Structural analysis of a Nb-based alloy for biomedical application

The purpose of research in the biomaterials field is to produce new materials with physical and chemical properties close to the tissue to be replaced with minimal toxic response to the foreign body. Among the various metallic materials, titanium and its alloys have this great combination of properties. The most promising alloys are those with niobium, molybdenum, tantalum, and zirconium as alloying elements added to titanium. Thus, this kind of alloys integrate a new class of alloys without aluminum and vanadium (which cause cytotoxicity) and have a low modulus of elasticity (below 100 GPa). The objective of this work is to analyze the structure and microstructure of a niobium-based alloy, Ti-50wt%Nb. This alloy was produced in an arc-melting furnace with an inert atmosphere of argon gas. After melting, the samples were characterized by density, X-ray diffraction, scanning electron microscopy, and hardness. The X-ray diffraction data shows the peaks corresponding to the beta phase (with body-centered cubic crystalline structure), corroborated by scanning electron microscopy images. The value of the lattice parameter of the body-centered cubic crystalline structure was 3.2868 Å.

Simultaneous alterations in ovaries and bone as a result of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is one of the most widely recognized endocrine disorders affecting reproductive-age women. The etiopathogenesis and mechanisms of this syndrome remain unclear. Diagnosis requires two of the following: polycystic ovaries, oligo- or anovulation, and hyperandrogenism. Most women with PCOS display conditions such as metabolic abnormalities, diabetes, obesity, cardiovascular disease, and/or bone dysfunction. Considering the ethical limitations of human studies, animal and cell culture models that reflect some features of PCOS are important for investigation of this syndrome. The aim of the present work was to study some of the endocrine relationships between ovaries and bone tissue in a polycystic ovary syndrome animal model. The study was performed using an estradiol valerate PCOS-induced rat model (n = 30) and bone mesenchymal stem cell cultured from bone marrow of those animals. It was hypothesized that changes of the endocrine relationship between ovaries and bones could be observed in from in vivo animal model and in vitro cell culture assays. The ovarian morphological and endocrine changes seem to be correlated with endocrine, biophysical, and biomechanical changes in bone properties. Mesenchymal stem cells obtained from PCOS-induced rats, cultured for up to 21 days and differentiated into osteoblasts, presented lower viability and reduced mineralization of the extracellular matrix. Taken together, these results indicate important endocrine and structural effects of PCOS in ovaries and bones, contributing to part of the understanding of the pathophysiological mechanisms of PCOS.

Study of ph effect on AZ31 magnesium alloy corrosion for using in temporary implants

Currently, magnesium alloys are gaining great interest for medical applications due to their degrading properties in the human body ensuring a great biocompatibility. These alloys also provide profitable mechanical properties due similarities with human bone. However, a difficulty in applying these materials in the biomaterials industries is the corrosion prior to cell healing. The effect of the chemical composition of Mg alloys on their corrosion behavior is well known. In this study, samples of AZ31 magnesium alloy were cut into chips for elemental chemical analysis by neutron activation analysis (NAA). Concentrations of the elements As, La, Mg, Mn, Na, Sb and Zn were determined in the AZ31 alloy. Visualization tests of agar corrosion development in various media, of 0.90% sodium chloride solution (mass), phosphate buffer saline (PBS) and simulated body fluid (SBF) were performed. Visualizations of the effect of agar gel corrosion revealed pH variation during the corrosion process due to the released into the cathode. The highest released of hydroxyl ions occurred in NaCl solution compared to PBS and SBF solutions indicating that NaCl solution was much more aggressive to the alloy compared to the others.

Productionof poly(L-CO-D,L LacticAcid) porous fibers by electrospinning

The production of porous scaffolds has been widely investigated by the scientific community due to its suitability for tissue engineering. Among techniques that allow the fabrication of porous materials, electrospinning is appealing for being robust and versatile. This research investigated the pore formation in poly (L-co-D,L lactic acid) fibers obtained by conventional electrospinning and the influence of chloroform as a single solvent on fiber morphology. Random and highly porous fibers with a mean diameter of 2.373 ± 0.564 µm were collected. Chloroform affects the fiber morphology, mainly for its fast evaporation and low density of charges. The solvent on the surface evaporates quickly, and the low stretch of the jet does not help the polymer to reorganize over the length of the fiber, forming pores. In conclusion, the low dielectric constant and boiling point of chloroform induce pores formation along the PLDLA fibers.

A study on corrosion resistance of ISO 5832-1 austenitic stainless steel used as orthopedic implant

The ISO 5832-1 austenitic stainless steel used as biomaterial is largely applied in the area of orthopedics, especially in the manufacture of implants, such as temporary or permanent replacement of bone structures. The objective of this study was to evaluate the localized corrosion resistance of the ISO 5832-1 stainless steel used in orthopedic implants by electrochemical tests in two different solutions. The results of this study are of great interest to evaluate the corrosion of metallic implants that can result in the release of corrosion products into bodily fluids causing possible adverse biological reactions. The determination of the chemical elements in the composition of the ISO 5832-1 stainless steel was performed by neutron activation analysis (NAA). The samples for electrochemical tests were grinded with silicon carbide paper up to #4000 finishing, followed by mechanical polishing with diamond paste. The open circuit potential measurements and anodic polarization curves were obtained in solution of 0.90 wt. % of NaCl and of simulated body fluid (SBF). The results indicated that the ISO 5832-1 stainless steel presented a high resistance to crevice corrosion in simulated body fluid solution but high susceptibility to this form of corrosion in the chloride solution.

