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1.
J Funct Biomater ; 14(12)2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-38132814

RESUMO

The current study reports the use of silver (Ag) and samarium (Sm) as dopants to improve the properties of standard bioglass in terms of biological performance. This experiment considers thin films of doped bioglass obtained by pulsed laser deposition (PLD) and spin coating (SC). For both methods, some parameters were gradually varied, as the main objective was to produce a bioglass that could be used in biomedical fields. In order to study the morphology, the phase composition and other properties, the samples obtained were subjected to multiple analyses, such as thermal analysis, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared (FT-IR), Raman spectroscopy, and x-ray diffraction (XRD). Furthermore, the in vitro bioactivity of the samples, as assessed through simulated body fluid (SBF) immersion, as well as immunocytochemistry and evaluation of actin filaments, assessed through fluorescence microscopy, are reported. The results confirmed the formation of the designed vitreous target employed as the source of material in the PLD experiments only at sintering temperatures below 800 °C; this vitreous nature was preserved in the grown film as well. The presence of Ag and Ce dopants in the parent glassy matrix was validated for all stages, from powder, to target, to PLD/SC-derived coatings. Additionally, it was demonstrated that the surface topography of the layers can be adjusted by using substrates with different roughness or by modulating the processing parameters, such as substrate temperature and working pressure in PLD, rotation speed, and number of layers in SC. The developed material was found to be highly bioactive after 28 days of immersion in SBF, but it was also found to be a potential candidate for inhibiting the growth of Gram-negative bacteria and a suitable support for cell growth and proliferation.

2.
Curr Health Sci J ; 49(1): 54-66, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37780191

RESUMO

In this study we investigated the relationship between vitamin D and markers of oxidative stress and apoptosis in patients with liver cirrhosis stratified according serum GGT activity. Forty-eight patients with liver cirrhosis of various aetiology were selected, among which 58% cases (n=28) diagnosed with alcoholic liver cirrhosis and 42% (n=20) with cirrhosis after hepatitis virus infection. Each group was divided into three quartiles according GGT activity. 25-hydroxyvitamin D [25-(HO) vit D], markers of oxidative stress (catalase, superoxide dismutase) and apoptosis (M30) were compared. Higher levels of GGT were correlated with elevated AST, ALT and ALP values in both groups. A statistically significant difference was observed when comparing 25-(OH) vit D levels of patients suffering from ethanol-induced liver cirrhosis versus control group for all the quartiles as well as for those from the first quartile of viral-induced liver cirrhosis. For SOD, statistically significant differences were noticed between all cirrhosis subgroups and the control group. CAT values in all cirrhosis subgroups were lower than in control, but significant differences were only between Q2.2 and Q1.3 quartiles and Q2.2 and control. Correlation of 25-(OH) vit D versus SOD yields statistically significant results in ethanol-induced cirrhosis patients. M30 activity was increased in patients with alcoholic cirrhosis compared to controls and those with virus-induced cirrhosis, being correlated with the degree of GGT activity. Our results emphasized that vitamin D deficiency is associated with enhanced liver dysfunction regardless of the trigger responsible for disease onset. Furthermore, vitamin D deficiency augments liver injury by promoting oxidative stress which influence the survival mechanisms of parenchymal liver cells.

3.
Int J Mol Sci ; 24(18)2023 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-37762504

RESUMO

The current study reports on the fabrication of composite scaffolds based on polycaprolactone (PCL) and cerium (Ce)-containing powders, followed by their characterization from compositional, structural, morphological, optical and biological points of view. First, CeO2, Ce-doped calcium phosphates and Ce-substituted bioglass were synthesized by wet-chemistry methods (precipitation/coprecipitation and sol-gel) and subsequently loaded on PCL fibres processed by electrospinning. The powders were proven to be nanometric or micrometric, while the investigation of their phase composition showed that Ce was present as a dopant within the crystal lattice of the obtained calcium phosphates or as crystalline domains inside the glassy matrix. The best bioactivity was attained in the case of Ce-containing bioglass, while the most pronounced antibacterial effect was visible for Ce-doped calcium phosphates calcined at a lower temperature. The scaffolds were composed of either dimensionally homogeneous fibres or mixtures of fibres with a wide size distribution and beads of different shapes. In most cases, the increase in polymer concentration in the precursor solution ensured the achievement of more ordered fibre mats. The immersion in SBF for 28 days triggered an incipient degradation of PCL, evidenced mostly through cracks and gaps. In terms of biological properties, the composite scaffolds displayed a very good biocompatibility when tested with human osteoblast cells, with a superior response for the samples consisting of the polymer and Ce-doped calcium phosphates.


