Navegando por Palavras-chave "nanobiotechnology"
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- ItemSomente MetadadadosBiogenic synthesis of nanostructured iron compounds: applications and perspectives(Inst Engineering Technology-iet, 2013-09-01) Seabra, Amedea Barozzi [UNIFESP]; Haddad, Paula [UNIFESP]; Duran, Nelson; Universidade Federal de São Paulo (UNIFESP); Universidade Estadual de Campinas (UNICAMP); Universidade Federal do ABC (UFABC)'Green nanotechnology' has attracted increasing attention in recent years because of the possibility to reduce and/or eliminate toxic substances. Indeed, biogenic syntheses of nanomaterials, such as nanoparticles (NPs), are considered economic and valuable alternatives for the production of metallic NPs for diverse applications. Recent studies have revealed that the development of eco-friendly technologies in material science is under extensive investigation in the field of nanobiotechnology. Considering this scenario, this review highlights the recent advances in the biogenic syntheses of metallic iron, iron sulphides and iron oxide NPs for a wide range of applications. Moreover, this review also discusses the medical, environmental and technological applications of biogenically synthesised NPs, and the challenges to be faced to optimise the eco-friendly production of these important nanomaterials.
- ItemAcesso aberto (Open Access)Membrane-translocating peptides and toxins: from nature to bedside(Sociedade Brasileira de Química, 2008-01-01) Rádis-Baptista, Gandhi; Kerkis, Alexandre; Prieto-Silva, Álvaro Rossan; Hayashi, Mirian Akemi Furuie [UNIFESP]; Kerkis, Irina; Tetsuo, Yamane; Universidade Federal de Pernambuco Departamento de Bioquímica; Clínica e Centro de Pesquisa em Reprodução Humana Roger Abdelmassih; Instituto Butantan Laboratório de Herpetologia; Universidade Federal de São Paulo (UNIFESP); Instituto Butantan Centro de Toxinologia Aplicada; Instituto Butantan Laboratório de Genética; Centro de Biotecnologia da Amazônia; Instituto de Pesquisas Energéticas e NuclearesToday, different functional classes of bioactive peptides and toxins isolated from diverse sources of living organisms are known. In medicine, these polypeptides present the potential to be used structurally unmodified or to serve as templates for molecular design of improved derivatives. Here, we refer to members of three classes of remarkable peptides and toxins that act at the cell membranes level and membrane trafficking systems: (i) the binary toxins (ii) the antimicrobial peptides and (iii) the cell penetrating peptides. Binary toxins have been genetically manipulated to generate specific immunotoxins, while antimicrobial peptides are in use as alternative agents against resistant microbes and tumor cells. Cell penetrating peptides have applications as diverse as cell transfection and transport of nanomaterials. Our group is dissecting the capacity of crotamine, a peptide from rattlesnake venom, to translocate cell membranes and use it as a delivery system in the transducing technology and molecular imaging.
- ItemSomente MetadadadosPoly(lactic acid-glycolic acid) nanoparticles markedly improve immunological protection provided by peptide P10 against murine paracoccidioidomycosis(Wiley-Blackwell, 2010-03-01) Amaral, Andre C.; Marques, Alexandre F.; Munoz, Julian E.; Bocca, Anamelia L.; Simioni, Andreza R.; Tedesco, Antonio C.; Morais, Paulo C.; Travassos, Luiz Rodolpho [UNIFESP]; Taborda, Carlos Pelleschi [UNIFESP]; Felipe, Maria Sueli S.; Universidade de Brasília (UnB); Univ Catolica Brasilia; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)Background and purpose:The present study reports on the preparation and testing of a sustained delivery system for the immunomodulatory peptide P10 aimed at reducing the in vivo degradation of the peptide and the amount required to elicit a protective immune response against paracoccidioidomycosis.Experimental approach:BALB/c mice were infected with the yeast Paracoccidioides brasiliensis to mimic the chronic form of paracoccidioidomycosis. the animals were treated daily with sulfamethoxazole/trimethoprim alone or combined with peptide P10, either emulsified in Freund's adjuvant or entrapped in poly(lactic acid-glycolic acid) (PLGA) nanoparticles at different concentrations (1 mu g, 5 mu g, 10 mu g, 20 mu g or 40 mu g center dot 50 mu L-1). Therapeutic efficacy was assessed as fungal burden in tissues and the immune response by quantitative determination of cytokines.Key results:Animals given combined chemotherapy and P10 nanotherapy presented a marked reduction of fungal load in the lungs, compared with the non-treated animals. After 30 days of treatment, P10 entrapped within PLGA (1 mu g center dot 50 mu L-1) was more effective than 'free' P10 emulsified in Freund's adjuvant (20 mu g center dot 50 mu L-1), as an adjuvant to chemotherapy. After treatment for 90 days, the higher doses of P10 entrapped within PLGA (5 or 10 mu g center dot 50 mu L-1) were most effective. Treatment with P10 emulsified in Freund's adjuvant (20 mu g center dot 50 mu L-1) or P10 entrapped within PLGA (1 mu g center dot 50 mu L-1) were accompanied by high levels of interferon-gamma in lung.Conclusions and implications:Combination of sulfamethoxazole/trimethoprim with the P10 peptide entrapped within PLGA demonstrated increased therapeutic efficacy against paracoccidioidomycosis. P10 incorporation into PLGA nanoparticles dramatically reduced the peptide amount necessary to elicit a protective effect.
