SERS determination of the antihypertensive drugs prazosin and losartan by using silver nanoparticles coated with β-cyclodextrin

Enlarged pore of worm mesoporous silica nanoparticles improves anti-inflammatory drug absorption

Searching for an effective pore-enlarging agent to form mesoporous silica nanoparticles (MSN) with a creative surface frame is of great importance. Herein, several polymers were attempted to be pore-enlarging agents to form seven types of worm mesoporous silica nanoparticles (W-MSN) and analgesic indometacin that exerted functions on inflammatory diseases (breast disease, arthrophlogosis, etc.) was studied to enhance its delivery efficiency. The porous morphology differences between MSN and W-MSN were that MSN had independent mesopores while the enlarged mesopores of W-MSN were interrelated and shaped as a worm. Among all these W-MSN, WG-MSN templated by hydroxypropyl cellulose acetate succinate HG with the highest drug-loading capacity (24.78%), shortest loading time (10 h), drug dissolution improvement of almost 4 times compared to that of the raw drug, and highest bioavailability (5.48 times higher than that of raw drug and 1.52 times higher than that of MSN) was an outstanding drug carrier and can shoulder the mission to deliver drugs with high efficiency.

Self-Assembled Plasmonic Nanojunctions Mediated by Host-Guest Interaction for Ultrasensitive Dual-Mode Detection of Cholesterol

Herein, a fluorescence and surface-enhanced Raman spectroscopy dual-mode system was designed for cholesterol detection based on self-assembled plasmonic nanojunctions mediated by the competition of rhodamine 6G (R6G) and cholesterol with β-cyclodextrin modified on gold nanoparticles (HS-β-CD@Au). The fluorescence of R6G was quenched by HS-β-CD@Au due to the fluorescence resonance energy transfer effect. When cholesterol was introduced as the competitive guest, R6G in the cavities of HS-β-CD@Au was displaced to recover its fluorescence. Moreover, two of HS-β-CD@Au can be linked by one cholesterol to form a more stable 2:1 complex, and then, plasmonic nanojunctions were generated, which resulted in the increasing SERS signal of R6G. In addition, fluorescence and SERS intensity of R6G increased linearly with the increase in the cholesterol concentrations with the limits of detection of 95 and 74 nM, respectively. Furthermore, the dual-mode strategy can realize the reliable and sensitive detection of cholesterol in the serum with good accuracy, and two sets of data can mutually validate each other, which demonstrated great application prospects in the surveillance of diseases related with cholesterol.

Current Status of Quantum Chemical Studies of Cyclodextrin Host-Guest Complexes

This article aims to review the application of various quantum chemical methods (semi-empirical, density functional theory (DFT), second order Møller-Plesset perturbation theory (MP2)) in the studies of cyclodextrin host-guest complexes. The details of applied approaches such as functionals, basis sets, dispersion corrections or solvent treatment methods are analyzed, pointing to the best possible options for such theoretical studies. Apart from reviewing the ways that the computations are usually performed, the reasons for such studies are presented and discussed. The successful applications of theoretical calculations are not limited to the determination of stable conformations but also include the prediction of thermodynamic properties as well as UV-Vis, IR, and NMR spectra. It has been shown that quantum chemical calculations, when applied to the studies of CD complexes, can provide results unobtainable by any other methods, both experimental and computational.

Quantitative analysis of solid dosage forms of Losartan potassium by Raman spectroscopy

