Irreversibility analysis of an unsteady micropolar CNT-blood nanofluid flow through a squeezing channel with activation energy-Application in drug delivery.

BACKGROUND AND OBJECTIVE: Due to the low toxicity, unique physiochemical properties, and appropriate surface modifications, Carbon Nanotubes (CNTs) are used as target carriers in drug delivery systems. In the present problem, we have considered both single-walled and multi-walled CNTs to study the impact of irreversibility on the micropolar nanofluid flow through a squeezing channel with the base fluid blood. The blood is considered a micropolar fluid in the presence of different blood cells and their rotational nature. Further, blood is influenced by the external magnetic field parallel to the microrotation along with viscous and Joule dissipations. METHOD: Highly coupled and nonlinear partial differential equations are solved with Homotopy Analysis Method (HAM) after simplified equations using similarity transformation. Further, we have concluded the minimum squared residual errors to show the method's accuracy. A comparison made with the existing literature and shows a good agreement. RESULTS: The angular velocity of the fluid particles is enhanced by increasing the squeezing number. In the case of the squeezing, volume fraction has improved the viscous drag and is found high for MWCNT embedded nanofluid. The heat transfer rate is higher for the MWCNT embedded nanofluid than the SWCNT embedded nanofluid. A descent found in entropy generation boosts up with the Brinkman parameter while opposite phenomena appear for radiation and Hartman number and vortex viscosity. Both Bejan number and entropy generation profiles are restricted with an increase in vortex viscosity. CONCLUSION: SWCNTs are showed to be more effective and efficient than the MWCNTs in elevating velocity, temperature and irreversibility of the system. Outcomes of this problem will help to understand the implementation of the drug carrier and irreversibility phenomena during drug delivery.

Magnetic drug targeting during Caputo-Fabrizio fractionalized blood flow through a permeable vessel.

Nanoparticle-based drug targeting is an important platform for the treatment of cardiovascular disorders. Magnetic drug targeting is more significant as it is a noninvasive procedure and biocompatible. The present problem aims to understand magnetic drug delivery to a specific location in a permeable blood vessel under the vibration and magnetic environment. Caputo-Fabrizio fractional-order time derivatives are used in the governing equations. The momentum equations are solved analytically and presented in the form of Lorenzo-Hartley and Robotonov-Hartley functions and convolution of the Laplace transform. Convolution integrations are solved by using the numerical integration technique. The Fourth order Runge-Kutta method (RK4) is used to solve the force balance equation. The influence of pertinent parameters such as Reynolds number, pulsatile frequency, magnetic field strength, Darcy number and fractional-order parameters are presented through graphs. It is observed that increasing Reynolds number results in decreasing the tendency of the drug to capture near the tumor site, whereas the pulsatile frequency presents an opposite phenomenon. Increasing the magnetic field strength and Darcy number boosts the capture efficiency of drug particles near the tumor site. The short memory effect efficiently captures the magnetic drug carriers to a specific location under the action of suitable magnetic field strength.

Fractional order model of thermo-solutal and magnetic nanoparticles transport for drug delivery applications.

We examine the capturing efficiency of magnetic nanoparticles bound with drug molecules infused into the blood stream and monitored them by the application of an external magnetic field. We analyzed the motion of the nanoparticles along with the blood velocity through a porous medium vessel under the effect of periodic vibration. The thermo-solutal transport with Caputo-Fabrizio fractional-order derivative is modeled with non-Newtonian biviscosity fluid, Soret and Dufour effect, thermal radiation, and linear variation of the chemical reaction. The Laplace transform, finite Hankel transform and their inverse techniques are used to find analytical solutions. The study shows that both the velocity of blood and nano-particles increase with the increase of particle mass and the concentration parameter, while the opposite behaviour is observed with increasing the fractional parameter, magnetic field effect, and thermal radiation. The heat and mass transfer rates at the wall are enhanced with an increase in the Peclet number and the metabolic heat source. Thermal radiation effect signifies the higher rate of heat transfer at the vessel wall. The study bears potential applications in drug delivery with magnetic nanoparticles at the targeted region.

