Hierarchical structuring of 3D prototyped scaffolds with human platelet's lysates and marine-origin polysaccharides induce and improve biomineralization of human adipose derived stem cells

Introduction: Bone tissue engineering demands hybrid 3D structures able to provide both mechanical stability and an adequate nano and micro-environment. Herein, we investigated a methodology to perform the structuring of 3D prototyped scaffolds, with nanocoatings and fibrillar structures where autologous growth factors (GFs) are stabilized and able to conduct and induce the osteogenic differentiation of human adipose derived stem cells (hASCs). Materials and methods: Poly(e-caprolactone)-PCL, ι-carrageenan and chitosan where obtained from Sigma-Aldrich. Human platelet lysate was obtained as explained elsewhere1 The assembling of the polyelec- trolytes (PEs) with PL was studied by QCM-D. PCL scaffolds were pre- pared by BioplotterTM and modified by dipping LbL similar to what we described before2. hASCs were culture in osteogenic (+dexamethasone,+Dex) and osteoconductive media (-Dex). After 28 days in culture, samples were harvested and characterized by several techniques for calcium, osteocalcin (OC) and fat deposition; and for chondro-, adipo-, angio-, and osteogenic-specific gene expression. Results: PL was incorporated in the LbL assembled structures in the form of nanocoatings and fibrillar structures (Fig. 1). The new structures supported hASCs osteogenesis both in the pres- ence and absence of PL. These structures conduced the deposition of CaP not only onto the surfaces (as in the case of PCL) but also in the void spaces of the pores. In the absence of Dex, PL and the hierarchical structures both induced the deposition of mineralized matrix and osteo- calcin (Fig. 2). An inhibitory effect was observed when the number of bilayers was triplicated (results not shown). Discussion and conclusions: The structuring method has shown to be effective for the introduction and stabilization of osteo-inductive factors derived from PL. The GF’s showed its bioactivity by inducing the depo- sition of OC and CaP, by hASCs, in absence of Dex. Gene expression was influenced by both structuring and PL; which tended to increase angio- and osteogenic-related expression. With this method, 3D scaf- folds can be structured with hybrid, multi-functional, inductive and hierarchical micro/nanostructures. By playing with the structuring parameters the density of the GFs which are presented to cells, the profile and even the spatial-temporal release can be controlled. Acknowledgments: FCT is gratefully acknowledged for fellowships of S.M.O. (SFRH/BD/ 70107/2010). Disclosures: The authors have noting to disclose. References 1. Santo EV, et al. Journal of Controlled Release. 162, 19-27, 2012. 2. Oliveira SM, et al. Adv Health Mat, 2, 3, 2013

Wireless interface for sensors in smart textiles

This paper describes a smart suit with sensors and electronics for monitoring patients at hydrotherapy sessions in swimming-pools. The smart suit allows the monitoring of the heart rate, patient posture and activity level. The sensors input are converted in a PWM using a V-F converter. A robust, low-voltage (3.0 V) and low-power electronic wireless CMOS RF interface was implemented at 433 MHz using ASK modulation.Fundação para a Ciência e a Tecnologia (FCT) - (SFRH/BD/4717/2001, POCTI/ESE/38468/2001)

Merging microarray studies to identify a common gene expression signature to several structural heart diseases

Background: Heart disease is the leading cause of death worldwide. Knowing a gene expression signature in heart disease can lead to the development of more efficient diagnosis and treatments that may prevent premature deaths. A large amount of microarray data is available in public repositories and can be used to identify differentially expressed genes. However, most of the microarray datasets are composed of a reduced number of samples and to obtain more reliable results, several datasets have to be merged, which is a challenging task. The identification of differentially expressed genes is commonly done using statistical methods. Nonetheless, these methods are based on the definition of an arbitrary threshold to select the differentially expressed genes and there is no consensus on the values that should be used. Results: Nine publicly available microarray datasets from studies of different heart diseases were merged to form a dataset composed of 689 samples and 8354 features. Subsequently, the adjusted p-value and fold change were determined and by combining a set of adjusted p-values cutoffs with a list of different fold change thresholds, 12 sets of differentially expressed genes were obtained. To select the set of differentially expressed genes that has the best accuracy in classifying samples from patients with heart diseases and samples from patients with no heart condition, the random forest algorithm was used. A set of 62 differentially expressed genes having a classification accuracy of approximately 95% was identified. Conclusions: We identified a gene expression signature common to different cardiac diseases and supported our findings by showing their involvement in the pathophysiology of the heart. The approach used in this study is suitable for the identification of gene expression signatures, and can be extended to different diseases.info:eu-repo/semantics/publishedVersio

Sequential injection determination of nitrate in vegetables by spectrophotometry with inline cadmium reduction

A sequential injection system for the determination of nitrate (NO3 2) in vegetables was developed to automate this determination, allowing for substantially reduced reagent consumption and generated waste using low-cost equipment. After extraction with water and filtration, the extracted nitrate is reduced inline to nitrite in a copperized cadmium (Cd) column and determined as nitrite. According to the Griess–Ilosvay reaction, nitrate is diazotized with sulfanilamide and coupled with N-(1-naphtyl)-ethylenediamine dihydrochloride to form a purple-red azo dye monitored at 538 nm. Nitrate can be determined within a range of 1.35–50.0 mg L21 of NO3 2 (corresponding to 0.270–10.0 g of NO3 2 per kg of vegetable), with a conversion rate of nitrate to nitrite of 99.1+0.8%. The results obtained for 15 vegetable extracts compare well with those provided by the classical procedure, with a sampling throughput of 24 determinations per hour and relative standard deviations better than 1.2%

