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1.
Ecotoxicol Environ Saf ; 223: 112575, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34352575

RESUMO

Treatment of liver cancer has always been a challenge for clinicians and development of appropriate drug against hepatocellular carcinoma is the major focus for researchers working in the field. The synthesis of metal-based nanoparticles (NPs) by green method for pharmacological uses has attained considerable attention recently. In current study three different NPs (AgO2, CeO2, CuO2) were synthesized by using Trianthima portulacastrum and Chinopodium quinoa leaf extracts. These biogenic NPs were analyzed by High-tech. approaches including Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray (EDX) spectroscope, SEM-EDS spot analysis, elemental mapping and X-ray diffraction (XRD). The anticancer potential of these nanoparticles was estimated using MTT assay, against hepatic cancer cell line (HepG2). SEM secondary electron images presented the nano size of prepared particles in agglomerated form with few porous forms. Average size of Ag-, Ce-, and CuNPs was observed 19-24 nm, 8-12 nm, 13-15 nm respectively. Elemental mapping and EDS-spot analysis ratifies the formation of AgNPs, CeNPs, and CuNPs. These NPs have shown good anticancer activity at different concentrations against HepG2 cell line. Further studies are however needed to identify the molecular mechanisms of these anticancer activities.


Assuntos
Antineoplásicos , Carcinoma Hepatocelular , Neoplasias Hepáticas , Nanopartículas Metálicas , Antibacterianos , Antineoplásicos/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Linhagem Celular , Células Hep G2 , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Nanopartículas Metálicas/toxicidade , Extratos Vegetais/farmacologia , Prata , Difração de Raios X
2.
Sci Total Environ ; 791: 148319, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34412386

RESUMO

Red gypsum is a type of iron-rich gypsum residue originated from industrial titanium dioxide process using Ilmenite. Currently, it has a low rate of comprehensive utilization about 20%, and deep removal of iron impurity is the crucial factor that directly limits its multipurpose utilization. In this study, the iron was efficiently removed from red gypsum residue by synergistic controlling the phase transformation of gypsum and the iron speciation under hydrothermal conditions. The iron removal efficiency was more than 99% under the optimized treatment condition (i.e. liquid-solid ratio of 10, with 1.5 M HCl as mineralizer, heating at 140 °C for 6 h). The X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) analyses showed that the phase transformation and crystal growth of gypsum accelerated by H+ was the essential reasons to fully remove iron. Moreover, H+ also provided acidic conditions (pH < 1) to change the iron speciation from amorphous oxide or hydroxide fine particles into soluble Fe3+ which release into the solution and easy to be removed by solid-liquid separation. In this work, based on the synergistic regulation of gypsum phase transformation and iron speciation, a feasible method for deep removal of iron from red gypsum was proposed, which is conducive to broadening the comprehensive utilization range of red gypsum. This work would inspire the treatment and resource utilization of industrial gypsum residues containing other contaminants or impurities, including heavy metals and organic matters.


Assuntos
Sulfato de Cálcio , Metais Pesados , Ferro , Compostos Orgânicos , Difração de Raios X
3.
J Biomed Nanotechnol ; 17(7): 1453-1458, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34446148

RESUMO

MMEO (3'-methoxy-3',4″(methylenedioxy)-2,5-epoksilignan-4'ol-6-on) is a derivative of DMEO (3'-methoxy-3″,4″(methylenedioxy)-2,5-epoksilignan-4',6-diol) synthesized through demethylation using dimethylsulfoxide-acetic anhydride reagent. MMEO inhibits Hedgehog signaling at a concentration of 4.1 µM. The current study aimed to formulate MMEO as solid dispersed nanoparticles and determine their physicochemical properties and inhibitory activities. XRD (X-ray diffraction) analysis showed that the crystalline particles of the pure compound MMEO was smaller than MMEO nanoparticles. Image J software showed that at concentrations of 25 mg/mL and 50 mg/mL, the average nanoparticle sizes were 852.26 nm and 178.65 nm, respectively. Therefore, the MMEO solid dispersion system with the PEG 4000 polymer increases the solubility of MMEO. The higher the concentration of PEG 4000 the greater the solubility of MMEO. Treating pancreatic cancer cell lines with MMEO silenced the smoothened function by downregulating mRNA Ptch expression. This study suggests that MMEO may inhibit pancreatic cancer disease.


