Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 675
Filtrar
Más filtros

Intervalo de año de publicación
1.
Small ; 20(5): e2306101, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37759427

RESUMEN

Polyvinyl pyrrolidone is blended in PbI2 with varied concentration, so as to study the coarsening dynamics of perovskite during the two-step growth method. It is observed that polyvinyl pyrrolidone hinders the crystallization of PbI2 and helps to form a more amorphous PbI2 matrix, which then improves perovskite crystallization. As the blending concentration increases from 0 to 2 mM, average crystallite/grain size of perovskite increases from 40.29 nm/0.79 µm to 84.35 nm/1.02 µm while surface fluctuation decreases slightly from 25.64 to 23.96 nm. The observations are caused by the "confinement effect" brought by polyvinyl pyrrolidone on PbI2 . Elevating blending concentration of polyvinyl pyrrolidone results in smaller PbI2 crystallites and more amorphous PbI2 matrix, thus reducing the diffusion/reaction barrier between PbI2 and organic salt and favoring perovskite crystallization. As blending concentration increases from 0 to 2 mM, the device efficiency rises from 19.76 (± 0.60) % to 20.50 (± 0.89) %, with the optimized value up to 22.05%, which is further improved to 24.48% after n-Octylammonium iodide (OAI)-basing surface modification. The study enlarges the scope of "confinement effect" brought by polymer molecules, which is beneficial for efficient and stable perovskite solar cell fabrication.

2.
Small ; 20(27): e2306125, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38282085

RESUMEN

Flexible polymer/single-wall carbon nanotube (SWCNT) composites are a vital component for wearable/portable electronics, but the development of their n-type counterpart is laggard. Furthermore, little attention is paid to the interaction between SWCNT and polymers, especially the unconjugated polymers, as well as the conversion mechanism of conduction characteristics. Here, the n-type flexible SWCNTs/Polyvinyl Pyrrolidone (PVP) films are successfully fabricated, where the oxygen atoms in PVP interacted with SWCNT via hydrogen bonds, which can lower the energy barrier of electron tunneling, providing the pathway for the electron transfer. Furthermore, with the increasing synthesis temperature, the hydrogen bonds strengthened and the thermal activation energy further improved, both of which enhanced the electron-donating ability of PVP, resulting in a high-power-factor value of 260 µW m-1 K-2. Based on the optimized SWCNTs/PVP films, a thermoelectric module is assembled, which achieved a power density of 400 µW cm-2 at a temperature difference of 56 K, coupled with excellent flexibility, showing a less than 1% variation of resistance after 5000 bending cycles. It shows the highest output-performance and the best flexibility among the reported SWCNT-based thermoelectric modules. This work provides significant insights into the interaction mechanism and performance optimization of hybrid thermoelectric composites, based on SWCNTs/unconjugated polymers.

3.
J Urol ; 211(1): 11-19, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37706750

RESUMEN

PURPOSE: The purpose of this American Urological Association (AUA) Guideline amendment is to provide a useful reference on the effective evidence-based management of male lower urinary tract symptoms secondary/attributed to BPH (LUTS/BPH). MATERIALS AND METHODS: The Minnesota Evidence Review Team searched Ovid MEDLINE, the Cochrane Library, and the Agency for Healthcare Research and Quality (AHRQ) database to identify studies relevant to the management of BPH. The guideline was updated in 2023 to capture eligible literature published between September 2020 and October 2022. When sufficient evidence existed, the body of evidence was assigned a strength rating of A (high), B (moderate), or C (low) for support of Strong, Moderate, or Conditional Recommendations. In the absence of sufficient evidence, additional information is provided as Clinical Principles and Expert Opinions. RESULTS: The BPH amendment resulted in changes to statements/supporting text on combination therapy, photoselective vaporization of the prostate (PVP), water vapor thermal therapy (WVTT), laser enucleation, and prostate artery embolization (PAE). A new statement on temporary implanted prostatic devices (TIPD) was added. In addition, statements on transurethral needle ablation (TUNA) and transurethral microwave thermotherapy (TUMT) were removed and information regarding these legacy technologies was added to the background section. References and the accompanying treatment algorithms were updated to align with the updated text. CONCLUSION: This guideline seeks to improve clinicians' ability to evaluate and treat patients with BPH/LUTS based on currently available evidence. Future studies will be essential to further support these statements to improve patient care.