Study of NAD-interacting proteins highlights the extent of NAD regulatory roles in the cell and its potential as a therapeutic target

Nicotinamide adenine dinucleotide (NAD) levels are essential for the normal physiology of the cell and are strictly regulated to prevent pathological conditions. NAD functions as a coenzyme in redox reactions, as a substrate of regulatory proteins, and as a mediator of protein-protein interactions. The main objectives of this study were to identify the NAD-binding and NAD-interacting proteins, and to uncover novel proteins and functions that could be regulated by this metabolite. It was considered if cancer-associated proteins were potential therapeutic targets. Using multiple experimental databases, we defined datasets of proteins that directly interact with NAD – the NAD-binding proteins (NADBPs) dataset – and of proteins that interact with NADBPs – the NAD-protein–protein interactions (NAD-PPIs) dataset. Pathway enrichment analysis revealed that NADBPs participate in several metabolic pathways, while NAD-PPIs are mostly involved in signalling pathways. These include disease-related pathways, namely, three major neurodegenerative disorders: Alzheimer’s disease, Huntington’s disease, and Parkinson’s disease. Then, the complete human proteome was further analysed to select potential NADBPs. TRPC3 and isoforms of diacylglycerol (DAG) kinases, which are involved in calcium signalling, were identified as new NADBPs. Potential therapeutic targets that interact with NAD were identified, that have regulatory and signalling functions in cancer and neurodegenerative diseases.info:eu-repo/semantics/acceptedVersio

Mechanical, surface and environmental evaluation of stone mastic asphalt mixtures with advanced asphalt binders using waste materials

The reuse of waste materials in asphalt mixtures has been recently investigated, in order to develop new sustainable solutions for the road-paving industry. Such materials should improve the mechanical performance and provide safe/comfortable pavement surface courses for road users, without compromising their environmental performance. Thus, the aim of this study is to evaluate the mechanical, surface and environmental properties of stone mastic asphalt (SMA) mixtures produced with forward-looking asphalt binders incorporating waste materials. These binders were designed to maximise the waste material content using motor oil, high-density polyethylene, styrene?butadiene?styrene and crumb rubber, while performing so well as a commercial modified bitumen. Finally, the overall performance of the SMA mixtures produced with the selected binders was evaluated. It was concluded that these mixtures improve the water sensitivity, fatigue cracking and permanent deformation performance. The requirements for macrotexture, skid resistance and presence of heavy metals in leachates of these mixtures were similarly fulfilled. Thus, this work shows that new asphalt mixtures with waste materials can be used in road-paving works to improve the performance without compromising human and environmental safety.Portuguese Government and EU/FSE within a PhD fellowship (SFRH/BD98379/2013) of the FCT, in the scope of POPH/QREN, by ERDF (European Regional Development Fund) funds through the Competitiveness Factors Operational Programme (COMPETE)info:eu-repo/semantics/publishedVersio

Carbon dioxide emissions and heavy metal contamination analysis of stone mastic asphalt mixtures produced with high rates of different waste materials

The incorporation of waste materials in asphalt mixtures has driven several studies mainly focused on improving their mechanical performance while minimizing the use of virgin materials. However, these could only be considered cleaner solutions for road paving works if their production and application do not present additional risks for human health and the environment. Therefore, this study aims at assessing the carbon dioxide emissions and possible leachates of stone mastic asphalt mixtures produced with high rates of different waste materials for binder modification or material recycling. Thus, a chemical analysis of eluates that were in contact with those mixtures and an estimation of the carbon dioxide emissions associated with their production and transportation were carried out under different scenarios. In conclusion, these mixtures comply with the established specifications for hazardous leachates. The addition of waste materials to these mixtures decreases carbon dioxide emissions, especially for recycled stone mastic asphalt mixtures with 50% reclaimed asphalt pavement material and bitumens modified with waste materials. Thus, the studied mixtures are innovative solutions for future use in pavement maintenance and rehabilitation operations, in line with the circular economy concept.The authors gratefully acknowledge the funding by the Portuguese Government and EU/FSE within a Portuguese Foundation for Science and Technology (FCT) Ph.D. grant (SFRH/BD98379/2013), in the scope of POPH/QREN

Combinatorial analysis of marine based biomaterials: high-throughput analysis of the effect of nanostructured multilayers on cell behaviour

Publicado em "Journal of Tissue Engineering and Regenerative Medicine", vol. 7, supp. 1 (2013)In a marine environment, specific proteins are secreted by mussels and used as a bioglue to stick to a surface allowing generate irreversible bonding. Adhesive secreted proteins of mussels present an unusual amino acid 3,4-dihydroxyphenylalanine (DOPA). Inspired by the struc- ture and properties of mussel adhesive proteins, layer-by-layer (LbL) coatings based on polymers that contain catechol groups were devel- oped. We used dopamine-modified hyaluronic acid (HA-DN) prepared by carbodiimide chemistry to form thin and surface-adherent dopamine films. The multilayer films were developed by electrostatic interactions using chitosan (CHT) as polycation and HA-DN as polyanion. Multilay- ers films of CHT and HA were used as control. The formation of these films was investigated in-situ by quartz crystal microbalance with dissi- pation monitoring (QCM-D). Afterwards, many combinations of the marine inspired biomaterials were analysed in a high-throughput (HTS) way. Such multilayers were constructed and individually dis- posed on isolated transparent spots, patterned onto biomimetic super- hydrophobic substrates. The adhesion properties of the coatings in the chips were also analyzed. In vitro tests using two distinct cell sources were carried out to evaluate the biological performance of the different combinations of multilayers that could be useful in different biomedical applications, including tissue engineering