Assuntos
Antineoplásicos , Nanopartículas , Neoplasias Pancreáticas , Antineoplásicos/farmacologia , Proteínas Hedgehog , Humanos , Neoplasias Pancreáticas/tratamento farmacológico , Solubilidade , Difração de Raios X
4.
Langmuir ; 37(33): 9952-9963, 2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34374545

RESUMO

Lipid hydroperoxides are key mediators of diseases and cell death. In this work, the structural and dynamic perturbations induced by the hydroperoxidized POPC lipid (POPC-OOH) in fluid POPC membranes, at both 23 and 37 °C, were addressed using advanced small-angle X-ray scattering (SAXS) and fluorescence methodologies. Notably, SAXS reveals that the hydroperoxide group decreases the lipid bilayer bending rigidity. This alteration disfavors the bilayer stacking and increases the swelling in-between stacked bilayers. We further investigated the changes in the apolar/polar interface of hydroperoxide-containing membranes through time-resolved fluorescence/anisotropy experiments of the probe TMA-DPH and time-dependent fluorescence shifts of Laurdan. A shorter mean fluorescence lifetime for TMA-DPH was obtained in enriched POPC-OOH membranes, revealing a higher degree of hydration near the membrane interface. Moreover, a higher microviscosity near TMA-DPH and lower order are predicted for these oxidized membranes, at variance with the usual trend of variation of these two parameters. Finally, the complex relaxation process of Laurdan in pure POPC-OOH membranes also indicates a higher membrane hydration and viscosity in the close vicinity of the -OOH moiety. Altogether, our combined approach reveals that the hydroperoxide group promotes alterations in the membrane structure organization, namely, at the level of membrane order, viscosity, and bending rigidity.


Assuntos
Peróxidos Lipídicos , Fosfatidilcolinas , Polarização de Fluorescência , Bicamadas Lipídicas , Espalhamento a Baixo Ângulo , Difração de Raios X
5.
Langmuir ; 37(33): 10166-10176, 2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34369787

RESUMO

Monoolein-based cubic and hexagonal mesophases were investigated as matrices for insulin loading, at low pH, as a function of temperature and in the presence of increasing amounts of oleic acid, as a structural stabilizer for the hexagonal phase. Synchrotron small angle X-ray diffraction, rheological measurements, and attenuated total reflection-Fourier transform infrared spectroscopy were used to study the effects of insulin loading on the lipid mesophases and of the effect of protein confinement in the 2D- and 3D-lipid matrix water channels on its stability and unfolding behavior. We found that insulin encapsulation has only little effects both on the mesophase structures and on the viscoelastic properties of lipid systems, whereas protein confinement affects the response of the secondary structure of insulin to thermal changes in a different manner according to the specific mesophase: in the cubic structure, the unfolding toward an unordered structure is favored, while the prevalence of parallel ß-sheets, and nuclei for fibril formation, is observed in hexagonal structures.


