Greener Strategy for Lupanine Purification from Lupin Bean Wastewaters Using a Molecularly Imprinted Polymer.

Lupanine is an alkaloid used in the pharma industry as a building block or precursor in the synthesis of sparteine and also explored for drug synthesis in the pharma industry as a chiral selector. This alkaloid is found in lupin bean processing wastewaters originated from the debittering process to make these beans edible. In this work, a computational chemistry approach was taken to design molecularly imprinted polymers (MIPs) selecting itaconic acid, a biobased building block, as a functional monomer that can provide higher affinities for lupanine. MIP-1 was prepared using lupanine as the template, itaconic acid as a functional monomer, and ethylene glycol dimethacrylate as a cross-linker by bulk polymerization. Lupanine was concentrated from lupin bean wastewater by nanofiltration, extracted with ethyl acetate, and purified using the synthesized MIP. MIP-1 was able to selectively recognize lupanine and improve the purity of lupanine from 78 to 88%, with 82% recovery of the alkaloid. These results show the potential application of this strategy to render the industrial process more sustainable.

Electrical stimulation of neural-differentiating iPSCs on novel coaxial electroconductive nanofibers.

Neural tissue engineering strategies are paramount to create fully mature neurons, necessary for new therapeutic strategies for neurological diseases or the creation of reliable in vitro models. Scaffolds can provide physical support for these neurons and enable cues for enhancing neural cell differentiation, such as electrical current. Coaxial electrospinning fibers, designed to fulfill neural cell needs, bring together an electroconductive shell layer (PCL-PANI), able to mediate electrical stimulation of cells cultivated on fibers mesh surface, and a soft core layer (PGS), used to finetune fiber diameter (951 ± 465 nm) and mechanical properties (1.3 ± 0.2 MPa). Those dual functional coaxial fibers are electroconductive (0.063 ± 0.029 S cm-1, stable over 21 days) and biodegradable (72% weigh loss in 12 hours upon human lipase accelerated assay). For the first time, the long-term effects of electrical stimulation on induced neural progenitor cells were studied using such fibers. The results show increase in neural maturation (upregulation of MAP2, NEF-H and SYP), up-regulation of glutamatergic marker genes (VGLUT1 - 15-fold) and voltage-sensitive channels (SCN1α - 12-fold, CACNA1C - 32-fold), and a down-regulation of GABAergic marker (GAD67 - 0.09-fold), as detected by qRT-PCR. Therefore, this study suggest a shift from an inhibitory to an excitatory neural cell profile. This work shows that the PGS/PCL-PANI coaxial fibers here developed have potential applications in neural tissue engineering.

POLYBENZIMIDAZOLE NANOFIBERS FOR NEURAL STEM CELL CULTURE.

Neurodegenerative diseases compromise the quality of life of increasing numbers of the world's aging population. While diagnosis is possible no effective treatments are available. Strong efforts are needed to develop new therapeutic approaches, namely in the areas of tissue engineering and deep brain stimulation (DBS). Conductive polymers are the ideal material for these applications due to the positive effect of conducting electricity on neural cell's differentiation profile. This novel study assessed the biocompatibility of polybenzimidazole (PBI), as electrospun fibers and after being doped with different acids. Firstly, doped films of PBI were used to characterize the materials' contact angle and electroconductivity. After this, fibers were electrospun and characterized by SEM, FTIR and TGA. Neural Stem Cell's (NSC) proliferation was assessed and their growth rate and morphology on different samples was determined. Differentiation of NSCs on PBI - CSA fibers was also investigated and gene expression (SOX2, NES, GFAP, Tuj1) was assessed through Immunochemistry and qPCR. All the samples tested were able to support neural stem cell (NSC) proliferation without significant changes on the cell's typical morphology. Successfully differentiation of NSCs towards neural cells on PBI - CSA fibers was also achieved. This promising PBI fibrous scaffold material is envisioned to be used in neural cell engineering applications, including scaffolds, in vitro models for drug screening and electrodes.

Cervical vertebrae maturation index estimates on cone beam CT: 3D reconstructions vs sagittal sections.

