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Graphene coatings developed by chemical vapor deposition (CVD) that possess extraordinary/unique characteristics as barrier against aggressive environment can improve the corrosion resistance of Ni and Cu by up to two orders of magnitude. However, because of some compelling technical reasons, it has thus far been a nontrivial challenge to develop graphene coatings on the most commonly used engineering alloy, mild steel (MS). To circumvent the challenge simply by first electroplating MS with a Ni layer is attempted, and then developing CVD graphene over the Ni layer. However, this approach proved too simplistic and does not work. This necessitated an innovative surface modification of MS (based on basic metallurgical principles) that enabled successful CVD of graphene coating on MS. The graphene coating thus developed is demonstrated to improve the corrosion resistance of mild steel by two orders of magnitude in an aggressive chloride solution, through electrochemical testing. This improvement was not only sustained for the entire test duration of >1000 h; but there is a clear trend for the resistance to be possibly everlasting. The optimized surface modification that enabled development of CVD graphene coating on mild steel is generic in nature, and it should enable graphene coating on other alloy systems, which would otherwise not be possible.
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Bipolar plates, a critical component of proton exchange membrane fuel cell (PEMFC), are constructed out of alloys of Ti, Pt, Cr, or graphitic materials that have limitations. Electrical conductivity, cost, and corrosion resistance are among the critical considerations for bi-polar plate material. Graphene, which possesses impressive conductivity and toughness, is an attractive option as coating on metallic substrates of PEMFC bipolar plates. This study investigates corrosion resistance and its durability due to graphene developed by chemical vapor deposition on a pure Ni-Cu alloy and a commercial Ni-Cu alloy in 0.5 m H2 SO4 environment, with a view to exploring use of graphene coated Ni-Cu alloys for the construction of PEMFC bipolar plates. The graphene coating on the pure alloy shows remarkably superior corrosion resistance than the commercial alloy that is attributed to the former's ability to develop considerably defect-free graphene.
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Lapatinib (LPT) is an orally administered drug for the treatment of metastatic breast cancer. For expanding its therapeutic horizon, we have prepared its nanocrystals (LPT-NCs) that were subsequently coated with hyaluronic acid (HA) to produce LPT-HA-NCs. The detailed in-vitro and in-vivo investigation of LPT-HA-NCs showed the superior anticancer activity due to active targeting to CD44 receptors than the counterparts LPT-NCs and free LPT. In the triple negative 4T1 cells induced breast tumor bearing female Balb/C mice; LPT-HA-NCs treatment caused significant retardation of tumor growth and overall increase in animal survival probability because of their higher tumor localization, increased residence time. Our findings clearly suggest that HA coated LPT-NCs formulation enhances the activity of LPT against triple negative breast cancer. It exhibited magnificent therapeutic outcome at low dose thus presenting a strategy to reduce dose administrations and minimize dose related toxicity.
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Antineoplásicos/farmacologia , Receptores de Hialuronatos/antagonistas & inibidores , Ácido Hialurônico/química , Lapatinib/farmacologia , Nanopartículas/química , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Animais , Antineoplásicos/química , Feminino , Lapatinib/química , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologia , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
PURPOSE: The aim of the present study was to prepare a patient friendly long acting donepezil (D) nanocrystals (NCs) formulation, with a high payload for i.m administration. As the native D hydrochloride salt has high aqueous solubility it is necessary to increase its hydrophobicity prior to the NCs formation. METHODS: D was ionically paired with embonic acid (E) in aqueous media and was successfully characterized using techniques like DSC, PXRD, FT-IR, NMR etc. Later, we converted the bulk ion pair into NCs using high pressure homogenization technique to study further in-vitro and in-vivo. RESULTS: The bulk ion pair has a drug content of 66% w/w and an 11,000 reduced solubility in comparison to native D hydrochloride. Also, its crystalline nature was confirmed by DSC and PXRD. The possible interaction sites responsible for the ion pair formation were identified though NMR. The prepared NCs has mean particle size 677.5 ± 72.5 nm and PDI 0.152 ± 0.061. In-vitro release showed a slow dissolution of NCs. Further, excellent bio compatibility of NCs were demonstrated in 3T3 cells. Following i.m administration of single dose of NCs, the D plasma level was found to be detectable up to 18 days. In vivo pharmacodynamic studies revealed that the single dose NCs i.m injection improved spatial memory learning and retention in ICV STZ model. CONCLUSION: Our results suggest that the developed formulation has a potential to replace the current daily dosing regimen to a less frequent dosing schedule. Graphical Abstract Improved pharmacokinetic and pharmacodynamic profile after administration of single dose donpezil embonate nanocrystals in Rats.