Assuntos
Insulina , Estrutura Secundária de Proteína , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Difração de Raios X
6.
Chemosphere ; 277: 130237, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34384171

RESUMO

In the present work, the cost effective and facile hydrothermal synthesis technique was adopted to synthesize the copper (׀׀) oxide (CuO)-Nanoparticles (NPs). Physico-chemical characterization of the synthesized CuO-NPs was done by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Ultraviolet-visible spectroscopy (UV-Vis), and scanning electron microscopy (SEM) analysis were carried out to study the structural, optical, and surface morphology of nanomaterial. XRD analysis revealed that the synthesized CuO-NPs had monoclinic structure and the average crystallite size is 20 nm. FTIR spectra indicate the vibrational bands of metal oxygen bonds (Cu-O). UV-visible absorption spectra were utilized to determine the energy band gap (Eg) of the CuO-NPs. In addition, we fabricated the chemiresistive sensor using synthesized CuO-NPs for detecting Volatile Organic Compounds (VOCs). These results demonstrate that CuO-NPs based chemiresistive sensor is ideal for qualitative detection of BTEX chemicals vapors (i.e. Benzene, Toluene, Ethylbenzene, and Xylene).


Assuntos
Cobre , Nanopartículas , Óxidos , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
7.
Langmuir ; 37(35): 10469-10480, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34427085

RESUMO

States of water molecules confined in a nanospace designed by montmorillonite (negatively charged silicate layer) and charge compensating benzylammonium were investigated. Caffeine was used as a probe because of its compatibility for the fine structure of the interlayer water. Powder synchrotron radiation X-ray diffraction (SXRD) and adsorption isotherms of the water vapor revealed a metastable structure of bimolecular water layers (2WLs) in the interlayer space. Water molecules readily penetrated to expand the interlayer space to 0.56 nm. The interlayer space did not increase further even in the presence of excess water. According to the isosteric heat of water, the expansion was limited because of moderate hydration as forming 2WLs. Caffeine molecules replaced a part of the water molecules in the 2WLs to expand the interlayer space to 0.65 nm. Time-resolved SXRD with an accumulation time of 500 ms revealed that the interlayer expansion reached a steady state within a few minutes. The caffeine intercalation proceeded, involving a change in the molecular orientation that increased the contact area of the caffeine molecules. The interlayer expansion was limited in all the solvents examined (mixtures of water with methanol, ethanol, acetone, and tetrahydrofuran), while the packing density of the incorporated caffeine was maximized in the absence of an organic solvent. The water molecules confined in the interlayer space acted as an actuator to accommodate a large quantity of amphiphilic molecules by adapting the nanostructure, which was achieved by releasing the confined water molecules.


Assuntos
Síncrotrons , Água , Adsorção , Bentonita , Difração de Raios X
8.
Int J Mol Sci ; 22(16)2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34445500

RESUMO

Cationic surfactants interact with DNA (Deoxyribonucleic acid), forming surfactant-DNA complexes that offer particularly efficient control for encapsulation and release of DNA from DNA gel particles. In the present work, DNA-based particles were prepared using CTAB (Cetyltrimethylammonium bromide) as the cationic surfactant and modified using two different additives: (Multi-Walled Carbon Nanotubes) MWNT or PEG (Poly Ethylene Glycol). The use of both additives to form composites increased the stability of the gel particles. The stability was monitored by the release of DNA and CTAB in different pH solutions. However, not much is known about the influence of pH on DNA-surfactant interaction and the release of DNA and surfactant from gel particles. It was observed that the solubilization of DNA occurs only in very acid media, while that of CTAB does not depend on pH and gets to a plateau after about 8 h. Within 2 h in contact with a pH = 2 solution, about 1% DNA and CTAB was released. Complete destruction for the gel particles was observed in pH = 2 solution after 17 days for PEG and 20 days for MWNT. The composite particles show a considerably enlarged sustained release span compared to the unmodified ones. The dehydration-rehydration studies show that the structure of the composite gel particles, as determined from SAXS (Small-Angle-X-Ray-Scattering) experiments, is similar to that of the unmodified ones. These studies will allow a better knowledge of these particles' formation and evolution in view of possible applications in drug delivery and release.


