scholarly journals OBTENÇÃO DE VATERITA ESTABILIZADA PARA APLICAÇÃO EM SISTEMAS DE LIBERAÇÃO CONTROLADA DE FÁRMACOS

2020 ◽  
Vol 11 (1) ◽  
pp. 138
Author(s):  
Eliane De Fátima Souza ◽  
Milton Beltrame Jr. ◽  
Erika Peterson Gonçalves ◽  
Andreza Ribeiro Simioni
Keyword(s):  
Applied Sciences ◽  
Target Tissue ◽  
Oxygen Species ◽  
New Materials ◽  
Stabilizing Agents ◽  
Phase Stabilization ◽  
Controlled Release System ◽  
Low Solubility ◽  
Spherical Microparticles ◽  
The Ideal

RESUMO Nas últimas décadas, avanços no campo das ciências e tecnologias aplicadas têm emergido, com pesquisas na área inovadora e multidisciplinar conhecida como nanobiotecnologia, referindo-se às tecnologias em que a matéria é manipulada às escalas atômica e molecular para criar novos materiais com características funcionais diferentes dos materiais comuns. O desenvolvimento destas tecnologias para aplicação em sistemas biológicos almeja viabilizar a utilização prática desse conhecimento nas áreas da saúde. A Terapia Fotodinâmica (TFD) se configura como uma terapia promissora para o tratamento de diversas doenças, baseado em fotoprocesso onde um fotossensibilizador é ativado por luz visível, em um comprimento de onda adequado, na presença de oxigênio molecular. Essa combinação é responsável por gerar espécies reativas de oxigênio (EROs) e oxigênio singlete, levando a morte do tecido alvo devido a uma cascata de eventos biológicos. Porém, muitos dos fotossensibilizadores apresentam baixa solubilidade em meio fisiológico, deste modo, faz-se necessária a utilização de sistema de liberação controlada.  Neste âmbito, destaca-se o processo de síntese das micropartículas precipitadas de carbonato de cálcio (CaCO3) de maneira controlada, buscando favorecer a nucleação e o crescimento de um determinado polimorfo de CaCO3. O objetivo do trabalho foi controlar os parâmetros na síntese das micropartículas, como supersaturação das soluções, agitação, adição de agentes estabilizantes, buscando as condições ideais para a obtenção das micropartículas esféricas na fase de vaterita (µ-CaCO3). A avaliação dos protocolos foi assistida por microscopia eletrônica de varredura a fim de determinar o processo que atingiu a estabilização da fase de vaterita.Palavras-chave: CaCO3. Vaterita. CMC. PSS. Estabilização de fase. ABSTRACTIn the last decades, advances in the field of applied sciences and technologies have emerged, with research in the innovative and multidisciplinary area known as nanobiotechnology, referring to technologies in which matter is manipulated at the atomic and molecular scales to create new materials with different functional characteristics. common materials. The development of these technologies for application in biological systems aims to enable the practical use of this knowledge in the areas of health. Photodynamic Therapy (PDT) is a promising therapy for the treatment of various diseases, based on a photoprocess where a photosensitizer is activated by visible light, at an appropriate wavelength, in the presence of molecular oxygen. This combination is responsible for generating reactive oxygen species (ROS) and singlet oxygen, leading to the death of the target tissue due to a cascade of biological events. However, many of the photosensitizers have low solubility in a physiological environment, so it is necessary to use a controlled release system. In this context, the process of synthesis of precipitated microparticles of calcium carbonate (CaCO3) stands out in a controlled manner, seeking to favor the nucleation and the growth of a specific CaCO3 polymorph. The objective of the work was to control the parameters in the synthesis of microparticles, such as supersaturation of solutions, agitation, addition of stabilizing agents, seeking the ideal conditions for obtaining spherical microparticles in the vaterite phase (µ-CaCO3). The evaluation of the protocols was assisted by scanning electron microscopy in order to determine the process that reached the stabilization of the vaterite phase.Keywords: CaCO3. Vaterite. CMC. PSS. Phase stabilization

scholarly journals The Hebrew Sources of Tortosa’s Disputation

Perichoresis ◽  
2020 ◽  
Vol 18 (4) ◽  
pp. 97-119
Author(s):  
Francesco Bianchi
Keyword(s):  
Middle Age ◽  
New Materials ◽  
Written Texts ◽  
The Ideal

