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Porous polymeric scaffolds provide a physical substrate for cells to attach and proliferate, allowing the formation of new tissue. These materials are broadly used in the tissue engineering field due to their ability to mimic native tissue. Each application requires specific morphologies and resistance, among other several features. To accomplish these requirements, various techniques are available, each one with its advantages and disadvantages. Among the most relevant techniques are salt leaching, solvent casting, gas foaming, thermally induced phase separation, freeze-drying, electrospinning, thermally induced self-agglomeration, and three-dimensional (3D) printing. In this review, a brief and simple explanation of each method is described, along with some recent results and each technique’s advantages and disadvantages. It is expected that this review will bring important guidance in the production of polymer scaffolds for tissue engineering.

Cases of respiratory diseases have been increasing around the world, affecting the health and quality of life of millions of people every year. Chronic respiratory diseases (CRDs) and acute respiratory infections (ARIs) are responsible for many hospital admissions and deaths, requiring sophisticated treatments that facilitate the delivery of therapeutics to specific target sites with controlled release. In this context, different nanoparticles (NPs) have been explored to match this demand, such as lipid, liposome, protein, carbon-based, polymeric, metallic, oxide, and magnetic NPs. The use of NPs as drug delivery systems can improve the efficacy of commercial drugs due to their advantages related to sustained drug release, targeting effects, and patient compliance. The current review presents an updated summary of recent advances regarding the use of NPs as drug delivery systems to treat diseases related to the respiratory tract, such as CRDs and ARIs. The latest applications presented in the literature were considered, and the opportunities and challenges of NPs in the drug delivery field are discussed.

The phase of crystalline α-wollastonite (α-CaSiO3) powders was prepared at low temperature via sol gel method. The formation mechanisms of α-wollastonite (α-CaSiO3) using different calcium salts were examined. The synthesis was carried out in absence of organic solvents, using as starting materials silicic acid and inorganic salts (CaCl2.H2O and Ca(NO3)2.4H2O). The samples were analyzed by Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetry/Differential Scanning Calorimetry (TGA-DSC), X-Ray Diffraction (XRD) and Field Emission Gun-Scanning Electron Microscopy (FEG-SEM). The experimental results demonstrate that the calcium source strongly influences the characteristics of the resultant powders, as phase purity and morphology of the wollastonite particles. XRD analysis showed that, using CaCl2.H2O on the synthesis, α-wollastonite started to crystallize as majority phase at 700 °C. The complete crystallization of α-wollastonite was observed after the calcination at 1000 °C for 5 h, while samples prepared with Ca(NO3)2.4H2O, only crystallized α-wollastonite at 1200 °C. This difference in crystallization temperature is probably related to the higher homogeneity and the elevated number of Si–O–Ca bonds present in samples prepared with CaCl2.H2O.

Life expectancy has been growing, and more people are developing bone diseases such as arthritis and osteoporosis. Degenerative pathologies, injuries, and trauma can damage the bone tissues, requiring treatments that facilitate its repair, replacement, or regeneration. In this context, many materials have been developed to match this demand. Bioglasses and ceramics are promising inorganic materials to produce scaffolds for bone regeneration due to their attractive properties, such as biocompatibility, osteoinduction, and osteoconduction, besides their similarity with bone composition. Although their established advantages, these materials present limitations such as inadequate mechanical properties and fast degradation rate. Research work has been widely carried out to develop bioglasses, silicate, and phosphate calcium ceramics scaffolds with appropriated properties to enlarge their applications in bioengineering. Different fabrication techniques have also been evaluated. Incorporating other materials or particles, such as polymers, oxides and metal particles into the scaffolds has shown beneficial effects in mechanical strength and bone production stimulation. In this review, we provide an overview concerning the recent advances in developing calcium phosphates, calcium silicates, bioglasses, and composites scaffolds for bone regeneration in medical and dental applications.

Nanoparticles (NPs) have been studied for a wide variety of applications, due to the elevated surface area and outstanding properties. Several types of NPs are available nowadays, each one with particular characteristics and challenges. Bionanocomposites, especially composed by polymer matrices, are gaining attention in the biomedical field. Although, several studies have shown the potential of adding NPs into these materials, some investigation is still needed until their clinical use for

Made available in DSpace on 2020-12-11T00:48:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-11-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Silver vanadate, especially beta-AgVO3, have a wide range of technological applications due to remarkable biological, optical, and electrical features. The structure, morphology, and properties of beta-AgVO3 are directly affected by synthesis conditions. A comparative study between two different synthesis routes (precipitation and hydrothermal) of beta-AgVO3 was systematically investigated in this work. X-ray diffraction, Raman spectroscopy, scanning electron microscopy, zeta potential, and UV-visible spectrometry results showed that the hydrothermal method produced more homogeneous samples of beta-AgVO3, with elevated purity and crystallinity. In addition, the sample of beta-AgVO3 obtained by hydrothermal method had a wire-like morphology while that obtained by precipitation had irregular shape. Finally, the hydrothermal procedure showed more elevated reproducibility. Inst Tecnol Aeronaut, LPP, Praca Marechal Eduardo Gomes 50, BR-12228970 Sao Jose Dos Campos, SP, Brazil Univ Estadual Paulista, UNESP, Lab Genoma, Inst Ciencia & Tecnol, Campus Sao Jose dos Campos ICT, BR-12247016 Sao Jose Dos Campos, SP, Brazil Univ Estadual Paulista, UNESP, Lab Genoma, Inst Ciencia & Tecnol, Campus Sao Jose dos Campos ICT, BR-12247016 Sao Jose Dos Campos, SP, Brazil FAPESP: 2017/02846-5 FAPESP: 2017/248734 FAPESP: 2018/12035-7

