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1.
Langmuir ; 2023 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-36607611

RESUMEN

Water electrolysis has attracted scientists' attention as a green route for energy generation. However, the sluggish kinetics of oxygen evolution reaction (OER) remarkably increases the reaction overpotential. In this work, we developed Co-based nanomaterials as cost-effective, highly efficient catalysts for OER. In this regard, different Co-based metal-organic frameworks (MOFs) were synthesized using different organic linkers. After annealing under inert atmosphere, the corresponding Co-embedded mesoporous carbon (Co/MC) materials were produced. Among them, Co/MC synthesized using 2-methyl imidazole (Co/NMC-2MeIM) expressed the highest surface area (412 m2/g) compared to its counterparts. Furthermore, it expressed a higher degree of defects as depicted by Raman spectra. Co/NMC-2MeIM exhibited the best catalytic performance toward OER in alkaline medium. It afforded an overpotential of 292 mV at a current density of 10 mA cm-2 and a Tafel slope of 99.2 mV dec-1. The superior electrocatalytic performance of Co/NMC-2MeIM is attributed to its high content of Co3+ on the surface, high surface area, and enhanced electrical conductivity induced by nitrogen doping. Furthermore, its high content of pyridinic-N and high degree of defects remarkably enhance the charge transfer between the adsorbed oxygen species and the active sites. These results may pave the avenue toward further investigation of metal/carbon materials in a wide range of electrocatalytic applications.

2.
Int J Mol Sci ; 21(12)2020 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-32575390

RESUMEN

The synergistic anticancer effect of docetaxel (DTX) and curcumin (CCM) has emerged as an attractive therapeutic candidate for lung cancer treatment. However, the lack of optimal bioavailability because of high toxicity, low stability, and poor solubility has limited their clinical success. Given this, an aerosolized nanoemulsion system for pulmonary delivery is recommended to mitigate these drawbacks. In this study, DTX- and CCM-loaded nanoemulsions were optimized using the D-optimal mixture experimental design (MED). The effect of nanoemulsion compositions towards two response variables, namely, particle size and aerosol size, was studied. The optimized formulations for both DTX- and CCM-loaded nanoemulsions were determined, and their physicochemical and aerodynamic properties were evaluated as well. The MED models achieved the optimum formulation for DTX- and CCM-loaded nanoemulsions containing a 6.0 wt% mixture of palm kernel oil ester (PKOE) and safflower seed oils (1:1), 2.5 wt% of lecithin, 2.0 wt% mixture of Tween 85 and Span 85 (9:1), and 2.5 wt% of glycerol in the aqueous phase. The actual values of the optimized formulations were in line with the predicted values obtained from the MED, and they exhibited desirable attributes of physicochemical and aerodynamic properties for inhalation therapy. Thus, the optimized formulations have potential use as a drug delivery system for a pulmonary application.


Asunto(s)
Antineoplásicos/farmacocinética , Curcumina/farmacocinética , Docetaxel/farmacocinética , Nanopartículas/química , Aerosoles , Antineoplásicos/química , Cápsulas , Curcumina/química , Docetaxel/química , Composición de Medicamentos , Emulsiones , Humanos , Modelos Teóricos , Tamaño de la Partícula , Solubilidad
3.
ScientificWorldJournal ; 2014: 756418, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24587751

RESUMEN

Here, we focused on a simple enzymatic epoxidation of alkenes using lipase and phenylacetic acid. The immobilised Candida antarctica lipase B, Novozym 435 was used to catalyse the formation of peroxy acid instantly from hydrogen peroxide (H2O2) and phenylacetic acid. The peroxy phenylacetic acid generated was then utilised directly for in situ oxidation of alkenes. A variety of alkenes were oxidised with this system, resulting in 75-99% yield of the respective epoxides. On the other hand, the phenylacetic acid was recovered from the reaction media and reused for more epoxidation. Interestingly, the waste phenylacetic acid had the ability to be reused for epoxidation of the 1-nonene to 1-nonene oxide, giving an excellent yield of 90%.


