Biocomposite Macrospheres Based on Strontium-Bioactive Glass for Application as Bone Fillers.

Traditional bioactive glass powders are typically composed of irregular particles that can be packed into dense configurations presenting low interconnectivity, which can limit bone ingrowth. The use of novel biocomposite sphere formulations comprising bioactive factors as bone fillers are most advantageous, as it simultaneously allows for packing the particles in a 3-dimensional manner to achieve an adequate interconnected porosity, enhanced biological performance, and ultimately a superior new bone formation. In this work, we develop and characterize novel biocomposite macrospheres of Sr-bioactive glass using sodium alginate, polylactic acid (PLA), and chitosan (CH) as encapsulating materials for finding applications as bone fillers. The biocomposite macrospheres that were obtained using PLA have a larger size distribution and higher porosity and an interconnectivity of 99.7%. Loose apatite particles were observed on the surface of macrospheres prepared with alginate and CH by means of soaking into a simulated body fluid (SBF) for 7 days. A dense apatite layer was formed on the biocomposite macrospheres' surface produced with PLA, which served to protect PLA from degradation. In vitro investigations demonstrated that biocomposite macrospheres had minimal cytotoxic effects on a human osteosarcoma cell line (SaOS-2 cells). However, the accelerated degradation of PLA due to the degradation of bioactive glass may account for the observed decrease in SaOS-2 cells viability. Among the biocomposite macrospheres, those composed of PLA exhibited the most promising characteristics for their potential use as fillers in bone tissue repair applications.

Injectable Thermoresponsive Microparticle/Hydrogel System with Superparamagnetic Nanoparticles for Drug Release and Magnetic Hyperthermia Applications.

Cancer is a disease that continues to greatly impact our society. Developing new and more personalized treatment options is crucial to decreasing the cancer burden. In this study, we combined magnetic polysaccharide microparticles with a Pluronic thermoresponsive hydrogel to develop a multifunctional, injectable drug delivery system (DDS) for magnetic hyperthermia applications. Gellan gum and alginate microparticles were loaded with superparamagnetic iron oxide nanoparticles (SPIONs) with and without coating. The magnetic microparticles' registered temperature increases up to 4 °C upon the application of an alternating magnetic field. These magnetic microparticles were mixed with drug-loaded microparticles, and, subsequently, this mixture was embedded within a Pluronic thermoresponsive hydrogel that is capable of being in the gel state at 37 °C. The proposed DDS was capable of slowly releasing methylene blue, used as a model drug, for up to 9 days. The developed hydrogel/microparticle system had a smaller rate of drug release compared with microparticles alone. This system proved to be a potential thermoresponsive DDS suitable for magnetic hyperthermia applications, thus enabling a synergistic treatment for cancer.

Extensive Investigation on the Effect of Niobium Insertion on the Physical and Biological Properties of 45S5 Bioactive Glass for Dental Implant.

Dental implants have emerged as one of the most consistent and predictable treatments in the oral surgery field. However, the placement of the implant is sometimes associated with bacterial infection leading to its loss. In this work, we intend to solve this problem through the development of a biomaterial for implant coatings based on 45S5 Bioglass® modified with different amounts of niobium pentoxide (Nb2O5). The structural feature of the glasses, assessed by XRD and FTIR, did not change in spite of Nb2O5 incorporation. The Raman spectra reveal the Nb2O5 incorporation related to the appearance of NbO4 and NbO6 structural units. Since the electrical characteristics of these biomaterials influence their osseointegration ability, AC and DC electrical conductivity were studied by impedance spectroscopy, in the frequency range of 102-106 Hz and temperature range of 200-400 K. The cytotoxicity of glasses was evaluated using the osteosarcoma Saos-2 cells line. The in vitro bioactivity studies and the antibacterial tests against Gram-positive and Gram-negative bacteria revealed that the samples loaded with 2 mol% Nb2O5 had the highest bioactivity and greatest antibacterial effect. Overall, the results showed that the modified 45S5 bioactive glasses can be used as an antibacterial coating material for implants, with high bioactivity, being also non-cytotoxic to mammalian cells.

Preparation and In Vitro Characterization of Magnetic CS/PVA/HA/pSPIONs Scaffolds for Magnetic Hyperthermia and Bone Regeneration.