Asunto(s)
Terapia por Láser , Síntomas del Sistema Urinario Inferior , Hiperplasia Prostática , Resección Transuretral de la Próstata , Humanos , Masculino , Síntomas del Sistema Urinario Inferior/terapia , Síntomas del Sistema Urinario Inferior/complicaciones , Próstata/cirugía , Hiperplasia Prostática/terapia , Hiperplasia Prostática/cirugía , Resección Transuretral de la Próstata/métodos , Resultado del Tratamiento , Guías de Práctica Clínica como Asunto
4.
Calcif Tissue Int ; 114(4): 360-367, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38308720

RESUMEN

Kummell's disease (KD) is a rare clinical complication of osteoporotic vertebral compression fractures (OVCFs). Minimally invasive surgery is an important way to treat KD. In this paper, we used Percutaneous Vertebroplasty (PVP) and Vesselplasty (VP) to treat KD. 125 patients with KD were admitted to our hospital. Among them, 89 patients received PVP and 36 received VP. All patients underwent operations successfully. VAS scores and ODI of both groups at each postoperative time point were lower than preoperatively. Postoperative Cobb angle of both groups postoperatively was lower than preoperatively (p < 0.05). The anterior height and ratio of vertebra compression of both groups postoperatively was lower than preoperatively (p < 0.05). Cement leakage occurred in 16 vertebrae (16/89) in PVP group and one (1/36) in VP group. Two patients suffered from transient paraplegia in PVP group immediately after operation. Adjacent vertebral fractures occurred in one patient in PVP group and one in VP group. Re-fracture of affected vertebra occurred in one patient in PVP group. Besides, four patients suffered from bone cement loosening in PVP group while one in VP group. Both PVP and VP play an important effect in pain relief and functional recovery for the treatment of KD. And VP is more effective than PVP in preventing cement leakage.


Asunto(s)
Fracturas por Compresión , Fracturas Osteoporóticas , Fracturas de la Columna Vertebral , Vertebroplastia , Humanos , Vertebroplastia/efectos adversos , Estudios Retrospectivos , Fracturas de la Columna Vertebral/etiología , Fracturas por Compresión/cirugía , Fracturas por Compresión/complicaciones , Resultado del Tratamiento , Cementos para Huesos/uso terapéutico , Fracturas Osteoporóticas/complicaciones
5.
Biopolymers ; 115(5): e23606, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38888357

RESUMEN

This study aimed to address a significant challenge in the application of bacterial cellulose (BC) within tissue engineering and regenerative medicine by tackling its inherent insolubility in water and organic solvents. Our team introduced a groundbreaking approach by utilizing zinc sulfate (ZnSO4) as a solvent to render BC soluble, a novel contribution to the literature. Subsequently, the obtained soluble BC was combined with varying concentrations of polyvinylpyrrolidone (PVP). Notably, we pioneered the fabrication of BC/PVP composite scaffolds with customizable fiber surface morphology and regulated degradation rates through the electrospun technique. Several key parameters, such as PVP concentration (8%, 15%, 12%, and 20% w/v), applied voltage (22, 15, and 12 kV), and a fixed nozzle-collector distance of 10 cm with a flow rate of 0.9 mL/h, were systematically evaluated so as to find the optimum parameter created BC/PVP product with electrospun. For electrospun BC/PVP products, a voltage of 12 kV was found to be optimal. Intriguingly, our findings revealed enhanced cell adhesion and proliferation in BC/PVP electrospun products compared with using PVP membranes alone. Specifically, cell viability for PVP and PVP/BC electrospun products was determined as 50.73% and 79.95%, respectively. In terms of thermal properties, the BC/PVP electrospun product exhibited a mass loss of 82.6% at 380°C, while PVP alone experienced 90.2% mass loss at around 280°C. Furthermore, the protein adhesion capacities were measured at 62.3 ± 1.2 µg for PVP and 99.4 ± 2 µg for BC/PVP electrospun products, whereas product showed no biodegradation over 28 days and had notable water retention capacity. In conclusion, our research not only successfully attained nanofiber morphology but also showcased enhanced cell attachment and proliferation on the BC/PVP electrospun product.