AbstractThe Disputation or Cathechesis of Tortosa with its sixty-nine sessions (February 7, 1413-November 12, 1413) was the longest of the Jewish Christian encounters in the Middle Age. Stirred by the Avignonesian Pope Benedict XIII, Geronimo de Sancta Fide, olim Yehoshua ha-Lorki, summoned a group of Catalan and Aragonese rabbis to inform them that the Messiah was already came. Not only the Papal notaries recorded the excruciating debates, but also two Hebrew sources: the anonymous and fragmentary letter published by Halberstam in 1868 and the chapter 40 of the Shebet Yehuda. They encompass the first nine sessions carried out orally, before the Pope requested for written texts to be debated lately. Since these sources disagree on many details, this paper aims at examining them anew. That examination has shown that the anonymous account is more accurate than the fictional report of the Shebet Yehuda as far as the internal chronology of the sessions, the speeches of the Jewish delegates and their identities are concerned. The internal evidence leads us to subscribe with Riera i Sans in ascribing its authorship to Bonastruc Desmestre from Girona, who was at Tortosa on request of the Pope. He probably knew other Jewish chronicle and added some new materials from the Vikkuach Ramban, Salomon Ibn Verga, the author of Shebet Yehuda, built upon this chronicle and created a fictional account around Vidal Benveniste or the ‘ideal’ portrait of the Pope and added some materials from the Latin Protocols or from unknown Jewish sources.

scholarly journals Special Issue of the Manufacturing Engineering Society 2019 (SIMES-2019)

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2133
Author(s):  
Eva María Rubio ◽  
Ana María Camacho
Keyword(s):  
Applied Sciences ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Manufacturing Industry ◽  
Green Manufacturing ◽  
Manufacturing Processes ◽  
New Materials ◽  
Special Issue ◽  
Engineering Society ◽  
Manufacturing Engineering

The Special Issue of the Manufacturing Engineering Society 2019 (SIMES-2019) has been launched as a joint issue of the journals “Materials” and “Applied Sciences”. The 29 contributions published in this Special Issue of Materials present cutting-edge advances in the field of manufacturing engineering focusing on additive manufacturing and 3D printing, advances and innovations in manufacturing processes, sustainable and green manufacturing, manufacturing of new materials, metrology and quality in manufacturing, industry 4.0, design, modeling, and simulation in manufacturing engineering and manufacturing engineering and society. Among them, these contributions highlight that the topic “additive manufacturing and 3D printing” has collected a large number of contributions in this journal because its huge potential has attracted the attention of numerous researchers over the last years.

scholarly journals Impact of Free Curcumin and Curcumin Nanocapsules on Viability and Oxidative Status of Neural Cell Lines

2021 ◽  
Author(s):  
BIANCA FAGAN BISSACOTTI ◽  
Priscila Copetti ◽  
Samanta Gundel ◽  
Alencar Machado ◽  
Michele Sagrillo ◽  
...  
Keyword(s):  
Cell Lines ◽  
Antioxidant Activities ◽  
Curcuma Longa ◽  
Free Form ◽  
Oxygen Species ◽  
Relative Difficulty ◽  
The Central Nervous System ◽  
Culture Supernatants ◽  
The Brain ◽  
The Ideal