Conventional bone cancer treatment often results in unwanted side effects, critical-sized bone defects, and inefficient cancer-cell targeting. Therefore, new approaches are necessary to better address bone cancer treatment and patient's recovery. One solution may reside in the combination of bone regeneration scaffolds with magnetic hyperthermia. By incorporating pristine superparamagnetic iron oxide nanoparticles (pSPIONs) into additively manufactured scaffolds we created magnetic structures for magnetic hyperthermia and bone regeneration. For this, hydroxyapatite (HA) particles were integrated in a polymeric matrix composed of chitosan (CS) and poly (vinyl alcohol) (PVA). Once optimized, pSPIONs were added to the CS/PVA/HA paste at three different concentrations (1.92, 3.77, and 5.54 wt.%), and subsequently additively manufactured to form a scaffold. Results indicate that scaffolds containing 3.77 and 5.54 wt.% of pSPIONs, attained temperature increases of 6.6 and 7.5 °C in magnetic hyperthermia testing, respectively. In vitro studies using human osteosarcoma Saos-2 cells indicated that pSPIONs incorporation significantly stimulated cell adhesion, proliferation and alkaline phosphatase (ALP) expression when compared to CS/PVA/HA scaffolds. Thus, these results support that CS/PVA/HA/pSPIONs scaffolds with pSPIONs concentrations above or equal to 3.77 wt.% have the potential to be used for magnetic hyperthermia and bone regeneration.

Engineering dual-stimuli responsive poly(vinyl alcohol) nanofibrous membranes for cancer treatment by magnetic hyperthermia.

The development of new cancer treatment options, such as multifunctional devices, allows for a more personalized treatment, avoiding the known severe side effects of conventional options. In this context, on-demand drug delivery systems can actively control the rate of drug release offering a precise control of treatment. Magnetically and thermally controlled drug delivery systems have been explored as on-demand devices to treat chronic diseases and cancer tumors. In the present work, dual-stimuli responsive systems were developed by incorporating Fe3O4 magnetic nanoparticles (NPs) and poly(N-isopropylacrylamide) (PNIPAAm) microgels into electrospun polymeric fibers for application in cancer treatment. First, Fe3O4 NPs with an average diameter of 8 nm were synthesized by chemical precipitation technique and stabilized with dimercaptosuccinic acid (DMSA) or oleic acid (OA). PNIPAAm microgels were synthesized by surfactant-free emulsion polymerization (SFEP). Poly(vinyl alcohol) (PVA) was used as a fiber template originating fibers with an average diameter of 179 ± 14 nm. Stress tests of the membranes showed that incorporating both microgels and Fe3O4 NPs in electrospun fibers increases their Young's modulus. Swelling assays indicate that PVA membranes have a swelling ratio of around 3.4 (g/g) and that the presence of microgels does not affect its swelling ability. However, with the incorporation of Fe3O4 NPs, the swelling ratio of the membranes decreases. Magnetic hyperthermia assays show that a higher concentration of NPs leads to a higher heating ability. The composite membrane with the most promising results is the one incorporated with DMSA-coated NPs, since it shows the highest temperature variation, 5.1 °C. To assess the membranes biocompatibility and ability to promote cell proliferation, indirect and direct contact cell viability assays were performed, as well as cell adhesion assays. Following an extract method viability assay, all membrane designs did not reveal cytotoxic effects on dermal fibroblasts and melanoma cancer cells, after 48 h exposure and support long-term viability. The present work demonstrates the potential of dual-stimuli composite membranes for magnetic hyperthermia and may in the future be used as an alternative cancer treatment particularly in anatomically reachable solid tumors.

Incorporation of Dual-Stimuli Responsive Microgels in Nanofibrous Membranes for Cancer Treatment by Magnetic Hyperthermia.

