scholarly journals Hyperthermia-Triggered Doxorubicin Release from Polymer-Coated Magnetic Nanorods

Pharmaceutics ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 517 ◽  
Author(s):  
Felisa Reyes-Ortega ◽  
Blanca Luna Checa Fernández ◽  
Angel V. Delgado ◽  
Guillermo R. Iglesias
Keyword(s):  
Shape Control ◽  
Drug Loading ◽  
Physical Property ◽  
Magnetic Hyperthermia ◽  
Layer By Layer ◽  
Heating Rates ◽  
Simultaneous Application ◽  
Magnetic Nanorods ◽  
Doxorubicin Release ◽  
Co Precipitation

In this paper, it is proposed that polymer-coated magnetic nanorods (MNRs) can be used with the advantage of a double objective: first, to serve as magnetic hyperthermia agents, and second, to be used as magnetic vehicles for the antitumor drug doxorubicin (DOX). Two different synthetic methodologies (hydrothermal and co-precipitation) were used to obtain MNRs of maghemite and magnetite. They were coated with poly(ethyleneimine) and poly(sodium 4-styrenesulfonate), and loaded with DOX, using the Layer-by-Layer technique. Evidence of the polymer coating and the drug loading was justified by ATR-FTIR and electrophoretic mobility measurements, and the composition of the coated nanorods was obtained by a thermogravimetric analysis. The nanorods were tested as magnetic hyperthermia agents, and it was found that they provided sufficiently large heating rates to be used as adjuvant therapy against solid tumors. DOX loading and release were determined by UV-visible spectroscopy, and it was found that up to 50% of the loaded drug was released in about 5 h, although the rate of release could be regulated by simultaneous application of hyperthermia, which acts as a sort of external release-trigger. Shape control offers another physical property of the particles as candidates to interact with tumor cells, and particles that are not too elongated can easily find their way through the cell membrane.

Field Assisted Sintering Technology (FAST) Model for Prediction of Final Properties

2010 ◽  
Author(s):  
Rajiv Paul ◽  
Anil K. Kulkarni ◽  
Jogender Singh
Keyword(s):  
Electrical Breakdown ◽  
Extensive Literature ◽  
Heating Rates ◽  
Predictive Tool ◽  
Simultaneous Application ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Data Points ◽  
Field Assisted Sintering ◽  
The Relationship

Sintering is the process of making materials from powder form by heating the powder below its melting point until the particles fuse to each other. Field assisted sintering technology (FAST), also sometimes known as spark plasma sintering (SPS), uses a pulsed and/or continuous electric current along with the simultaneous application of compressive pressure which leads to extremely high heating rates and short processing durations. A high relative density and small grain size promote superior properties such as greater hardness and electrical breakdown. Hence, selection of the proper sintering parameters is of paramount importance and a predictive model would be extremely useful in narrowing the range of experimental parameters. This will drastically reduce the number of extra attempts at obtaining certain properties in a material and save experimentation time, effort and material to name a few. Four of the most important FAST parameters: target temperature, holding time, heating rate and initial particle size, have been reviewed to assess their effect on the densification, hardening and grain growth of Alumina, Copper, Silicon Carbide, Tungsten and Tungsten Carbide through extensive literature survey. The relationship between each has been incorporated in a Microsoft Excel program which acts as a predictive tool to determine an estimate of the final properties based on the initial parameters chosen. This is done by curve fitting a polynomial onto the existing data points as closely as possible and using the polynomial to obtain final properties as a function of the initial parameters. The model was verified against an existing paper which sought to obtain the optimum sintering parameters for Copper. While the actual experimentation range was 400°C to 800°C, the program would have suggested a much narrower range from 650°C to 800°C and hence saved unnecessary additional efforts.

scholarly journals Спектральный мониторинг процесса иммобилизации препарата нафтифин в субмикронные частицы ватерита-=SUP=-*-=/SUP=-

2019 ◽  
Vol 126 (5) ◽  
pp. 620
Author(s):  
О.И. Гуслякова ◽  
Е.В. Ленгерт ◽  
В.С. Аткин ◽  
В.В. Тучин ◽  
Ю.И. Свенская
Keyword(s):  
Drug Loading ◽  
Optical Methods ◽  
Submicron Particles ◽  
Laser Raman Spectroscopy ◽  
Future Application ◽  
Recrystallization Process ◽  
Laser Raman ◽  
Drug Molecules ◽  
Co Precipitation ◽  
Particulate Delivery