Asunto(s)
Celulosa , Nanofibras , Povidona , Celulosa/química , Nanofibras/química , Povidona/química , Ingeniería de Tejidos/métodos , Proliferación Celular/efectos de los fármacos , Adhesión Celular , Supervivencia Celular/efectos de los fármacos , Animales , Andamios del Tejido/química , Ratones
6.
Protein Expr Purif ; 215: 106402, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37956916

RESUMEN

Antibiotic resistance, a major global concern, highlights the need for discovering alternative therapies. Recently, endolysins have garnered attention as antibacterial tools with a lower resistance development rate compared to conventional antibiotics, and their production in various expression hosts holds significance. Given its generally recognized as safe (GRAS) status and other advantages, Hansenula polymorpha offers a promising host for endolysin production. PVP-SE1gp146 originates from the Salmonella Enteritidis-specific phage PVP-SE1, which has been previously characterized. We inserted the PVP-SE1gp146 coding gene into the H. polymorpha expression vector pHIPX4. The resulting recombinant, pHIPX4-PVP-SE1gp146, was then introduced into H. polymorpha NCYC495 to facilitate the production of the endolysin PVP-SE1gp146. The expression level of the PVP-SE1gp146 protein was assessed, and it was determined to be approximately 43 mg/l of yeast culture medium. The enzymatic (muralytic) activity of this endolysin was also evaluated, corresponding to the version produced by the E. coli Bl21 strain. The endolysin exhibited admissible antibacterial activity against several gram-negative species, including P. aeruginosa, E. coli, and A. baumannii, while showing an almost negligible impact on K. pneumoniae. Endolysin production within GRAS-approved hosts holds potential for combating antibiotic-resistant bacteria. Challenges involve optimizing concentrations, targeting gram-negative species and improving attachment to bacterial cell walls. Addressing these issues requires dedicated research in endolysin engineering and a comprehensive evaluation of their production in diverse expression hosts.


Asunto(s)
Bacteriófagos , Bacteriófagos/genética , Escherichia coli/genética , Antibacterianos/farmacología , Antibacterianos/metabolismo , Endopeptidasas/genética , Endopeptidasas/farmacología , Endopeptidasas/metabolismo
7.
Nanotechnology ; 35(33)2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38723610

RESUMEN

The self-powered PVP-Co@C nanofibers/n-GaAs heterojunction photodetector (HJPD) was fabricated by electrospinning of the nanofibers onto GaAs. An excellent rectification ratio of 6.60 × 106was obtained fromI-Vmeasurements of the device in the dark. TheI-Vmeasurements of the fabricated device under 365 nm, 395 nm and 850 nm lights, as well asI-Vmeasurements in visible light depending on the light intensity, were performed. The HJPD demonstrated excellent photodetection performance in terms of a good responsivity of âˆ¼225 mA W-1(at -1.72 V) and at zero bias, an impressive detectivity of 6.28 × 1012Jones, and a high on/off ratio of 8.38 × 105, all at 365 nm wavelength. In addition, the maximum external quantum efficiency and NPDR values were 3495% (V = -1.72 V) and 2.60 × 1010W-1(V= 0.0 V), respectively, while the minimum NEP value was ∼10-14W.Hz-1/2for 365 nm atV= 0.V volts. The HJPD also exhibited good long-term stability in air after 30 d without any encapsulation.

8.
Environ Res ; 241: 117681, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-37984786

RESUMEN

Copper (Cu) is one of the essential micronutrients for plants and has been used extensively in agricultural applications from the past to the present. However, excess copper causes toxic effects such as inhibiting photosynthesis, and disrupting biochemical processes in plants. Nanotechnology applications have offered a critical method for minimizing adverse effects and improving the effectiveness of copper nanoparticles. For this purpose, this study investigated the physiological and biochemical effects of polyvinylpyrrolidone (PVP)-coated Cu nanoparticles (PVP-Cu NP, N1, 100 mg L-1; N2, 400 mg L-1) in Triticum aestivum under alone or combined with salt (S, 150 mM NaCl) and/or drought (D, %10 PEG-6000) stress. Salinity and water deprivation caused 51% and 22% growth retardation in wheat seedlings. The combined stress condition (S + D) resulted in an approximately 3-fold reduction in the osmotic potential of the leaves. PVP-Cu NP treatments to plants under stress, especially N1 dose, were effective in restoring growth rate and regulating water relations. All stress treatments limited gas exchange in stomata and suppressed the maximal quantum yield of PSII (Fv/Fm). More than 50% improvement was observed in stomatal permeability and carbon assimilation rate under S + N1 and S + N2 applications. Examination of OJIP transient parameters revealed that N1 treatments protected photochemical reactions by reducing the dissipated energy flux (DIo/RC) in drought and S + D conditions. Exposure to S and/or D stress caused high hydrogen peroxide (H2O2) accumulation and lipid peroxidation in wheat leaves. The results indicated that S + N1 and S + N2 treatments reduced oxidative damage by stimulating the activities of antioxidant enzymes superoxide dismutase (SOD), peroxidase (POX), and ascorbate peroxidase (APX). Although similar effects were observed at D and S + D conditions with 100 mg L-1 PVP-Cu NP treatments (N1), the curative effect of the N2 dose was not observed. In D + N1 and S + D + N1 groups, AsA regeneration and GSH redox status were maintained by triggering APX, GR, and other enzyme activities belonging to the AsA-GSH cycle. In these groups, N2 treatment did not contribute to the availability of enzymatic and non-enzymatic antioxidants. As a result, this study revealed that N1 dose PVP-Cu NP application was successful in providing stress tolerance and limiting copper-induced adverse effects under all stress conditions.