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Doença de Alzheimer/tratamento farmacológico , Indanos/química , Indanos/farmacocinética , Nanopartículas/química , Naftóis/química , Piperidinas/química , Piperidinas/farmacocinética , Células 3T3 , Acetilcolinesterase/metabolismo , Animais , Sobrevivência Celular , Química Farmacêutica , Donepezila , Liberação Controlada de Fármacos , Feminino , Humanos , Interações Hidrofóbicas e Hidrofílicas , Indanos/sangue , Camundongos , Tamanho da Partícula , Piperidinas/sangue , Polietilenoglicóis/química , Estudo de Prova de Conceito , Ratos Sprague-Dawley , Solubilidade , Estreptozocina , Propriedades de SuperfícieRESUMO
OBJECTIVE: Curcumin, the golden spice from Indian saffron, has shown chemoprotective action against many types of cancer including breast cancer. However, poor oral bioavailability is the major hurdle in its clinical application. In the recent years, self-nanoemulsifying drug delivery system (SNEDDS) has emerged as a promising tool to improve the oral absorption and enhancing the bioavailability of poorly water-soluble drugs. In this context, complexation with lipid carriers like phospholipid has also shown the tremendous potential to improve the solubility and therapeutic efficacy of certain drugs with poor oral bioavailability. METHODS: In the present investigation, a systematic combination of both the approaches is utilized to prepare the phospholipid complex of curcumin and facilitate its incorporation into SNEDDS. The combined use of both the approaches has been explored for the first time to enhance the oral bioavailability and in turn increase the anticancer activity of curcumin. RESULTS: As evident from the pharmacokinetic studies and in situ single pass intestinal perfusion studies in Sprague-Dawley rats, the optimized SNEDDS of curcumin-phospholipid complex has shown enhanced oral absorption and bioavailability of curcumin. The cytotoxicity study in metastatic breast carcinoma cell line has shown the enhancement of cytotoxic action by 38.7%. The primary tumor growth reduction by 58.9% as compared with the control group in 4T1 tumor-bearing BALB/c mice further supported the theory of enhancement of anticancer activity of curcumin in SNEDDS. CONCLUSION: The developed formulation can be a potential and safe carrier for the oral delivery of curcumin.
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Antineoplásicos/química , Antineoplásicos/farmacologia , Curcumina/química , Emulsões/química , Administração Oral , Animais , Disponibilidade Biológica , Química Farmacêutica/métodos , Curcumina/metabolismo , Curcumina/farmacologia , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos/efeitos dos fármacos , Masculino , Nanopartículas/química , Tamanho da Partícula , Fosfolipídeos/química , Polietilenoglicóis/química , Ratos , Ratos Sprague-Dawley , Solubilidade/efeitos dos fármacos , Tensoativos/química , Água/químicaRESUMO
Lutembacher's syndrome is a rare congenital cardiac syndrome comprising of a combination of an atrial septal defect complicated by congenital or acquired mitral stenosis. The applied physiology of the patient depends upon the severity and the interactions of the lesions. They pose certain difficulties to the administration of both general or neuraxial anesthesia. A preference of one form of anesthesia over the other should be based on the understanding of the physiology of the patient. There should not be an orthodox avoidance of neuraxial anesthesia in complex cardiac pathologies as general anesthesia can be associated with certain complications of its own. Here, we report our successful experience of neuraxial anesthesia being administered in a patient with Lutembacher's syndrome.