Abstract Curcumin is an active polyphenol substance found in the highest concentrations in the roots of Curcuma longa. Its health benefits have led to recent increases in the consumption of curcumin. It has anti-inflammatory and antioxidant activities and is a potent neuroprotective against diseases of the brain. Nevertheless, its low bioavailability and its relative difficulty crossing the blood-brain barrier limit curcumin’s use for these purposes. Curcumin-loaded nanoparticles may be an effective treatment for several diseases although there is a paucity of studies reporting its safety in the central nervous system (CNS). Therefore, this study aimed to identify non-neurotoxic concentrations of free curcumin and two nanoformulations of curcumin. Cell lines BV-2 and SH-SY5Y, both originating from the CNS, were evaluated after 24, 48, and 72 h of treatment with free curcumin and nanocapsules We measured viability, proliferation and dsDNA levels. We measured levels of reactive oxygen species and nitric oxide as proxies for oxidative stress in culture supernatants. We found that free curcumin was toxic at 10 and 20 µM, principally at 72 h. Nanoformulations were more neurotoxic than the free form. Safe concentrations of free curcumin are between 1-5 µM, and these concentrations were lower for nanoformulations. We determined the ideal concentrations of free curcumin and nanocapsules serving as a basis for studies of injuries that affect the CNS.

scholarly journals Dendrimers: Amazing Platforms for Bioactive Molecule Delivery Systems

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 570 ◽  
Author(s):  
Claudia Sandoval-Yañez ◽  
Cristian Castro Rodriguez
Keyword(s):  
Drug Delivery Systems ◽  
Structural Modification ◽  
Physicochemical Characteristics ◽  
Therapeutic Strategies ◽  
Delivery Systems ◽  
Bioactive Molecules ◽  
Target Tissue ◽  
Bioactive Molecule ◽  
Low Solubility ◽  
Low Solubility Drugs

Today, dendrimers are the main nanoparticle applied to drug delivery systems. The physicochemical characteristics of dendrimers and their versatility structural modification make them attractive to applied as a platform to bioactive molecules transport. Nanoformulations based on dendrimers enhance low solubility drugs, arrival to the target tissue, drugs bioavailability, and controlled release. This review describes the latter approaches on the transport of bioactive molecules based on dendrimers. The review focus is on the last therapeutic strategies addressed by dendrimers conjugated with bioactive molecules. A brief review of the latest studies in therapies against cancer and cardiovascular diseases, as well as future projections in the area, are addressed.

scholarly journals An EPR characterisation of stable and transient reactive oxygen species formed under radiative and non-radiative conditions

2019 ◽  
Vol 45 (12) ◽  
pp. 5763-5779 ◽  
Author(s):  
E. Richards ◽  
D. M. Murphy ◽  
M. Che
Keyword(s):  
Reactive Oxygen Species ◽  
Epr Spectroscopy ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Intermediate Species ◽  
Paramagnetic Resonance ◽  
General Terms ◽  
Electron Paramagnetic ◽  
Ideal Method ◽  
The Ideal

Abstract Electron paramagnetic resonance (EPR) spectroscopy is the ideal method of choice when detecting and studying the wide variety of paramagnetic oxygen-centred radicals. For simple diatomic radicals, such as the superoxide (O2−) or peroxy $$ ({\text{ROO}}^{\bullet})$$(ROO∙) species, the CW EPR profile (in particular the g-values) of these species can appear similar and indeed indistinguishable in some cases. Experiments using 17O-enriched oxygen, revealing a rich 17O hyperfine pattern, are therefore essential to distinguish between the two species. However, in many cases, particularly involving TiO2 photocatalysis, the peroxy-type $$ ({\text{ROO}}^{\bullet})$$(ROO∙) radicals or other intermediate species such as the [O2−…organic]-type adducts can be transient in nature and once again can produce similar g-values. In general terms, these reactive oxygen species (ROS) are formed and detected at low-temperature conditions. Hence, the application of EPR spectroscopy to studies of surface-stabilised oxygen-centred radicals must be performed under carefully selected conditions in order to confidently distinguish between the differing types of diatomic radicals, such as O2−, $$ {\text{ROO}}^{\bullet}$$ROO∙ or [O2−…organic].

