Novel bilayered Gellan gum/Gellan gum hydroxyapatite scaffolds for osteochondral tissue engineering applications

Osteoarthritis is a major cause of disability during aging. By the age of 60, close to 100% of the population will have histologic changes of degeneration in their knee cartilage (Loeser, 2000). Because of its avascular nature, cartilage has little capacity to self-regenerate. Despite the progress already achieved in osteochondral regeneration, some limitations have to be overcome. The formation of fibrocartilage has to be avoided and the innervation has to be improved. Further, one main feature to be promoted is the induction of vascularization in the bony part but not in the cartilage part and to avoid de-differentiation processes. A promising strategy could pass through the development and optimization of novel culture systems. The ideal approach could integrate scaffolds presenting regions with different physical characteristics, combined with different growth factors to support different stem cells fates, regarding the complex tissue physiology to be regenerate. This work aims to develop novel bilayered gellan gum (GG)/gellan gumhydroxyapatite (HAp) hydrogels based structures for osteochondral tissue engineering applications. Bilayered GG/GG-HAp hydrogels were produced by joining both solutions of GG 2% (w/v) with and without HAp (20% wt.) for bony and cartilage parts, respectively. The solutions were introduced into a silicone mould with 20:10 mm (height and diameter, respectively). Gelation of GG was promoted by immersion in PBS solution for 24 h. The architecture of the bilayered scaffolds was investigated by micro-computed tomography. Results have shown that the freeze-dried bilayered scaffolds composed by low acyl GG(2%(w/ v)/low acyl GG(2%(w/v)-HAp20%(w/w) possess a porosity of 83.4 ± 0.8%, pore size of 279.3 ± 38.6 lm and interconnectivity of 62.2 ± 5.4%. Degradability assays are being performed with the intent to use this system to culture human adipose derived stem cells inducing cell co-differentiation into chondrocytes and osteoblasts. Ultimately, the developed bilayered scaffolds will provide new therapeutic possibilities for the regeneration of osteochondral defects

Gellan gum-based hydrogel bilayered scaffolds for osteochondral tissue engineering

It has been shown that hydrogel bilayered scaffolds combining cartilage- and bone-like layers are most advantageous for treating osteochondral defects. In this study, it is proposed the use of low acyl gellan gum (LAGG) for developing bilayered hydrogel scaffolds for osteochondral tissue engineering. The cartilage-like layer of the GG-based bilayered hydrogel scaffolds is composed of LAGG (2 wt%). By adding a 2 wt% LAGG aqueous solution to different amounts of HAp (5-20 wt%) it was possible to produce the bone-like layer. In vitro bioactivity tests were performed by means of soaking the LAGG/LAGG-HAp hydrogel scaffolds in a simulated body fluid solution up to 14 days. Scanning electron microscopy, Fourier transform infra-red spectroscopy and X-ray diffraction analyses demonstrated that apatite formation is limited to the bone-like layer of the LAGG/LAGG-HAp bilayered hydrogel scaffolds

Fatty Acid Profile of Elephant Grass Pastures with Different Grazing Heights

Ruminant milk and meat are a source of CLA and omega-3 in the human diet and these fatty acids (FAs) have a beneficial effect on human health (Mcguire and Mcguire 2000). The increase in CLA and omega-3 in ruminant products is mainly related to proportion of C18:2 and C18:3 in the animal feed, like forage and to incomplete ruminal biohydrogenation (Bauman et al. 2000). Evaluation of FAs have been performed in temperate forage pastures, without the interaction of animal grazing, and presenting samples collected at ground level and at fixed re-growth intervals or seasons as the main sampling criteria. Therefore, the objective of this study was to evaluate the proportion of fatty acid in strata of elephant grass cv. Pioneiro with different grazing heights

Sun-Graphyne: A New 2D Carbon Allotrope with Dirac Cones

Due to the success achieved by graphene, several 2D carbon-based allotropes were theoretically predicted and experimentally synthesized. Here, we propose a new 2D carbon allotrope named Sun-Graphyne (S-GY). We used density functional theory and reactive molecular dynamics simulations to investigate its mechanical, structural, electronic, and optical properties. The results showed that S-GY exhibits good dynamical and thermal stabilities. Its formation energy and elastic moduli are -8.57 eV/atom and 262.37 GPa, respectively. S-GY is a semi-metal and presents two Dirac cones in its band structure. This material is transparent, and its intense optical activity is limited to the infrared region. Remarkably, the band structure of S-GY remains practically unchanged at even moderate strain regimes. As far as we know, this is the first 2D carbon allotrope to exhibit this behaviour.Comment: 17 pages, and 11 figure