Simultaneous alterations in ovaries and bone as a result of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is one of the most widely recognized endocrine disorders affecting reproductive-age women. The etiopathogenesis and mechanisms of this syndrome remain unclear. Diagnosis requires two of the following: polycystic ovaries, oligo- or anovulation, and hyperandrogenism. Most women with PCOS display conditions such as metabolic abnormalities, diabetes, obesity, cardiovascular disease, and/or bone dysfunction. Considering the ethical limitations of human studies, animal and cell culture models that reflect some features of PCOS are important for investigation of this syndrome. The aim of the present work was to study some of the endocrine relationships between ovaries and bone tissue in a polycystic ovary syndrome animal model. The study was performed using an estradiol valerate PCOS-induced rat model (n = 30) and bone mesenchymal stem cell cultured from bone marrow of those animals. It was hypothesized that changes of the endocrine relationship between ovaries and bones could be observed in from in vivo animal model and in vitro cell culture assays. The ovarian morphological and endocrine changes seem to be correlated with endocrine, biophysical, and biomechanical changes in bone properties. Mesenchymal stem cells obtained from PCOS-induced rats, cultured for up to 21 days and differentiated into osteoblasts, presented lower viability and reduced mineralization of the extracellular matrix. Taken together, these results indicate important endocrine and structural effects of PCOS in ovaries and bones, contributing to part of the understanding of the pathophysiological mechanisms of PCOS.

Biotechnology applied for sustainable development: social responsibility in the Industry 4.0

This research was conducted from a review of bibliographic content on Biotechnology, sustainable development, social responsibility and Industry 4.0. The goal endows the understanding of the role of Biotechnology as a science in sustainable development in this historical phase experienced by humanity, the Fourth Industrial Revolution, verifying what would be the social responsibility of Industry 4.0 in this context. Dialectical and historical methods were used to systematize the obtained data. The importance of maintaining the environmental balance through sustainable practices in the daily life of Industry 4.0 has been demonstrated to comply with the constitutional principle of the social function of property. However, in order to achieve sustainable development, the economic and social aspects, besides the environmental, must be considered. The relevance of Biotechnology in this process has been proven as a driving force for sustainable development. It is hoped with this research to mobilize the academic community and the society in the fight against environmental degradation, bringing knowledge about the role of Biotechnology in this process, in the context of Industry 4.0, and demonstrating the need for companies, professionals and governments to adapt to this new and unknown reality in order to face the problems that are already emerging, always taking into consideration the protection of human rights, especially the healthy and balanced environment, safety, life and dignity of the human person.

Effect of crosslinker and nanostructure on adsorption and release of paraquat herbicide from different natural hydrogel nanocomposites

Hidrogéis compostos em polímeros naturais que tenham sido usados em diferentes setores devido a suas propriedades de biocompatibilidade, biodegradabilidade, custo relativamente baixo e atoxicidade. O objetivo deste estudo foi preparar hidrogéis de alginato / amido reticulados com diferentes ícones (Mn 2+ , Zn 2+ ou Ca 2+ ), incluir zeólito ou nanoclay, e avaliar o efeito do reticador e nanoestrutura na adsorção e comportamento de seleção do herbicida paraquat. Os hidrogéis e seus nanocompósitos foram preparados por imersão de soluções de alginato / amido, alginato / amido / nanoclay ou alginato / amido / zeólita em recipientes que recebem uma solução reticuladora (MnCl 2 , ZnCl 2ou CaCl 2 ) a 25 ° C. Todos os hidrogênios apresentaram boa capacidade de adsorção, principalmente os hidrogênios nanoestruturados com nanoclay e zeólito. Como recursos polares, selecione alta interação com moléculas de paraquat. O comportamento da liberação também foi muito interessante, sendo que a quantidade de solução de formação de nanocompósitos de hidrogel pode controlar a liberação de paraquat, que tipos de materiais podem ser usados como veículos de transporte no sistema de liberação controlada.

PLA membranes loaded with dba analogs. Controlled release study during hydrolitic degradation

In this research two dibenzylideneacetone (DBA) analogs compounds: (1E,4E)-1-(4-(dimethylamino)phenyl)-5-(4-methoxyphenyl)penta-1,4-dien-3-one (DBA-1) and (1E,4E)-1-(4-methoxyphenyl)-5-(4-nitrophenyl)penta-1,4-dien-3-one (DBA-2) were encapsulated in poly(lactic acid) (PLA) membranes. These DBA analogs can have several applications such as in the development of controlled drug release systems and tissue engineering. The membranes were elaborated by solvent casting. It was found that these fluorescent compounds have a small percentage of hemolysis in human blood red cells at concentrations between 200-500 µg/mL. Therefore, they can be considered not-toxic at these concentrations. The hydrolytic degradation of PLA membranes loaded with the DBA analogs was studied at a temperature of 37 °C under solutions at acid, neutral, and basic pH conditions for a maximum time of six weeks. The hydrolysis was monitored by measuring the loss of mass of the membranes, changes in pH environments, variations in the molecular weight of PLA matrix, and changes in surface morphology observed through Scanning the Electron Microscopy (SEM) technique. Applying UV-visible spectrophotometry, the amount released from the DBA analogs in the PLA membranes was determined during the degradation time, and finally, the release profile was obtained. It was observed employing SEM that the membranes presented a major degradation under basic pH conditions, with a higher percentage of release in an acid medium for both analogues of DBA studied