Assuntos
Cetrimônio/química , DNA/química , Nanotubos de Carbono/química , Tensoativos/química , Géis , Concentração de Íons de Hidrogênio , Polietilenoglicóis , Espalhamento a Baixo Ângulo , Difração de Raios X
9.
Talanta ; 234: 122619, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34364428

RESUMO

The market for nano-additive materials has been growing exponentially since 2012, with almost 5040 consumer products containing nanoparticles in 2021. In parallel, the increasing recommendations, definitions and legislations underline the need for traceability of manufactured nanoparticles and for methods able to identify and quantify the "nano" dimensional character in manufactured product. From a multi-technic approach, this paper aims to compare the mesurands extracted from SAXS/BET (specific surface area) and SEM (diameter equivalent to a projected surface area) on different TiO2 powder issued from referenced, synthesized materials, raw materials (additives) and extracted materials from manufactured products. The influence of various parameters such as the anisotropic factor, the interaction between particles, the size distribution and the extraction steps are discussed to illustrate their impact on the diameter values issued from two different measurands. These results illustrate the difficulties in (nano)particles characterization. SEM and SAXS are complementary techniques depending on the level of dimensional characterization required.


Assuntos
Nanopartículas , Titânio , Tamanho da Partícula , Pós , Espalhamento a Baixo Ângulo , Difração de Raios X
10.
Nat Commun ; 12(1): 4950, 2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-34400635

RESUMO

Upon ligand binding, bone morphogenetic protein (BMP) receptors form active tetrameric complexes, comprised of two type I and two type II receptors, which then transmit signals to SMAD proteins. The link between receptor tetramerization and the mechanism of kinase activation, however, has not been elucidated. Here, using hydrogen deuterium exchange mass spectrometry (HDX-MS), small angle X-ray scattering (SAXS) and molecular dynamics (MD) simulations, combined with analysis of SMAD signaling, we show that the kinase domain of the type I receptor ALK2 and type II receptor BMPR2 form a heterodimeric complex via their C-terminal lobes. Formation of this dimer is essential for ligand-induced receptor signaling and is targeted by mutations in BMPR2 in patients with pulmonary arterial hypertension (PAH). We further show that the type I/type II kinase domain heterodimer serves as the scaffold for assembly of the active tetrameric receptor complexes to enable phosphorylation of the GS domain and activation of SMADs.


Assuntos
Receptores de Ativinas Tipo I/química , Receptores de Ativinas Tipo I/metabolismo , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/química , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/metabolismo , Transdução de Sinais/fisiologia , Receptores de Ativinas Tipo I/genética , Receptores de Proteínas Morfogenéticas Ósseas/metabolismo , Receptores de Proteínas Morfogenéticas Ósseas Tipo II/genética , Proteínas Morfogenéticas Ósseas/metabolismo , Hipertensão Pulmonar Primária Familiar/metabolismo , Humanos , Ligantes , Modelos Moleculares , Mutação , Fosforilação , Ligação Proteica , Domínios Proteicos , Hipertensão Arterial Pulmonar , Espalhamento a Baixo Ângulo , Transdução de Sinais/genética , Proteínas Smad/metabolismo , Difração de Raios X
11.
Food Res Int ; 147: 110524, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34399502

RESUMO

Cultivars and fertilization levels influence rice productivity and can be associated with grain quality. Thus, it is possible to make decisions regarding the choice of cultivars and application of fertilizer levels based on the type of milling, a necessary post-harvest process that may minimize the nutrient load in the grains and result in loss in quality. This study relates the physicochemical composition and morphological quality of brown and polished milled rice grains, cultivar types, and different levels of soil fertilization using near-infrared spectroscopy analysis, X-ray diffraction and scanning electron microscopy. Statistical tools were used to test the various treatments and identify the relationship between factors and variables. A high fertilization level is related to increasing crude protein composition and starch for cultivar IRGA 431 CL associated with polished rice. However, the combination of cultivar IRGA 424 RI and brown rice demonstrated a higher grain resistance, and different percentages of whole, chalky, and damaged rice. The correlation between ash × crude protein and starch × crude fiber was found to be positive for brown rice and negative for the polished rice. Further, an increase in starch content was inversely proportional to the ash content, whereas an increase in crude protein was inversely proportional to the low-fat content in milled rice. The crystalline characteristics of rice starch were preserved at high fertilization levels associated with polished grains that demonstrated high starch content. Polished grains, however, showed more pores and cavities, and consequently greater permeabilities in the surface. It is recommended that batches of grains produced from cultivar IRGA 431 CL with high levels of fertilization be subjected to polished rice milling to achieve high protein and starch quality. However, grains from cultivar IRGA 424 RI with high levels of fertilization are recommended for brown rice milling owing to the high percentage of physical defects observed.