Posterior talar process as a suitable cell source for treatment of cartilage and osteochondral defects of the talus

Osteochondral defects of the ankle are common lesions affecting the talar cartilage and subchondral bone. Current treatments include cell-based therapies but are frequently associated with donor-site morbidity. Our objective is to characterize the posterior process of the talus (SP) and the os trigonum (OT) tissues and investigate its potential as a new source of viable cells for application in tissue engineering and regenerative medicine.SP and OT tissues obtained from six patients were characterized by micro-computed tomography, and histological, histomorphometric and immunohistochemical analyses. Isolated cells proliferation and viability were evaluated by MTS assay, DNA quantification and Live/Dead staining. The TUNEL assay was performed to evaluate cell death by apoptosis. Moreover, the production of extracellular matrix was evaluated by toluidine blue staining, whereas cells phenotype was investigated by flow cytometry. Ankle explants characterization showed the presence of a cartilage tissue layer in both SP and OT tissues, which represent, at least 20% in average of the explant. The presence of type II collagen was detected in the extracellular matrix. Isolated cells presented a round morphology typical of chondrocytes. In in vitro studies, cells were viable and proliferating up to 21 days of culturing. No signs of apoptosis were detected. Flow cytometry analysis revealed that isolated cells maintained the expression of several chondrocytic markers during culturing. The results indicate that the SP and OT tissues are a reliable source of viable chondrocytes, which can find promising applications in ACI/MACI strategies with minimal concerns regarding donor zone complications.Portuguese Foundation for Science and Technology (FCT) through the project OsteoCart (Grant No. PTDC/CTM-BPC/115977/2009), Fundación MAPFRE (Ayudas a la Investigación Ignacio H. de Larramendi, Prevención, Salud y Medio Ambiente, Spain) under the project 'Preventing the progression of the knee osteoarthritis: advanced therapies combining injectable hydrogels, autologous stem cells and PRP' (Grant No. BIL/13/SA/235). This study was also carried out with the support of Fundo Europeu de Desenvolvimento Regional (FEDER) through Programa Operacional do Norte through the project Articulate (Grant No. 23189

Soybean Breeding Aiming at increasing Productivity and Root-Knot Nematode Resistance

In Brazil, the root-knot nematode (Pratylenchus brachyurus) has gained importance, whatever because of the damage caused to soybean crops or because of its broad dispersion and incidences in producing areas. Therefore, this invention aimed at developing a new cultivar resistant to the major soybean diseases as well as to the root-knot nematode. As a result, we developed a soybean cultivar designated UFUS 8301. Generations were advanced by the single seed descent method. Value for Cultivation and Use assays were carried out during a 3-year period (2010/13). Distinctness, uniformity, and stability experiments were carried out during a 2-year period (2011/13). We used the reproduction factor (RF) statistics to assess damage and reproductive potentials of P. Brachyurus; analysis of variance tested differences between means. We accepted the null hypothesis there was no difference between UFUS 8301 and the parameter of resistance Crotalaria spectabilis. UFUS 8301 was found distinct from any other cultivar, homogeneous to the descriptors that had identified it and stable through generations. UFUS 8301 presented 19% oil and 39% protein on the seeds, and yield (3687.5 kg ha-1) above Brazilian national average

Capacitação dos profissionais de informação visando a gestão no Arca – Repositório Institucional da Fundação Oswaldo Cruz

O texto aborda a importância da realização dos trabalhos de sensibilização e capacitação em palestras e cursos ministrados para os profissionais de informação/Bibliotecários que trabalham na gestão do Arca - Repositório Institucional da Fundação Oswaldo Cruz (Brasil), visando assim aprimorar as competências internas para a melhoria da eficiência, eficácia e qualidade dos documentos inseridos no RI como também disponibilizar o conteúdo em saúde pública para toda a Sociedade.Ibero-American Science and Technology Education Consortiu

Mutations, Clinical Findings and Survival Estimates in South American Patients with X-Linked Adrenoleukodystrophy

In this study, we analyzed the ABCD1 gene in X-linked adrenoleukodystrophy (X-ALD) patients and relatives from 38 unrelated families from South America, as well as phenotypic proportions, survival estimates, and the potential effect of geographical origin in clinical characteristics