Assuntos
Cério , Poliésteres , Humanos , Polímeros , Antibacterianos , Pós
4.
Rom J Morphol Embryol ; 64(2): 181-188, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37518875

RESUMO

Oral papillomatosis represents a benign lesion of the oral mucosa often induced by human papillomavirus (HPV) or having a non-infection local or general etiology. HPVs are very well adapted and efficient viruses able to produce changes in the immune system, endowed with the ability to replicate in the keratinocytes and to remain silent. The natural evolution of HPV infection is different, depending on the efficiency of the innate immune system. The purpose of this study was to explore Toll-like receptor 9 (TLR9) immunohistochemical expression in low-risk (LR)-HPV oral infection and its ability to facilitate an efficient immune response by activating the macrophages, which serve as main antigen-presenting cells. Samples of two groups of oral mucosae - LR-HPV-positive and HPV-negative - were processed for immunohistochemistry technique and incubated with antibody against TLR9 and cluster of differentiation 68 (CD68). Image analysis and morphometry were conducted to assess the intensity of TLR9 immune signal in the epithelium and the number of macrophages labeled by CD68. We found a statistically significant difference between macrophage count for the subjects in HPV-positive and HPV-negative groups; thought no significant differences of TLR9 immune signal was noted, which demonstrates a diminished immune response in HPV-positive group, probably influencing the time of lesion's clearance.


Assuntos
Papiloma , Infecções por Papillomavirus , Humanos , Receptor Toll-Like 9/metabolismo , Infecções por Papillomavirus/complicações , Queratinócitos/metabolismo , Imunidade , Papiloma/metabolismo , Papillomaviridae
5.
Molecules ; 28(6)2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36985462

RESUMO

Ultrasound-assisted extraction (UAE) was applied to extract oil from blackberry (BB) seeds. The effect of UAE conditions on oil recovery and quality was investigated. Favorable experimental conditions (ultrasound intensity (UI), extraction temperature, and time) were investigated using response surface methodology (RSM). A Box-Behnken design was used to predict optimized conditions for BB seed oil extraction. These conditions were as follows: 13.77 W/cm2 UI, 45 °C extraction temperature, and 15 min extraction time. The experimental value obtained for extraction efficiency under optimal conditions was 87 ± 0.34%, in good agreement with the optimized predicted value. UAE does not affect the oil composition and confers higher antioxidant values in BB seed oil in comparison with Soxhlet extraction.

6.
Int J Mol Sci ; 24(2)2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36675235

RESUMO

Bacterial cellulose (BC) is a biopolymer whose properties have been intensively studied, especially for biomedical applications. Since BC has no antimicrobial activity, it is necessary to use bioactive substances for developing wound healing applications. Another drawback of BC is the loss if its water retention capacity after dehydration. In order to overcome these problems, carboxymethyl cellulose (CMC) and turmeric extract (TE) were selected for the preparation of BC composites. Citric acid (CA) was used as the crosslinking agent. These composites were tested as potential antimicrobial wound dressing materials. TE-loaded BC-CMC composites were characterized in terms of their morphology, crystallinity, and thermal behavior. Swelling tests and curcumin-release kinetic analysis were also performed. All the composites tested had high swelling degrees, which is an advantage for the exudate adsorption from chronic wounds. The antibacterial potential of such composites was tested against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Candida albicans (C. albicans). The in vitro cytotoxicity toward L929 fibroblast cells was studied as well. The obtained results allow us to recommend these composites as good candidates for wound dressing applications.


