5,519 research outputs found

    Conceptual design of harvesting energy system for road application

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    Energy harvesting becomes more and more important in our life. It refers to the practice of acquiring energy from the environment which would be otherwise wasted and converting it into usable electric energy. For this, every kind of energy can be exploited such as solar, wind or strain and kinetic energy. The idea is to propose a conceptual design that will carry out a suitable energy harvesting conversion to be applied for road application. Harvesting energy using piezoelectric generators has been chosen for this project. The project conduct a simulation analysis using a piezoelectric generator based on a model by S Roundy and P K Wright. The data used from a 15 mm x 3.2 mm x 0.14 mm single layer piezoelectric bending element which produce 0.95mW with a 1.727e6 Nm of input stress. The simulation is done using MATLAB-Simulink-SimPowerSystems which also tested with others value by Luigi Pinna et al.. Piezoelectric generator can be one of the green solutions for sustainable development in energy generation

    Hybrid organic-inorganic Scaffolding Biomaterials for Regenerative Therapies

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    The introduction of hybrid materials in regenerative medicine has solved some problems related to the mechanical and bioactive properties of biomaterials. Calcium phosphates and their derivatives have provided the basis for inorganic components, thanks to their good bioactivity, especially in bone regeneration. When mixed with biodegradable polymers, the result is a synergic association that mimics the composition of many tissues of the human body and, additionally, exhibits suitable mechanical properties. Together with the development of nanotechnology and new synthesis methods, hybrids offer a promising option for the development of a third or fourth generation of smart biomaterials and scaffolds to guide the regeneration of natural tissues, with an optimum efficiency/cost ratio. Their potential bioactivity, as well as other valuable features of hybrids, open promising new pathways for their use in bone regeneration and other tissue repair therapies. This review provides a comprehensive overview of the different hybrid organic-inorganic scaffolding biomaterials developed so far for regenerative therapies, especially in bone. It also looks at the potential for research into hybrid materials for other, softer tissues, which is still at an initial stage, but with very promising results

    Three-dimensional glass-derived scaffolds for bone tissue engineering: current trends and forecasts for the future

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    3D bioactive composite scaffolds for bone tissue engineering

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    Bone is the second most commonly transplanted tissue worldwide, with over four million operations using bone grafts or bone substitute materials annually to treat bone defects. However, significant limitations affect current treatment options and clinical demand for bone grafts continues to rise due to conditions such as trauma, cancer, infection and arthritis. Developing bioactive three-dimensional (3D) scaffolds to support bone regeneration has therefore become a key area of focus within bone tissue engineering (BTE). A variety of materials and manufacturing methods including 3D printing have been used to create novel alternatives to traditional bone grafts. However, individual groups of materials including polymers, ceramics and hydrogels have been unable to fully replicate the properties of bone when used alone. Favourable material properties can be combined and bioactivity improved when groups of materials are used together in composite 3D scaffolds. This review will therefore consider the ideal properties of bioactive composite 3D scaffolds and examine recent use of polymers, hydrogels, metals, ceramics and bio-glasses in BTE. Scaffold fabrication methodology, mechanical performance, biocompatibility, bioactivity, and potential clinical translations will be discussed

    Ancient and historical systems

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    Ceramic biomaterials for tissue engineering

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    Bioceramics, natural and synthetic, are designed to induce a strong bonding to bone and appeared as an alternative to metallic implants. Bioceramic materials currently used for the repair and reconstruction of hard and soft tissues can be categorized according its composition, structure, and properties. These biomaterials are grouped bioinert ceramics as alumina and zirconia, bioactive glasses and glass ceramics and bioresorbable calcium phosphates-based materials. The bioceramics concepts, namely physico-chemical, mechanical and biological properties, and respective applications in diverse fields of tissue engineering are discussed in depth herein. An up-to-date of bioceramics clinical trials is also considered. Based on the stringent requirements for clinical application, prospects for the development of advanced functional bioceramics for tissue engineering are highlighted for the future.The authors thank to the project FROnTHERA (NORTE-01-0145-FEDER-000023), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). The financial support from the Portuguese Foundation for Science and Technology to M-ERA-NET/0001/2014 project, for the fellowship grant (SFRH/BPD/108763/2015) and for the funds provided under the program Investigador FCT 2012 and 2015 (IF/00423/2012 and IF/01285/2015) are also greatly acknowledge.info:eu-repo/semantics/publishedVersio

    Calcium orthophosphate-based biocomposites and hybrid biomaterials

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    Novel hydroxyapatite/carboxymethylchitosan composite scaffolds prepared through an innovative ‘‘autocatalytic’’ electroless coprecipitation route

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    A developmental composite scaffold for bone tissue engineering applications composed of hydroxyapatite (HA) and carboxymethylchitosan (CMC) was obtained using a coprecipitation method, which is based on the ‘‘autocatalytic’’ electroless deposition route. The results revealed that the pores of the scaffold were regular, interconnected, and possess a size in the range of 20–500 lm. Furthermore, the Fourier transform infra-red spectrum of the composite scaffolds exhibited all the characteristic peaks of apatite, and the appearance of typical bands from CMC, thus showing that coprecipitation of both organic and inorganic phases was effective. The X-ray diffraction pattern of composite scaffolds demonstrated that calciumphosphates consisted of crystalline HA. From microcomputed tomography analysis, it was possible to determine that composite scaffolds possess a 58.9% 6 6% of porosity. The 2D morphometric analysis demonstrated that on average the scaffolds consisted of 24% HA and 76% CMC. The mechanical properties were assessed using compressive tests, both in dry and wet states. Additionally, in vitro tests were carried out to evaluate the wateruptake capability, weight loss, and bioactive behavior of the composite scaffolds. The novel hydroxyapatite/ carboxymethylchitosan composite scaffolds showed promise whenever degradability and bioactivity are simultaneously desired, as in the case of bone tissue-engineering scaffolding applications.Contract grant sponsor: European Union (STREP Project HIPPOCRATES); contract grant number: NMP3-CT-2003-50575

    Natural-origin materials for tissue engineering and regenerative medicine

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    Recent advances in tissue engineering and regenerative medicine have shown that combining biomaterials, cells, and bioactive molecules are important to promote the regeneration of damaged tissues or as therapeutic systems. Natural origin polymers have been used as matrices in such applications due to their biocompatibility and biodegradability. This article provides an up-to-date review on the most promising natural biopolymers, focused on polysaccharides and proteins, their properties and applications. Membranes, micro/nanoparticles, scaffolds, and hydrogels as biomimetic strategies for tissue engineering and processing are described, along with the use of bioactive molecules and growth factors to improve tissue regeneration potential. Finally, current biomedical applications are also presented.The authors would like to thank to the financial support from the Portuguese Foundation for Science and Technology (FCT) for the fellowship grants of Simone S Silva (SFRH/BPD/112140/2015), Emanuel M Fernandes (SFRH/BPD/96197/2013), Joana-Silva Correira (SFRH/BPD/100590/2014), Sandra Pina (SFRH/BPD/108763/2015), Silvia Vieira (SFRH/BD/102710/2014), “Fundo Social Europeu”- FSE and “ Programa Diferencial de Potencial Humano POPH”, and to the distinction attributed to J.M. Oliveira under the Investigator FCT program (IF/00423/2012). It is also greatly acknowledged the funds provided by FCT through the project EPIDisc (UTAP-EXPL/BBBECT/0050/2014), financed in the Framework of the “International Collaboratory for Emerging Technologies, CoLab”, UT Austin|Portugal Program.info:eu-repo/semantics/publishedVersio
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