Fractional order model for thermochemical flow of blood with Dufour and Soret effects under magnetic and vibration environment.

We examine the effect of the Caputo-Fabrizio derivative of fractional-order model on the flow of blood in a porous tube having thermochemical properties under the magnetic and vibration mode. Blood is considered as the biviscosity non-Newtonian fluid having thermal radiation and chemical reaction properties to observe its impact on energy flux and mass flux gradients. We provided analytical solution via the Laplace, finite Hankel transform, and the corresponding inverse techniques. The study shows that blood velocity and temperature both decrease in ascending values of the fractional-order parameter as memory effect. The permeability of blood flow medium resists to drive the fluid fast. The chemical reaction causes an increase in wall shear stress. Dufour effect influences to rise in the Nusselt number. Thus the study may help to explore further information about the fractional-order model, adsorption of nutrients and their strong correlation with the surface chemistry and applied them in pathology.

Dispersion characteristics of blood during nanoparticle assisted drug delivery process through a permeable microvessel.

Nanoparticle assisted drug delivery holds considerable promise as a means of next generation of medicine that allows for the intravascular delivery of drugs and contrast agents. We analyze the dispersion characteristics of blood during a nanoparticle-assisted drug delivery process through a permeable microvessel. The contribution of molecular and convective diffusion is based on Taylor's theory of shear dispersion. The aggregation of red blood cells in blood flowing through small tubes (less than 40 µm) leads to the two-phase flow with a core of rouleaux surrounded by a cell-depleted peripheral layer. The core region models as a non-Newtonian Casson fluid and the peripheral region acts as a Newtonian fluid. We investigate the influence of the nanoparticle volume fraction, the permeability of the blood vessel, pressure distribution, yield stress and the radius of the nanoparticle on the effective dispersion. We show that the effective diffusion of the nanoparticles reduces with an increase in nanoparticle volume fraction. The permeability of the blood vessels increases the effective dispersion at the inlet. The present study contributes to the fundamental understanding on how the particulate nature of blood influences nanoparticle delivery, and is of particular significance in nanomedicine design for targeted drug delivery applications.

Magnetic targeting in the impermeable microvessel with two-phase fluid model--non-Newtonian characteristics of blood.

The present investigation deals with finding the trajectories of the drug dosed magnetic carrier particle in a microvessel with two-phase fluid model which is subjected to the external magnetic field. The radius of the microvessel is divided into the endothelial glycocalyx layer in which the blood is assumed to obey Newtonian character and a core and plug regions where the blood obeys the non-Newtonian Herschel-Bulkley character which is suitable for the microvessel of radius 50 microm. The carrier particles, bound with nanoparticles and drug molecules are injected into the vascular system upstream from malignant tissue, and captured at the tumor site using a local applied magnetic field. The applied magnetic field is produced by a cylindrical magnet positioned outside the body and near the tumor position. The expressions for the fluidic force for the carrier particle traversing in the two-phase fluid in the microvessel and the magnetic force due to the external magnetic field are obtained. Several factors that influence the magnetic targeting of the carrier particles in the microvasculature, such as the size of the carrier particle, the volume fraction of embedded magnetic nanoparticles, and the distance of separation of the magnet from the axis of the microvessel are considered in the present problem. An algorithm is given to solve the system of coupled equations for trajectories of the carrier particle in the invasive case. The trajectories of the carrier particle are found for both invasive and noninvasive targeting systems. A comparison is made between the trajectories in these cases. Also, the present results are compared with the data available for the impermeable microvessel with single-phase fluid flow. Also, a prediction of the capture of therapeutic magnetic nanoparticle in the impermeable microvasculature is made for different radii, distances and volume fractions in both the invasive and noninvasive cases.