Raman spectroscopy is an outstanding analytical tool increasingly utilized in the pharmaceutical field for the solid-state pharmaceutical drug analysis. In current study, the potential of Raman spectroscopy has been investigated for qualitative and quantitative analysis of solid dosage form of Losartan potassium. For this purpose, different solid dosage forms/concentrations of losartan potassium were prepared to compensate the commercially available pharmaceutical drug formulations and their Raman spectral data showed a gradual change in the specific Raman spectral features associated with the active pharmaceutical ingredient (API) of Losartan potassium as a function of change in the concentration. The Raman spectral data was analyzed by using Principal Component Analysis (PCA) for the classification of different spectral data sets of different concentrations of drug. Moreover, partial least square regression (PLSR) analysis was performed for monitoring the quantitative relation among different concentrations of Losartan potassium API and spectral data by constructing a predictive model. From the model, the value of root mean square error of calibration (RMSEC) and root mean square error of prediction (RMSEP) were observed to be 0.38 and 2.98 respectively and the value of goodness of fit was found to be 0.99. Furthermore, the quantity of unknown/blind sample of Losartan potassium formulation was also estimated by using PLSR model. From these results, it is demonstrated that Raman spectroscopy can be considered to be used for quick and reliable quantitative analysis of pharmaceutical solids.

Flexible membrane composite based on sepiolite/chitosan/(silver nanoparticles) for enrichment and surface-enhanced Raman scattering determination of sulfamethoxazole in animal-derived food

A sepiolite/chitosan/silver nanoparticles (Sep/CTs/AgNPs) membrane substrate has been developed for the fast separation, enrichment, and surface-enhanced Raman scattering (SERS) determination of sulfamethoxazole all-in-one. The Sep/CTs/AgNPs membrane substrate possessed the ability of rapid separation and enrichment to simplify the process for pretreatment and improve the efficiency of analysis. The grown AgNPs can provide abundant hot spots and plasmonic areas to amplify the Raman signals of target molecules effectively. The membrane substrate exhibited good stability with relative standard deviations of 5.8% and 7.1% to same batch and different batches membrane substrate, respectively,  by detecting sulfamethoxazole. The SERS method based on Sep/CTs/AgNPs membrane substrate was used for the determination of sulfamethoxazole with a linear range of 0.05-2.0 mg/L, and the limit of detection was 0.020 mg/L. The established SERS method was finally applied to the quantification of sulfamethoxazole in animal-derived food samples. Sulfamethoxazole was actually found in crucian sample with 12.4 μg/kg, and the result was confirmed by a high-performance liquid chromatography method with relative error of 5.3%. The whole process of analysis can be finished within 25 min with recoveries of 89.3-102.2%. The SERS method based on Sep/CTs/AgNPs membrane substrate provided an integrated strategy for rapid and accurate SERS analysis in food safety issues.

Role of Organic and Inorganic Nanoparticles in the Drug Delivery System for Hypertension Treatment: A Systematic Review

BACKGROUND

The present investigation was designed to systematically review the antihypertensive effects of all the organic and inorganic nanoparticles in the in vitro, in vivo, and clinical trials.

METHODS

The current study was carried out using 06-PRISMA guideline and registered in the CAMARADES- NC3Rs Preclinical Systematic Review and Meta-analysis Facility (SyRF) database. The search was performed on five English databases, including Scopus, PubMed, Web of Science, EMBASE, and Google Scholar, without time limitation for publications worldwide related to the anti-hypertensive effects of all the organic and inorganic nanoparticles without date limitation, so as to identify all the published articles (in vitro, in vivo, clinical, and case-control). Studies in any language were entered in the search step if they had an English abstract.

RESULTS

Out of 3602 papers, 60 including 25 werein vitro (41.7%), 17 in vitro / in vivo (28.3%), 16 in vivo (26.7%), and 2 in vitro / ex vivo (3.3%) up to 2020 met the inclusion criteria for discussion in this systematic review. The most widely used nanoparticles were organic nanoparticles such as polylactic acid, poly lactic-co-glycolic acid (PLGA), lipid, chitosan, etc., followed by inorganic nanoparticles such as silver and palladium nanoparticles.