- ItemSomente MetadadadosSilver nanoparticles: a brief review of cytotoxicity and genotoxicity of chemically and biogenically synthesized nanoparticles(Wiley-Blackwell, 2012-11-01) Lima, Renata de; Seabra, Amedea B. [UNIFESP]; Duran, Nelson; Univ Sorocaba; Universidade Federal de São Carlos (UFSCar); Universidade Federal de São Paulo (UNIFESP); Universidade Federal do ABC (UFABC); Universidade Estadual de Campinas (UNICAMP)In recent years interest in silver nanoparticles and their applications has increased mainly because of the important antimicrobial activities of these nanomaterials, allowing their use in several industrial sectors. However, together with these applications, there is increasing concerning related to the biological impacts of the use of silver nanoparticles on a large scale, and the possible risks to the environment and health. in this scenario, some recent studies have been published based on the investigation of potential inflammatory effects and diverse cellular impacts of silver nanoparticles. Another important issue related to nanoparticle toxicity in biological media is the capacity for increased damage to the genetic material, since nanoparticles are able to cross cell membranes and reach the cellular nucleus. in this regard, there is increasing interest in the analysis of potential nanoparticle genotoxicity, including the effects of different nanoparticle sizes and methods of synthesis. However, little is known about the genotoxicity of different silver nanoparticles and their effects on the DNA of organisms; thus further studies in this field are required. This mini-review aims to present and to discuss recent publications related to genotoxicity and the cytotoxicity of silver nanoparticles in order to better understand the possible applications of these nanomaterials in a safe manner. This present work concludes that biogenic silver nanoparticles are generally less cyto/genotoxic in vivo compared with chemically synthesized nanoparticles. Furthermore, human cells were found to have a greater resistance to the toxic effects of silver nanoparticles in comparison with other organisms. Copyright (c) 2012 John Wiley & Sons, Ltd.
- ItemSomente MetadadadosTargeting cancer stem cells with monoclonal antibodies: a new perspective in cancer therapy and diagnosis(Expert Reviews, 2008-07-01) Okamoto, Oswaldo Keith [UNIFESP]; Perez, Jose Fernando [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)This review discusses some of the impacts that biotechnology, genomics and nanotechnology convergence should have on future cancer management, in particular, the development of innovative diagnostic and therapeutic approaches based on monoclonal antibodies (mAbs) and cancer stem cells. Emergent therapeutic strategies in cancer have been focusing on the use of mAbs to stimulate an immune response against tumors, to block signaling pathways, or to refine delivery of cytotoxic agents. Now that cancer stem cells are being identified and characterized in different tumor types, their relevance to cancer physiopathology is becoming evident, making them natural targets for mAb development. Cancer stem cells are postulated to be responsible for tumor development, metastasis and relapse after conventional therapies. Therefore, mAbs targeting specific antigens and related pathways altered in cancer stem cells should facilitate earlier diagnosis through molecular imaging techniques and more efficient destruction of tumor initiating cells, thus improving clinical outcome.
- ItemSomente MetadadadosUltrastructural characterization of CD133(+) stem cells bound to superparamagnetic nanoparticles: possible biotechnological applications(Blackwell Publishing, 2008-09-01) Pavon, L. F.; Gamarra, L. F.; Marti, L. C.; Amaro Junior, E.; Moreira-Filho, C. A.; Camargo-Mathias, M. I.; Okamoto, Oswaldo Keith [UNIFESP]; Albert Einstein Res & Educ Inst IEPAE; Universidade de São Paulo (USP); UNESP; Universidade Federal de São Paulo (UNIFESP)CD133 antigen is an integral membrane glycoprotein that can bind with different cells. Originally, however. this cellular surface antigen was expressed in human stem cells and in various cellular progenitors of the haematopoietic system. Human cord blood has been described as an excellent source of CD133(+) haematopoietic progenitor cells with a large application potential. One of the main objectives of the present study is to describe for the first time the ultrastructural characteristics of CD133(+) stem cells using transmission electronic microscopy. Another objective of the manuscript is to demonstrate through transmission electronic microscopy the molecular image of magnetic nanoparticles connected to the stein cells of great biotechnological importance, as well as demonstrating the value of this finding for electronic paramagnetic resonance and its related nanobioscientific value. Ultrastructural results showed the monoclonal antibody anti-CD133 bound to the superparamagnetic nanoparticles by the presence of electrondense granules in cell membrane, as well as in the cytoplasm, revealing the ultrastructural characteristics of CD133(+) cells, exhibiting a round morphology with discrete cytoplasmic projections, having an active nucleus that follows this morphology. the cellular cytoplasm was filled up with mitochondrias, as well as microtubules and vesicles pinocitic. characterizing the process as being related to internalization of the magnetic nanoparticles that were endocyted by the cells in question. Electronic paramagnetic resonance analysis of the CD133(+) stem cells detected that the small (spectrum) generated by the labelled cells comes from the superparamagnetic nanoparticles that are bound to them. These results strongly suggest that these CD133(+) cells can be used in nanobiotechnology applications, with benefits in different biomedical areas.