Development of novel drug delivery systems providing the enhanced accumulation of the therapeutic agents in the area of pathology reducing in the meantime the systemic toxic effects is of great research interest. Here we introduce the study on the antifungal drug “Naftifine” immobilization into the particulate delivery system based on vaterite submicron particles. Two different techniques are proposed for the antimycotic incorporation: adsorption onto the surface of freshly-prepared vaterite particles from the drug solution and co-precipitation of the drug molecules during the particle synthesis. Various optical methods were used to investigate the immobilization process. Thus, laser Raman spectroscopy was used to confirm the successful carrier loading with naftifin hydrochloride. A spectrofluorimetric method was applied for the quantitative determination of the drug loading efficiency into vaterite matrix . The study revealed that the co-precipitation technique allows the immobilization of the highest antimycotic percentage (9% wt). Scanning electron microscopy was used to monitor the stability of the naftifin-loaded carriers under their incubation in deionized water, saline and cell culture medium. The slowdown of vaterite recrystallization process was observed for the protein-containing medium. Such effect holds out the prospect of drug release prolongation for the future application of the proposed carries in living systems.

scholarly journals The Effect of Polyvinyl Alcohol Concentration on the Growth Kinetics of KTiOPO4 Nanoparticles Synthesized by the Co-precipitation Method

2020 ◽  
Vol 1 (4) ◽  
pp. 187-193
Author(s):  
Elaheh Gharibshahian
Keyword(s):  
Polyvinyl Alcohol ◽  
Shape Control ◽  
Second Harmonic ◽  
Precipitation Method ◽  
Capping Agent ◽  
X Ray Diffraction ◽  
X Ray ◽  
Size And Shape ◽  
Diffraction Patterns ◽  
Co Precipitation

KTiOPO4 nanoparticles are known as the best candidate to utilize for second-harmonic generation in multiphoton microscopes and bio labels. Size and shape are important and effective parameters to control the properties of nanoparticles. In this paper, we will investigate the role of capping agent concentration on the size and shape control of KTP nanoparticles. We synthesized KTP nanoparticles by the co-precipitation method. Polyvinyl alcohol with different mole ratios to titanium ion (1:3, 1:2, 1:1) was used as a capping agent. Products were examined by X-ray diffraction patterns and scanning electron microscopy analyses. X-ray diffraction patterns confirmed the formation of the KTP structure. The biggest (56.36nm) and smallest (39.42nm) grain size were obtained by 1:3 and 1:1 mole ratios of capping agent, respectively. Dumbly, spherical and polyhedral forms of KTP nanoparticles were observed by the change in capping agent mole ratio. The narrowest size distribution of KTiOPO4 nanoparticles was obtained at 1:1 mole ratio of capping agent. Doi: 10.28991/HIJ-2020-01-04-06 Full Text: PDF

Effect of Modified Hydroxypropyl Tapioca Starch and Percentage of Drug Loading on Physical Property of Paracetamol Tablet

2020 ◽  
Vol 859 ◽  
pp. 3-8
Author(s):  
Vipaluk Patomchaiviwat ◽  
Sontaya Limmatvapirat ◽  
Chaisai Sirisapaya ◽  
Rohanee Kolae ◽  
Kulmanee Anantakul ◽  
...  
Keyword(s):  
Drug Loading ◽  
Physical Property ◽  
High Hardness ◽  
Direct Compression ◽  
Compression Method ◽  
Disintegration Time ◽  
Tapioca Starch ◽  
Drug Concentrations ◽  
Model Drug ◽  
Better Than

The objective of this study was to investigate the effect of modified hydroxypropyl tapioca starch (HPTS) and % drug loading on physical property of tablet. Paracetamol was used as model drug because of its poor compressibility. The filler ability of modified HPTS such as hydroxyl propyl oxidized tapioca starch (HPOTS), hydroxyl propyl crosslinked tapioca starch (HPCTS) and pregelatinized tapioca starch (PTS) were evaluated and compared with the commercial starch (Starch 1500®). Tablets were prepared by direct compression method and the percent drug loading were 15, 30, 45, 60, 75%. For modified HPTS, the hardness of the tablets tended to decrease when the concentration of paracetamol increased. At drug concentrations of 15-30%, HPOTS exhibited good performance of tablet as indicated by the high hardness, low friability and acceptable disintegration time. The obtained results were better than HPTS and comparable to Starch 1500®. Moreover, the results revealed that tablet containing PTS provided the highest hardness and prolonged disintegration time (>30 min) while tablet containing HPCTS showed rapid disintegration time (<2 min). Therefore, modified HPTS disclosed promising properties for application as tablet filler

scholarly journals Nanoformulation Design Including MamC-Mediated Biomimetic Nanoparticles Allows the Simultaneous Application of Targeted Drug Delivery and Magnetic Hyperthermia