CONCLUSION

This review demonstrated the anti-hypertensive effects of some organic and inorganic nanoparticles alone or in combination with the available anti-hypertensives. We found that organic nanoparticles such as PGLA and chitosan can be considered as preferred options in nanomedicine for treating high blood pressure. The results also showed these nanoparticles displayed antihypertensive effects through some mechanisms such as sustained release forms via increasing bioavailability, increasing oral bioavailability and improving oral and non-oral absorption, counteracting excessive superoxide, decreasing blood pressure, etc. However, further investigations are required to prove these effects, particularly in clinical settings, as well as their accurate possible mechanisms and toxicity.

Bimetallic AgNPs@dopamine modified-halloysite nanotubes-AuNPs for adenine determination using surface-enhanced Raman scattering

A bimetallic nanoparticles modified halloysite nanotubes (HNTs) hybrid was prepared by embedding AgNPs and modifying AuNPs on the inner or outer wall of dopamine-modified HNTs (DHNTs) in sequence. The resulting bimetallic AgNPs@DHNTs-AuNPs hybrid as surface-enhanced Raman scattering (SERS) substrate exhibited improved enhancement ability over monometallic AgNPs@DHNTs, and DHNTs-AuNPs substrates, with intensity ratios of about 48:1:9 (crystal violet) and 11:1:2 (p-phenylenediamine). The giant SERS effect of AgNPs@DHNTs-AuNPs substrate is probably attributed to the synergetic enhancement of the electromagnetic field (Au/Ag), optical plasmon force, molecular enrichment (HNTs), and charge transfer (NPs-dopamine-molecules). The sensitive and reproductive AgNPs@DHNTs-AuNPs substrate was applied for SERS determination of adenine with a linear range of 0.010-0.50 mg·L-1 and a detection limit of 2.2 μg·L-1. The SERS method enables the rapid determination of adenine in fish, chicken kidney and heart, and serum samples, with recoveries of 83.5-121.6% and relative standard deviations of 2.5-7.9%. The SERS substrate has high value for rapid analysis of food and biomarker determinations. Schematic illustration of the preparation of AgNPs@HNTs-AuNPs for SERS analysis of adenine in complex sample.

Flower-like Ag coated with molecularly imprinted polymers as a surface-enhanced Raman scattering substrate for the sensitive and selective detection of glibenclamide

Flower-like Ag was formed by nanosheet self-assembly as a SERS-active substrate and was utilized for the preparation of flower-like Ag@molecularly imprinted polymers (MIPs) as a surface-enhanced Raman scattering (SERS) sensor. Based on the combination of the molecular imprinting technique and SERS technology, the flower-like Ag@MIPs with high sensitivity and excellent selectivity were used as SERS substrates for the detection of glibenclamide. The imprinted layer could effectively protect the flower-like Ag from oxidation and thereby may improve the stability of the SERS substrate. The intensities of the characteristic peaks obtained for the flower-like Ag@MIPs were higher than that of flower-like Ag. By applying the flower-like Ag@MIPs as an efficient and ultra-sensitive SERS platform, glibenclamide was quantitatively detected in trace concentrations as low as 1 ng mL-1. Furthermore, the SERS enhancement for the flower-like Ag@MIPs was due to the synergetic effect between electromagnetic enhancement and chemical enhancement. We believe that this reliable method can open up new opportunities for practical chemosensor or biosensor applications.

Optical sensors based on silver nanoparticles for determination of pharmaceuticals: An overview of advances in the last decade

This review focuses on optical nanosensors based on silver nanoparticles (Ag NPs) and demonstrates their applications in the determination of pharmaceutical compounds in the last decade. Such optical sensors have received high attention in the analytical field owing to their low cost and simplicity since they do not require any complex or expensive instrumentation. This article reviews Ag NP-based optical methods for the determination of pharmaceutical compounds from 2010 to 2020. The reported optical methods are classified into four types: spectrophotometry, spectrofluorimetry, scattering and chemiluminescence. Ag NPs play different roles in the different sensing platforms used by these methods, the details of which are carefully explained in this review. Moreover, the relevant analytical parameters of the developed methods are categorized by role and tabulated. It is hoped that this review will stimulate further research in this field with similar nanostructures.