scholarly journals Practical bioinstrumentation developments for AC magnetic field-mediated magnetic nanoparticle heating applications

2018 ◽  
Author(s):  
Mahendran Subramanian ◽  
Arkadiusz Miaskowski ◽  
Ajit K. Mahapatro ◽  
Ondrej Hovorka ◽  
Jon Dobson

AbstractHeat dissipation during magnetization reversal processes in magnetic nanoparticles (MNP), upon exposure to alternating magnetic fields (AMF), has been extensively studied in relation to applications in magnetic fluid hyperthermia (MFH). This current paper demonstrates the design, fabrication, and evaluation of an efficient instrument, operating on this principle, for use as (i) a non-contact, in vitro, real-time temperature monitor; (ii) a drug release analysis system (DRAS); (iii) a high flux density module for AMF-mediated MNP studies; and (iv) an in vivo coil setup for real-time, whole body thermal imaging. The proposed DRAS is demonstrated by an AMF-mediated drug release proof-of-principle experiment. Also, the technique described facilitates non-contact temperature measurements of specific absorption rate (SAR) as accurately as temperature measurements using a probe in contact with the sample. Numerical calculations estimating the absolute and root mean squared flux densities, and other MNP – AMF studies suggest that the proposed stacked planar coil module could be employed for calorimetry. Even though the proposed in vivo coil setup could be used for real-time, whole body thermal imaging (within the limitations due to issues of penetration depth), further design effort is required in order to enhance the energy transfer efficiency.

2015 ◽  
Vol 51 (32) ◽  
pp. 6948-6951 ◽  
Author(s):  
Yanfeng Zhang ◽  
Qian Yin ◽  
Jonathan Yen ◽  
Joanne Li ◽  
Hanze Ying ◽  
...  

Anin vitroandin vivodrug-reporting system is developed for real-time monitoring of drug release via the analysis of the concurrently released near-infrared fluorescence dye.


Talanta ◽  
2012 ◽  
Vol 88 ◽  
pp. 631-637 ◽  
Author(s):  
Mira Kim ◽  
Ji Hye Seo ◽  
Won Il Jeon ◽  
Mi-Yeon Kim ◽  
Keunchang Cho ◽  
...  

Author(s):  
Natalia Feiner-Gracia ◽  
Adrianna Glinkowska Mares ◽  
Marina Buzhor ◽  
Romen Rodriguez-Trujillo ◽  
Josep Samitier ◽  
...  

ABSTRACTThe performance of supramolecular nanocarriers as drug delivery systems depends on their stability in the complex and dynamic biological media. After administration, nanocarriers are challenged by confronting different barriers such as shear stress and proteins present in blood, endothelial wall, extracellular matrix and eventually cancer cell membranes. While early disassembly will result in a premature drug release, extreme stability of the nanocarriers can lead to poor drug release and low efficiency. Therefore, comprehensive understanding of the stability and assembly state of supramolecular carriers in each stage of delivery is a key factor for the rational design of these systems. One of the key challenges is that current 2D in vitro models do not provide exhaustive information, as they do not fully recapitulate the 3D tumor microenvironment. This deficiency of the 2D models complexity is the main reason for the differences observed in vivo when testing the performance of supramolecular nanocarriers. Herein, we present a real-time monitoring study of self-assembled micelles stability and extravasation, combining spectral confocal microscopy and a microfluidic tumor-on-a-chip. The combination of advanced imaging and a reliable organ-on-a-chip model allow us to track micelle disassembly by following the spectral properties of the amphiphiles in space and time during the crucial steps of drug delivery. The spectrally active micelles were introduced under flow and their position and conformation followed during the crossing of barriers by spectral imaging, revealing the interplay between carrier structure, micellar stability and extravasation. Integrating the ability of the micelles to change their fluorescent properties when disassembled, spectral confocal imaging and 3D microfluidic tumor blood vessel-on-a-chip, resulted in the establishment of a robust testing platform, suitable for real-time imaging and evaluation of supramolecular drug delivery carrier’s stability.


2020 ◽  
Vol 08 ◽  
Author(s):  
Adella Aparna ◽  
Yamsani Shravan Kumar ◽  
D.V.R.N. Bhikshapathi

Background: Ticagrelor (TGR) being antiplatelet agent belongs to BCS class IV drug with low solubility and permeability that undergoes first-pass metabolism leads to reduced bioavailability of 36%. Objective: The main goal of the present study was to develop TGR SNEDDS for improving solubility and oral bioavailability. Methods: An oil, surfactant and co-surfactant (miglyol 810, brij 35 and lauro glycol FCC) were chosen based on the maximum solubility of TGR. The chosen vehicles were mixed in varying ratios and agitated mildly and transmittance values more than 80 were noted and used for constructing pseudo ternary phase diagram. Formulations that passed stability testing were evaluated for % transmission, drug content and in vitro drug release analysis. In-vivo bioavailability studies of optimized SNEDDS were performed in wistar rats. Results: From evaluation studies of TGR, formulation F13 with maximum drug release of 98.99% in 60 minutes that is higher than 31.99 % of pure drug is considered the optimised formulation. The particle size, Z average and zeta potential of the optimized TGR formulation F13 was 289.6 nm, 185.1 nm and -18.3 mV respectively. The FTIR and SEM studies do not indicate any drug excipient interaction and confirm nanosize and stable for 3 months. From in vivo bioavailability studies in rats, the Cmax of optimized TGR SNEDDS (302.43±4.78ng/ml) was higher than pure TGR suspension (47.32±2.75ng/ml) and optimized SNEDDS exhibited 5 folds increased oral bioavailability than pure drug. Conclusion: Hence, the results revealed that application of SNEDDS formulation technique for TGR increased solubility and oral bioavailability.