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1832 ◽  
Author(s):  
Ylenia Jabalera ◽  
Francesca Oltolina ◽  
Ana Peigneux ◽  
Alberto Sola-Leyva ◽  
Maria P. Carrasco-Jiménez ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Drug Delivery ◽  
Magnetic Nanoparticles ◽  
Targeted Drug Delivery ◽  
Magnetic Hyperthermia ◽  
Simultaneous Application ◽  
Biomimetic Nanoparticles ◽  
Targeted Drug ◽  
Model Drug ◽  
Drug Nanocarriers

The design of novel nanomaterials that can be used as multifunctional platforms allowing the combination of therapies is gaining increased interest. Moreover, if this nanomaterial is intended for a targeted drug delivery, the use of several guidance methods to increase guidance efficiency is also crucial. Magnetic nanoparticles (MNPs) allow this combination of therapies and guidance strategies. In fact, MNPs can be used simultaneously as drug nanocarriers and magnetic hyperthermia agents and, moreover, they can be guided toward the target by an external magnetic field and by their functionalization with a specific probe. However, it is difficult to find a system based on MNPs that exhibits optimal conditions as a drug nanocarrier and as a magnetic hyperthermia agent. In this work, a novel nanoformulation is proposed to be used as a multifunctional platform that also allows dual complementary guidance. This nanoformulation is based on mixtures of inorganic magnetic nanoparticles (M) that have been shown to be optimal hyperthermia agents, and biomimetic magnetic nanoparticles (BM), that have been shown to be highly efficient drug nanocarriers. The presence of the magnetosome protein MamC at the surface of BM confers novel surface properties that allow for the efficient and stable functionalization of these nanoparticles without the need of further coating, with the release of the relevant molecule being pH-dependent, improved by magnetic hyperthermia. The BM are functionalized with Doxorubicin (DOXO) as a model drug and with an antibody that allows for dual guidance based on a magnetic field and on an antibody. The present study represents a proof of concept to optimize the nanoformulation composition in order to provide the best performance in terms of the magnetic hyperthermia agent and drug nanocarrier.

Preparation, Characterization and Properties Evaluation of Buprofezin Nanocomposites Obtained by Polyelectrolytes Assembly

2011 ◽  
Vol 183-185 ◽  
pp. 1677-1681 ◽  
Author(s):  
Zhe Zhang ◽  
De Fu Chi ◽  
Jia Yu
Keyword(s):  
Laser Scanning ◽  
Orthogonal Experiment ◽  
Drug Loading ◽  
In Vitro Release ◽  
Average Diameter ◽  
Laser Scanning Microscopy ◽  
Release Time ◽  
Confocal Laser ◽  
Layer By Layer

Buprofezin (BPF) microcrystals were directly encapsulated with nature polysaccharides chitosan (CHI) and sodium alginate (ALG) through layer-by-layer (LbL) self-assembly. The coated colloids were characterized using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The surface of the coated microcrystal was smoothened and the coating was uniform. Different concentrations of the ALG, CHI, BPF and CaCl2 were selected as the influencing factors, and then, the microcapsules were optimized by orthogonal experiment. The size distribution of microcapsules was determined by Laser Diffraction Size Analyzer. It showed statistically normal distribution. The average diameter of BPF was 1.5m. The encapsulation efficiency of the BPF loaded microparticles was about 67.2±0.73%. The drug loading content was about 66.7±0.31% after encapsulated. The in vitro release experiments revealed that the polyelectrolytes prolonged the release time of the encapsulated BPF microcrystals.

Synthesis, Characterization and In Vitro Drug Release of Melphalan Magnetic Microspheres

2013 ◽  
Vol 22 ◽  
pp. 31-40
Author(s):  
Jin Qiao Xu ◽  
Hai Xing Xu ◽  
Zubad Newaz ◽  
Ran Li ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Drug Release ◽  
Drug Loading ◽  
Phosphate Buffer Solution ◽  
Magnetic Microspheres ◽  
Targeted Chemotherapy ◽  
Buffer Solution ◽  
Magnetization Measurements ◽  
Co Precipitation