Assuntos
Oryza , Fertilização , Microscopia Eletrônica de Varredura , Espectroscopia de Luz Próxima ao Infravermelho , Difração de Raios X
12.
Food Res Int ; 147: 110527, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34399505

RESUMO

Understanding the changes in milk at a nanostructural level during high-pressure (HP) treatment can provide new insights to improve the safety and functionality of dairy products. In this study, modifications of milk nanostructure during HP were studied in situ by small-angle X-ray scattering (SAXS). Skimmed milk was pressurized to 200 or 400 MPa at 25, 40 or 60 °C and held for 5 or 10 min, and the effect of single- and double-HP treatment was also investigated. In most cases, the SAXS patterns of skimmed milk are well fitted with a three-population model: a low-q micellar feature reflecting the overall micelle size (~0.002 Å-1), a small casein cluster contribution at intermediate-q (around 0.01 Å-1) and a high-q (0.08-0.1 Å-1) population of milk protein inhomogeneities. However, at 60 °C a scattering feature of colloidal calcium phosphate (CCP) which is normally only seen with neutron scattering, was observed at 0.035 Å-1. By varying the pressure, temperature, holding and depressurization times, as well as performing cycled pressure treatment, we followed the dynamic structural changes in the skimmed milk protein structure at different length scales, which depending on the processing conditions, were irreversible or reversible within the timescales investigated. Pressure and temperature of the HP process have major effects, not only on size of casein micelles, but also on "protein inhomogeneities" within their internal structure. Under HP, increasing processing time at 200 MPa induced re-association of the micelles, however, the changes in the internal structure were more pressure-dependent than time dependent.


Assuntos
Caseínas , Leite , Animais , Pressão Hidrostática , Espalhamento a Baixo Ângulo , Difração de Raios X
13.
Food Res Int ; 147: 110557, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34399534

RESUMO

The crystallisation behaviour of milk fat plays an important role in the functionality and sensory properties of fat-rich dairy products. In this study, we investigated the impact of tempering to 25 °C on the viscoelastic properties, particle size and thermal behaviour of 20% w/w unprocessed and homogenised creams prepared from bovine milk. The crystallisation properties were examined by synchrotron X-ray diffraction (XRD) at small (SAXS) and wide angle (WAXS) and differential scanning calorimetry (DSC). Oscillation rheology was performed to characterise the cream's viscoelastic properties. Homogenisation (35 MPa) reduced the average droplet size from 4.4 to 1.3 µm. After 24 h storage at 4 °C, milk fat structures showed triacylglycerol (TAG) 2L and 3L(001, 002, 003, 005) lamellar stacking orders associated predominantly with the α and ß' polymorphic forms. Tempering to 25 °C induced the complete melting of the 3L crystals and led to an irreversible loss in the elastic modulus (G') and a reduction in the viscous modulus (G'') once returned to refrigerated conditions, due to changes in the particle-particle interactions and structure of the reformed milk fat crystals. The results demonstrate that crystallisation behaviour of milk fat is influenced by droplet size and the rearrangement of triacylglycerol (TAG) upon tempering, and lead to changes in the viscoelastic behaviour of dairy products containing a high level of milk fat.