The delivery of multiple anti-cancer agents holds great promise for better treatments. The present work focuses on developing multifunctional materials for simultaneous and local combinatory treatment: Chemotherapy and hyperthermia. We first produced hybrid microgels (MG), synthesized by surfactant-free emulsion polymerization, consisting of Poly (N-isopropyl acrylamide) (PNIPAAm), chitosan (40 wt.%), and iron oxide nanoparticles (NPs) (5 wt.%) as the inorganic component. PNIPAAm MGs with a hydrodynamic diameter of about 1 µm (in their swollen state) were successfully synthesized. With the incorporation of chitosan and NPs in PNIPAAm MG, a decrease in MG diameter and swelling capacity was observed, without affecting their thermosensitivity. We then sought to produce biocompatible and mechanically robust membranes containing these dual-responsive MG. To achieve this, MG were incorporated in poly (vinyl pyrrolidone) (PVP) fibers through colloidal electrospinning. The presence of NPs in MG decreases the membrane swelling ratio from 10 to values between 6 and 7, and increases the material stiffness, raising its Young modulus from 20 to 35 MPa. Furthermore, magnetic hyperthermia assay shows that PVP-MG-NP composites perform better than any other formulation, with a temperature variation of about 1 °C. The present work demonstrates the potential of using multifunctional colloidal membranes for magnetic hyperthermia and may in the future be used as an alternative treatment for cancer.

Informações pedagógicas de cursos de psicologia em sites de instituições de ensino superior / Psychology programs' pedagogical data in websites of Brazilian higher education institutions

Nos últimos 30 anos, o ensino superior brasileiro cresceu vertiginosamente, e cursos de Psicologia apresentaram um dos maiores crescimentos de matrículas. Este artigo objetivou analisar a disponibilidade on-line de informações pedagógicas sobre cursos de Psicologia. Trata-se de estudo exploratório, documental, que analisou estatisticamente as taxas de disponibilidade das informações pesquisadas nos sites das respectivas Instituições de Ensino Superior. Os resultados apontam que cursos públicos e privados incorreram em omissão na publicização de informações relevantes, em desacordo com as noções de transparência e accountability e contrariando disposições legais.

Brazilian higher education has expanded in the past 30 years, and Psychology programs have presented a higher growth in enrollment compared to other areas. This article aimed to analyze the online availability of pedagogical data on Psychology courses, such as course description and syllabus. We performed an exploratory, documental research, which analyzed statistics on the availability of such data in websites of Higher Education Institutions. Results indicate that public and private institutions have failed to publish relevant information, in disagreement with the notions of transparency and accountability, in disagreement to Brazilian Law.

Electrospun composite cellulose acetate/iron oxide nanoparticles non-woven membranes for magnetic hyperthermia applications.

In the present work composite membranes were produced by combining magnetic nanoparticles (NPs) with cellulose acetate (CA) membranes for magnetic hyperthermia applications. The non-woven CA membranes were produced by electrospinning technique, and magnetic NPs were incorporated by adsorption at fibers surface or by addition to the electrospinning solution. Therefore, different designs of composite membranes were obtained. Superparamagnetic NPs synthesized by chemical precipitation were stabilized either with oleic acid (OA) or dimercaptosuccinic acid (DMSA) to obtain stable suspensions at physiological pH. The incorporation of magnetic NP into CA matrix was confirmed by scanning and transmission electron microscopy. The results showed that adsorption of magnetic NPs at fibers' surface originates composite membranes with higher heating ability than those produced by incorporation of magnetic NPs inside the fibers. However, adsorption of magnetic NPs at fibers' surface can cause cytotoxicity depending on the NPs concentration. Tensile tests demonstrated a reinforcement effect caused by the incorporation of magnetic NPs in the non-woven membrane.

Towards the development of multifunctional chitosan-based iron oxide nanoparticles: Optimization and modelling of doxorubicin release.

In the present work composite nanoparticles with a magnetic core and a chitosan-based shell were produced as drug delivery systems for doxorubicin (DOX). The results show that composite nanoparticles with a hydrodynamic diameter within the nanometric range are able to encapsulate more DOX than polymeric nanoparticles alone corresponding also to a higher drug release. Moreover the synthesis method of the iron oxide nanoparticles influences the total amount of DOX released and a high content of iron oxide nanoparticles inhibits DOX release. The modelling of the experimental results revealed a release mechanism dominated by Fickian diffusion.

Thermal and magnetic properties of chitosan-iron oxide nanoparticles.