Asunto(s)
Alquenos/química , Compuestos Epoxi/síntesis química , Fenilacetatos/síntesis química , Biocatálisis , Candida/enzimología , Enzimas Inmovilizadas , Compuestos Epoxi/química , Proteínas Fúngicas/química , Peróxido de Hidrógeno/química , Lipasa/química , Fenilacetatos/química
4.
Environ Pollut ; 341: 122980, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-37992953

RESUMEN

The presence of emerging water pollutants such as endocrine-disrupting compounds (EDCs), including 17-ethynylestradiol (EE2), bisphenol A (BPA), and perfluorooctanoic acid (PFOA), in contaminated water sources poses significant environmental and health challenges. This study aims to address this issue by investigating the efficiency of novel calcium-based metal-organic frameworks, known as mixed-linker calcium-based metal-organic frameworks (Ca-MIX), in adsorbing these endocrine-disrupting compounds. This study analyzed the influence of influent concentration, bed height, and flow rate on pollutant removal, with bed height emerging as a crucial factor. From the breakthrough curves, it was determined that the column maximum adsorption capacities followed the order of 17-ethynylestradiol (101.52 µg/g; 40%) > bisphenol A (99.07 µg/g; 39%) > perfluorooctanoic acid (81.28 µg/g; 32%). Three models were used to predict the adsorption process, with the Yan model outperforming the other models. This suggests the potential of mixed-linker calcium-based metal-organic frameworks for removing endocrine-disrupting compounds from water, using the Yan model as an effective predictor. Overall, this study provides valuable insights for the development of effective water treatment methods using mixed-linker calcium-based metal-organic frameworks to remove endocrine-disrupting compounds from contaminated water sources.


Asunto(s)
Disruptores Endocrinos , Estructuras Metalorgánicas , Contaminantes Químicos del Agua , Purificación del Agua , Calcio , Adsorción , Contaminantes Químicos del Agua/análisis , Etinilestradiol/análisis , Compuestos de Bencidrilo/análisis , Purificación del Agua/métodos
5.
J Mol Graph Model ; 129: 108732, 2024 06.
Artículo en Inglés | MEDLINE | ID: mdl-38412813

RESUMEN

Recent evidence from in vitro and in vivo studies has shown that anthocyanins and anthocyanidins can reduce and inhibit the amyloid beta (Aß) species, one of the hallmarks of Alzheimer's disease (AD). However, their inhibition mechanisms on Aß species at molecular details remain elusive. Therefore, in the present study, molecular modelling methods were employed to investigate their inhibitory mechanisms on Aß(1-42) peptide. The results highlighted that anthocyanidins effectively inhibited the conformational transitions of helices into beta-sheet (ß-sheet) conformation within Aß(1-42) peptide by two different mechanisms: 1) the obstruction of two terminals from coming into contact due to the binding of anthocyanidins with residues of N- and second hydrophobic core (SHC)-C-terminals, and 2) the prevention of the folding process due to the binding of anthocyanidin with the central polar (Asp23 and Lys28) and native helix (Asp23, Lys28, and Leu34) residues. These new findings on the inhibition of ß-sheet formation by targeting both N- and SHC-C-terminals, and the long-established target, D23-K28 salt bridge residues, not with the conventional central hydrophobic core (CHC) as reported in the literature, might aid in designing more potent inhibitors for AD treatment.


Asunto(s)
Enfermedad de Alzheimer , Péptidos beta-Amiloides , Humanos , Péptidos beta-Amiloides/química , Antocianinas/farmacología , Simulación de Dinámica Molecular , Simulación del Acoplamiento Molecular , Fragmentos de Péptidos/química , Enfermedad de Alzheimer/metabolismo
6.
Chirality ; 25(11): 726-34, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23966316

RESUMEN

A series of tripeptide organocatalysts containing a secondary amine group and two amino acids with polar side chain units were developed and evaluated in the direct asymmetric intermolecular aldol reaction of 4-nitrobenzaldehyde and cyclohexanone. The effectiveness of short polar peptides as asymmetric catalysts in aldol reactions to attain high yields of enantio- and diastereoselective isomers were investigated. In a comparison, glutamic acid and histidine produced higher % ee and yields when they were applied as the second amino acid in short trimeric peptides. These short polar peptides were found to be efficient organocatalysts for the asymmetric aldol addition reaction in aqueous media.