Assuntos
Leite , Animais , Bovinos , Cristalização , Espalhamento a Baixo Ângulo , Temperatura , Difração de Raios X
14.
Molecules ; 26(11)2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34200376

RESUMO

The dissolution rate is the rate-limiting step for Biopharmaceutics Classification System (BCS) class II drugs to enhance their in vivo pharmacokinetic behaviors. There are some factors affecting the dissolution rate, such as polymorphism, particle size, and crystal habit. In this study, to improve the dissolution rate and enhance the in vivo pharmacokinetics of sorafenib tosylate (Sor-Tos), a BCS class II drug, two crystal habits of Sor-Tos were prepared. A plate-shaped crystal habit (ST-A) and a needle-shaped crystal habit (ST-B) were harvested by recrystallization from acetone (ACN) and n-butanol (BuOH), respectively. The surface chemistry of the two crystal habits was determined by powder X-ray diffraction (PXRD) data, molecular modeling, and face indexation analysis, and confirmed by X-ray photoelectron spectroscopy (XPS) data. The results showed that ST-B had a larger hydrophilic surface than ST-A, and subsequently a higher dissolution rate and a substantial enhancement of the in vivo pharmacokinetic performance of ST-B.


Assuntos
Solubilidade/efeitos dos fármacos , Sorafenibe/química , Acetona/química , Biofarmácia/métodos , Química Farmacêutica/métodos , Cristalização/métodos , Interações Hidrofóbicas e Hidrofílicas , Tamanho da Partícula , Pós/química , Difração de Raios X/métodos
15.
Molecules ; 26(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200814

RESUMO

Multi-drug resistant pathogens are a rising danger for the future of mankind. Iodine (I2) is a centuries-old microbicide, but leads to skin discoloration, irritation, and uncontrolled iodine release. Plants rich in phytochemicals have a long history in basic health care. Aloe Vera Barbadensis Miller (AV) and Salvia officinalis L. (Sage) are effectively utilized against different ailments. Previously, we investigated the antimicrobial activities of smart triiodides and iodinated AV hybrids. In this work, we combined iodine with Sage extracts and pure AV gel with polyvinylpyrrolidone (PVP) as an encapsulating and stabilizing agent. Fourier transform infrared spectroscopy (FT-IR), Ultraviolet-visible spectroscopy (UV-Vis), Surface-Enhanced Raman Spectroscopy (SERS), microstructural analysis by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-Ray-Diffraction (XRD) analysis verified the composition of AV-PVP-Sage-I2. Antimicrobial properties were investigated by disc diffusion method against 10 reference microbial strains in comparison to gentamicin and nystatin. We impregnated surgical sutures with our biohybrid and tested their inhibitory effects. AV-PVP-Sage-I2 showed excellent to intermediate antimicrobial activity in discs and sutures. The iodine within the polymeric biomaterial AV-PVP-Sage-I2 and the synergistic action of the two plant extracts enhanced the microbial inhibition. Our compound has potential for use as an antifungal agent, disinfectant and coating material on sutures to prevent surgical site infections.


Assuntos
Antibacterianos/química , Antibacterianos/síntese química , Aloe/química , Antifúngicos/química , Gentamicinas/química , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura/métodos , Nistatina/química , Extratos Vegetais/química , Povidona/química , Salvia/química , Salvia officinalis/química , Espectrometria por Raios X/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Difração de Raios X/métodos
16.
Int J Mol Sci ; 22(12)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207149