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The proper disposal of large stockpiles of tire wastes has become a major challenge today. Through this study, an attempt was made to effectively utilize the large chunk of tire wastes as a reinforcement for improving the bearing capacity of shallow foundations subjected to purely inclined loads. The study was accomplished in two phases. In the first phase, the tests were conducted on reinforced beds by varying the quantity of tire chips, the thickness of the reinforced zone, the inclination of loading, and the equivalent relative density of the reinforced zone. The bearing capacity ratio (BCR) was used as a factor to quantify the gains. It was observed that the optimum quantity and thickness of the reinforced zone were 20% by weight and 1B, respectively, where B is the width of the footing. Improvements were found significant at both loose and dense equivalent relative densities. The BCR values under inclined loads were higher than in central vertical loading conditions indicating that the technique is more useful in the latter. The study also compares the environmental impacts generated from tire chip and geogrid foundations in terms of various midpoint and endpoint impact categories using cradle-to-gate LCA. Midpoint environmental impacts have been shown in climate change, freshwater ecotoxicity, fossil depletion, ozone depletion, and water depletion, and endpoint impacts are represented in terms of damage to ecosystem quality, damage to human health, and damage to resources. The study found that foundation prepared with waste tire chips is less polluting to the environment compared to geogrid foundation. In addition to this, landfill of waste tires will be reduced by this technology which will further help in the reduction of the total environmental impact of the system. Henceforth, by adopting the current technology into construction practices, the large stockpiles of discarded tires can be disposed of in a sustainable way.
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Ecossistema , Areia , Humanos , Animais , Meio Ambiente , Mudança Climática , Estágios do Ciclo de VidaRESUMO
There have been several strategies developed to increase the diversified supply of energy so that it can meet all of the future demands for energy. As a result, to ensure a healthy and sustainable energy future, it is imperative to warrant reliable and diverse energy supply sources if the "green energy economy" is to be realized. The purpose of developing and deploying clean energy technologies is to improve our overall energy security, reduce our carbon footprint, and ensure that the generation of energy is secure and reliable in the future, making sure that we can spur economic growth in the future. In this paper, advancements in alternative sources of energy sustainability and strategies will be examined to ensure there will be enough fuel to supply all the future demands for energy. Several emerging clean energy technologies rely heavily on the availability of materials that exhibit unique properties that are necessary for their development. This paper examines the roles that rare earth and other energy-critical materials play in securing a clean energy economy and the development of clean energy economies in general. For the development of these technologies to be successful and sustainable, a number of these energy-critical materials are at risk of becoming unavailable. This is due to their limited availability, disruptions in supply, and a lack of suitable resources for their development. An action plan focusing on producing energy-critical materials in energy-efficient ways is discussed as part of an initiative to advance the development of clean and sustainable energy.
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Metais Terras Raras , Energia Renovável , Fontes Geradoras de Energia , Tecnologia , Pegada de Carbono , Desenvolvimento EconômicoRESUMO
ProSealTM Laryngeal Mask Airway (PLMA) (Teleflex Medical, Westmeath, Ireland) is a versatile and popular reusable supraglottic airway device. The manufacturer advises maximum reuse of up to 40 times. However, excessive reuse of the device can cause rare complications. Here, we report a rather uncommon complication of intraoperative cuff rupture of a PLMA probably due to the combination of a forceful metal introducer tip insertion and nitrous oxide-based anaesthesia.
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In the present study, we designed Bicalutamide (BCT) and Hesperetin (HSP) co-loaded self nano-emulsifying drug delivery system (SNEDDS) to encounter the problem of BCT induced toxicity, low solubility, and bioavailability. Optimized BCT-HSP SNEDDS would produce an emulsion of globule size 30.84±1.24nm with a high encapsulation efficiency of BCT (91.29%) and HSP (88.19%), and showed rapid drug release. DPPH assay confirmed the retention of antioxidant potential of HSP in SNEDDS. DCFH-DA confirmed intense green fluorescence in HSP treated groups due to the generation of reactive oxygen species. Thermogravimetric analysis showed the change in the polymorphic form of BCT. After 14days of sub-acute toxicity study, no significant increase (p>0.05) in the hepatotoxicity markers was observed but BCT-HSP SNEDDS significantly decreased (p<0.001) the levels of nephrotoxicity biochemical markers. Additionally, the histopathological study showed that pulmonary fibrosis and alteration in the bowman's by BCT treatment were conquered by co-administration of HSP. BCT-HSP SNEDDS revealed high AUC0-t of BCT (1.23 fold) and HSP (3.42 fold) than aqueous suspension in male Sprague-Dawley rats. The BCT-HSP SNEDDS were absorbed by clathrin-mediated endocytosis and lymphatic transport absorption pathway. Our results proposed that the co-delivery approach may be useful for in vivo management of prostate cancer.