Chitosan is a biopolymer widely used for biomedical applications such as drug delivery systems, wound healing, and tissue engineering. Chitosan can be used as coating for other types of materials such as iron oxide nanoparticles, improving its biocompatibility while extending its range of applications. In this work iron oxide nanoparticles (Fe3O4 NPs) produced by chemical precipitation and thermal decomposition and coated with chitosan with different molecular weights were studied. Basic characterization on bare and chitosan-Fe3O4 NPs was performed demonstrating that chitosan does not affect the crystallinity, chemical composition, and superparamagnetic properties of the Fe3O4 NPs, and also the incorporation of Fe3O4 NPs into chitosan nanoparticles increases the later hydrodynamic diameter without compromising its physical and chemical properties. The nano-composite was tested for magnetic hyperthermia by applying an alternating current magnetic field to the samples demonstrating that the heating ability of the Fe3O4 NPs was not significantly affected by chitosan.

Estigma moral e sofrimento psi: problematizando a individualização do superendividamento do consumidor / Moral stigma and psychological suffering: problematizing theindividualization of consumer overindebtness

Em face da ausência de estudos no campo da Psicologia Social sobre o tema, desenvolvemos uma pesquisa exploratória que objetivou conhecer asimplicações subjetivas da situação de superendividamento do consumidor.Entrevistamos 24 consumidores que, estando nessa condição, aderiram aum projeto do judiciário gaúcho que propõe a conciliação paraprocessualcom os credores; realizamos a análise do material obtido nas entrevistas emconsonância com a metodologia da análise de discurso. Dois aspectosinterligados que se evidenciaram – a individualização e a dimensão moralizante do superendividamento, que acarretam considerável sofrimentopsíquico aos sujeitos – são discutidos e problematizados aqui a luz da perspectiva foucaultiana e das proposições de Nietzsche sobre a moral.Indicamos a necessidade de políticas públicas e estratégias de enfrentamento que considerem a complexidade da situação...

Given the lack of studies in the field of Social Psychology on this topic, wedeveloped an exploratory research aiming to know the subjectiveimplications of consumer’s overindebtedness. We interviewed 24 consumers who, being in this condition, joined a project developed by the southern Brazil Judiciary, which proposes legal paraprocedural conciliation with creditors. We analyzed the material obtained in interviews according to the methodology of discourse analysis. Two interrelated aspects that were revealed – individualization and the moralizing dimension of overindebtedness, which cause considerable psychological distress to the subjects – are discussed and problematized here in the light of Foucault’s perspective, and Nietzsche’s propositions about morality. We indicate the need for public policies and facing-up strategies that take into account thecomplexity of this situation...

Mapeamento de competências profissionais de Tutores de cursos na Modalidade à Distância / Mapping the Professional Competences by Tutors in Distance Courses

O presente trabalho, de natureza teórica/empírica, objetiva identificar competências necessárias ao desempenho das atribuições de tutores que atuam em eventos instrucionais ofertados à distância. Quanto ao método,este estudo foi desenvolvido no contexto de cursos a distância ofertados pela Universidade Aberta do Brasil (UAB) na Universidade de Brasília. Os dados foram coletados presencialmente, por meio de entrevistas, individuais e grupais, semi-estruturadas, com tutores. Como procedimentos de análise de dados, procedeu-se à extração das competências profissionais por meio de seus critérios de ocorrência e condições de mensuração utilizando como parâmetros os conhecimentos, habilidades e atitudes associadas.Identificou-se um conjunto de competências técnicas e interpessoais relacionadas ao planejamento/execução do desempenho. Como limitações,verificou-se dificuldades dos participantes em identificarem e nomearem as competências. Sugere-se que as organizações efetivem ações de desenvolvimento profissional e de capacitação, inclusive para seus gestores, no sentido de implementarem uma cultura de apoio e suporte ao desenvolvimento de competências...

This work, theoretical/empirical, aims to identify competencies needed to perform the tasks of tutors who work in instructional events offered entirelyat a distance. As to the method, this study was developed in the context ofdistance learning courses offered by the Open University of Brazil (UAB) inUniversity of Brasília. Data were collected by some interviews, individual and group semi-structured interviews with tutors that performed at distance courses. As procedures for data analysis, was proceeded to the extraction of professional skills through their criteria and conditions of occurrence measurement using, as parameters, the knowledge, skills and attitudes associated. It was identified a set of technical and interpersonal skills related to planning/execution performance. As limitations, there are difficulties in identifying the participants and nominate skills. It is suggested that organizations effective action for professional development and training, including their managers, to implement a culture of support his skills development...