RESUMO

In this study, four different coal fly ashes (CFAs) were used as raw materials of silica and alumina for the preparation of the alumina-containing Mobil Composition of Matter No. 41 (Al-MCM-41) and the exploration of an activation strategy that is efficient and universal for various CFAs. Alkaline hydrothermal and alkaline fusion activations proceeded at different temperatures to determine the best treatment parameters. We controlled the pore structure and surface hydroxyl density of the CFA-derived Al-MCM-41 by changing the crystallization temperature and aging time. The products were characterized by small-angle X-ray diffraction, nitrogen isotherms, Fourier-transform infrared spectroscopy, 29Si silica magic-angle spinning nuclear magnetic resonance, and transmission electron microscopy, and they were then grafted with thiol groups to remove Pb(II) from aqueous solutions. This paper innovatively evaluates the CFA activation strategies using energy consumption analysis and determines the optimal activation methodology and parameters. This paper also unveils the effect of the crystallization condition of Al-MCM-41 on its subsequent Pb(II) removal capacity. The results show that the appropriate selection of crystallization parameters can considerably increase the removal capacity over Pb(II), providing a new path to tackle the ever-increasing concern of aquic heavy-metal pollution.


Assuntos
Óxido de Alumínio/química , Cinza de Carvão/química , Carvão Mineral/análise , Chumbo/química , Dióxido de Silício/química , Algoritmos , Cristalização , Modelos Teóricos , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
17.
Int J Mol Sci ; 22(12)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207212

RESUMO

Long-acting (LA) HIV pre-exposure prophylaxis (PrEP) can mitigate challenges of adhering to daily or on-demand regimens of antiretrovirals (ARVs). We are developing a subcutaneous implant comprising polycaprolactone (PCL) for sustained delivery of ARVs for PrEP. Here we use tenofovir alafenamide (TAF) as a model drug. Previously, we demonstrated that the release rates of drugs are controlled by the implant surface area and wall thickness, and the molecular weight (MW) of PCL. Here, we further advance the implant design and tailor the release rates of TAF and the mechanical integrity of the implant through unique polymer blend formulations. In vitro release of TAF from the implant exhibited zero-order release kinetics for ~120 days. TAF release rates were readily controlled via the MW of the polymer blend, with PCL formulations of higher MW releasing the drug faster than implants with lower MW PCL. Use of polymer MW to tune drug release rates is partly explained by PCL crystallinity, as higher PCL crystalline material is often associated with a slower release rate. Moreover, results showed the ability to tailor mechanical properties via PCL blends. Blending PCL offers an effective approach for tuning the ARV release rates, implant duration, and integrity, and ultimately the biodegradation profiles of the implant.


Assuntos
Implantes Absorvíveis , Fármacos Anti-HIV/administração & dosagem , Materiais Biocompatíveis , Preparações de Ação Retardada , Polímeros , Profilaxia Pré-Exposição/métodos , Materiais Biocompatíveis/química , Fenômenos Químicos , Portadores de Fármacos , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Infecções por HIV/tratamento farmacológico , Infecções por HIV/prevenção & controle , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , Humanos , Polímeros/química , Difração de Raios X
18.
Int J Mol Sci ; 22(12)2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34208563

RESUMO

Bone exhibits piezoelectric properties. Thus, electrical stimulations such as pulsed electromagnetic fields (PEMFs) and stimuli-responsive piezoelectric properties of scaffolds have been investigated separately to evaluate their efficacy in supporting osteogenesis. However, current understanding of cells responding under the combined influence of PEMF and piezoelectric properties in scaffolds is still lacking. Therefore, in this study, we fabricated piezoelectric scaffolds by functionalization of polycaprolactone-tricalcium phosphate (PCL-TCP) films with a polyvinylidene fluoride (PVDF) coating that is self-polarized by a modified breath-figure technique. The osteoinductive properties of these PVDF-coated PCL-TCP films on MC3T3-E1 cells were studied under the stimulation of PEMF. Piezoelectric and ferroelectric characterization demonstrated that scaffolds with piezoelectric coefficient d33 = -1.2 pC/N were obtained at a powder dissolution temperature of 100 °C and coating relative humidity (RH) of 56%. DNA quantification showed that cell proliferation was significantly enhanced by PEMF as low as 0.6 mT and 50 Hz. Hydroxyapatite staining showed that cell mineralization was significantly enhanced by incorporation of PVDF coating. Gene expression study showed that the combination of PEMF and PVDF coating promoted late osteogenic gene expression marker most significantly. Collectively, our results suggest that the synergistic effects of PEMF and piezoelectric scaffolds on osteogenesis provide a promising alternative strategy for electrically augmented osteoinduction. The piezoelectric response of PVDF by PEMF, which could provide mechanical strain, is particularly interesting as it could deliver local mechanical stimulation to osteogenic cells using PEMF.