Nanoscale ◽  
2015 ◽  
Vol 7 (32) ◽  
pp. 13503-13510 ◽  
Author(s):  
Jinfeng Zhang ◽  
Shengliang Li ◽  
Fei-Fei An ◽  
Juan Liu ◽  
Shubin Jin ◽  
...  

The use of different nanocarriers for delivering hydrophobic pharmaceutical agents to tumor sites has garnered major attention.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Oliver Ritter ◽  
Peter Nordbeck ◽  
Florian Fidler ◽  
Marcus Warmuth ◽  
Karl-Heinz Hiller ◽  
...  

Background: Cardiac magnetic resonance imaging (MRI) offers 3D real time imaging with unsurpassed soft tissue contrast without X-ray exposure. However, electrophysiological (EP) examinations of patients with rhythm disorders and ablation procedures are still not possible in the MRI environment. To minimize safety concerns and imaging artifacts, we aimed at developing a setup including catheters for interventional EP based on carbon technology. Methods and Results: The setup, which includes a steerable carbon catheter, was tested for safety, image distortion, pacing and sensing properties, and feasibility of ablation at 1.5 Tesla. MR imaging was performed in two different 1.5-T whole-body scanners. To assess unintentional heating of the catheters by radio frequency (RF) pulses of the MR scanner in vitro , a fluoroptic thermometry system was used to record heating at the catheter tip. In vivo tests for pacing and sensing properties and ablation therapy were performed in eight pigs. There was no significant heating of the carbon catheters while using short, repetitive RF pulses from the MR system. Since there was no image distortion when using the carbon catheters, exact targeting of the lesion sites was possible. During imaging, pacing of in vivo pig hearts and sensing the intra cardiac electrogram was possible without any artifacts. Several RF-ablation procedures, including AV node modulation were performed successfully in the scanner. Potential complications during ablation such as perforation of the RV free wall could be monitored in real time as well. Conclusion: Here we describe a newly developed EP technology for interventional electrophysiology based on carbon catheters. These catheters are suitable for electrophysiological diagnostic and ablation procedures. Their feasibility was demonstrated by performing safety EP studies and ablation therapy with carbon catheters in the MRI environment.


2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Chen Du ◽  
Yan Liang ◽  
Qingming Ma ◽  
Qianwen Sun ◽  
Jinghui Qi ◽  
...  

Abstract Background Synergistic therapy of tumor is a promising way in curing cancer and in order to achieve effective tumor therapy with real-time drug release monitoring, dynamic cellular imaging and antitumor activity. Results In this work, a polymeric nanoparticle with Forster resonance energy transfer (FRET) effect and chemo-photodynamic properties was fabricated as the drug vehicle. An amphiphilic polymer of cyclo(RGDfCSH) (cRGD)-poly(ethylene glycol) (PEG)-Poly(l-histidine) (PH)-poly(ε-caprolactone) (PCL)-Protoporphyrin (Por)-acting as both a photosensitizer for photodynamic therapy (PDT) and absorption of acceptor in FRET was synthesized and self-assembled into polymeric nanoparticles with epirubicin (EPI)-acting as an antitumor drug for chemotherapy and fluorescence of donor in FRET. Spherical EPI-loaded nanoparticles with the average size of 150 ± 2.4 nm was procured with negatively charged surface, pH sensitivity and high drug loading content (14.9 ± 1.5%). The cellular uptake of EPI-loaded cRGD-PEG-PH-PCL-Por was monitored in real time by the FRET effect between EPI and cRGD-PEG-PH-PCL-Por. The polymeric nanoparticles combined PDT and chemotherapy showed significant anticancer activity both in vitro (IC50 = 0.47 μg/mL) and better therapeutic efficacy than that of free EPI in vivo. Conclusions This work provided a versatile strategy to fabricate nanoassemblies for intracellular tracking of drug release and synergistic chemo-photodynamic therapy.


Author(s):  
Bhikshapathi D. V. R. N. ◽  
Haarika B ◽  
Jyothi Sri S ◽  
K Abbulu

The purpose of present investigation was to develop floating matrix tablets of gemifloxacin mesylate, which after oral administration could prolong the gastric residence time, increase the drug bioavailability and diminish the side effects of irritating drugs. Tablets containing drug, various viscosity grades of hydroxypropyl methylcellulose such as HPMC K4M and HPMC K15M as matrix forming agent, Sodium bicarbonate as gas-forming agent and different additives were tested for their usefulness in formulating gastric floating tablets by direct compression method. The physical parameters, in vitro buoyancy, release characteristics and in vivo radiographic study were investigated in this study. The gemifloxacin mesylate floating tablets were prepared using HPMC K4M polymer giving more sustained drug release than the tablet containing HPMC K15M. All these formulations showed floating lag time of 30 to 47 sec and total floating time more than 12 h. The drug release was decreased when polymer concentration increases and gas generating agent decreases. Formulation that contains maximum concen-tration of both HPMC K15M and sodium bicarbonate (F9) showing sufficiently sustained with 99.2% of drug release at 12 h. The drug release from optimized formulation follows Higuchi model that indicates the diffusion controlled release. The best formulation (F9) was selected based on in vitro characteristics and used in vivo radiographic studies by incorporating barium sulphate as a radio-opaque agent and the tablet remained in the stomach for about 6 h.   


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