Asunto(s)
Aldehídos/química , Oligopéptidos/química , Compuestos Orgánicos/química , Agua/química , Catálisis , Solventes/química
7.
AAPS PharmSciTech ; 14(1): 456-63, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23386307

RESUMEN

Fatty acid esters are long-chain esters, produced from the reaction of fatty acids and alcohols. They possess potential applications in cosmetic and pharmaceutical formulations due to their excellent wetting behaviour at interfaces and a non-greasy feeling when applied on the skin surfaces. This preliminary work was carried out to construct pseudo-ternary phase diagrams for oleyl laurate, oleyl stearate and oleyl oleate with surfactants and piroxicam. Then, the preparation and optimization study via 'One-At-A-Time Approach' were carried out to determine the optimum amount of oil, surfactants and stabilizer using low-energy emulsification method. The results revealed that multi-phase region dominated the three pseudo-ternary phase diagrams. A composition was chosen from each multi-phase region for preparing the nanoemulsions systems containing piroxicam by incorporating a hydrocolloid stabilizer. The results showed that the optimum amount (w/w) of oil for oleyl laurate nanoemulsions was 30 and 20 g (w/w) for oleyl stearate nanoemulsions and oleyl oleate nanoemulsions. For each nanoemulsions system, the amount of mixed surfactants and stabilizer needed for the emulsification to take place was found to be 10 and 0.5 g (w/w), respectively. The emulsification process via high-energy emulsification method successfully produced nano-sized range particles. The nanoemulsions systems passed the centrifugation test and freeze-thaw cycle with no phase failures, and stable for 3 months at various storage temperatures (3°C, 25°C and 45°C). The results proved that the prepared nanoemulsions system cannot be formed spontaneously, and thus, energy input was required to produce nano-sized range particles.


Asunto(s)
Inhibidores de la Ciclooxigenasa/química , Emulsiones , Ácidos Grasos/química , Piroxicam/química , Ésteres
8.
Pharmaceutics ; 15(2)2023 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-36839974

RESUMEN

Lung cancer is one of the deadliest pulmonary diseases in the world. Although docetaxel (DTX) has exhibited superior efficacy in lung cancer treatment, it has demonstrated numerous adverse effects and poor bioavailability. The natural product extract, curcumin (CCM), has reportedly reduced toxicity and synergistically improved DTX bioavailability. Nonetheless, the hydrophobic nature of DTX and CCM limits their clinical use. Nanoemulsion pulmonary delivery of DTX and CCM has demonstrated potential as a drug carrier to alleviate these drawbacks. The controlled preparation of inhalable DTX- and CCM-loaded nanoemulsions within the 100 to 200 nm range was explored in this study. A response surface methodology (RSM) based on a central composite design (CCD) was utilized to fabricate the desired size of the nanoemulsion under optimized conditions. Different process parameters were employed to control the size of the nanoemulsions procured through a high-energy emulsification technique. The size of the resultant nanoemulsions decreased with increasing energy input. The actual response according to the targeted sizes for DTX- and CCM-loaded nanoemulsion models exhibited excellent agreement with the predicted value at below 5% residual standard error under optimized conditions. The nanoemulsion of 100 nm particle size demonstrated better membrane permeability than their larger counterparts. Moreover, the formulations documented favorable physicochemical and aerodynamic pulmonary delivery properties and reduced toxicity in human lung fibroblast (MRC-5) cells. Hence, this tunable size of nanoemulsions could be a suitable alternative drug delivery for pulmonary diseases with increased local lung concentration.

9.
Polymers (Basel) ; 15(3)2023 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-36772061

RESUMEN

In this study, the ability of the highly scalable metal-organic framework (MOF) CALF-20 to adsorb polar and non-polar gases at low pressure was investigated using grand canonical Monte Carlo (GCMC) and molecular dynamics (MD) simulations. The results from the simulated adsorption isotherms revealed that the highest loading was achieved for SO2 and Cl2, while the lowest loading was found for F2 molecules. The analysis of interaction energies indicated that SO2 molecules were able to form the strongest adsorbent-adsorbate interactions and had a tight molecular packing due to their polarity and angular structure. Additionally, Cl2 gas was found to be highly adsorbed due to its large van der Waals surface and strong chemical affinity in CALF-20 pores. MD simulations showed that SO2 and Cl2 had the lowest mobility inside CALF-20 pores. The values of the Henry coefficient and isosteric heat of adsorption confirmed that CALF-20 could selectively adsorb SO2 and Cl2. Based on the results, it was concluded that CALF-20 is a suitable adsorbent for SO2 and Cl2 but not for F2. This research emphasizes the importance of molecular size, geometry, and polarity in determining the suitability of a porous material as an adsorbent for specific adsorbates.