Assuntos
Anti-Infecciosos , Carboximetilcelulose Sódica , Carboximetilcelulose Sódica/farmacologia , Staphylococcus aureus , Celulose/farmacologia , Escherichia coli , Cinética , Antibacterianos/farmacologia , Bactérias , Bandagens
7.
Rom J Morphol Embryol ; 64(4): 549-557, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38184836

RESUMO

BACKGROUND: The effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy remain relatively unknown. AIM: We present this original paper where we analyzed 60 parturients, at term, 30 without associated infection (C-) and 30 with associated infection (C+), present at birth. METHODS: We analyzed the blood count and placental microscopic structure through classical and immunohistochemical staining and observed the placental areas affected by the presence of SARS-CoV-2. RESULTS: SARS-CoV-2 infection was accompanied by a decrease in the number of lymphocytes, the number of platelets and the presence of placental structural changes, identifying extensive areas of amyloid deposits, placental infarcts, vascular thrombosis, syncytial knots, with a decrease in placental vascular density and the presence of infection in the cells located at decidual level, at syncytiotrophoblast level and at the level of the cells of the chorionic plate, still without overcoming this barrier and without causing any fetal infection in the analyzed cases. CONCLUSIONS: This study shows that the invasion of SARS-CoV-2 in the placenta can produce significant structural changes, with a decrease in placental vascular density that can have significant implications on proper fetal perfusion. Also, the presence of immunoreactivity at the level of decidua, the placental villi, as well as the chorionic plate proves that the virus can overcome the maternal-fetal barrier. However, in the analyzed cases there were no fetal infections at birth, which may show that local placental factors can be a protective filter for the fetus.


Assuntos
COVID-19 , Doenças Placentárias , Gravidez , Recém-Nascido , Feminino , Humanos , Placenta , SARS-CoV-2 , Sistema Imunitário
8.
Int J Mol Sci ; 23(24)2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36555821

RESUMO

Bacterial cellulose (BC) is a unique microbial biopolymer with a huge number of significant applications in the biomedical field, including bone tissue engineering. The present study proposes to obtain and characterize BC hybrid composites with calcium phosphate as biocompatible and bioactive membranes for bone tissue engineering. BC precursor membranes were obtained in static culture fermentation, and after purification, were oxidized to obtain 2,3-dialdehyde bacterial cellulose (DABC). Calcium phosphate-BC oxidized membranes were produced by successive immersion in precursor solutions under ultrasonic irradiation. The samples were characterized for their physicochemical properties using scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy grazing incidence X-ray diffraction (GI-XRD), solid-state 13C nuclear magnetic resonance (CP/MAS 13C NMR), and complex thermal analysis. In vitro cell studies were also performed to evaluate the influence of modified morphological characteristics on cell adhesion and proliferation. The results showed an increase in porosity and biodegradability for DABC hybrid composites compared with BC. In vitro cell studies have revealed that both hybrid composites favor cell adhesion to the surface. The new BC and DABC hybrid composites with calcium phosphate could be considered promising materials for bone tissue regeneration.


Assuntos
Materiais Biocompatíveis , Celulose , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/química , Celulose/química , Engenharia Tecidual , Materiais Dentários , Bactérias/metabolismo , Microscopia Eletrônica de Varredura , Difração de Raios X , Regeneração Óssea , Fosfatos de Cálcio/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier
9.
Polymers (Basel) ; 14(21)2022 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-36365605

RESUMO

The present work reports the synthesis and characterization of polycaprolactone fibers loaded with particulate calcium magnesium silicates, to form composite materials with bioresorbable and bioactive properties. The inorganic powders were achieved through a sol-gel method, starting from the compositions of diopside, akermanite, and merwinite, three mineral phases with suitable features for the field of hard tissue engineering. The fibrous composites were fabricated by electrospinning polymeric solutions with a content of 16% polycaprolactone and 5 or 10% inorganic powder. The physico-chemical evaluation from compositional and morphological points of view was followed by the biological assessment of powder bioactivity and scaffold biocompatibility. SEM investigation highlighted a significant reduction in fiber diameter, from around 3 µm to less than 100 nm after the loading stage, while EDX and FTIR spectra confirmed the existence of embedded mineral entities. The silicate phases were found be highly bioactive after 4 weeks of immersion in SBF, enriching the potential of the polymeric host that provides only biocompatibility and bioresorbability. Moreover, the cellular tests indicated a slight decrease in cell viability over the short-term, a compromise that can be accepted if the overall benefits of such multifunctional composites are considered.