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Anilidas , Hesperidina , Nitrilas , Neoplasias da Próstata/tratamento farmacológico , Compostos de Tosil , Anilidas/efeitos adversos , Anilidas/química , Anilidas/farmacocinética , Anilidas/farmacologia , Animais , Hesperidina/efeitos adversos , Hesperidina/química , Hesperidina/farmacocinética , Hesperidina/farmacologia , Humanos , Masculino , Nitrilas/efeitos adversos , Nitrilas/química , Nitrilas/farmacocinética , Nitrilas/farmacologia , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Ratos , Ratos Sprague-Dawley , Compostos de Tosil/efeitos adversos , Compostos de Tosil/química , Compostos de Tosil/farmacocinética , Compostos de Tosil/farmacologiaRESUMO
In the present work, we prepared memantine-pamoic acid (MEM-PAM) salt by counter ion exchange in the aqueous phase to reduce the water solubility of MEM hydrochloride (native form) to make it suitable for long acting injection. The ratio of MEM to PAM in salt formation was optimized to maximize the loading efficiency and complexation efficiency. The 2:1 molar ratio of MEM to PAM salt form displayed nearly 95% complexation efficiency and 50% drug loading. The solubility was decreased by a â¼1250 folds. Thermo Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), and Powder X-ray Diffraction Analysis (PXRD) studies revealed the formation of new solid phase. Additionally, Nuclear Magnetic Resonance (NMR) spectroscopy confirmed the anhydrous nature of the salt form. Through Fourier transformation infrared spectroscopy (FT-IR) we identified the molecular interactions. Further, the microcrystals of the salt were transformed into nanocrystals (NCs) using high pressure homogenization. The particle size distribution and atomic force microscopy confirmed the monodispersed and spherical shape of the NCs. The in vitro dissolution studies were performed under sink condition in phosphate buffer saline pH 6.8. The results of MTT assay in murine fibroblast 3T3 cell line show that the NCs were less cytotoxic and more tolerable than plain MEM HCl. The in vivo performance of NCs administered as i.m. injection at three different doses in female Sprague-Dawley rats showed that the plasma levels lasted till the 24th day of the study. The pharmacokinetic parameters AUC0-∞ and Cmax increased linearly with increasing dose. Therefore, the results suggest that injectable NCs could represent a therapeutic alternative for the treatment of AD.
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Memantina/química , Nanopartículas/química , Naftóis/química , Sais/química , Células 3T3 , Animais , Varredura Diferencial de Calorimetria/métodos , Linhagem Celular , Feminino , Injeções/métodos , Espectroscopia de Ressonância Magnética/métodos , Memantina/administração & dosagem , Camundongos , Microscopia Eletrônica de Varredura/métodos , Nanopartículas/administração & dosagem , Naftóis/administração & dosagem , Tamanho da Partícula , Ratos , Ratos Sprague-Dawley , Sais/administração & dosagem , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Difração de Raios X/métodosRESUMO
AIM: Development and optimization of ormeloxifene-loaded PEGylated chitosan nanoparticles (CNPs) for enhancing its literature profound therapeutic activity against breast cancer. METHODS: CNPs were prepared by ionotropic gelation method and characterized. RESULTS: Optimized formulation (CNPs10) had average 304 nm particle size with 0.247 polydispersity index and spherical shape with +31 mV surface charge. CNPs10 had 88.37% entrapment efficiency and 20.93% loading efficiency. CNPs10 demonstrated dose-dependent enhancement in cytotoxicity, cellular uptake, apoptosis, disruption of mitochondrial membrane potential and activation of caspase-3 in breast cancer MDA-MB-231 and MCF-7 cells over free ormeloxifene. In vivo studies divulged improved pharmacokinetic parameters, reduced toxicity, suppressed tumor burden and increased survival in CNPs10-treated female Sprague-Dawley rats. CONCLUSION: PEGylated CNPs enhanced anticancer activity of ormeloxifene.