scholarly journals Cranioplasty: Review of materials and techniques

2011 ◽  
Vol 02 (02) ◽  
pp. 162-167 ◽  
Author(s):  
Seckin Aydin ◽  
Baris Kucukyuruk ◽  
Bashar Abuzayed ◽  
Sabri Aydin ◽  
Galip Zihni Sanus
Keyword(s):  
Surgical Intervention ◽  
New Materials ◽  
Biomedical Technology ◽  
The Social ◽  
Different Types ◽  
History Of ◽  
The Ideal

ABSTRACTCranioplasty is the surgical intervention to repair cranial defects. The aim of cranioplasty is not only a cosmetic issue; also, the repair of cranial defects gives relief to psychological drawbacks and increases the social performances. Many different types of materials were used throughout the history of cranioplasty. With the evolving biomedical technology, new materials are available to be used by the surgeons. Although many different materials and techniques had been described, there is still no consensus about the best material, and ongoing researches on both biologic and nonbiologic substitutions continue aiming to develop the ideal reconstruction materials. In this article, the principle materialsand techniques of cranioplasty are reviewed.

scholarly journals Possible Growth Retrieval Simulation on the Heat-Stressed Pseudomonas aeruginosa (SUBP01) Cells

2016 ◽  
pp. 59-64
Author(s):  
M Sakil Munna ◽  
Kazi Rumana Tanzim ◽  
M Mohibul Hassan Afrad ◽  
Sanjida Humayun ◽  
M Sidiqur Rahman ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Ethylenediaminetetraacetic Acid ◽  
Positive Impact ◽  
Morphological Changes ◽  
Cellular Damage ◽  
Bacillus Species ◽  
Oxygen Species ◽  
Stabilizing Agents ◽  
Spot Tests ◽  
The Given

Earlier observation of cellular damage of Pseudomonas aeruginosa (SUBP01) by the extrinsic oxidative agent (H2O2) and the assumptive accumulation of the reactive oxygen species (ROS) through aeration further led to the growth retrieval assay of the bacterium. Current study investigated the influence of the inorganic growth stabilizers (20 mM MgSO4 plus 5 mM ethylenediaminetetraacetic acid, EDTA) and the organic extracellular fractions of the heat-resistant Bacillus species (SUBB01) and P. fluorescens (SUBP02) on the growth pattern of P. aeruginosa at 45° and 46°C. Bacterial growth (cfu) was measured on the minimal agar plates up to 72 hours, microscopic experiments to monitor the subsequent morphological changes, and finally by the spot tests to examine the cell viability under the given heat stressed conditions. As expected, growth revival was observed at both 45° and 46°C after 48 to 72 hours, upon supplementation with inorganic growth stabilizing agents and the extracellular fractions (secretions) of P. fluorescens compared to that of the control; i.e., untreated with inorganic or organic supplements. Interestingly, compared to that of P. fluorescens extracellular extracts, no positive impact on growth retrieval was noticed by the application of the extracellular fractions of Bacillus species.Bangladesh J Microbiol, Volume 31, Number 1-2,June-Dec 2014, pp 59-64

scholarly journals The Water-Soluble Chitosan Derivative, N-Methylene Phosphonic Chitosan, Is an Effective Fungicide against the Phytopathogen Fusarium eumartii

2021 ◽  
Vol 37 (6) ◽  
pp. 533-542
Author(s):  
Florencia Anabel Mesas ◽  
María Cecilia Terrile ◽  
María Ximena Silveyra ◽  
Adriana Zuñiga ◽  
María Susana Rodriguez ◽  
...  
Keyword(s):  
Water Solubility ◽  
Water Soluble ◽  
Phytopathogenic Fungus ◽  
Oxygen Species ◽  
Chitosan Derivative ◽  
Solubility In Water ◽  
Environmental Friendly ◽  
Antifungal Effects ◽  
Species Production ◽  
Low Solubility