10.
Materials (Basel) ; 15(19)2022 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-36234283

RESUMO

Due to the urgent need to develop and improve biomaterials, the present article proposes a new strategy to obtain porous scaffolds based on forsterite (Mg2SiO4) for bone tissue regeneration. The main objective is to restore and improve bone function, providing a stable environment for regeneration. The usage of magnesium silicate relies on its mechanical properties being superior to hydroxyapatite and, in general, to calcium phosphates, as well as its high biocompatibility, and antibacterial properties. Mg2SiO4 powder was obtained using the sol-gel method, which was calcinated at 800 °C for 2 h; then, part of the powder was further used to make porous ceramics by mixing it with a porogenic agent (e.g., sucrose). The raw ceramic bodies were subjected to two sintering treatments, at 1250 or 1320 °C, and the characterization results were discussed comparatively. The porogenic agent did not influence the identified phases or the samples' crystallinity and was efficiently removed during the heat treatment. Moreover, the effect of the porogenic agent no longer seems significant after sintering at 1250 °C; the difference in porosity between the two ceramics was negligible. When analysing the in vitro cytotoxicity of the samples, the ones that were porous and treated at 1320 °C showed slightly better cell viability, with the cells appearing to adhere more easily to their surface.

11.
Rom J Morphol Embryol ; 63(1): 39-48, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36074666

RESUMO

Cortisol is a key element in acute stress including a severe infection. However, in coronavirus-associated disease, 20% of subjects experience hypocortisolemia due to direct or immune damage of pituitary and adrenal glands. One extreme form of adrenal insufficiency is found in 2∕3 of cases with viral and post-viral adrenal infarction (AI) (with∕without adrenal hemorrhage) that is mostly associated with a severe coronavirus disease 2019 (COVID-19) infection; it requires prompt glucocorticoid intervention. Some reports are incidental findings at computed tomography (CT)∕magnetic resonance imaging (MRI) scans for non-adrenal complications like pulmonary spreading and others are seen on post-mortem analysis. This is a review of PubMed-accessible, English papers focusing on AI in addition to the infection, between March 1, 2020 and November 1, 2021. Exclusion criteria were acute adrenal insufficiency without the histopathological (HP) and∕or imaging report of adrenal enlargement, necrosis, etc., respective adrenal failure due to pituitary causes, or non-COVID-19-related adrenal events. We identified a total of 84 patients (different levels of statistical evidence), as follows: a retrospective study on 51 individuals, two post-mortem studies comprising nine, respectively 12 patients, a case series of five subjects, seven single-case reports. HP aspects include necrosis associated with ischemia, cortical lipid degeneration (+/- focal adrenalitis), and infarcts at the level of adrenal cortex, blood clot into vessels, acute fibrinoid necrosis in arterioles and capsules, as well as subendothelial vacuolization. Collateral potential contributors to adrenal damage are thrombotic events, coagulation anomalies, antiphospholipid syndrome, endothelial dysfunction, severe COVID-19 infection with multiorgan failure, etc. Clinical picture is variable from acute primary adrenal insufficiency to asymptomatic or mild evolution, even a retrospective diagnostic; it may be a part of long COVID-19 syndrome; glucocorticoid therapy for non-adrenal considerations might mask cortisol deficient status due to AI∕hemorrhage. Despite its rarity, the COVID-19-associated AI/hemorrhage represents a challenging new chapter, a condition that is essential to be recognized due to its gravity since prompt intervention with glucocorticoid replacement is lifesaving.