Asunto(s)
Antioxidantes , Triticum , Antioxidantes/farmacología , Antioxidantes/metabolismo , Cobre/toxicidad , Povidona/farmacología , Sequías , Salinidad , Peróxido de Hidrógeno , Estrés Oxidativo/fisiología , Cloruro de Sodio/farmacología
9.
Environ Res ; 259: 119534, 2024 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-38960361

RESUMEN

This study presents a novel blend of synthesis techniques for shape-controlled ZnS nanoparticles. Zinc sulfide (ZnS) nanoparticles with distinct morphologies cauliflower-like microstructures (∼4.5 µm) and uniform nanospheres (200-700 nm) were synthesized through an innovative blend of precipitation and hydrothermal techniques. Capping with polyvinylpyrrolidone (PVP) significantly decreased crystallite size (3.93 nm-2.36 nm), modulated the band gap (3.57 eV-3.71 eV), and dramatically influenced morphology, highlighting the novelty of shape-controlled synthesis and its impact on optoelectronic and functional properties. X-ray diffraction confirmed crystallinity and revealed the size-controlling influence of PVP. UV-vis spectroscopy suggested potential tuning of optical properties due to band gap widening upon PVP capping. Field-emission scanning electron microscopy (FESEM) unveiled distinct morphologies: cauliflower-like microstructures for ZnS and uniform nanospheres (200-700 nm) for PVP-ZnS. Both structures were composed of smaller spherical nanoparticles, demonstrating the role of PVP in promoting controlled growth and preventing agglomeration. High-resolution transmission electron microscope (HRTEM) images depicted that the majority of nanoparticles maintain a spherical shape, though slight deviations from perfect sphericity can be discerned. Fourier-transform infrared (FTIR) spectroscopy confirmed that successful PVP encapsulation is crucial for shaping nanospheres and minimizing aggregation through steric hindrance. Photocatalytic activity evaluation using methylene blue (MB) dye degradation revealed significantly faster degradation by PVP-ZnS under ultraviolet (UV) irradiation (within 60 min as compared to 120 min for ZnS), showcasing its superior performance. This improvement can be attributed to the smaller size, higher surface area, and potentially optimized band gap of PVP-ZnS. Additionally, PVP-ZnS exhibited promising antibacterial activity against S. aureus and P. aeruginosa, with increased activity at higher nanoparticle concentrations.


Asunto(s)
Antibacterianos , Sulfuros , Compuestos de Zinc , Compuestos de Zinc/química , Sulfuros/química , Antibacterianos/química , Antibacterianos/farmacología , Aguas Residuales/química , Precipitación Química , Povidona/química , Purificación del Agua/métodos , Nanoestructuras/química
10.
Luminescence ; 39(7): e4817, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39019841

RESUMEN

Alternate antibiotics developed through the involvement of nanomaterials are gaining interest due to their economical and lower toxicity concerns. A newly developed biopolymer-based polyvinylpyrrolidone/zinc oxide (PVP/ZnO) nanocomposite (NCs) was efficiently synthesized by an environment-friendly approach, utilizing onion and garlic peel extract as a bio-surfactant, zinc acetate as the source, PVP as the stabilizing agent, and sodium hydroxide as the precipitant. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) investigations verified the crystalline properties of ZnO, PVP, and PVP/ZnO-based NCs. The structure of the biopolymer-linked ZnO particles interpolated inside the PVP array was seen to have a layered and flaky structure, as validated by field emission scanning electron microscopy (FE-SEM) analysis, which revealed its occurrence in the nanometer range. The XRD examination verified that the surface topographical image of PVP/ZnO NCs had an average thickness of 21 nm. The PVP/ZnO nanocrystals demonstrated exceptional photocatalytic efficacy, with a breakdown rate of 88% and almost 92% for the methylene blue dye. Therefore, the PVP/ZnO matrix exhibits superior antibacterial activity compared to other extracts, resulting in greater microbial suppression. The results above indicate that the ZnO-intercalated PVP array has a stronger reinforcing effect than other components. Hence, PVP/ZnO nanocrystals exhibit enormous potential as a favorable substance for environmental and biomedical intentions.