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Antineoplásicos/administração & dosagem , Benzopiranos/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Mama/efeitos dos fármacos , Quitosana/análogos & derivados , Portadores de Fármacos/química , Polietilenoglicóis/química , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Benzopiranos/farmacocinética , Benzopiranos/farmacologia , Benzopiranos/uso terapêutico , Mama/metabolismo , Mama/patologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Caspase 3/metabolismo , Linhagem Celular Tumoral , Reposicionamento de Medicamentos , Feminino , Humanos , Células MCF-7 , Nanopartículas/química , Ratos Sprague-DawleyRESUMO
Withania somnifera Dunal (Solanaceae) known as Ashwagandha, a popular plant of Indian origin is known to possess tremedous medicinal potential, often used as anti-inflammatory, anti-platelet, antihypertensive, hypoglycemic, hypolipidemic and adaptogenic candidate. Some of its chemotypes developed by CSIR, India includes NMITLI-101, NMITLI-118, NMITLI-128. In this study the investigators have attempted development of a phytosomal complex of NMITLI118RT + (standardized ethanolic extract of a new chemotype of W. somnifera Dunal.), its pharmaceutical characterization and evaluation of its neuro-protective potential against experimenal stroke in rats in continuation with their previous work in this area. The phytosomal complex (NIMPLC) was prepared by following a cohesive optimization design and was characterized on the basis of solubility, dissolution profile, FT-IR, DSC-TGA analysis, zeta potential, physical stability, forced degradation and photolytic degradation. Results were suggestive of a pharmaceutically acceptable formulation. NIMPLC was taken up further for biological evaluation using the middle cerebral artery occlusion (MCAO) model in rats. It could be demonstrated that the beneficial effects of NMITLI118RT + could be augmented by NIMPLC in 1 h pre and 6 h post treatment as was evident from reduction in MDA levels, increment in GSH levels, reduction in neurological deficit (ND) scores and reduction in infarct size. The study could successfully demonstrate the beneficial effects of NIMPLC in brain function restoration following stroke.
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Isquemia Encefálica/tratamento farmacológico , Fosfolipídeos/química , Extratos Vegetais/farmacologia , Acidente Vascular Cerebral/tratamento farmacológico , Withania/química , Animais , Infarto da Artéria Cerebral Média/tratamento farmacológico , Masculino , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/química , Raízes de Plantas/química , Ratos , Ratos Sprague-DawleyRESUMO
Bicalutamide is a non-steroidal anti-androgen drug used for the treatment of androgen-dependent prostate cancer. Hesperetin is a natural bioflavonoid that can be used in combination with bicalutamide to improve efficacy and decrease tolerance. The aim of the present work was to develop and validate a simple, sensitive, rapid reverse phase-high performance liquid chromatographic method for simultaneous estimation of bicalutamide and hesperetin. The validation parameters such as specificity, linearity, precision and accuracy, limit of detection (LOD) and limit of quantification (LOQ) were determined according to International Conference on Harmonization ICH Q2 (R1) guidelines. Chromatographic separation was achieved on Lichrocart(®) CN column (250 × 4 mm, 5 µm, MERCK) with isocratic elution. The retention times and detection wavelength, for hesperetin and bicalutamide were 4.28 min, 288 nm and 5.90 min, 270 nm respectively. The intra-day and inter-day assay precision and accuracy were found to be <2% over linearity of 50-2000 ng/mL with R(2) 0.999. LOD and LOQ, of bicalutamide and hesperetin was 14.70, 44.57 ng/mL and 16.11, 48.84 ng/mL, respectively. The method was successfully applied for encapsulation efficiency and drug release studies from bicalutamide and hesperetin loaded nanoparticles.