Assuntos
Insuficiência Adrenal , COVID-19 , Trombose , Glândulas Suprarrenais , Insuficiência Adrenal/complicações , COVID-19/complicações , Glucocorticoides , Hemorragia/complicações , Humanos , Hidrocortisona , Infarto/complicações , Necrose/complicações , Estudos Retrospectivos , Trombose/complicações , Síndrome de COVID-19 Pós-Aguda
12.
Gels ; 8(9)2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-36135286

RESUMO

In this work, calcium magnesium silicate ceramics were processed through the sol-gel method in order to study the crystalline and morphological properties of the resulting materials in correlation with the compositional and thermal parameters. Tetraethyl orthosilicate and calcium/magnesium nitrates were employed as sources of cations, in ratios specific to diopside, akermanite and merwinite; they were further subjected to gelation, calcination (600 °C) and thermal treatments at different temperatures (800, 1000 and 1300 °C). The properties of the intermediate and final materials were investigated by thermal analysis, scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction and Rietveld refinement. Such ceramics represent suitable candidates for tissue engineering applications that require porosity and bioactivity.

13.
Medicina (Kaunas) ; 58(8)2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-36013570

RESUMO

Oral papilloma lesions may appear as a result of HPV infection, or not, and only special molecular methods could differentiate them. Low-risk and high-risk HPV types could induce oral HPV papillomatosis with different natural evolution, clearance and persistence mechanisms. The pathogenic mechanisms are based on the crosstalk between the oral epithelial and immune cells and this very efficient virus. HPV acts as a direct inducer in the process of transforming a benign lesion into a malignant one, the cancerization process being also debated in this paper. According to the degree of malignity, three types of papillomatous lesions can be described in the oral cavity: benign lesions, potential malign disorders and malignant lesions. The precise molecular diagnostic is important to identify the presence of various virus types and also the virus products responsible for its oncogenicity. An accurate diagnostic of oral papilloma can be established through a good knowledge of etiological and epidemiological factors, clinical examination and laboratory tests. This review intends to update the pathogenic mechanisms driving the macroscopic and histological features of oral papillomatosis having HPV infection as the main etiological factor, focusing on its interreference in the local immunity. In the absence of an accurate molecular diagnostic and knowledge of local immunological conditions, the therapeutic strategy could be difficult to decide.


Assuntos
Neoplasias Bucais , Papiloma , Infecções por Papillomavirus , Humanos , Neoplasias Bucais/etiologia , Neoplasias Bucais/patologia , Papiloma/diagnóstico , Papiloma/patologia , Papillomaviridae , Infecções por Papillomavirus/complicações
14.
Int J Biol Macromol ; 203: 80-92, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35092736

RESUMO

A new core-shell pH-responsive nanocarrier was prepared based on magnetic nanoparticle (MNP) core. Magnetic nanoparticles were first modified with hyperbranched polyglycerol as the first shell. Then the magnetic core was decorated with doxorubicin anticancer drug (DOX) and covered with PEGylated carboxymethylcellulose as the second shell. Borax was used to partially cross-link organic shells in order to evaluate drug loading content and pH-sensitivity. The structure of nanocarrier, organic shell loadings, magnetic responsibility, morphology, size, dispersibility, and drug loading content were investigated by IR, NMR, TG, VSM, XRD, DLS, HR-TEM and UV-Vis analyses. In vitro release investigations demonstrated that the use of borax as cross-linker between organic shells make the nanocarrier highly sensitive to pH so that more that 70% of DOX is released in acidic pH. A reverse pH-sensitivity was observed for the nanocarrier without borax cross-linker. The MTT assay determined that the nanocarrier exhibited excellent biocompatibility toward normal cells (HEK-293) and high toxicity against cancerous cells (HeLa). The nanocarrier also showed high hemocompatibility. Cellular uptake revealed high ability of nanocarrier toward HeLa cells comparable with free DOX. The results also suggested that low concentration of nanocarrier has a great potential for use as contrast agent in magnetic resonance imaging (MRI).