The improvement of compatibility between carbon nanotubes (CNTs) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was achieved using CNT functionalized with γ-aminobutyric acid (GABA). The efficiency of the CNT functionalization with GABA was evaluated by X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (FT-IR), Raman spectroscopy, and transmission electron microscopy (TEM). The PHBV/CNT nanocomposites were produced in the molten state with the addition of 0.5 wt% of CNT (pristine, oxidized and functionalized with GABA) and characterized concerning the Izod impact strength tests. The impact fracture morphologies were analyzed using scanning electron microscopy. The results showed that GABA was covalently attached to CNT, resulting in the detection of nitrogen in the XPS survey, the shift of carbonyl peak wavelength on FT-IR, and a higher degree of structural disorder, detected by Raman and observed in TEM images. The impact strength was not significantly affected by the introduction of CNT; however, the impact fracture mechanism was changed from fragile to ductile when CNT was functionalized with GABA. These results are promising for the production of environmentally friendly nanocomposites with superior properties.

Nanocristais semicondutores com diâmetro inferior a 10nm, também conhecidos como quantum dots, têm sido alvo de muitos estudos devido a suas potenciais aplicações tanto na engenharia como na área biomédica. Semicondutores II-VI dopados com Mn2+ tem atraído muita atenção devido à mudança das propriedades ópticas destes semicondutores magnéticos. Neste trabalho foram sintetizados pontos quânticos semicondutores magnéticos com estrutura núcleo-casca de CdxMn1-xS/CdSe visando aplicações como marcadores florescentes na área biomédica. As amostras foram sintetizadas em solução aquosa atemperatura ambiente utilizando poli(álcool vinílico) com agente estabilizante. Para produção do núcleo foram investigadas diferentes frações de Cd2+/Mn2+ com o objetivo de produzir nanopartículas estáveis com diferentes propriedades fotoluminescentes. Sobre os núcleos de foram crescidos diferentes espessuras de casca de CdSe. As propriedades ópticas das amostras foram estudadas por espectroscopia de absorção na região do ultravioleta e visível (UV-Vis) e através de medidas de fotoluminescência. A caracterização morfológica foi realizada por microscopia óptica de transmissão (TEM) e Microscopia de Força Atômica (AFM). Além disso, Microscopia de Força Magnética foi utilizada para avaliar as propriedades magnéticas dos núcleos deCdxMn1-xS. Os resultados mostraram a influência da substituição parcial dos íons de Cd2+ por íons Mn2+ nas propriedades ópticas do semicondutor. As imagens de TEM não indicaram a segregação ou separação de fase causada pela quantidade de Mn2+ incorporadas às nanopartículas de CdS. Através dos ensaios de MFM não foi possívelobservar interações magnéticas nas amostras. Além disso, os resultados indicaram a formação de nanopartículas de CdS/CdSe e a formação de ligas de CdxMn1-xS(Se). Este novo sistema abre novas possibilidades de pesquisa para aplicação na área biomédica como biomarcadores como propriedades magnéticas. Colloidal luminescent semiconductor nanocrystals, also known as quantum dots, have attracted considerable attention due to their significant potential application. The doping of nanocrystalline semiconductors with divalent manganese ions results in new opticalproperties of these semimagnetic semiconductor quantum dots.In this work we report the synthesis and characterization CdxMn1-xS/CdSe quantum dots with core/shell structure to the applications such luminescent biomarkers. The samples were synthesized in aqueous solution at room temperature using poly(vinyl alcohol) as stabilizing agent. Different fractions of Cd2+/Mn2+ ions were investigated aiming the production of stable nanoparticles with different photoluminescence properties. Different shell thicknesses of CdSe were growth on CdxMn1-xS cores. The optical proprieties of the resulting samples were studied by UV-visible spectroscopy and photoluminescence spectroscopy. The morphological characterization was carried out with transmission electrons microscopy (TEM) and Atomic Force Miroscopy (AFM). In addition, Magnetic Force Microscopy (MFM) was used to evaluate the magnetic properties of CdxMn1-xS cores. The results have shown the influence of the Mn2+ partially replacing Cd2+ in the optical behavior of the semiconductor QDs produced. The TEM images have not indicated any detectable segregation or phase separation caused by the Mn2+ added to the CdS system. Through the results of MFM was not possible to observe magnetic interactions in the samples Moreover, the results indicate the formation of CdS/CdSe core/shell nanoparticles and the formation of CdxMn1-xS(Se) alloys. This novel nanostructured system opens a wide window of possibilities in biomedical research and possible applications as biomarkers with magnetic proprieties.