Asunto(s)
Antibacterianos , Nanocompuestos , Procesos Fotoquímicos , Povidona , Óxido de Zinc , Óxido de Zinc/química , Óxido de Zinc/farmacología , Povidona/química , Nanocompuestos/química , Catálisis , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/síntesis química , Pruebas de Sensibilidad Microbiana , Luminiscencia , Tamaño de la Partícula , Sustancias Luminiscentes/química , Sustancias Luminiscentes/síntesis química , Azul de Metileno/química
11.
Int J Toxicol ; 43(4_suppl): 5-41, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39045851

RESUMEN

The Expert Panel for Cosmetic Ingredient Safety (Panel) reviewed the safety of 30 vinylpyrrolidone polymers as used in cosmetic products; most of these ingredients have the reported cosmetic function of film former in common. The Panel reviewed data relevant to the safety of these ingredients, and determined that 27 vinylpyrrolidone polymers are safe in cosmetics in the present practices of use and concentration described in the safety assessment. The Panel also concluded that the available data are insufficient to make a determination that 3 vinylpyrrolidone polymers (all urethanes) are safe under the intended conditions of use in cosmetic formulations.


Asunto(s)
Seguridad de Productos para el Consumidor , Cosméticos , Polímeros , Pirrolidinonas , Cosméticos/toxicidad , Cosméticos/química , Humanos , Animales , Polímeros/toxicidad , Polímeros/química , Pirrolidinonas/toxicidad , Pirrolidinonas/química , Pirrolidinonas/farmacocinética , Pruebas de Toxicidad , Medición de Riesgo
12.
Sensors (Basel) ; 24(16)2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-39204984

RESUMEN

The effectiveness of copper oxide-modified electrochemical sensors using different polymers is being studied. The commercial powder was sonicated in an isopropyl alcohol solution and distilled water with 5 wt% polymers (chitosan, Nafion, PVP, HPC, α-terpineol). It was observed that the chitosan and Nafion caused degradation of CuO, but Nafion formed a stable mixture when diluted. The modified electrodes were drop-casted and analyzed using cyclic voltammetry in 0.1 M KCl + 3 mM [Fe(CN)6]3-/4- solution to determine the electrochemically active surface area (EASA). The results showed that α-terpineol formed agglomerates, while HPC created uneven distributions, resulting in poor stability. On the other hand, Nafion and PVP formed homogeneous layers, with PVP showing the highest EASA of 0.317 cm2. In phosphate-buffered saline (PBS), HPC and PVP demonstrated stable signals. Nafion remained the most stable in various electrolytes, making it suitable for sensing applications. Testing in 0.1 M NaOH revealed HPC instability, partial dissolution of PVP, and Cu ion reduction. The type of polymer used significantly impacts the performance of CuO sensors. Nafion and PVP show the most promise due to their stability and effective dispersion of CuO. Further optimization of polymer-CuO combinations is necessary for enhanced sensor functionality.

13.
Drug Dev Ind Pharm ; 50(3): 236-247, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38318700

RESUMEN

CONTEXT: Determining solubility of drugs is laborious and time-consuming process that may not yield meaningful results. Amorphous solid dispersion (ASD) is a widely used solubility enhancement technique. Predictive models could streamline this process and accelerate the development of oral drugs with improved aqueous solubilities. OBJECTIVE: This study aimed to develop a predictive model to estimate the solubility of a compound from the ASDs in polymer matrices. METHODS: ASDs of model drugs (acetazolamide, chlorothiazide, furosemide, hydrochlorothiazide, sulfamethoxazole) with model polymers (PVP, PVPVA, HPMC E5, Soluplus) and a surfactant (TPGS) were prepared using hotmelt process. The prepared ASDs were characterized using DSC, FTIR, and XRD. The aqueous solubility of the model drugs was determined using shake-flask method. Multiple linear regression was used to develop a predictive model to determine aqueous solubility using the molecular descriptors of the drug and polymer as predictor variables. The model was validated using Leave-One-Out Cross-Validation. RESULTS: The ASDs' drug components were identified as amorphous via DSC and XRD Studies. There were no significant chemical interactions between the model drugs and the polymers based on FTIR studies. The ASDs showed a significant (p < 0.05) improvement in solubility, ranging from a 3-fold to 118-fold, compared with the pure drug. The developed empirical model predicted the solubility of the model drugs from the ASDs containing model polymer matrices with an accuracy greater than 80%. CONCLUSION: The developed empirical model demonstrated robustness and predicted the aqueous solubility of model drugs from the ASDs of model polymer matrices with an accuracy greater than 80%.