Assuntos
Carboximetilcelulose Sódica , Nanopartículas , Boratos , Doxorrubicina/química , Doxorrubicina/farmacologia , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Glicerol , Células HEK293 , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Polímeros
15.
Materials (Basel) ; 14(23)2021 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-34885413

RESUMO

The corrosion of mild steel and Al alloy in Fomtec P 6% and 6% P Profoam 806 protein-based foam concentrates was investigated. Weight-loss data for steel showed corrosion penetration of 0.745 mipy in Fomtec and 2.269 mipy in Profoam, whereas for Al alloy the penetration levels were 0.474 and 1.093 mipy, respectively. Scanning electron microscopy and energy dispersive X-ray spectroscopy allowed characterization of the metallic surface covered or free from corrosion products. Values of corrosion potential, corrosion current density and corrosion penetration were calculated by using potentiodynamic polarization curves. Electrochemical impedance spectra illustrated the change in polarization resistance during anodic polarization. Data obtained by accelerated electrochemical methods confirm the greater aggressiveness of the Profoam concentrate compared to Fomtec concentrate.

16.
Rom J Morphol Embryol ; 62(1): 159-168, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34609418

RESUMO

Skin burns are one of the most common injuries associated with increased morbidity and mortality, especially in the children and the elderlies. Severe burns, especially, result in a systemic immune and inflammatory response, which may reflect in multiple organ insufficiency, and a fast and effective local restorative process is essential for functionality recovering, as well as for interrupting the generalized systemic response. We have aimed here to assess the effect of different wound dressings in what it regards the morphology and clinical restoration after a skin burn. On a rat animal model, we have evaluated the macroscopic and histopathological features of controlled third degree skin burns in control animals versus treatments with local dressings of silver sulfadiazine (SDA) cream, simple gel (G), gel + silver nanoparticles (AgNPs) (G+NPS), gel + exosomes (G+EXO) and gel + AgNPs + exosomes (Gel+NPS+EXO), at 14 days and, respectively, 21 days after the lesion. Tissue fragments were harvested and processed for histopathology and immunohistochemistry. Immunofluorescence was utilized to evaluate the maturity of underlaying granulation tissue based on double stainings for smooth muscle actin (SMA) and cluster of differentiation 31 (CD31). Our study showed variability in what it regards the vessel density and immunoexpression of SMA between the treatments, and image analysis revealed that most SMA reduction and blood vessel density reduction in the maturing granulation tissue occurred for the G+NPS and G+NPS+EXO treatments. A complete re-epithelization was also observed for the G+NPS+EXO treatment. Overall, our results show that improved topic treatments promote faster re-epithelization and reparation of the dermis after skin burn lesions, providing thus an avenue for new treatments that aim both local recuperation and systemic infection prevention.


Assuntos
Queimaduras , Nanopartículas Metálicas , Animais , Bandagens , Queimaduras/tratamento farmacológico , Ratos , Prata , Pele , Cicatrização
17.
Sci Rep ; 11(1): 17518, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34471182

RESUMO

This study aimed to develop a facile synthesis procedure for heterogeneous catalysts based on organic guanidine derivatives superbases chemically grafted on silica-coated Fe3O4 magnetic nanoparticles. Thus, the three organosilanes that were obtained by reacting the selected carbodiimides (N,N'-dicyclohexylcarbodiimide (DCC), N,N'-diisopropylcarbodiimide (DIC), respectively 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) with 3-aminopropyltriethoxysilane (APTES) were used in a one-pot synthesis stage for the generation of a catalytic active protective shell through the simultaneous hydrolysis/condensation reaction with tetraethyl orthosilicate (TEOS). The catalysts were characterized by FTIR, TGA, SEM, BET and XRD analysis confirming the successful covalent attachment of the organic derivatives in the silica shell. The second aim was to highlight the capacity of microwaves (MW) to intensify the transesterification process and to evaluate the activity, stability, and reusability characteristics of the catalysts. Thus, in MW-assisted transesterification reactions, all catalysts displayed FAME yields of over 80% even after 5 reactions/activation cycles. Additionally, the influence of FFA content on the catalytic activity was investigated. As a result, in the case of Fe3O4@SiO2-EDG, a higher tolerance towards the FFA content can be noticed with a FAME yield of over 90% (for a 5% (weight) vs oil catalyst content) and 5% weight FFA content.