OBJECTIVES: The aim of this study was to evaluate the performance of CBCT three-dimensional (3D) reconstructions and sagittal sections for estimates of cervical vertebrae maturation index (CVMI). METHODS: The sample consisted of 72 CBCT examinations from patients aged 8-16 years (45 females and 27 males) selected from the archives of two private clinics. Two calibrated observers (kappa scores: ≥0.901) interpreted the CBCT settings twice. Intra- and interobserver agreement for both imaging exhibition modes was analyzed by kappa statistics, which was also used to analyze the agreement between 3D reconstructions and sagittal sections. Correlations between cervical vertebrae maturation estimates and chronological age, as well as between the assessments by 3D reconstructions and sagittal sections, were analyzed using gamma Goodman-Kruskal coefficients (α = 0.05). RESULTS: The kappa scores evidenced almost perfect agreement between the first and second assessments of the cervical vertebrae by 3D reconstructions (0.933-0.983) and sagittal sections (0.983-1.000). Similarly, the agreement between 3D reconstructions and sagittal sections was almost perfect (kappa index: 0.983). In most divergent cases, the difference between 3D reconstructions and sagittal sections was one stage of CVMI. Strongly positive correlations (>0.8, p < 0.001) were found not only between chronological age and CVMI but also between the estimates by 3D reconstructions and sagittal sections (p < 0.001). CONCLUSIONS: Although CBCT imaging must not be used exclusively for this purpose, it may be suitable for skeletal maturity assessments.

Análise da alteração de cor em sistemas adesivos ortodônticos / Analysis of the color change in orthodontic adhesive systems

A análise da alteração de cor em sistemas adesivos ortodônticos é importante para o entendimento de seu comportamento óptico frente a situações clínicas, como a ingestão de substâncias corantes. Este trabalho estudou a pigmentação de sistemas adesivos ortodônticos, de diversas marcas comerciais, em determinados intervalos de tempo, quando expostos a fatores extrínsecos. Foram confeccionados corpos de prova – com 1 mm de espessura por 12 mm de largura – dos adesivos das marcas Aqualite (Orthosource), Natural Orto (DFL), Orthobond (Morelli), Transbond Color Change e Transbond XT, fabricados pela 3M (n=4). Os corpos de prova foram polidos por meio de uma série de lixas abrasivas e imersos no café, como substância corante, e água bidestilada, como substância controle. As curvas espectrais de reflectância foram obtidas em contato óptico, sobre fundo branco, através de um espectrofotômetro com esfera de integração acoplada. Os resultados mostraram que os fatores tempo, marca comercial e meios pigmentadores exerceram influência para o manchamento dos corpos de prova. Quanto ao fator tempo, houve alteração para todas as marcas comerciais em todos os períodos analisados.

The color change analysis of orthodontic adhesive systems is important to understand its optical behavior in clinical situations such as the ingestion of staining solutions. This study tested the pigmentation of orthodontic adhesive systems, from various commercial brands, in a period of time, after exposition to extrinsic factors. The discs with 12 mm in diameter and thickness of 1 mm were prepared with five orthodontic adhesives: Aqualite (Orthosource), Natural Orto (DFL), Orthobond (Morelli), and Transbond Color Change and Transbond XT manufactured by 3M (n=4). The samples were polished with a series of polishing discs and immersed in coffee, as staining solution, and bidestilled water, as control solution. The spectral reflectance curves were acquired on optical contact, against white background, with a integration sphere attached spectrometer. The results showed that the period of time, commercial brands and staining solutions has an influence on the disks discoloration. Regarding the time factor, all the commercial brands showed perceptible color change in all periods analyzed.

A influência do atrito na mecânica ortodôntica / The influence of friction in orthodontics

São inúmeros os fatores a serem considerados pelo profissional quando do planejamento mecânico de uma terapia ortodôntica. Dentre esses, o coeficiente de atrito tem chamado grande atenção de clínicos e pesquisadores, principalmente após a popularização dos braquetes autoligados. No presente artigo são listadas as diversas características do aparelho ortodôntico que interferem na geração de forças de atrito, ou fricção, entre o fio ortodôntico e o braquete, quando da realização de uma mecânica de deslize. Objetiva-se fornecer ao ortodontista subsídios para um melhor controle biomecânico e, desta forma, agilizar a movimentação dentária, reduzir o dano tecidual decorrente da terapia, assim como encurtar o tempo total de tratamento.