehicle.
A continuous release of both bFGF and EGF was noted for a period of 21 days. The concentrations
of released GFs were sufficient to promote extensive NPC proliferation at initial cultivation times;
the number of neurospheres in the scaffold was twice the number found in the 2D cultures
supplemented with 20 ng/ml each factor every 3 days. Between days 10–14, when the GF concentrations
had substantially declined, extensive cell migration from the neurospheres as well as lineage
differentiation were noted in the scaffold; immunocytochemical analyses confirmed the presence of
neurons, astrocytes and oligodendrocytes.The scaffold has a potential to serve as cell delivery
vehicle, with proven capability to promote cell retention and expansion, while enabling NPC lineage
differentiation in situ.

Nanoparticles of late have come to be of great importance due to their extremely small size and a wide range of properties. In our proposed project the silver nanoparticles are coated on a material of hydroxyapatite to enhance its performance, stability and reproducibility. The hydroxyapatite is coated with silver nanoparticles and is used in the preparation of a scaffold. The scaffold is tested for anti-microbial activity and characterization studies are carried out. The coated nanoparticles enhance the formation of osteoblasts and hence contribute to bone regeneration.

Intervertebral disc (IVD) degeneration (IDD) is associated with low back pain and significantly affects the patient's quality of life. Degeneration of the IVD alters disk height and the mechanics of the spine, leading to chronic segmental spinal instability. The pathophysiology of IVD disease is still not well understood. Current therapies for IDD include conservative and invasive approaches, but none of those treatments are able to restore the disc structure and function. Recently, tissue engineering techniques emerged as a possible approach to treat IDD, by replacing a damaged IVD with scaffolds and appropriate cells. Advances in manufacturing techniques, material processing and development, surface functionalization, drug delivery systems and cell incorporation furthered the development of tissue engineering therapies. In this review, biomaterial scaffolds and cell-based therapies for IVD regeneration are briefly discussed.

, IVD, cell-based therapies, biomaterials, scaffolds, tissue engineering, IVD degeneration, IDD

Medicines developed from traditional systems are well known for their various important pharmaceutical uses. Cancer has been known since ancient times and has been mentioned in the ancient Ayurvedic books. Thus natural based products play a significant role in cancer chemotherapeutics. Further, approximately 70% of anticancer compounds are based on natural products or have been derived from their structural scaffolds. Hence, there is a growing interest for developing medicines from these natural resources. Amongst the methods of treating cancer, therapies targeting cancer stem cell are found to control metastatic tumor which is a newly identified factor associated with relapse. This patent review aims to highlight the use of natural products to treat cancer by targeting the cancer stem cells. The review will also provide insights into the reported mechanisms by which the natural products act in order to suppress or kill cancer stem cells. The analysis has been done using various criteria such as the patenting trend over the years, comparison of active assignee and a comparison of the technical aspects as disclosed in the different patent documents. The analysis further highlights different bioactives, the scaffolds of which could thus be a promising candidate in the development of anti-cancer drugs by targeting the cancer stem cells. The technical aspects covered in this review include: Bioactives and formulations comprising the extracts or bioactives, their mode of action and the type of assay considered to study the efficacy of the natural products. Further the mapping has helped us to identify potential therapeutic areas to evaluate herbs/bioactives and their uses for developing new formulations.

Bioengineering a functional organ holds great potential to overcome the current gap between the organ need and shortage of available organs. Whole organ decellularization allows the removal of cells from large-scale organs, leaving behind extracellular matrices containing different growth factors, structural proteins, and a vascular network with a bare surface. Successful application of decellularized tissues as transplantable organs is hampered by the inability to completely reline the vasculature by endothelial cells (ECs), leading to blood coagulation, loss of vascular patency, and subsequent death of reseeded cells. Therefore, an intact, continuous layer of endothelium is essential to maintain proper functioning of the vascular system, which includes the transfer of nutrients to surrounding tissues and protecting other types of cells from shear stress. Here, we aimed to summarize the available cell sources that can be used for reendothelialization in addition to different trials performed by researchers to reconstruct vascular-ization of decellularized solid organs. Additionally, different techniques for enhancing reendothelialization and the methods used for evaluating reendothelialization efficiency along with the future prospective applications of this field are discussed. Statement of significance Despite the great progress in whole organ decellularization, reconstruction of vasculature within the engineered constructs is still a major roadblock. Reconstructed endothelium acts as a multifunctional barrier of vessels, which can reduce thrombosis and help delivering of oxygen and nutrients throughout the whole organ. Successful reendothelialization can be achieved through reseeding of appropriate cell types on the naked vasculature with or without modification of its surface. Here, we present the current research milestones that so far established to reconstruct the vascular network in addition to the methods used for evaluating the efficiency of reendotheilization. Thus, this review is quite significant and will aid the researchers to know where we stand toward biofabricating a transplantable organ from decellularizd extracellular matrix.

Elaboration of novel biocomposites providing simultaneously both biodegradability and stimulated bone tissue repair is essential for regenerative medicine. In particular, piezoelectric biocomposites are attractive because of a possibility to electrically stimulate cell response. In the present study, novel CaCO 3-mineralized piezoelectric biodegradable scaffolds based on two polymers, poly[(R)3-hydroxybutyrate] (PHB) and poly[3-hydroxybutyrate-co-3-hydroxyvalerate] (PHBV), are presented. Mineralization of the scaffold surface is carried out by the in situ synthesis of CaCO 3 in the vaterite and calcite polymorphs using ultrasound (U/S). Comparative characterization of PHB and PHBV scaffolds demonstrated an impact of the porosity and surface charge on the mineralization in a dynamic mechanical system, as no essential distinction was observed in wettability, structure, and surface chemical compositions. A significantly higher (4.3 times) piezoelectric charge and a higher porosity (∼15%) lead to a more homogenous CaCO 3 growth in 3-D fibrous structures and result in a two times higher relative mass increase for PHB scaffolds compared to that for PHBV. This also increases the local ion concentration incurred upon mineralization under U/S-generated dynamic mechanical conditions. The modification of the wettability for PHB and PHBV scaffolds from hydrophobic (nonmineralized fibers) to superhydrophilic (mineralized fibers) led to a pronounced apatite-forming behavior of scaffolds in a simulated body fluid. In turn, this results in the formation of a dense monolayer of well-distributed and proliferated osteoblast cells along the fibers. CaCO 3-mineralized PHBV surfaces had a higher osteoblast cell adhesion and proliferation assigned to a higher amount of CaCO 3 on the surface compared to that on PHB scaffolds, as incurred from micro-computed tomography (μCT). Importantly, a cell viability study confirmed biocompatibility of all the scaffolds. Thus, hybrid biocomposites based on the piezoelectric PHB polymers represent an effective scaffold platform functionalized by an inorganic phase and stimulating the growth of the bone tissue.