10.
Pharmaceutics ; 15(5)2023 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-37242561

RESUMEN

Lung cancer is currently the most prevalent cause of cancer mortality due to late diagnosis and lack of curative therapies. Docetaxel (Dtx) is clinically proven as effective, but poor aqueous solubility and non-selective cytotoxicity limit its therapeutic efficacy. In this work, a nanostructured lipid carrier (NLC) loaded with iron oxide nanoparticles (IONP) and Dtx (Dtx-MNLC) was developed as a potential theranostic agent for lung cancer treatment. The amount of IONP and Dtx loaded into the Dtx-MNLC was quantified using Inductively Coupled Plasma Optical Emission Spectroscopy and high-performance liquid chromatography. Dtx-MNLC was then subjected to an assessment of physicochemical characteristics, in vitro drug release, and cytotoxicity. Dtx loading percentage was determined at 3.98% w/w, and 0.36 mg/mL IONP was loaded into the Dtx-MNLC. The formulation showed a biphasic drug release in a simulated cancer cell microenvironment, where 40% of Dtx was released for the first 6 h, and 80% cumulative release was achieved after 48 h. Dtx-MNLC exhibited higher cytotoxicity to A549 cells than MRC5 in a dose-dependent manner. Furthermore, the toxicity of Dtx-MNLC to MRC5 was lower than the commercial formulation. In conclusion, Dtx-MNLC shows the efficacy to inhibit lung cancer cell growth, yet it reduced toxicity on healthy lung cells and is potentially capable as a theranostic agent for lung cancer treatment.

11.
Artículo en Inglés | MEDLINE | ID: mdl-38109287

RESUMEN

Agrichemical adjuvants that combine a highly selective, efficient, and active mode of operation are critically needed to realize a more sustainable approach to their usage. Herein, we report the synthesis and full characterization of two new metal-organic frameworks (MOFs), termed UPMOF-1 and UPMOF-2, that were constructed from eco-friendly Ca2+ ions and naturally occurring, low-molecular weight plant acids, l-malic and d-tartaric acid, respectively. Upon structural elucidation of both MOFs, a widely used fungicide, hexaconazole (Hex), was loaded on the structures, reaching binding affinities of -5.0 and -3.5 kcal mol-1 and loading capacities of 63% and 62% for Hex@UPMOF-1 and Hex@UPMOF-2, respectively, as a result of the formation of stable host-guest interactions. Given the framework chemistry of the MOFs and their predisposition to disassembly under relevant agricultural conditions, the sustained release kinetics were determined to show nearly quantitative release (98% and 95% for Hex@UPMOF-1 and Hex@UPMOF-2, respectively) after >500 h, a release profile drastically different than the control (>80% release in 24 h), from which the high efficiency of these new systems was established. To confirm their high selectivity and activity, in vitro and in vivo studies were performed to illustrate the abilities of Hex@UPMOF-1 and Hex@UPMOF-2 to combat the known aggressive pathogen Ganoderma boninense that causes basal stem rot disease in oil palm. Accordingly, at an extremely low concentration of 0.05 µg mL-1, both Hex@UPMOF-1 and Hex@UPMOF-2 were demonstrated to completely inhibit (100%) G. boninense growth, and during a 26 week in vivo nursery trial, the progression of basal stem rot infection was completely halted upon treatment with Hex@UPMOF-1 and Hex@UPMOF-2 and seedling growth was accelerated given the additional nutrients supplied via the disassembly of the MOFs. This study represents a significant step forward in the design of adjuvants to support the environmentally responsible use of agrichemical crop protection.

12.
Int J Mol Sci ; 13(8): 9572-9583, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22949816

RESUMEN

Palm oil-based esters (POEs) are unsaturated and non-ionic esters with a great potential to act as chemical penetration enhancers and drug carriers for transdermal drug nano-delivery. A ratio of palmitate ester and nonionic Tween80 with and without diclofenac acid was chosen from an experimentally determined phase diagram. Molecular dynamics simulations were performed for selected compositions over a period of 15 ns. Both micelles showed a prolate-like shape, while adding the drug produced a more compact micellar structure. Our results proposed that the drug could behave as a co-surfactant in our simulated model.