Asunto(s)
Polímeros , Agua , Solubilidad , Cristalización , Polímeros/química , Agua/química , Tensoactivos
14.
Molecules ; 29(7)2024 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-38611837

RESUMEN

Silver (Ag) nanowires, as an important one-dimensional (1D) nanomaterial, have garnered wide attention, owing to their applications in electronics, optoelectronics, sensors, and other fields. In this study, an alternative hydrothermal route was developed to synthesize Ag nanowires via modified reduction of Ag+. Silver sulfamate plays an important role in the formation of Ag nanowires via controlled release of free Ag+. Results of controlled experiments and characterizations such as UV-vis spectroscopy, FTIR, XPS, and 1H NMR revealed that sulfamic acid does not function as a reductant, supporting by the generation of free Ag+ instead of Ag nanostructures in hydrothermally treated silver sulfamate solution. The initial reduction of Ag+ was induced by the combination of poly (vinylpyrrolidone) (PVP) end group and degradation products. This phenomenon was supported by abundant free Ag+ in the mixed preheated silver sulfamatic and preheated PVP aqueous solutions, indicating a second and distinct Ag+ autocatalytic reduction. Thus, the roles of different reagents and Ag+ reduction must be studied for nanomaterial syntheses.

15.
Molecules ; 29(3)2024 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-38338458

RESUMEN

Porous materials are widely used as an effective strategy for the solubilization of insoluble drugs. In order to improve the solubility and bioavailability of low water-solubility drugs, it is necessary to prepare porous materials. Mannitol is one of the most popular excipients in food and drug formulations. In this study, porous mannitol was investigated as a drug carrier for low water solubility drugs. Its fabrication, drug loading, and drug release mechanisms were investigated. Porous mannitol was fabricated using the co-spray-antisolvent process and utilizing polyvinylpyrrolidone K30 (PVP K30) as the template agent. Porous mannitol particles were prepared by changing the proportion of the template agent, spraying the particles with mannitol, and eluting with ethanol in order to regulate their pore structure. In subsequent studies, porous mannitol morphology and characteristics were determined systematically. Furthermore, curcumin and ibuprofen, two poorly water-soluble drugs, were loaded into porous mannitol, and their release profiles were analyzed. The results of the study indicated that porous mannitol can be prepared using PVP K30 as a template and that the amount of template agent can be adjusted in order to control the structure of the porous mannitol. When the template agent was added in amounts of 1%, 3%, and 5%, the mannitol pore size increased by 167.80%, 95.16%, and 163.98%, respectively, compared to raw mannitol. Molecular docking revealed that mannitol and drugs are adsorbents and adhere to each other by force interaction. The cumulative dissolution of curcumin and ibuprofen-loaded porous mannitol reached 69% and 70%, respectively. The release mechanism of curcumin and ibuprofen from drug-loaded mannitol was suitable for the Korsmeyer-Peppas kinetic model. In summary, the co-spray-antisolvent method proved effective in fabricating porous materials rapidly, and porous mannitol had a remarkable effect on drug solubilization. The results obtained are conducive to the development of porous materials.


Asunto(s)
Curcumina , Ibuprofeno , Porosidad , Curcumina/química , Manitol/química , Simulación del Acoplamiento Molecular , Solubilidad , Povidona/química , Agua/química , Portadores de Fármacos
16.
AAPS PharmSciTech ; 25(5): 134, 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38862663