Chitosan has been considered an environmental-friendly polymer. However, its use in agriculture has not been extended yet due to its relatively low solubility in water. N-Methylene phosphonic chitosan (NMPC) is a water-soluble derivative prepared by adding a phosphonic group to chitosan. This study demonstrates that NMPC has a fungicidal effect on the phytopathogenic fungus Fusarium solani f. sp. eumartii (F. eumartii) judged by the inhibition of F. eumartti mycelial growth and spore germination. NMPC affected fungal membrane permeability, reactive oxygen species production, and cell death. Also, this chitosan-derivative exerted antifungal effects against two other phytopathogens, Botrytis cinerea, and Phytophthora infestans. NMPC did not affect tomato cell viability at the same doses applied to these phytopathogens to exert fungicide action. In addition to water solubility, the selective biological cytotoxicity of NMPC adds value in its application as an antimicrobial agent in agriculture.

Carbon Nanohorns as Photochemical and Photothermal Agents

2009 ◽  
Author(s):  
Saugata Sarkar ◽  
Amy Lutkus ◽  
James Mahaney ◽  
Harry Dorn ◽  
Tom Campbell ◽  
...  
Keyword(s):  
Laser Excitation ◽  
Treatment Effectiveness ◽  
Tissue Injury ◽  
Target Tissue ◽  
Oxygen Species ◽  
Treatment Alternative ◽  
Carbon Nanohorns ◽  
Therapy Effectiveness ◽  
Minimal Damage ◽  
Chemical Mediators

Laser therapies based on photochemical or photothermal mechanisms can provide a minimally invasive and potentially more effective treatment alternative to conventional surgical resection procedures by delivering prescribed optical/thermal doses to a targeted tissue volume with minimal damage to intervening and surrounding tissues. However laser therapy effectiveness is limited due to nonspecific excitation/heating of target tissue which often results in healthy tissue injury. Nanostructures targeted to tumor cells and utilized in combination with laser excitation can enhance treatment effectiveness by increasing thermal deposition and generating toxic photo-chemical mediators in the form of reactive oxygen species for targeted cell destruction.

How Should Chemists Think?

2012 ◽  
Author(s):  
Roald Hoffmann
Keyword(s):  
Sulfuric Acid ◽  
Interesting Problem ◽  
Human Beings ◽  
New Materials ◽  
Tyrian Purple ◽  
The Past ◽  
The Earth ◽  
Modern Chemistry ◽  
School Of Athens ◽  
The Ideal

The Vatican holds a fresco by Raphael entitled The School of Athens. Plato and Aristotle stride toward us. Plato’s hand points to the heavens, Aristotle’s outward, along the plane of the earth. The message is consistent with their philosophies—whereas Plato had a geometric prototheory of the chemistry of matter, Aristotle described in reliable detail how Tyrian purple (now known to be mainly indigo and dibromoindigo) was extracted from rock murex snails. Plato searched for the ideal; Aristotle looked to nature. Modern chemistry faces the quandary that Raphael’s fresco epitomizes. Should it follow the hand sign of Aristotle or that of Plato? Is nature as fertile a source for new materials as some assert it to be? Can we, for example, hope to make better composites by mimicking the microstructure of a feather or of a strand of spider’s silk? Are chemists better advised to seek their inspiration in ideal mathematical forms, in icosahedra and in soccer balls? Or should we hazard chance? To some, the division between natural and unnatural is arbitrary; they would argue that man and woman are patently natural, and so are all their transformations. Such a view is understandable and has a venerable history, but it does away with a distinction that troubles ordinary and thoughtful people. So I will distinguish between the actions, mostly intended, of human beings and those of animals, plants and the inanimate world around us. A sunset is natural; a sulfuric acid factory is not. The 1.3 billion head of cattle in this world pose an interesting problem for any definition. Most of them are both natural and unnatural—the product of breeding controlled by humans. The molecules that exist naturally on the earth emerged over billions of years as rocks cooled, oceans formed, gases escaped, and life evolved. The number of natural molecules is immense; perhaps a few hundred thousand have been separated, purified, and identified. The vast majority of the compounds that fit into the unnatural category were created during the past three centuries. Chemists have added some 70 million well-characterized molecules to nature’s bounty.

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