Asunto(s)
Diclofenaco/química , Ésteres/química , Micelas , Simulación de Dinámica Molecular , Palmitatos/química , Tensoactivos/química , Portadores de Fármacos , Estructura Molecular , Polisorbatos/química , Propiedades de Superficie
13.
ACS Biomater Sci Eng ; 8(6): 2445-2454, 2022 06 13.
Artículo en Inglés | MEDLINE | ID: mdl-35583465

RESUMEN

Cancer-targeting nanotherapeutics offer promising opportunities for selective delivery of cytotoxic chemotherapeutics to cancer cells. However, the understanding of dissolution behavior and safety profiles of such nanotherapeutics is scarce. In this study, we report the dissolution profile of a cancer-targeting nanotherapeutic, gemcitabine (GEM) encapsulated within RGD-functionalized zeolitic imidazolate framework-8 (GEM⊂RGD@nZIF-8), in dissolution media having pH = 6.0 and 7.4. GEM⊂RGD@nZIF-8 was not only responsive in acidic media (pH = 6.0) but also able to sustain the dissolution rate (57.6%) after 48 h compared to non-targeting nanotherapeutic GEM⊂nZIF-8 (76%). This was reflected by the f2 value of 36.1, which indicated a difference in the dissolution behaviors of GEM⊂RGD@nZIF-8 and GEM⊂nZIF-8 in acidic media compared to those in neutral media (pH = 7.4). A dissolution kinetic study showed that the GEM release mechanism from GEM⊂RGD@nZIF-8 followed the Higuchi model. In comparison to a non-targeting nanotherapeutic, the cancer-targeting nanotherapeutic exhibited an enhanced permeability rate in healthy zebrafish embryos but did not induce lethality to 50% of the embryos (LC50 > 250 µg mL-1) with significantly improved survivability (75%) after 96 h of incubation. Monitoring malformation showed minimal adverse effects with only 8.3% of edema at 62.5 µg mL-1. This study indicates that cancer-targeting GEM⊂RGD@nZIF, with its pH-responsive behavior for sustaining chemotherapeutic dissolution in a physiologically relevant environment and its non-toxicity toward the healthy embryos within the tested concentrations, has considerable potential for use in cancer treatment.


Asunto(s)
Neoplasias , Pez Cebra , Animales , Línea Celular Tumoral , Sistemas de Liberación de Medicamentos , Neoplasias/tratamiento farmacológico , Solubilidad
14.
Nanomaterials (Basel) ; 12(14)2022 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-35889714

RESUMEN

Covalent organic frameworks are porous crystalline compounds made up of organic material bonded together by strong reversible covalent bonds (these are novel types of materials which have the processability of extended or repeated structures with high performance, like those of thermosets and thermoplastics that produce high surface coverage). These have a long-term effect on an arrangement's geometry and permeability. These compounds are entirely made up of light elements like H, B, C, N, O and Si. Pharmaceuticals and personal care products (PPCPs) have emerged as a new threatened species. A hazardous substance known as an "emerging toxin," such as naproxen, is one that has been established or is generated in sufficient amounts in an environment, creating permanent damage to organisms. COF-S7, OAPS and 2-methylanthraquionone(2-MeAQ), and COF-S12, OAPS and terephthalaldehyde (TPA) were effectively synthesized by condensation (solvothermal) via a Schiff base reaction (R1R2C=NR'), with a molar ratio of 1:8 for OAPS to linker (L1 and L2), at a temperature of 125 °C and 100 °C for COF-S7 and COF-S12, respectively. The compounds obtained were assessed using several spectroscopy techniques, which revealed azomethine C=N bonds, aromatic carbon environments via solid 13C and 29Si NMR, the morphological structure and porosity, and the thermostability of these materials. The remedied effluent was investigated, and a substantial execution was noted in the removal ability of the naproxen over synthesized materials, such as 70% and 86% at a contact time of 210 min and 270 min, respectively, at a constant dose of 0.05 g and pH 7. The maximum adsorption abilities of the substances were found to be 35 mg/g and 42 mg/g. The pH result implies that there is stable exclusion with a rise in pH to 9. At pH 9, the drop significance was attained for COF-S7 with the exception of COF-S12, which was detected at pH 11, due to the negative Foster charge, consequent to the repulsion among the synthesized COFs and naproxen solution. From the isotherms acquired (Langmuir and Freundlich), the substances displayed a higher value (close to 1) of correlation coefficient (R2), which showed that the substances fit into the Freundlich isotherm (heterogenous process), and the value of heterogeneity process (n) achieved (less than 1) specifies that the adsorption is a chemical process. Analysis of the as-prepared composites revealed remarkable reusability in the elimination of naproxen by adsorption. Due to its convenience of synthesis, significant adsorption effectiveness, and remarkable reusability, the as-synthesized COFs are expected to be able to be used as potential adsorbents for eliminating AIDs from water.