RESUMEN

Inclusion complexes require higher concentration of Beta cyclodextrins (ßCD) resulting in increased formulation bulk, toxicity, and production costs. This systematic review offers a comprehensive analysis using Quality by design (QbD) as a tool to predict potential applications of Polyvinylpyrrolidone (PVP) as a ternary substance to address issues of inclusion complexes. We reviewed 623 documents from 2013 to 2023 and Eighteen (18) research papers were selected for statistical and meta-analysis using the QbD concept to identify the most critical factors for selecting drugs and effect of PVP on inclusion complexes. The QbD analysis revealed that Molecular weight (MW), Partition coefficient (Log P), and the auxiliary substance ratio directly affected complexation efficiency (CE), thermodynamic stability in terms of Gibbs free energy (ΔG), and percent drug release. However, Stability constant (Ks) remained unaffected by any of these parameters. The results showed that low MW (250), median Log P (6), and a ßCD: PVP ratio of 2:3 would result in higher CE, lower G, and improved drug release. PVP improves drug solubility, enhances delivery and therapeutic outcomes, and counteracts increased drug ionization due to decreased pH. In certain cases, its bulky nature and hydrogen bonding with CD molecules can form non-inclusion complexes. The findings of the study shows that there is potential molecular interaction between PVP and ß-cyclodextrins, which possibly enhances the stability of inclusion complexes for drug with low MW and log P values less than 9. The systematic review shows a comprehensive methodology based on QbD offers a replicable template for future investigations into drug formulation research.


Asunto(s)
Ciclodextrinas , Povidona , Solubilidad , beta-Ciclodextrinas , beta-Ciclodextrinas/química , Química Farmacéutica/métodos , Ciclodextrinas/química , Liberación de Fármacos , Excipientes/química , Peso Molecular , Proyectos Piloto , Povidona/química , Termodinámica
17.
BMC Plant Biol ; 23(1): 385, 2023 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-37563739

RESUMEN

BACKGROUND: Fagopyrum tataricum (Tartary buckwheat) is a valuable crop of great nutritional importance due to its high level of bioactive compounds. Excellent opportunities to obtain plants with the high level or the desired profile of valuable metabolites may be provided by in vitro cultures. Among known in vitro techniques, protoplast technology is an exciting tool for genetic manipulation to improve crop traits. In that context, protoplast fusion may be applied to generate hybrid cells between different species of Fagopyrum. To apply protoplast cultures to the aforementioned approaches in this research, we established the protoplast-to-plant system in Tartary buckwheat. RESULTS: In this work, cellulase and pectinase activity enabled protoplast isolation from non-morphogenic and morphogenic callus (MC), reaching, on average, 2.3 × 106 protoplasts per g of fresh weight. However, to release protoplasts from hypocotyls, the key step was the application of driselase in the enzyme mixture. We showed that colony formation could be induced after protoplast embedding in agarose compared to the alginate matrix. Protoplasts cultured in a medium based on Kao and Michayluk supplemented with phytosulfokine (PSK) rebuilt cell walls, underwent repeated mitotic division, formed aggregates, which consequently led to callus formation. Plating efficiency, expressing the number of cell aggregate formed, in 10-day-old protoplast cultures varied from 14% for morphogenic callus to 30% for hypocotyls used as a protoplast source. However plant regeneration via somatic embryogenesis and organogenesis occurred only during the cultivation of MC-derived protoplasts. CONCLUSIONS: This study demonstrated that the applied protoplast isolation approach facilitated the recovery of viable protoplasts. Moreover, the embedding of protoplasts in an agarose matrix and supplementation of a culture medium with PSK effectively stimulated cell division and further development of Tartary buckwheat protoplast cultures along with the plant regeneration. Together, these results provide the first evidence of developing a protoplast-to-plant system from the MC of Fagopyrum tataricum used as source material. These findings suggest that Tartary buckwheat's protoplast cultures have potential implications for the species' somatic hybridization and genetic improvement.


Asunto(s)
Fagopyrum , Fagopyrum/genética , Protoplastos , Sefarosa/farmacología , Péptidos , Péptidos y Proteínas de Señalización Intercelular
18.
Small ; 19(25): e2207848, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36929269

RESUMEN

Polyvinyl pyrrolidone (PVP) is doped to PbI2 and organic salt during two-step growth of halideperovskite. It is observed that PVP molecules can interact with both PbI2 and organic salt, reduce the aggregation and crystallization of the two, and then slow down the coarsening rate of perovskite. As doping concentration increases from 0 to 1 mM in organic salt, average crystallite size of perovskite decreases monotonously from 90 to 34 nm; Surface fluctuation reduces from 259.9 to 179.8 nm at first, and then increases; Similarly, surface roughness decreases from 45.55 to 26.64 nm at first, and then rises. Accordingly, a kind of "confinement effect" is resolved to crystallite growth and surface fluctuation/roughness, which helps to build compact and uniform perovskite film. Density of trap states (t-DOS) is cut down by ≈60% at moderate doping  (0.2 mM). Due to the "confinement effect", power conversion efficiency of perovskite solar cells is improved from 19.46 (±2.80) % to 21.50 (±0.99) %, and further improved to 24.11% after surface modification. Meanwhile, "confinement effect" strengthens crystallite/grain boundaries and improves thermal stability of both film and device. T80 of device increases to 120 h, compared to 50 h for reference ones.