Assuntos
Fosfatos de Cálcio , Materiais Revestidos Biocompatíveis , Campos Eletromagnéticos , Osteogênese , Poliésteres , Polivinil , Tecidos Suporte , Regeneração Óssea , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Materiais Revestidos Biocompatíveis/química , Expressão Gênica , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Osteogênese/efeitos da radiação , Poliésteres/química , Poliésteres/farmacologia , Polivinil/química , Solventes , Engenharia Tecidual , Difração de Raios X
19.
Int J Mol Sci ; 22(12)2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34208594

RESUMO

This article describes the synthesis and characterization of ß-cyclodextrin-based nano-sponges (NS) inclusion compounds (IC) with the anti-tumor drugs melphalan (MPH) and cytoxan (CYT), and the addition of gold nanoparticles (AuNPs) onto both systems, for the potential release of the drugs by means of laser irradiation. The NS-MPH and NS-CYT inclusion compounds were characterized using scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), UV-Vis, and proton nuclear magnetic resonance (1H-NMR). Thus, the inclusion of MPH and CYT inside the cavities of NSs was confirmed. The association of AuNPs with the ICs was confirmed by SEM, EDS, TEM, and UV-Vis. Drug release studies using NSs synthesized with different molar ratios of ß-cyclodextrin and diphenylcarbonate (1:4 and 1:8) demonstrated that the ability of NSs to entrap and release the drug molecules depends on the crosslinking between the cyclodextrin monomers. Finally, irradiation assays using a continuous laser of 532 nm showed that photothermal drug release of both MPH and CYT from the cavities of NSs via plasmonic heating of AuNPs is possible.


Assuntos
Ciclodextrinas , Ciclofosfamida/administração & dosagem , Portadores de Fármacos , Ouro , Melfalan/administração & dosagem , Nanopartículas Metálicas , Técnicas de Química Sintética , Ciclodextrinas/química , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos/efeitos da radiação , Ouro/química , Luz , Espectroscopia de Ressonância Magnética , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Temperatura , Termogravimetria , Tocoferóis , Difração de Raios X
20.
Int J Mol Sci ; 22(12)2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34208767

RESUMO

Promoting fluid transportation in porous media has important applications in energy, pedology, bioscience, etc. For this purpose, one effective way is to prevent swelling through surface modification; however, it is far from enough in real cases, such as ultra-low permeability reservoirs and tight oils. In this study, we considered the comprehensive effects of inhibiting clay swelling, flocculation performance, reducing water clusters and interfacial tension and developed a series of imidazole-based tetrafluoroborate ionic liquids (ILs) with different lengths of alkyl chains. Through measurements of anti-swelling rates, XRD, SEM, 17O NMR, molecular dynamics simulation, zeta potential, flocculation evaluation, interfacial tension and a core flooding experiment based on ultra-low permeability reservoirs, the relationships between the molecular structure and physicochemical properties of ILs have been revealed. Interestingly, one of the selected ILs, imidazole-based tetrafluoroborate ILs (C8-OMImBF4), shows excellent performance, which is helpful to design an effective strategy in promoting fluid transportation in narrow spaces.


Assuntos
Argila/química , Imidazóis/química , Líquidos Iônicos/química , Água/química , Algoritmos , Fenômenos Químicos , Modelos Moleculares , Modelos Teóricos , Conformação Molecular , Estrutura Molecular , Difração de Raios X
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