15.
Front Chem ; 10: 1076350, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36545218

RESUMEN

To improve the selective delivery of cisplatin (Cis) to cancer cells, we report and establish the significance of active, targeting drug delivery nanosystems for efficient treatment of lung cancer. Specifically, pH-responsive nano-sized zeolitic imidazolate framework (nZIF-90) was synthesized, post-synthetically modified with an Arg-Gly-Asp peptide motif (RGD@nZIF-90), a known cancer cell homing peptide, and loaded with a large amount of Cis (RGD@Cis⊂nZIF-90). RGD@Cis⊂nZIF-90 was shown to be highly stable under physiological conditions (pH = 7.4) with framework dissociation occurring under slightly acidic conditions (pH = 5.0)-conditions relevant to tumor cells-from which 90% of the encapsulated Cis was released in a sustained manner. In vitro assays demonstrated that RGD@Cis⊂nZIF-90 achieved significantly better cytotoxicity (65% at 6.25 µg ml-1) and selectivity (selectivity index = 4.18 after 48 h of treatment) against adenocarcinoma alveolar epithelial cancer cells (A549) when compared with the unmodified Cis⊂nZIF-90 (22%). Cellular uptake using A549 cells indicated that RGD@Cis⊂nZIF-90 was rapidly internalized leading to significant cell death. After successfully realizing this nanocarrier system, we demonstrated its efficacy in transporting and delivering Cis to cancer cells.

16.
Biosci Biotechnol Biochem ; 75(8): 1446-50, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21821960

RESUMEN

The utilization of natural mica as a biocatalyst support in kinetic investigations is first described in this study. The formation of lactose caprate from lactose sugar and capric acid, using free lipase (free-CRL) and lipase immobilized on nanoporous mica (NER-CRL) as a biocatalyst, was evaluated through a kinetic study. The apparent kinetic parameters, K(m) and V(max), were determined by means of the Michaelis-Menten kinetic model. The Ping-Pong Bi-Bi mechanism with single substrate inhibition was adopted as it best explains the experimental findings. The kinetic results show lower K(m) values with NER-CRL than with free-CRL, indicating the higher affinity of NER-CRL towards both substrates at the maximum reaction velocity (V(max,app)>V(max)). The kinetic parameters deduced from this model were used to simulate reaction rate data which were in close agreement with the experimental values.


Asunto(s)
Proteínas Bacterianas/metabolismo , Biocatálisis , Biotecnología/métodos , Enzimas Inmovilizadas/metabolismo , Ésteres/metabolismo , Lactobacillus plantarum/enzimología , Lactosa/metabolismo , Lipasa/metabolismo , Silicatos de Aluminio/química , Reactivos de Enlaces Cruzados , Ácidos Decanoicos/metabolismo , Cinética , Lactobacillus plantarum/química , Microscopía Electrónica de Rastreo , Modelos Estadísticos , Nanoestructuras/química
17.
J Ind Microbiol Biotechnol ; 38(1): 229-34, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20803246

RESUMEN

Esterification of succinic acid with oleyl alcohol catalyzed by immobilized Candida antarctica lipase B (Novozym 435) was investigated in this study. Response surface methodology (RSM) based on a five-level, four-variable central composite design (CCD) was used to model and analyze the reaction. A total of 21 experiments representing different combinations of the four parameters including temperature (35-65°C), time (30-450 min), enzyme amount (20-400 mg), and alcohol:acid molar ratio (1:1-8:1) were generated. A partial cubic equation could accurately model the response surface with a R(2) of 0.9853. The effect and interactions of the variables on the ester synthesis were also studied. Temperature was found to be the most significant parameter that influenced the succinate ester synthesis. At the optimal conditions of 41.1°C, 272.8 min, 20 mg enzyme amount and 7.8:1 alcohol:acid molar ratio, the esterification percentage was 85.0%. The model can present a rapid means for estimating the conversion yield of succinate ester within the selected ranges.