A new method of reversible association of melphalan (MEL) to magnetic Fe3O4 nanoparticles preparing MEL magnetic microspheres was developed for magnetically targeted chemotherapy. The efficacy of this approach was evaluated in terms of encapsulation efficiency (EE), drug loading content (DLC), delivery properties and cytotoxicity in vitro. Magnetic Fe3O4 nanoparticles were synthesized by co-precipitation methods and characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and magnetization measurements. The MEL magnetic microspheres were obtained through emulsion cross-linking method and characterized by FTIR, magnetization measurements and scan electron microscopy (SEM). The EE and DLC were determined using a Spectro Vision DB-18805 spectrophotometer. The MEL magnetic microspheres showed good EE values, between 60.6% and 75.6%, as well as good DLC values, between 16.7% and 32.2%, and the magnetic properties were not significantly affected by incorporation of the drug. The in vitro drug release study was carried out in phosphate buffer solution (PBS), simulating physiologic body fluid conditions at 37o C with pH = 7.4. The release profiles showed an initial fast release rate, which decreased as time progressed; about 60% of the drug was released in the first 4 h, and about 78.23 % had been released after 24 h. The results indicated that the prepared magnetic microspheres may be useful for potential applications of MEL for magnetically targeted chemotherapy.

scholarly journals Development of a Layer-by-Layer Assembled Film on Hydrogel for Ocular Drug Delivery

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Pin Chen ◽  
Xin Wang ◽  
Yan Dong ◽  
Xiaohong Hu
Keyword(s):  
Drug Delivery ◽  
Self Assembly ◽  
Ph Value ◽  
Drug Loading ◽  
Drug Carriers ◽  
Ocular Drug Delivery ◽  
Layer By Layer ◽  
Uv Spectrum ◽  
Modification Technique ◽  
Assembly Procedure

Hydrogel is a kind of attractive drug carriers because of its good biocompatibility and transparency. But traditional hydrogel showed some restrictions in its application in ocular drug delivery. A simple surface modification technique based on layer-by-layer (LbL) self-assembled multilayer for ocular drug delivery was developed in this work. Polycarboxymethyl-β-cyclodextrin (poly(CM-β-CD))/poly-l-lysine (PLL) multilayer film was designed and constructed for ocular drug delivery, sinceβ-CD showed good drug delivery property. The properties such as the contact angle and transparency varied a little with the deposition of poly(CM-β-CD)/PLL multilayer. Orfloxacin and puerarin were loaded into multilayer during the self-assembly procedure by two methods, which were tracked by the largest drug absorbance of UV spectrum. The loaded drug amount by incorporating drugs into poly(CM-β-CD) solution was larger than that by incorporating drugs into PLL solution. The loaded drug in the multilayer could gradually be released from multilayer in some period either for orfloxacin or for puerarin. The drug release behavior was influenced by drug loading method and pH value of released medium. Moreover, the balanced released drug amount by incorporating drugs into poly(CM-β-CD) solution is much smaller than that by incorporating drugs into PLL solution.

scholarly journals A Ferrofluid with Surface Modified Nanoparticles for Magnetic Hyperthermia and High ROS Production

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 544
Author(s):  
Oscar Cervantes ◽  
Zaira del Rocio Lopez ◽  
Norberto Casillas ◽  
Peter Knauth ◽  
Nayeli Checa ◽  
...  
Keyword(s):  
Colloidal Stability ◽  
Average Diameter ◽  
Magnetic Hyperthermia ◽  
Human Cell Line ◽  
Superparamagnetic Nanoparticles ◽  
Blocking Temperature ◽  
Precipitation Method ◽  
Colloidal System ◽  
Ros Production ◽  
Co Precipitation

A ferrofluid with 1,2-Benzenediol-coated iron oxide nanoparticles was synthesized and physicochemically analyzed. This colloidal system was prepared following the typical co-precipitation method, and superparamagnetic nanoparticles of 13.5 nm average diameter, 34 emu/g of magnetic saturation, and 285 K of blocking temperature were obtained. Additionally, the zeta potential showed a suitable colloidal stability for cancer therapy assays and the magneto-calorimetric trails determined a high power absorption density. In addition, the oxidative capability of the ferrofluid was corroborated by performing the Fenton reaction with methylene blue (MB) dissolved in water, where the ferrofluid was suitable for producing reactive oxygen species (ROS), and surprisingly a strong degradation of MB was also observed when it was combined with H2O2. The intracellular ROS production was qualitatively corroborated using the HT-29 human cell line, by detecting the fluorescent rise induced in 2,7-dichlorofluorescein diacetate. In other experiments, cell metabolic activity was measured, and no toxicity was observed, even with concentrations of up to 4 mg/mL of magnetic nanoparticles (MNPs). When the cells were treated with magnetic hyperthermia, 80% of cells were dead at 43 °C using 3 mg/mL of MNPs and applying a magnetic field of 530 kHz with 20 kA/m amplitude.

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