18.
Materials (Basel) ; 14(6)2021 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-33800992

RESUMO

Three different inorganic scaffolds were obtained starting from the oxide system SiO2‒P2O5‒CaO‒MgO, to which Ce4+/Sm3+/Sr2+ cations were added in order to propose novel materials with potential application in the field of hard tissue engineering. Knowing the beneficial effects of each element, improved features in terms of mechanical properties, antibacterial activity and cellular response are expected. The compositions were processed in the form of scaffolds by a common sol-gel method, followed by a thermal treatment at 1000 and 1200 °C. The obtained samples were characterized from thermal, compositional, morphological and mechanical point of view. It was shown that each supplementary component triggers the modification of the crystalline phase composition, as well as microstructural details. Moreover, the shrinkage behavior is well correlated with the attained compression strength values. Sm was proven to be the best choice, since in addition to a superior mechanical resistance, a clear beneficial influence on the viability of 3T3 fibroblast cell line was observed.

19.
Curr Health Sci J ; 47(3): 338-347, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35003764

RESUMO

Colorectal cancer is one of the most frequently occurring malignancies which associates increasing mortality and morbidity rates. According to data provided by the World Health Organization, colorectal cancer deaths account for approximately 13% of all cancer fatalities. The carcinogenesis of this type of malignancy is a very complex process characterized by various molecular changes which in turn are influenced by factors likes sex, diet, intestinal microbiota, exposure to environmental factors, hosts' immune response and also genetic factors. Our study looked at a total number of 1024 patients, which were all diagnosed with colorectal cancer in a hospital in the north of England, a country that is known for both a high prevalence of this type of cancer but also its robust screening programmers. In our analyses, we concluded that this type of malignancies affected mostly males, aged between 60 and 80. The most commonly affected regions were the rectum, the sigmoid colon and also the cecum. The majority of colorectal cancers (51%) were diagnosed by GPs (general practitioners) or other medical specialties; 43.55% of all cases presented as surgical emergencies and 5.47% were diagnosed through national screening programs. Majority of tumors were diagnosed in late stages, mainly T3 and T4 whilst in was observed that rectal cancers were mainly diagnosed in T2 and T3 stages.

20.
Mater Sci Eng C Mater Biol Appl ; 118: 111498, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33255062

RESUMO

Two core-double-shell pH-sensitive nanocarriers were fabricated using Fe3O4 as magnetic core, poly(glycidyl methacrylate-PEG) and salep dialdehyde as the first and the second shell, and doxorubicin as the hydrophobic anticancer drug. Two nanocarriers were different in the drug loading steps. The interaction between the first and the second shell assumed to be pH-sensitive via acetal cross linkages. The structure of nanocarriers, organic shell loading, magnetic responsibility, morphology, size, dispersibility, and drug loading content were investigated by IR, NMR, TG, VSM, XRD, DLS, HRTEM and UV-Vis analyses. The long-term drug release profiles of both nanocarriers showed that the drug loading before cross-linking between the first and second shell led to a more pH-sensitive nanocarrier exhibiting higher control on DOX release. Cellular toxicity assay (MTT) showed that DOX-free nanocarrier is biocompatible having cell viability greater than 80% for HEK-293 and MCF-7 cell lines. Besides, high cytotoxic effect observed for drug-loaded nanocarrier on MCF-7 cancer cells. Cellular uptake analysis showed that the nanocarrier is able to transport DOX into the cytoplasm and perinuclear regions of MCF-7 cells. In vitro hemolysis and coagulation assays demonstrated high blood compatibility of nanocarrier. The results also suggested that low concentration of nanocarrier have a great potential as a contrast agent in magnetic resonance imaging (MRI).


Assuntos
Doxorrubicina , Portadores de Fármacos , Doxorrubicina/farmacologia , Compostos de Epóxi , Células HEK293 , Humanos , Concentração de Íons de Hidrogênio , Metacrilatos , Tamanho da Partícula , Ácidos Polimetacrílicos
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