Asunto(s)
Enzimas Inmovilizadas/metabolismo , Lipasa/metabolismo , Modelos Químicos , Succinatos/metabolismo , Esterificación , Ésteres/metabolismo , Alcoholes Grasos/metabolismo , Proteínas Fúngicas , Temperatura
18.
Pharmaceutics ; 13(2)2021 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-33498885

RESUMEN

Cancer treatment and therapy have made significant leaps and bounds in these past decades. However, there are still cases where surgical removal is impossible, metastases are challenging, and chemotherapy and radiotherapy pose severe side effects. Therefore, a need to find more effective and specific treatments still exists. One way is through the utilization of drug delivery agents (DDA) based on nanomaterials. In 2001, mesoporous silica nanoparticles (MSNs) were first used as DDA and have gained considerable attention in this field. The popularity of MSNs is due to their unique properties such as tunable particle and pore size, high surface area and pore volume, easy functionalization and surface modification, high stability and their capability to efficiently entrap cargo molecules. This review describes the latest advancement of MSNs as DDA for cancer treatment. We focus on the fabrication of MSNs, the challenges in DDA development and how MSNs address the problems through the development of smart DDA using MSNs. Besides that, MSNs have also been applied as a multifunctional DDA where they can serve in both the diagnostic and treatment of cancer. Overall, we argue MSNs provide a bright future for both the diagnosis and treatment of cancer.

19.
Pharmaceutics ; 13(1)2021 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-33466428

RESUMEN

Gemcitabine (Gem) and cisplatin (Cis) are currently being used for lung cancer treatment, but they are highly toxic in high dosages. This research aimed to develop a niosome formulation containing a low-dosage Gem and Cis (NGC), as an alternative formulation for lung cancer treatment. NGC was prepared using a very simple heating method and was further optimized by D-optimal mixture design. The optimum NGC formulation with particle size, polydispersity index (PDI), and zeta potential of 166.45 nm, 0.16, and -15.28 mV, respectively, was obtained and remained stable at 27 °C with no phase separation for up to 90 days. The aerosol output was 96.22%, which indicates its suitability as aerosolized formulation. An in vitro drug release study using the dialysis bag diffusion technique showed controlled release for both drugs up to 24 h penetration. A cytotoxicity study against normal lung (MRC5) and lung cancer (A549) cell lines was investigated. The results showed that the optimized NGC had reduced cytotoxicity effects against both MRC5 and A549 when compared with the control (Gem + Cis alone) from very toxic (IC50 < 1.56 µg/mL) to weakly toxic (IC50 280.00 µg/mL) and moderately toxic (IC50 = 46.00 µg/mL), respectively, after 72 h of treatment. These findings revealed that the optimized NGC has excellent potential and is a promising prospect in aerosolized delivery systems to treat lung cancer that warrants further investigation.

20.
Polymers (Basel) ; 13(11)2021 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-34205141

RESUMEN

Covalent organic frameworks (COFs) have a distinguished surface as they are mostly made by boron, carbon, nitrogen and oxygen. Many applications of COFs rely on polarity, size, charge, stability and hydrophobicity/hydrophilicity of their surface. In this study, two frequently used COFs sheets, COF-1 and covalent triazine-based frameworks (CTF-1), are studied. In addition, a theoretical porous graphene (TPG) was included for comparison purposes. The three solid sheets were investigated for aromaticity and stability using quantum mechanics calculations and their ability for water and ethanol adsorption using molecular dynamics simulations. COF-1 demonstrated the poorest aromatic character due to the highest energy delocalization interaction between B-O bonding orbital of sigma type and unfilled valence-shell nonbonding of boron. CTF-1 was identified as the least kinetically stable and the most chemically reactive. Both COF-1 and CTF-1 showed good surface properties for selective adsorption of water via hydrogen bonding and electrostatic interactions. Among the three sheets, TPG's surface was mostly affected by aromatic currents and localized π electrons on the phenyl rings which in turn made it the best platform for selective adsorption of ethanol via van der Waals interactions. These results can serve as guidelines for future studies on solvent adsorption for COFs materials.

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