19.
Small ; 19(10): e2205607, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36585387

RESUMEN

Aggredation-induced electrochemiluminescence (AIECL) promises an efficient strategy for synthesize highly luminescent emitter and co-reactant for ECL analysis, however, rational control of electrogenerated emission intensity is still challenging. The low electroconductivity and amorphous molecular configuration are intrinsic bottleneck. This work reveals the impact of polyvinyl pyrrolidone backbone regulated silver nanocrystallines (AgNCs/PVP) on the cathode AIECL properties in near infrared region, by employing the Box-Behnken designed response surface computation model to modulate crystal aggregates. Electron paramagnetic resonance spectroscopy discovered hydrogen radical (HO• ) dominant reductive-oxidative (R-O) ECL mechanism with AgNCs acting as the co-reaction accelerator in graphene oxide/persulfate system (GO/S2 O8 2- ). Both theoretical calculation and experimental measurement testified that the ECL of AgNCs in GO/S2 O8 2- dependent on the concentration of in situ electrochemical oxidized Ag+ . The high efficiency of crystallization-induced enhanced ECL (CIECL) originates from 1) the effective electron transfer of Ag+ accelerated HO• produce to notable promote radioactive transition, and 2) twisted intramolecular charge transfer from the electron-rich donor of PVP to electron-deficient receptor of Ag0 to restrict nonradioactive transition. The AgNCs/PVP with CIECL effect are applied to construct an ultrasensitive platform for miR-221 assay with a lower detection limit of 7.47 × 103  copies mL-1 than typical qPCR method.


Asunto(s)
Técnicas Biosensibles , Nanopartículas del Metal , Mediciones Luminiscentes/métodos , Cristalización , Técnicas Electroquímicas/métodos , Técnicas Biosensibles/métodos , Límite de Detección , Electrodos , Nanopartículas del Metal/química
20.
Toxicol Appl Pharmacol ; 467: 116497, 2023 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-37003365

RESUMEN

Novel psychoactive substances (NPS) consumption has increased in recent years, thus NPS-induced cognitive decline is a current source of concern. Alpha-pyrrolidinovalerophenone (α-PVP), as a member of NPS, is consumed throughout regions like Washington, D.C., Eastern Europe, and Central Asia. Mitochondrial dysfunction plays an essential role in NPS-induced cognitive impairment. Meanwhile, no investigations have been conducted regarding the α-PVP impact on spatial learning/memory and associated mechanisms. Consequently, our study investigated the α-PVP effect on spatial learning/memory and brain mitochondrial function. Wistar rats received different α-PVP doses (5, 10, and 20 mg/kg) intraperitoneally for 10 sequential days; 24 h after the last dose, spatial learning/memory was evaluated by the Morris Water Maze (MWM). Furthermore, brain mitochondrial protein yield and mitochondrial function variables (Mitochondrial swelling, succinate dehydrogenase (SDH) activity, lipid peroxidation, Mitochondrial Membrane Potential (MMP), Reactive oxygen species (ROS) level, brain ADP/ATP proportion, cytochrome c release, Mitochondrial Outer Membrane (MOM) damage) were examined. α-PVP higher dose (20 mg/kg) significantly impaired spatial learning/memory, mitochondrial protein yield, and brain mitochondrial function (caused reduced SDH activity, increased mitochondrial swelling, elevated ROS generation, increased lipid peroxidation, collapsed MMP, increased cytochrome c release, elevated brain ADP/ATP proportion, and MOM damage). Moreover, the lower dose of α-PVP (5 mg/kg) did not alter spatial learning/memory and brain mitochondrial function. These findings provide the first evidence regarding impaired spatial learning/memory following repeated administration of α-PVP and the possible role of brain mitochondrial dysfunction in these cognitive impairments.


Asunto(s)
Encefalopatías , Aprendizaje Espacial , Ratas , Animales , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Citocromos c/metabolismo , Aprendizaje por Laberinto , Mitocondrias , Encéfalo , Adenosina Trifosfato/metabolismo , Hipocampo , Estrés Oxidativo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA